Att G.17_Surgical Site Infection

Procedure-associated Module
SSI

Surgical Site Infection (SSI) Event
Introduction: In 2010, an estimated 16 million operative procedures were performed in acute care
hospitals in the United States [1]. A recent prevalence study found that SSIs were the most common
healthcare-associated infection, accounting for 31% of all HAIs among hospitalized patients [2].
NHSN data for 2006-2008 (16,147 SSIs following 849,659 operative procedures) showed an
overall SSI rate of 1.9% [3].
While advances have been made in infection control practices, including improved operating room
ventilation, sterilization methods, barriers, surgical technique, and availability of antimicrobial
prophylaxis, SSIs remain a substantial cause of morbidity, prolonged hospitalization, and death. SSI
is associated with a mortality rate of 3%,and 75% of SSI-associated deaths are directly attributable
to the SSI [4].
Surveillance of SSI with feedback of appropriate data to surgeons has been shown to be an
important component of strategies to reduce SSI risk [5-8]. A successful surveillance program
includes the use of epidemiologically-sound infection definitions and effective surveillance
methods, stratification of SSI rates according to risk factors associated with SSI development, and
data feedback [6, 7]. A new CDC and Healthcare Infection Control Practices Advisory Committee
guideline for the prevention of surgical site infection is scheduled for publication, and will replace
the previous Guideline for Prevention of Surgical Site Infection, 1999 [8].
Settings: Surveillance of surgical patients will occur in any inpatient and/or outpatient setting
where the selected NHSN operative procedure(s) are performed.
Requirements: Perform surveillance for SSI following at least one NHSN operative procedure
category (Table 1) as indicated in the Patient Safety Monthly Reporting Plan (CDC 57.106).
Collect SSI (numerator) and operative procedure category (denominator) data on all procedures
included in the selected procedure categories for at least one month to meet NHSN requirements, or
as otherwise specified by state or federal reporting requirements. A procedure must meet the NHSN
definition of an operative procedure in order to be included in the surveillance. For the procedures
that you follow you will report superficial, deep, and organ space SSIs.
SSI monitoring requires active, patient-based, prospective surveillance. Post-discharge and antedischarge surveillance methods should be used to detect SSIs following inpatient and outpatient
operative procedures. These methods include 1) direct examination of patients’ wounds during
follow-up visits to either surgery clinics or physicians’ offices, 2) review of medical records or
surgery clinic patient records, 3) surgeon surveys by mail or telephone, and 4) patient surveys by
mail or telephone (though patients may have a difficult time assessing their infections). Any
combination of these methods is acceptable for use; however, CDC criteria for SSI must be used.
To minimize Infection Preventionists’ (IPs) workload of collecting denominator data, operating
room data may be downloaded (see file specifications at:
http://www.cdc.gov/nhsn/PDFs/ImportingProcedureData_current.pdf).

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SSI

An SSI will be associated with a particular NHSN operative procedure and the facility in which that
procedure was performed. Refer to the NHSN application’s Help system for instruction on linking
an SSI to an operative procedure.
The International Classification of Diseases, 9th Revision Clinical Modifications (ICD-9-CM)
codes, which are defined by the ICD-9 Coordination and Maintenance Committee of the National
Center for Health Statistics and the Centers for Medicare and Medicaid Services (CMS), are
developed as a tool for classification of morbidity data. The wide use enables the grouping of
surgery types for the purpose of determining SSI rates. . Table 1 lists NHSN operative procedure
category groupings by ICD-9-CM codes. Because ambulatory surgery centers and hospital
outpatient surgery departments may not use ICD-9-CM procedure codes, Table 1 provides Current
Procedural Terminology (CPT) code mapping for certain NHSN operative procedure categories to
assist users in determining the correct NHSN code to report for outpatient surgery cases. However,
when available, ICD-9-CM codes take precedence over CPTcodes when determining the
appropriate NHSN operative procedure category for inpatient surgery cases. Table 1 also includes a
general description of the types of operations contained in the NHSN operative procedure
categories. NHSN will provide updates as needed regarding the planned transition from ICD-9-CM
to ICD-10 procedure terminology by late 2015.
Definition of an NHSN operative procedure:
An NHSN operative procedure is a procedure





that is included in Table 1
and
takes place during an operation where at least one incision (including laporoscopic
approach) is made through the skin or mucous membrane, or reoperation via an incision that
was left open during a prior operative procedure
and
takes place in an operating room [OR], defined as a patient care area that met the Facilities
Guidelines Institute’s (FGI) or American Institute of Architects’ (AIA) criteria for an
operating room when it was constructed or renovated [9]. This may include an operating
room, C-section room, interventional radiology room, or a cardiac catheterization lab.

Exclusions: Otherwise eligible procedures that are assigned an ASA score of 6 are not eligible for
NHSN SSI surveillance
NOTE: Incisional closure is NOT a part of the NHSN operative procedure definition; all otherwise
eligible procedures are included, regardless of closure type. Therefore both primarily closed
procedures and those that are not closed primarily should be entered into the denominator data for
procedures in the facility’s monthly reporting plan. Any SSIs attributable to either primarily closed
or non primarily closed procedures should be reported.

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Table 1. NHSN Operative Procedure Category Mappings to ICD-9-CM Codes and CPT Codes
(NHSN will provide updates as needed concerning the transition from ICD-9-CM to ICD-10
procedure coding)
When available, ICD-9-CM codes take precedence over CPT codes when determining the
appropriate NHSN operative procedure category for inpatient surgery cases.
Legacy
Code
AAA

AMP

APPY
AVSD
BILI

BRST

Operative
Procedure
Abdominal
aortic
aneurysm
repair
Limb
amputation

Appendix
surgery
Shunt for
dialysis
Bile duct, liver
or pancreatic
surgery

Breast surgery

January 2014

Description

ICD-9-CM Codes / CPT Codes

Resection of abdominal
aorta with anastomosis or
replacement

38.34, 38.44, 38.64

Total or partial amputation
or disarticulation of the
upper or lower limbs,
including digits
Operation of appendix

84.00-84.19, 84.91

Arteriovenostomy for renal
dialysis
Excision of bile ducts or
operative procedures on the
biliary tract, liver or
pancreas (does not include
operations only on
gallbladder)

Excision of lesion or tissue
of breast including radical,
modified, or quadrant
resection, lumpectomy,
incisional biopsy, or
mammoplasty

9-3

47.01, 47.09, 47.2, 47.91, 47.92,
47.99
39.27, 39.42
50.0, 50.12, 50.14, 50.21-50.23,
50.25, 50.26, 50.29, 50.3, 50.4,
50.61, 50.69, 51.31-51.37, 51.39,
51.41-51.43, 51.49, 51.51, 51.59,
51.61-51.63, 51.69, 51.71, 51.72,
51.79, 51.81-51.83, 51.89, 51.9151.95, 51.99, 52.09, 52.12, 52.22,
52.3, 52.4, 52.51-52.53, 52.5952.6, 52.7, 52.92, 52.95, 52.96,
52.99
85.12, 85.20-85.23, 85.31-85.36,
85.41-85.48, 85.50, 85.53-85.55,
85.6, 85.70-85.76, 85.79, 85.9385.96
19101, 19112, 19120, 19125,
19126, 19300, 19301, 19302,
19303, 19304, 19305, 19306,
19307, 19316, 19318, 19324,
19325, 19328, 19330, 19340,
19342, 19350, 19355, 19357,
19361, 19364, 19366, 19367,
19368, 19369, 19370, 19371,
19380

Procedure-associated Module
SSI

Legacy
Code
CARD

Operative
Procedure
Cardiac
surgery

CEA

Carotid
endarterectomy

CBGB

Coronary
artery bypass
graft with both
chest and
donor site
incisions

CBGC

Coronary
artery bypass
graft with chest
incision only

CHOL

Gallbladder
surgery

COLO

Colon surgery

Incision, resection, or
anastomosis of the large
intestine; includes large-tosmall and small-to-large
bowel anastomosis; does
not include rectal operations

CRAN

Craniotomy

Excision repair, or
exploration of the brain or
meninges; does not include
taps or punctures

January 2014

Description

ICD-9-CM Codes / CPT Codes

Procedures on the heart;
includes valves or septum;
does not include coronary
artery bypass graft, surgery
on vessels, heart
transplantation, or
pacemaker implantation

35.00-35.04, 35.06, 35.08, 35.1035.14, 35.20-35.28, 35.31-35.35,
35.39, 35.42, 35.50, 35.51, 35.53,
35.54, 35.60-35.63, 35.70-35.73,
35.81-35.84, 35.91-35.95, 35.9835.99, 37.10-37.12, 37.31-37.33,
37.35-37.37, 37.41, 37.49, 37.60

Endarterectomy on vessels
of head and neck (includes
carotid artery and jugular
vein)
Chest procedure to perform
direct revascularization of
the heart; includes obtaining
suitable vein from donor
site for grafting

38.12

Chest procedure to perform
direct vascularization of the
heart using, for example the
internal mammary
(thoracic) artery
Cholecystectomy and
cholecystotomy

36.15-36.17, 36.2

9-4

36.10-36.14, 36.19

51.03, 51.04, 51.13, 51.21-51.24
47480, 47562, 47563, 47564,
47600, 47605, 47610, 47612,
47620
17.31-17.36, 17.39, 45.03, 45.26,
45.41, 45.49, 45.52, 45.71-45.76,
45.79, 45.81-45.83, 45.92-45.95,
46.03, 46.04, 46.10, 46.11, 46.13,
46.14, 46.43, 46.52, 46.75, 46.76,
46.94
44140, 44141, 44143, 44144,
44145, 44146, 44147, 44150,
44151, 44160, 44204, 44205,
44206, 44207, 44208, 44210
01.12, 01.14, 01.20-01.25, 01.28,
01.29, 01.31, 01.32, 01.39, 01.41,
01.42, 01.51-01.53, 01.59, 02.1102.14, 02.91-02.93, 07.51-07.54,
07.59, 07.61-07.65, 07.68, 07.69,
07.71, 07.72, 07.79, 38.01, 38.11,
38.31, 38.41, 38.51, 38.61, 38.81,
39.28

Procedure-associated Module
SSI

Legacy
Code
CSEC
FUSN

Operative
Procedure
Cesarean
section
Spinal fusion

FX

Open reduction
of fracture

GAST

Gastric surgery

HER

Herniorrhaphy

HPRO

Hip prosthesis

January 2014

Description

ICD-9-CM Codes / CPT Codes

Obstetrical delivery by
Cesarean section
Immobilization of spinal
column
Open reduction of fracture
or dislocation of long bones
with or without internal or
external fixation; does not
include placement of joint
prosthesis

74.0, 74.1, 74.2, 74.4, 74.91, 74.99

Incision or excision of
stomach; includes subtotal
or total gastrectomy; does
not include vagotomy and
fundoplication
Repair of inguinal, femoral,
umbilical, or anterior
abdominal wall hernia; does
not include repair of
diaphragmatic or hiatal
hernia or hernias at other
body sites

Arthroplasty of hip

9-5

81.00-81.08
79.21, 79.22, 79.25, 79.26, 79.31,
79.32, 79.35, 79.36, 79.51, 79.52,
79.55, 79.56
23615, 23616, 23630, 23670,
23680, 24515, 24516, 24538,
24545, 24546, 24575, 24579,
24586, 24587, 24635, 24665,
24666, 24685, 25337, 25515,
25525, 25526, 25545, 25574,
25575, 25607, 25608, 25609,
25652, 27236, 27244, 27245,
27248, 27254, 27269, 27283,
27506, 27507, 27511, 27513,
27514, 27535, 27536, 27540,
27758, 27759, 27766, 27769,
27784, 27792, 27814, 27822,
27826, 27827, 27828
43.0, 43.42, 43.49, 43.5, 43.6,
43.7, 43.81, 43.82, 43.89, 43.91,
43.99, 44.15, 44.21, 44.29, 44.31,
44.38-44.42, 44.49, 44.5, 44.6144.65, 44.68-44.69, 44.95-44.98
17.11-17.13, 17.21-17.24, 53.0053.05, 53.10-53.17, 53.21, 53.29,
53.31, 53.39, 53.41-53.43, 53.49,
53.51, 53.59, 53.61-53.63, 53.69
49491, 49492, 49495, 49496,
49500, 49501, 49505, 49507,
49520, 49521, 49525, 49550,
49553, 49555, 49557, 49560,
49561, 49565, 49566, 49568,
49570, 49572, 49580, 49582,
49585, 49587, 49590, 49650,
49651, 49652, 49653, 49654,
49655, 49656, 49657, 49659,
55540
00.70-00.73, 00.85-00.87, 81.5181.53
27125, 27130, 27132, 27134,
27137, 27138, 27236, 27299

Procedure-associated Module
SSI

Legacy
Code
HTP

Operative
Procedure
Heart
transplant

HYST

Description

ICD-9-CM Codes / CPT Codes

Transplantation of heart

37.51-37.55

Abdominal
hysterectomy

Abdominal hysterectomy;
includes that by laparoscope

KPRO

Knee
prosthesis

Arthroplasty of knee

68.31, 68.39, 68.41, 68.49, 68.61,
68.69
58150, 58152, 58180, 58200,
58210, 58541, 58542, 58543,
58544, 58548, 58570, 58571,
58572, 58573, 58951, 58953,
58954, 58956
00.80-00.84, 81.54, 81.55
27438, 27440, 27441, 27442,
27443, 27445, 27446, 27447,
27486, 27487

KTP

Kidney
transplant
Laminectomy

Transplantation of kidney

55.61, 55.69

Exploration or
decompression of spinal
cord through excision or
incision into vertebral
structures
Transplantation of liver

03.01, 03.02, 03.09, 80.50, 80.51,
80.53, 80.54, 80.59, 84.60-84.69,
84.80-84.85

30.1, 30.21, 30.22, 30.29, 30.3,
30.4, 31.45, 40.40-40.42

LAM

LTP
NECK

Liver
transplant
Neck surgery

NEPH

Kidney surgery

OVRY

Ovarian
surgery

Major excision or incision
of the larynx and radical
neck dissection; does not
include thyroid and
parathyroid operations
Resection or manipulation
of the kidney with or
without removal of related
structures
Operations on ovary and
related structures

PACE

Pacemaker
surgery

Insertion, manipulation or
replacement of pacemaker

PRST

Prostate
surgery

Suprapubic, retropubic,
radical, or perineal excision
of the prostate; does not
include transurethral

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50.51, 50.59

55.01, 55.02, 55.11, 55.12, 55.24,
55.31, 55.32, 55.34, 55.35, 55.39,
55.4, 55.51, 55.52, 55.54, 55.91
65.01, 65.09, 65.12, 65.13, 65.2165.25, 65.29, 65.31, 65.39, 65.41,
65.49, 65.51-65.54, 65.61-65.64,
65.71-65.76, 65.79, 65.81, 65.89,
65.92-65.95, 65.99
00.50-00.54, 17.51, 17.52, 37.7037.77, 37.79-37.83, 37.85-37.87,
37.89, 37.94-37.99
60.12, 60.3, 60.4, 60.5, 60.61,
60.69

Procedure-associated Module
SSI

Legacy
Code

Operative
Procedure

Description

ICD-9-CM Codes / CPT Codes

resection of the prostate

PVBY

REC

RFUSN
SB

Peripheral
vascular
bypass surgery
Rectal surgery

Bypass operations on
peripheral arteries

39.29

Operations on rectum

Refusion of
spine
Small bowel
surgery

Refusion of spine

48.25, 48.35, 48.40, 48.42, 48.43,
48.49-48.52, 48.59, 48.61-48.65,
48.69, 48.74
81.30-81.39

Incision or resection of the
small intestine; does not
include small-to-large
bowel anastomosis
Resection or manipulation
of spleen
Noncardiac, nonvascular
thoracic surgery; includes
pneumonectomy and hiatal
hernia repair or
diaphragmatic hernia repair
(except through abdominal
approach)

SPLE

Spleen surgery

THOR

Thoracic
surgery

THYR

Thyroid and/or
parathyroid
surgery

Resection or manipulation
of thyroid and/or
parathyroid

VHYS

Vaginal
hysterectomy

Vaginal hysterectomy;
includes that by laparoscope

VSHN

Ventricular
shunt

XLAP

Exploratory
laparotomy

Ventricular shunt
operations, including
revision and removal of
shunt
Procedures involving a
incision through abdominal
wall to gain access into the
abdominal cavity;
diagnostic procedure on
abdominal region

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45.01, 45.02, 45.15, 45.31-45.34,
45.51, 45.61-45.63, 45.91, 46.01,
46.02, 46.20-46.24, 46.31, 46.39,
46.41, 46.51, 46.71-46.74, 46.93
41.2, 41.33, 41.41-41.43, 41.5,
41.93, 41.95, 41.99
32.09, 32.1, 32.20-32.23, 32.25,
32.26, 32.29, 32.30, 32.39, 32.41,
32.49, 32.50, 32.59, 32.6, 32.9,
33.0, 33.1, 33.20, 33.25, 33.28,
33.31-33.34, 33.39, 33.41-33.43,
33.48, 33.49, 33.98, 33.99, 34.0134.03, 34.06, 34.1, 34.20, 34.26,
34.3, 34.4, 34.51, 34.52, 34.59,
34.6, 34.81-34.84, 34.89, 34.93,
34.99, 53.80-53.84
06.02, 06.09, 06.12, 06.2, 06.31,
06.39, 06.4, 06.50-06.52, 06.6,
06.7, 06.81, 06.89, 06.91-06.95,
06.98, 06.99
68.51, 68.59, 68.71, 68.79
02.21, 02.22, 02.31-02.35, 02.39,
02.42, 02.43, 54.95†
53.71, 53.72, 53.75, 54.0, 54.11,
54.12, 54.19, 54.3, 54.4, 54.51,
54.59, 54.61, 54.63, 54.64, 54.7154.75, 54.92, 54.93

Procedure-associated Module
SSI

†

Include only if this procedure involves ventricular shunt (i.e., is not a Ladd procedure to repair
malrotation of intestines).
For a complete list of all ICD-9-CM codes mapped to their assignment as an NHSN operative
procedure category, a surgical procedure other than an NHSN operative procedure (OTH), or a nonoperative procedure (NO), see ICD-9-CM Procedure Code Mapping to NHSN Operative Procedure
Categories at http://www.cdc.gov/nhsn/XLS/ICD-9-cmCODEScurrent.xlsx.
Denominator for Procedure Definitions:
ASA physical status: Assessment by the anesthesiologist of the patient’s preoperative physical
condition using the American Society of Anesthesiologists’ (ASA) Classification of Physical Status
[10, 11]. Patient is assigned one of the following:
1. A normally healthy patient
2. A patient with mild systemic disease
3. A patient with severe systemic disease
4. A patient with severe systemic disease that is a constant threat to life
5. A moribund patient who is not expected to survive without the operation.
NOTE: Do NOT report procedures with an ASA physical status of 6 (a declared brain-dead
patient whose organs are being removed for donor purposes) to NHSN.
Date of event: For an SSI the date of event is the date when the last element used to meet the SSI
infection criterion occurred. Synonym: infection date.
Diabetes: The NHSN, SSI surveillance definition of diabetes indicates that the patient has a
discharge ICD-9 principal or secondary code in the 250.XX to 250.XX code.
Duration of operative procedure: The interval in hours and minutes between the Procedure/Surgery
Start Time, and the Procedure/Surgery Finish Time, as defined by the Association of Anesthesia
Clinical Directors (AACD) [12]:
 Procedure/Surgery Start Time (PST): Time when the procedure is begun (e.g., incision for a
surgical procedure).
 Procedure/Surgery Finish (PF): Time when all instrument and sponge counts are completed
and verified as correct, all postoperative radiologic studies to be done in the OR are
completed, all dressings and drains are secured, and the physicians/surgeons have completed
all procedure-related activities on the patient.
Emergency operative procedure: A nonelective, unscheduled operative procedure. Emergency
operative procedures are those that do not allow for the standard immediate preoperative
preparation normally done within the facility for a scheduled operation (e.g., stable vital signs,
adequate antiseptic skin preparation, colon decontamination in advance of colon surgery, etc.).

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Procedure-associated Module
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General anesthesia: The administration of drugs or gases that enter the general circulation and affect
the central nervous system to render the patient pain free, amnesic, unconscious, and often
paralyzed with relaxed muscles.
Height: The patient’s most recent height documented in the medical record in feet (ft) and inches
(in), or meters (m).
NHSN Inpatient: A patient whose operative procedure occurs in an acute care OR setting regardless
of the duration of the admission.
NHSN Outpatient: A patient whose date of admission to the healthcare facility and date of
discharge are the same calendar day. ?? how to updata??
Non-primary Closure is defined as closure that is other than primary and includes surgeries in
which the superficial layers are left completely open during the original surgery and therefore
cannot be classified as having primary closure. For surgeries with non-primary closure, the deep
tissue layers may be closed by some means (with the superficial layers left open), or the deep and
superficial layers may both be left completely open. An example of a surgery with non-primary
closure would be a laparotomy in which the incision was closed to the level of the deep tissue
layers, sometimes called “fascial layers” or “deep fascia,” but the superficial layers are left open.
Another example would be an “open abdomen” case in which the abdomen is left completely open
after the surgery. If the deep fascial levels of an incision are left open but the skin is closed, this is
considered a non-primary closure since the incision was not closed at all tissue levels. Wounds that
are “closed secondarily” at some later date, or described as “healing by secondary intention” should
also be classified as having non-primary closure. Wounds with non-primary closure may or may not
be described as "packed” with gauze or other material, and may or may not be covered with plastic,
“wound vacs,” or other synthetic devices or materials.

* Primary Closure is defined as closure of all tissue levels during the original surgery, regardless of
the presence of wires, wicks, drains, or other devices or objects extruding through the incision. This
category includes surgeries where the skin is closed by some means, including incisions that are
described as being “loosely closed” at the skin level. Thus, if any portion of the incision is closed at
the skin level, by any manner, a designation of primary closure should be assigned to the surgery.

Scope: An instrument used to visualize the interior of a body cavity or organ. In the context of an
NHSN operative procedure, use of a scope involves creation of several small incisions to perform
or assist in the performance of an operation rather than use of a traditional larger incision (i.e., open
approach). Robotic assistance is considered equivalent to use of a scope for NHSN SSI
surveillance. See also Instructions for Completion of Denominator forProcedure Form and both
Numerator Data and Denominator Data reporting instructions in this chapter.
Trauma: Blunt or penetrating injury.

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Procedure-associated Module
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Weight: The patient’s most recent weight documented in the medical record in pounds (lbs) or
kilograms (kg) prior to or otherwise closest to the procedure.
Wound class: An assessment of the degree of contamination of a surgical wound at the time of the
operation. Wound class should be assigned by a person involved in the surgical procedure, e.g.,
surgeon, circulating nurse, etc. The wound class system used in NHSN is an adaptation of the
American College of Surgeons wound classification schema8.
Wounds are divided into four classes:
Clean: An uninfected operative wound in which no inflammation is encountered and the
respiratory, alimentary, genital, or uninfected urinary tracts are not entered. In addition, clean
wounds are primarily closed and, if necessary, drained with closed drainage. Operative incisional
wounds that follow nonpenetrating (blunt) trauma should be included in this category if they meet
the criteria. NOTE: The clean wound classification level will not be available for denominator data
entry for the following NHSN operative procedure categories: APPY, BILI, CHOL, COLO, REC,
SB, and VHYS
Clean-Contaminated: Operative wounds in which the respiratory, alimentary, genital, or urinary
tracts are entered under controlled conditions and without unusual contamination. Specifically,
operations involving the biliary tract, appendix, vagina, and oropharynx are included in this
category, provided no evidence of infection or major break in technique is encountered.
Contaminated: Open, fresh, accidental wounds. In addition, operations with major breaks in sterile
technique (e.g., open cardiac massage) or gross spillage from the gastrointestinal tract, and incisions
in which acute, nonpurulent inflammation is encountered including necrotic tissue without evidence
of purulent drainage (e.g., dry gangrene) are included in this category.
Dirty or Infected: Includes old traumatic wounds with retained devitalized tissue and those that
involve existing clinical infection or perforated viscera. This definition suggests that the organisms
causing postoperative infection were present in the operative field before the operation.

January 2014

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Procedure-associated Module
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Table 2. Surgical Site Infection Criteria
Criterion
Surgical Site Infection (SSI)
Superficial incisional SSI
Must meet the following criteria:
Infection occurs within 30 days after any NHSN operative procedure (where
day 1 = the procedure date), including those coded as ‘OTH’*
and
involves only skin and subcutaneous tissue of the incision
and
patient has at least one of the following:
a. purulent drainage from the superficial incision.
b. organisms isolated from an aseptically-obtained culture of fluid or
tissue from the superficial incision or subcutaneous tissue.
c. superficial incision that is deliberately opened by a surgeon, attending
physician** or other designee and is culture positive or not
cultured
and
patient has at least one of the following signs or symptoms: pain or
tenderness; localized swelling; redness; or heat. A culture negative
finding does not meet this criterion.
d. diagnosis of a superficial incisional SSI by the surgeon or attending
physician** or other designee.
*http://www.cdc.gov/nhsn/XLS/ICD-9-cmCODEScurrent.xlsx
** The term attending physician for the purposes of application of the NHSN
SSI criteria may be interpreted to mean the surgeon(s), infectious disease,
other physician on the case, emergency physician or physician’s designee
(nurse practitioner or physician’s assistant).
There are two specific types of superficial incisional SSIs:
Comments
1. Superficial Incisional Primary (SIP) – a superficial incisional SSI that
is identified in the primary incision in a patient that has had an
operation with one or more incisions (e.g., C-section incision or chest
incision for CBGB)
2. Superficial Incisional Secondary (SIS) – a superficial incisional SSI
that is identified in the secondary incision in a patient that has had an
operation with more than one incision (e.g., donor site incision for
CBGB)
REPORTING
The following do not qualify as criteria for meeting the NHSN definition
INSTRUCTIONS of superficial SSI:
for Superficial
 A stitch abscess alone (minimal inflammation and discharge confined to
SSI
the points of suture penetration)
 A localized stab wound or pin site infection. While it would be considered
either a skin (SKIN) or soft tissue (ST) infection, depending on its depth, it
is not reportable under this module.

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

Diagnosis of “cellulitis”, by itself, does not meet criterion d for superficial
incisional SSI. If the MD treats a cellulits this should still not be attributed
to the operative procedure.
 Circumcision is not an NHSN operative procedure. An infected
circumcision site in newborns is classified as CIRC and is not reportable
under this module.
 An infected burn wound is classified as BURN and is not reportable under
this module.
Deep incisional SSI
Must meet the following criteria:
Infection occurs within 30 or 90 days after the NHSN operative procedure
(where day 1 = the procedure date) according to the list in Table 3
and
involves deep soft tissues of the incision (e.g., fascial and muscle layers)
and
patient has at least one of the following:
a. purulent drainage from the deep incision.
b. a deep incision that spontaneously dehisces, is deliberately opened. or
percutaneous aspiration by a surgeon, attending physician** or other
designee and is culture-positive or not cultured
and
patient has at least one of the following signs or symptoms: fever
(>38°C); localized pain or tenderness. A culture-negative finding
does not meet this criterion.
c. an abscess or other evidence of infection involving the deep incision
that is detected on gross anatomical or histopathologic exam, or
imaging test.

Comments

January 2014

** The term attending physician for the purposes of application of the NHSN
SSI criteria may be interpreted to mean the surgeon(s), infectious disease,
other physician on the case, emergency physician or physician’s designee
(nurse practitioner or physician’s assistant).
There are two specific types of deep incisional SSIs:
1. Deep Incisional Primary (DIP) – a deep incisional SSI that is identified
in a primary incision in a patient that has had an operation with one or
more incisions (e.g., C-section incision or chest incision for CBGB)
2. Deep Incisional Secondary (DIS) – a deep incisional SSI that is
identified in the secondary incision in a patient that has had an
operation with more than one incision (e.g., donor site incision for
CBGB)

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Organ/Space SSI
Must meet the following criteria:
Infection occurs within 30 or 90 days after the NHSN operative procedure
(where day 1 = the procedure date) according to the list in Table 3
and
infection involves any part of the body, excluding the skin incision, fascia, or
muscle layers, that is opened or manipulated during the operative procedure
and
patient has at least one of the following:
a. purulent drainage from a drain that is placed into the organ/space (e.g.,
closed suction drainage system, open drain, T-tube drain, CT guided
drainage)
b. organisms isolated from an aseptically-obtained culture of fluid or
tissue in the organ/space
c. an abscess or other evidence of infection involving the organ/space that
is detected on gross anatomical or histopathologic exam, or imaging
test
and
meets at least one criterion for a specific organ/space infection site listed in
Table 4.
Because an organ/space SSI involves any part of the body, excluding the skin
Comments
incision, fascia, or muscle layers, that is opened or manipulated during the
operative procedure, the criterion for infection at these body sites must be met
in addition to the organ/space SSI criteria. For example, an appendectomy
with subsequent subdiaphragmatic abscess would be reported as an
organ/space SSI at the intraabdominal specific site (SSI-IAB) when both
organ/space SSI and IAB criteria are met. Table 4 list the specific sites that
must be used to differentiate organ/space SSI. These criteria are in the
Surveillance Definitions for Specific Types of Infections chapter.
REPORTING
 If a patient has an infection at the site of the operative procedure,
INSTRUCTIONS
subsequent continuation of this infection type during the remainder of the
surveillance period is considered an SSI ( see PATOS definition in
denominator reporting instructions), Report mediastinitis following cardiac
surgery that is accompanied by
osteomyelitis as SSI-MED rather than SSI-BONE.
 If meningitis (MEN) and a brain abscess (IC) are present together after
operation, report as SSI-IC. Similarly, if meningitis and spinal abscess
(SA) are present together after an operation, report as SSI-SA.
 Report CSF shunt infection as SSI-MEN if it occurs within 90 days of
placement; if later or after manipulation/access, it is considered CNS-MEN
and is not reportable under this module.
Table 3. Surveillance Period for Deep Incisional or Organ/Space SSI Following Selected NHSN
Operative Procedure Categories. Day 1 = the date of the procedure.

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30-day Surveillance
Code
AAA
AMP
APPY
AVSD
BILI
CEA
CHOL
COLO
CSEC
GAST
HTP

Operative Procedure
Abdominal aortic aneurysm repair
Limb amputation
Appendix surgery
Shunt for dialysis
Bile duct, liver or pancreatic surgery
Carotid endarterectomy
Gallbladder surgery
Colon surgery
Cesarean section
Gastric surgery
Heart transplant

Code
LAM
LTP
NECK
NEPH
OVRY
PRST
REC
SB
SPLE
THOR
THYR

HYST
KTP

Abdominal hysterectomy
Kidney transplant

VHYS
XLAP
OTH

Operative Procedure
Laminectomy
Liver transplant
Neck surgery
Kidney surgery
Ovarian surgery
Prostate surgery
Rectal surgery
Small bowel surgery
Spleen surgery
Thoracic surgery
Thyroid and/or parathyroid
surgery
Vaginal hysterectomy
Exploratory Laparotomy
Other operative procedures not
included in the NHSN categories

90-day Surveillance
Code
BRST
CARD
CBGB
CBGC
CRAN
FUSN
FX
HER
HPRO
KPRO
PACE
PVBY
RFUSN
VSHN

Operative Procedure
Breast surgery
Cardiac surgery
Coronary artery bypass graft with both chest and donor site incisions
Coronary artery bypass graft with chest incision only
Craniotomy
Spinal fusion
Open reduction of fracture
Herniorrhaphy
Hip prosthesis
Knee prosthesis
Pacemaker surgery
Peripheral vascular bypass surgery
Refusion of spine
Ventricular shunt

NOTE: Superficial incisional SSIs are only followed for a 30-day period for all procedure types.

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Table 4. Specific Sites of an Organ/Space SSI. Criteria for these sites can be found in the NHSN
Help system (must be logged in to NHSN) or the Surveillance Definitions for Specific Types of
Infections chapter.
Code
BONE

Site
Osteomyelitis

BRST
CARD
DISC
EAR

Breast abscess or mastitis
Myocarditis or pericarditis
Disc space
Ear, mastoid

EMET
ENDO
EYE
GIT
HEP
IAB
IC
JNT

Endometritis
Endocarditis
Eye, other than conjunctivitis
GI tract
Hepatitis
Intraabdominal, not specified
Intracranial, brain abscess or dura
Joint or bursa

Code
Site
LUNG Other infections of the respiratory
tract
MED
Mediastinitis
MEN
Meningitis or ventriculitis
ORAL Oral cavity (mouth, tongue, or gums)
OREP Other infections of the male or female
reproductive tract
OUTI Other infections of the urinary tract
PJI
Periprosthetic Joint Infection
SA
Spinal abscess without meningitis
SINU Sinusitis
UR
Upper respiratory tract
VASC Arterial or venous infection
VCUF Vaginal cuff

Numerator Data: All patients having any of the procedures included in the selected NHSN
operative procedure category(s) are monitored for signs of SSI. The Surgical Site Infection (SSI)
form is completed for each such patient found to have an SSI. If no SSI events are identified during
the surveillance month, check the “Report No Events” field in the Missing PA Events tab of the
Incomplete/Missing List.
The Instructions for Completion of the Surgical Site Infection form include brief instructions for
collection and entry of each data element on the form. The SSI form includes patient demographic
information and information about the operative procedure, including the date and type of
procedure. Information about the SSI includes the date of SSI, specific criteria met for identifying
the SSI, when/how the SSI was detected, whether the patient developed a secondary bloodstream
infection, whether the patient died, and the organisms isolated from cultures and the organisms’
antimicrobial susceptibilities.

SSI EVENT REPORTING INSTRUCTIONS:
1. Attributing SSI to an NHSN procedure that was infected at the time of the primary surgery:
POA does not apply to SSI and this is stated in the HAI protocol.If the procedure that was
performed met criteria for an NSHN operative procedure and is in the facilitys denominator data
and then later in the surveillance period the patient developed an infection that meets the NHSN
SSI criteria it would be attributed to the procedure. A high wound class does not discount a
patient later meeting criteria for an SSI.If a patient has an infection at the time of surgery,
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subsequent continuation of this infection type during the remainder of the surveillance period is
considered an SSI, if SSI criteria are met.
2. Infection present at time of surgery (PATOS) denotes that an infection is present at the time of
the start of or during the index surgical procedure (in other words, it is present preoperatively).
PATOS does not apply if there is a period of wellness between the time of this preoperative
condition and surgery. The infection must be noted/documented preoperatively or found
intraoperatively. Only select PATOS if it applies to the depth of SSI that is being attributed to
the procedures (e.g., if a Superficial Incisional SSI is assigned as a postoperative occurrence -only Superficial Incisional SSI PATOS can be selected if the patient meets criteria for
Superficial Incisional PATOS [Cannot assign Deep Incisional or Organ/Space PATOS unless
the corresponding postoperative occurrence is assigned])
3. Multiple tissue levels are involved in the infection:The type of SSI (superficial incisional,
deep incisional, or organ/space) reported should reflect the deepest tissue layer involved in the
infection:
a) Report infection that involves the organ/space as an organ/space SSI, whether or not it
also involves the superficial or deep incision sites.
b) Report infection that involves the superficial and deep incisional sites as a deep
incisional SSI.
4. Reporting of SSI after a non-primary closure: If a patient develops an SSI after a non-primary
closure it should be reported as attributable to that procedure if it meets criteria for an SSI
within the surveillance period.
5. Attributing SSI to a NHSN procedure when several are performed on different dates: If a
patient has several NHSN operative procedures performed on different dates prior to an
infection, report the operative procedure code of the operation that was performed most closely
in time prior to the infection date, unless there is evidence that the infection was associated with
a different operation. Note: for multiple NHSN operative procedures performed within a 24
hour period, see Denominator Reporting Instruction 7.
6. Attributing SSI to NHSN procedures that involve multiple primary incision sites: If
multiple primary incision sites of the same NHSN operative procedure become infected, only
report as a single SSI, and assign the type of SSI (superficial incisional, deep incisional, or
organ/space) that represents the deepest tissue level involved at any of the infected sites. For
example:
a) If one laparoscopic incision meets criteria for a superficial incisional SSI and another
meets criteria for a deep incisional SSI, only report one deep incisional SSI.
b) If one or more laparoscopic incision sites meet criteria for superficial incisional SSI but
the patient also has an organ/space SSI related to the laparoscopic procedure, only report
one organ/space SSI.
c) If an operative procedure is limited to a single breast and involves multiple incisions in
that breast that become infected, only report a single SSI.
d) In a colostomy formation or reversal (take down) procedure, the stoma and other
abdominal incision sites are considered primary incisions. If both the stoma and another
abdominal incision site develop superficial incisional SSI, report only as one SSI (SIP).

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7. Attributing SSI to NHSN procedures that have secondary incision sites: Certain procedures
can involve secondary incisions, when applicable, including BRST, CBGB, CEA, FUSN, REC,
PVBY, RFUSN. The superficial incisionaland deep incisional SSI surveillance periods for any
secondary incision site are 30 days, regardless of the required deep incisional or organ/space
SSI surveillance period for the primary incision site(s) (Table 3). Procedures meeting this
designation are reported as only one operative procedure. For example:
a) A saphenous vein harvest incision site in a CBGB procedure is considered the secondary
incision. One CBGB procedure is reported, the saphenous vein harvest site is monitored
for 30 days after surgery for SSI, and the chest incision is monitored for 90 days.
b) A tissue harvest site (e.g., Transverse Rectus Abdominis Myocutaneous [TRAM] flap)
in a BRST procedure is considered the secondary incision site. One BRST procedure is
reported, and if the secondary incision gets infected, report as either SIS or DIS as
appropriate.
8. SSI detected at another facility: It is required that if an SSI is detected at a facility other than
the one in which the operation was performed, notify the IP of the index facility with enough
detail so the infection can be reported to NHSN. When reporting the SSI, the index facility
should indicate that Detected = RO.
9. SSI Attribution after Surgical Multiple types of NHSN procedures are performed during a
single trip to the OR: If more than one NHSN operative procedure category was performed
through a single incision during a single trip to the operating room, attribute the SSI to the
procedure that is thought to be associated with the infection. If it is not clear, as is often the case
when the infection is an incisional SSI, use the NHSN Principal Operative Procedure Category
Selection Lists (Table 5) to select the operative procedure to which the SSI should be attributed.
For example, if a patient develops SSI after a single trip to the OR in which both a COLO and
SB were performed, and the source of the SSI is not apparent, assign the SSI to the COLO
procedure.
10. SSI following invasive manipulation/accession of the operative site: If during the postoperative period the surgical site has an invasive manipulation/accession for diagnostic or
therapeutic purposes (e.g., needle aspiration), and following this manipulation/accession an SSI
develops, the infection is not attributed to the operation. This reporting instruction does NOT
apply to closed manipulation (e.g., closed reduction of a dislocated hip after an orthopedic
procedure). Invasive manipulation does not include wound packing, or changing of wound
packing materials as part of postoperative care.
11. Reporting instructions for specific post-operative infection scenarios: As of 2014, an SSI
that otherwise meets the NHSN definitions should be reported to NHSN without regard to postoperative accidents, falls, inappropriate showering or bathing practices, or other occurrences
that may or may not be attributable to patients’ intentional or unintentional postoperative
actions. Also, SSI should also be reported regardless of the presence of certain skin conditions
(e.g., dermatitis, blister, impetigo) that occur near an incision, and regardless of the possible

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occurrence of a “seeding” event from an unrelated procedure (e.g., dental work). This revised
instruction concerning various postoperative circumstances is necessary to reduce subjectivity
and data collection burden associated with the previously exempted scenarios.

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Table 5. NHSN Principal Operative Procedure Category Selection Lists
The following lists are derived from the operative procedures listed in Table 1. The categories with
the highest risk of SSI are listed before those with lower risks.
Priority
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Priority
1
2
3
4
5
Priority
1
2
3
4
5
Priority
1
2

January 2014

Code
LTP
COLO
BILI
SB
REC
KTP
GAST
AAA
HYST
CSEC
XLAP
APPY
HER
NEPH
VHYS
SPLE
CHOL
OVRY
Code
HTP
CBGB
CBGC
CARD
THOR
Code
VSHN
RFUSN
CRAN
FUSN
LAM
Code
NECK
THYR

Abdominal Operations
Liver transplant
Colon surgery
Bile duct, liver or pancreatic surgery
Small bowel surgery
Rectal surgery
Kidney transplant
Gastric surgery
Abdominal aortic aneurysm repair
Abdominal hysterectomy
Cesarean section
Laparotomy
Appendix surgery
Herniorrhaphy
Kidney surgery
Vaginal Hysterectomy
Spleen surgery
Gall bladder surgery
Ovarian surgery
Thoracic Operations
Heart transplant
Coronary artery bypass graft with donor incision(s)
Coronary artery bypass graft, chest incision only
Cardiac surgery
Thoracic surgery
Neurosurgical (Brain/Spine) Operations
Ventricular shunt
Refusion of spine
Craniotomy
Spinal fusion
Laminectomy
Neck Operations
Neck surgery
Thyroid and or parathyroid surgery

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Denominator Data: For all patients having any of the procedures included in the NHSN Operative
Procedure category(s) selected for surveillance during the month, complete the Denominator for
Procedure form. The data are collected individually for each operative procedure performed during
the month specified on the Patient Safety Monthly Reporting Plan. The Instructions for Completion
of the Denominator for Procedure Form include brief instructions for collection and entry of each
data element on the form.
DENOMINATOR REPORTING INSTRUCTIONS:
1. Closure type:Incisional closure is NOT a part of the NHSN operative procedure definition; all
otherwise eligible procedures are included in the denominator reporting, regardless of closure
type. The closure technique is entered for each denominator for procedure. If a procedure has
multiple incision sites and any of the incisions are closed primarily then the procedure is entered
as having been closed primarly.
2. Wound class: A wound class is not an exclusion for denominator reporting. If the procedure
meets the definition of an NHSN operative procedure it should be reported in the denominator
data regardless of wound class. NHSN will use the wound class for risk adjustment, as
appropriate.
3. Different operative procedure categories performed during same trip to the OR: If
procedures in more than one NHSN operative procedure category are performed during the
same trip to the operating room through the same or different incisions, a Denominator for
Procedure form is reported for each NHSN operative procedure category being monitored. For
example, if a CARD and CBGC are done through the same incision, a Denominator for
Procedure form is reported for each. In another example, if following a motor vehicle accident,
a patient has an open reduction of fracture (FX) and splenectomy (SPLE) performed during the
same trip to the operating room and both procedure categories are being monitored, complete a
Denominator for Procedure form for each.
EXCEPTION: If a patient has both a CBGC and CBGB during the same trip to the operating
room, report only as a CBGB. Only report as a CBGC when there is a chest incision only.
CBGB and CBGC are never reported for the same patient for the same trip to the operating
room. The time from chest incision to chest primary closure is reported as the duration of the
procedure.
4. Duration of the procedure when more than one category of NHSN operative procedure is
done through the same incision: If more than one NHSN operative procedure category is
performed through the same incision during the same trip to the operating room, record the
combined duration of all procedures, which is the time from procedure/surgery start time to
procedure/surgery finish time. For example, if a CBGC and a CARD are performed on a patient
during the same trip to the operating room, the time from start time to finish time is reported for
both operative procedures.

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5. Same operative procedure category but different ICD-9-CM codes during same trip to the
OR: If procedures of different ICD-9-CM codes from the same NHSN operative procedure
category are performed through the same incision, record only one procedure for that category.
For example, a facility is performing surveillance for CARD procedures. A patient undergoes a
replacement of both the mitral and tricuspid valves (35.23 and 35.27, both CARD) during the
same trip to the operating room. Complete one CARD Denominator for Procedure form
because ICD-9-CM codes 35.23 and 35.27 fall in the same operative procedure category
[CARD] (see Table 1).
NOTE: When the patient returns to the OR within 24 hours of the end of the first procedure assign
the surgical wound closure that applies when the patient leaves the OR from the first operative
procedure.

6. For HPRO and KPRO procedures: If total or partial revision is is performed note on the
denominator for procedure form if the revision was associated with prior infection at index
joint.
7. Bilateral procedures: For operative procedures that can be performed bilaterally during same
trip to operating room (i.e.,, KPRO, HPRO, BRST), two separate Denominator for Procedure
forms are completed. To document the duration of the procedures, indicate the
procedure/surgery start time to procedure/surgery finish time for each procedure separately or,
alternatively, take the total time for both procedures and split it evenly between the two.
8.
9. More than one operative procedure through same incision within 24 hours: If a patient
goes to the operating room more than once during the same admission and another procedure of
the same or different NHSN procedure category is performed through the same incision and the
start time of the second procedure is within 24 hours of the finish time of the original operative
incision, report only one Denominator for Procedure form for the original procedure,
combining the durations for both procedures based on the procedure start times and finish times
for both procedures. For example, a patient has a CBGB lasting 4 hours. He returns to the OR
six hours later to correct a bleeding vessel (OTH). The second operation has a duration of 1.5
hours. Record the operative procedure as one CBGB and the duration of operation as 5 hour 30
minutes. If the wound class has changed, report the higher wound class. If the ASA class has
changed, report the higher ASA class. Do not report an ‘OTH’ record. Report the incisional
closure method of the first procedure.
10. Procedure with multiple incisions: If one of the incisions is primarily closed than report the
incisional closure method for the procedure as a primary closure.
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11. Patient expires in the OR: If a patient expires in the operating room, do not complete a
Denominator for Procedure form. This operative procedure is excluded from the denominator.
12. Laparoscopic hysterectomy – HYST or VHYS: When assigning the correct ICD-9-CM
hysterectomy procedure code, a trained coder must determine what structures were detached
and how they were detached based on the medical record documentation. The code assignment
is based on the surgical technique or approach used for the detachment of those structures, not
on the location of where the structures were physically removed from the patient’s body.
Therefore, a total laparoscopic HYST procedure will have detachment of the entire uterus and
cervix from the surrounding supporting structures via the laparoscopic technique. A
laparoscopically-assisted VHYS involves detachment of the uterus and upper supporting
structures via laparoscope but the lower supporting structures and cervix are detached via
vaginal incision.
13. Incidental appendectomy: Any appendectomy (APPY) should be reported regardless of
whether it is incidental.
14. XLAP: Any exploratory laparotomy (XLAP) should be reported regardless of whether it results
in a procedure from another category being performed.

Data Analyses: The Standardized Infection Ratio (SIR) is calculated by dividing the number of
observed infections by the number of predicted infections. The number of predicted infections is
calculated using SSI probabilities estimated from multivariate logistic regression models
constructed from NHSN data during a baseline time period, which represents a standard
population’s SSI experience [3].
There are three SSI SIR models available from NHSN, each briefly described in the table below.
All SSI SIR Model





Complex A/R SSI
Model






January 2014

Includes Superficial, Deep & Organ/Space SSIs
Superficial & Deep incisional SSIs limited to primary
incisional SSIs only
Includes SSIs identified on admission, readmission & via postdischarge surveillance
Includes only Deep incisional primary SSIs & Organ/Space
SSIs
Includes only SSIs identified on Admission/Readmission to
facility where procedure was performed
Includes only inpatient procedures
Used for the National SIR Report, published annually

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Complex 30-day SSI
model (used for CMS
IPPS)






Includes only in-plan, inpatient COLO and HYST procedures
in adult patients (i.e., ≥ 18 years of age)
Includes only deep incisional primary SSIs and organ/space
SSIs with an event date within 30 days of the procedure
Uses only age and ASA to determine risk
Used only for CMS IPPS reporting and for public reporting on
Hospital Compare

NOTE: The SIR will be calculated only if the number of expected HAIs (numExp) is ≥ 1 to help
enforce a minimum precision criterion .
NOTE: In the NHSN application, “predicted” is referred to as “expected”.
NOTE: All of the SSI SIRs that utilize the 2006-2008 SSI baseline data will include only those
procedures that were reported with a primary closure method.3
SIR = Observed (O) HAIs
Expected (E) HAIs
While the SSI SIR can be calculated for single procedure categories and for specific surgeons, the
measure also allows you to summarize your data across multiple procedure categories while
adjusting for differences in the estimated probability of infection among the patients included
across the procedure categories. For example, you will be able to obtain one SSI SIR adjusting for
all procedures reported. Alternatively, you can obtain one SSI SIR for all colon surgeries (COLO)
only within your facility.
NOTE: SSIs will be included in the numerator of an SIR based on the date of procedure, not the
date of event.
SSI rates per 100 operative procedures are calculated by dividing the number of SSIs by the number
of specific operative procedures and multiplying the results by 100. SSIs will be included in the
numerator of a rate based on the date of procedure, not the date of event. Using the advanced
analysis feature of the NHSN application, SSI rate calculations can be performed separately for the
different types of operative procedures and stratified by the basic risk index.
Descriptive analysis options of numerator and denominator data are available in the NHSN
application, such as line listings, frequency tables, and bar and pie charts. SIRs and SSI rates and
run charts are also available. Guides on using NHSN analysis features are available from:
http://www.cdc.gov/nhsn/PS-Analysis-resources/reference-guides.html.
REFERENCES

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1.

2.
3.
4.
5.
6.

7.

8.

9.
10.
11.

12.

CDC. Data from the National Hospital Discharge Survey. 2010 [cited 2013 Dec 10];
Available from:
http://www.cdc.gov/nchs/data/nhds/4procedures/2010pro_numberpercentage.pdf.
Magill, S.S., et al., Prevalence of healthcare-associated infections in acute care hospitals in
Jacksonville, Florida. Infect Control Hosp Epidemiol, 2012. 33(3): p. 283-91.
Mu, Y., et al., Improving risk-adjusted measures of surgical site infection for the national
healthcare safety network. Infect Control Hosp Epidemiol, 2011. 32(10): p. 970-86.
Awad, S.S., Adherence to surgical care improvement project measures and post-operative
surgical site infections. Surg Infect (Larchmt), 2012. 13(4): p. 234-7.
Condon, R.E., et al., Effectiveness of a surgical wound surveillance program. Arch Surg,
1983. 118(3): p. 303-7.
Consensus paper on the surveillance of surgical wound infections. The Society for Hospital
Epidemiology of America; The Association for Practitioners in Infection Control; The
Centers for Disease Control; The Surgical Infection Society. Infect Control Hosp
Epidemiol, 1992. 13(10): p. 599-605.
Haley, R.W., et al., The efficacy of infection surveillance and control programs in
preventing nosocomial infections in US hospitals. Am J Epidemiol, 1985. 121(2): p. 182205.
Mangram, A.J., et al., Guideline for prevention of surgical site infection, 1999. Hospital
Infection Control Practices Advisory Committee. Infect Control Hosp Epidemiol, 1999.
20(4): p. 250-78; quiz 279-80.
Institute, F.G., Guidelines for design and construction of health care facilities. 2010,
Chicago, IL: American Society for Healthcare Engineering.
Anonymous, New classification of physical status. Anesthesiology, 1963. 24: p. 111.
ASA. ASA Physical Status Classification System. [cited 2013 Dec 10]; Available from:
http://www.asahq.org/Home/For-Members/Clinical-Information/ASA-Physical-StatusClassification-System.
Donham, R.T., W.J. Mazzei, and R.L. Jones, Association of Anesthesia Clinical Directors'
Procedure Times Glossary. Am J Anesthesiol, 1996. 23(5S): p. S1-S12.

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SSI

Instructions for Completion of Surgical Site Infection (SSI) Form (CDC
57.120)
Data Field
Facility ID
Event #
Patient ID

Social Security #
Secondary ID
Medicare #
Patient Name
Gender
Date of Birth
Ethnicity
Race

Event Type
Date of Event

NHSN Procedure
Code

ICD-9-CM Procedure
Code

Date of Procedure
January 2014

Instructions for Data Collection
The NHSN-assigned facility ID will be auto-entered by the computer.
Event ID number will be auto-entered by the computer.
Required. Enter the alphanumeric patient ID number. This is the patient
identifier assigned by the hospital and may consist of any combination of
numbers and/or letters.
Optional. Enter the 9-digit numeric patient Social Security Number.
Optional. Enter the alphanumeric ID number assigned by the facility.
Required. Enter the patient’s Medicare number.
Optional. Enter the last, first, and middle name of the patient.
Required. Check Female, Male, or Other to indicate the gender of the patient.
Required. Record the date of the patient birth using this format:
MM/DD/YYYY.
Optional. Specify if the patient is either Hispanic or Latino, or Not Hispanic or
Not Latino.
Optional. Specify one or more of the choices below to identify the patient’s
race:
American Indian/Alaska Native
Asian
Black or African American
Native Hawaiian/Other Pacific Islander
White
Required. Enter SSI.
For an HAI (excludes VAE), the date of event is the date when the last element
used to meet the CDC/NHSN site-specific infection criterion occurred.
Synonyms: infection date, date of infection.
Date of event must be within 30 days or 90 days of the date of procedure,
depending on the operative procedure category (see Table 3 of the SSI chapter).
Required. Enter the appropriate NHSN procedure code. For detailed
instructions on how to report NHSN operative procedures, see the SSI chapter.
NOTE: An SSI cannot be “linked” to an operative procedure unless that
procedure has already been added to NHSN. If the procedure was previously
added, and the “Link to Procedure” button is clicked, the fields pertaining to the
operation will be auto-entered by the computer.
Optional. The ICD-9-CM code may be entered here instead of (or in addition
to) the NHSN Procedure Code. If the ICD-9-CM code is entered, the NHSN
code will be auto-entered by the computer. If the NHSN code is entered first,
you will have the option to select the appropriate ICD-9-CM code. In either
case, it is optional to select the ICD-9-CM code. The only allowed ICD-9-CM
codes are shown in Table 1 of the SSI chapter.
Required. Enter date using this format: MM/DD/YYYY.
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SSI

Data Field
Outpatient Procedure

MDRO Infection
Surveillance

Date Admitted to
Facility

Location

Event Details:
Specific event

Event Details:
Specify Criteria Used

Infection present at
January 2014

Instructions for Data Collection
Required. Check Y if this operative procedure was performed on an NHSN
outpatient, defined as a patient whose date of admission to the healthcare
facility and date of discharge are the same calendar day; otherwise check N.
Required. Enter “Yes”, if the pathogen is being followed for Infection
Surveillance in the MDRO/CDI Module in that location as part of your
Monthly Reporting Plan: MRSA, MSSA (MRSA/MSSA), VRE, CephRKlebsiella, CRE-E. coli, CRE-Klebsiella, MDR-Acinetobacter or C. difficile.
If the pathogen for this infection happens to be an MDRO but your facility is
not following the Infection Surveillance in the MDRO/CDI Module in your
Monthly Reporting Plan, answer “No” to this question.
NOTE: For an SSI, the location of attribution is the post-op location, so if1. The event occurs in a different calendar month from the surgical
procedure AND
2. Your facility is performing Infection Surveillance for the organism
causing the SSI in the post-op location for the month reported in the
Date of Event, then answer “Yes” to this question.
Required. Enter date patient admitted to facility using this format:
MM/DD/YYYY. If a patient is readmitted with a previously unreported SSI
associated with an operative procedure performed during a previous admission,
enter the date of admission of the facility stay in which the operative procedure
was performed. An NHSN Inpatient is defined as a patient whose date of
admission to the healthcare facility and the date of discharge are different
calendar days. When determining a patient’s admission dates to both the facility
and specific inpatient location, the NHSN user must take into account all such
days, including any days spent in an inpatient location as an “observation”
patient before being officially admitted as an inpatient to the facility, as these
days contribute to exposure risk. Therefore, all such days are included in the
counts of admissions and patient days for the facility and specific location, and
facility and admission dates must be moved back to the first day spent in the
inpatient location.
Conditionally required if MDRO Infection Surveillance field is Yes. Enter the
patient care area where the patient was assigned in the postoperative period.
Inpatient or outpatient locations are allowed, but Operating Room locations are
not allowed.
Required. Check the appropriate level of SSI from the list
___Superficial incisional primary (SIP)
___Superficial incisional secondary (SIS)
___Deep incisional primary (DIP)
___Deep incisional secondary (DIS)
___ Organ/space: __ (Indicate specific site code from Table 2 of the SSI
chapter.)
Required. Check each of the elements of the definition that were used to
identify the specific type of SSI. Specific organ/space event types have their
own unique criteria which must be met. They are found in the Surveillance
Definitions chapter.
Required. Check Y if an infection is present at the time of the start of or during
26

SSI

Data Field
the time of surgery
(PATOS)

Instructions for Data Collection
the index surgical procedure (in other words, it is present preoperatively).
PATOS does not apply if there is a period of wellness between the time of this
preoperative condition and surgery. The infection must be noted/documented
preoperatively or found intraoperatively; otherwise check N.

Event Details:
Detected

Required.
Check A if SSI was identified before the patient was discharged from the
facility following the operation.
Check P if SSI was identified only as part of post-discharge surveillance.
Include as P those SSI identified in the Emergency Department but not
readmitted to the facility. Alternatively, if patient was identified by postdischarge surveillance but was also readmitted to the facility, check either RF
or RO as appropriate.
Check RF if SSI was identified due to patient readmission to the facility where
the operation was performed.
Check RO if SSI was identified due to readmission to facility other than where
the operation was performed.
Required. Check Y if there is a culture-confirmed bloodstream infection (BSI)
and a related healthcare-associated infection at the surgical site, otherwise
check N. For detailed instructions on identifying whether the blood culture
represents a secondary BSI, refer to the Secondary BSI Guide (Appendix 1 of
the Surveillance Definitions chapter).
Required. Check Y if patient died during the hospitalization, otherwise check
N.
Conditionally required. If patient died, check Y if the SSI contributed to death,
otherwise check N.

Event Details:
Secondary
bloodstream infection

Event Details:
Died
Event Details:
SSI Contributed to
Death
Event Details:
Discharge Date

Event Details:
Pathogens Identified
Pathogen # for
specified Grampositive Organisms,
Gram-negative
Organisms, Fungal
Organisms, or Other
Organisms
Antimicrobial agent
and susceptibility
results

January 2014

Optional. Enter date patient discharged from facility using this format:
MM/DD/YYYY. If a patient is readmitted with a previously unreported SSI
associated with an operative procedure performed in a previous admission,
enter the date of discharge of the facility stay in which the operative procedure
was performed.
Required. Enter Y if a pathogen was identified, N if otherwise. If Y, specify
organism name on reverse.
Up to three pathogens may be reported. If multiple pathogens are identified,
enter the pathogen judged to be the most important cause of infection as #1, the
next most as #2, and the least as #3 (usually this order will be indicated on the
laboratory report). If the species is not given on the lab report or is not found on
the NHSN organism list, then select the “spp” choice for the genus (e.g.,
Bacillus natto is not on the list so would be reported as Bacillus spp.).
Conditionally required if Pathogen Identified = Y.
 For those organisms shown on the back of an event form, susceptibility
results are required only for the agents listed.
 For organisms that are not listed on the back of an event form, the entry
of susceptibility results is optional.
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SSI

Data Field

Instructions for Data Collection
Circle the pathogen’s susceptibility result using the codes on the event forms.
Additional antimicrobial agents and susceptibility results may be reported for
up to a total of 20 agents.

Custom Fields

Comments

January 2014

Optional. Up to 50 fields may be customized for local or group use in any
combination of the following formats: date (MM/DD/YYYY), numeric, or
alphanumeric.
NOTE: Each Custom Field must be set up in the Facility/Custom Options
section of the application before the field can be selected for use.
Optional. Enter any information on the event.

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SSI

Instructions for Completion of Denominator for Procedure Form
(CDC 57.121)
This form is used for reporting data on each patient having one of the NHSN operative procedures
selected for monitoring.
Data Field
Facility ID
Procedure #

The NHSN-assigned Procedure # will be auto-entered by
the computer.
Required. Enter the alphanumeric patient ID number.
This is the patient identifier assigned by the hospital and
may consist of any combination of numbers and/or
letters.
Optional. Enter the 9-digit numeric patient Social
Security Number.
Optional. Enter the alphanumeric ID number assigned by
the facility.
Optional. Enter the patient’s Medicare number.

Patient ID

Social Security #
Secondary ID #
Medicare #
Patient name
Gender
Date of birth
Ethnicity

Instructions for Data Collection
The NHSN-assigned facility ID will be auto-entered by
the computer.

Optional. Enter the last, first, and middle name of the
patient.
Required. Check Female, Male, or Other to indicate the
gender of the patient.
Required. Record the date of the patient birth using this
format: MM/DD/YYYY.
Optional.
Hispanic or Latino If patient is Hispanic or Latino, check this box.

Not Hispanic or Not Latino If patient is not Hispanic or not Latino, check this box.
Race
Optional.
Check all the boxes that apply to identify the patient’s
race.
Event type
Required. Enter the code for procedure (PROC).
NHSN Procedure code
Date of procedure

January 2014

Required. Enter the appropriate NHSN procedure code.
Required. Record the date when the NHSN procedure
was begun using this format: MM/DD/YYYY.
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SSI

Data Field
ICD-9-CM procedure code

Instructions for Data Collection
Optional. The ICD-9-CM code may be entered here
instead of (or in addition to) the NHSN Procedure Code.
If the ICD-9-CM code is entered, the NHSN code will be
auto-entered by the computer. If the NHSN code is
entered first, you will have the option to select the
appropriate ICD-9-CM code. In either case, it is optional
to select the ICD-9-CM code. The only allowed ICD-9CM codes are listed in Table 1 of the SSI chapter.

Procedure Details:
Outpatient: Required. Check Y if this operative procedure was
performed on an NHSN outpatient, otherwise check N.
Duration: Required. The interval in hours and minutes between the
Procedure/Surgery Start Time, and the
Procedure/Surgery Finish Time, as defined by the
Association of Anesthesia Clinical Directors (AACD):
 Procedure/Surgery Start Time (PST): Time when
the procedure is begun (e.g., incision for a
surgical procedure).
 Procedure/Surgery Finish (PF): Time when all
instrument and sponge counts are completed and
verified as correct, all postoperative radiologic
studies to be done in the OR are completed, all
dressings and drains are secured, and the
physicians/surgeons have completed all
procedure-related activities on the patient.
Wound class: Required. Check the appropriate wound class from the
list. If the wound class is unknown or not listed work
with your OR liaison to obtain a wound class for the
procedure. If this is not possible, assign a wound class
based on the operative procedure and OR notes.
General anesthesia: Required. Check Y if general anesthesia was used for the
operative procedure, otherwise check N. General
anesthesia is defined as the administration of drugs or
gases that enter the general circulation and affect the
central nervous system to render the patient pain free,
amnesic, unconscious, and often paralyzed with relaxed
muscles.

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SSI

Data Field

Instructions for Data Collection
ASA score: Conditionally Required. Required for Inpatient
procedures only. Check numeric ASA classification at
the time of the operative procedure. NOTE: Do NOT
report procedures with an ASA physical status of 6 (a
declared brain-dead patient whose organs are being
removed for donor purposes) to NHSN.
Emergency: Required. Check Y if this operative procedure was a nonelective, unscheduled operative procedure, otherwise
check N. Emergency operative procedures are those that
do not allow for the standard immediate preoperative
preparation normally done within the facility for a
scheduled operation (e.g., stable vital signs, adequate
antiseptic skin preparation, colon decontamination in
advance of colon surgery, etc.).
Trauma: Required. Check Y if operative procedure was performed
because of blunt or penetrating traumatic injury to the
patient, otherwise check N.
Scope: Required. Check Y if the entire NHSN operative
procedure was performed using a laparoscope/robotic
assist, otherwise check N
NOTES:



For CBGB, if the donor vessel was harvested using a
scope, check Y.
Check Y if scope was used for HYST or VHYS, even if
uterus was removed from the vagina.

Diabetes Mellitus Required. Indicate Y if the patient has a diagnosis of
diabetes requiring management with insulin or a noninsulin anti-diabetic agent. This includes patients with
“insulin resistance” who are on management with an
anti-diabetic agent. This also includes patients with a
diagnosis of diabetes requiring management with an antidiabetic agent, but who are noted to be non-compliant
with their prescribed medications.
Indicate N if the patient has no known diagnosis of
diabetes, or a diagnosis of diabetes that is controlled by
diet alone. Also indicate N if the patient receives insulin
for perioperative control of hyperglycemia but has no
diagnosis of diabetes. See December 2013 NHSN
newsletter for interim reporting guidance.
January 2014

31

SSI

Data Field

Instructions for Data Collection
Height Required. Height: The patient’s most recent height
documented in the medical record in feet and inches or
meters (m) prior to or otherwise closest to the operative
procedure.
Weight Required. Weight: The patient’s most recent weight
documented in the medical record in pounds (lbs) or
kilograms (kg) prior to or otherwise closest to the
procedure.

Closure Technique Required. Select Primary or Other than Primary
* Primary Closure is defined as closure of all tissue
levels during the original surgery, regardless of the
presence of wires, wicks, drains, or other devices or
objects extruding through the incision. This category
includes surgeries where the skin is closed by some
means, including incisions that are described as being
“loosely closed” at the skin level. Thus, if any portion of
the incision is closed at the skin level, by any manner, a
designation of primary closure should be assigned to the
surgery.
Other than Primary includes surgeries in which the
superficial layers are left completely open during the
original surgery and therefore cannot be classified as
having primary closure. For surgeries with non-primary
closure, the deep tissue layers may be closed by some
means (with the superficial layers left open), or the deep
and superficial layers may both be left completely open.
An example of a surgery with non-primary closure would
be a laparotomy in which the incision was closed to the
level of the deep tissue layers, sometimes called “fascial
layers” or “deep fascia,” but the superficial layers are left
open. Another example would be an “open abdomen”
case in which the abdomen is left completely open after
the surgery. If the deep fascial levels of an incision are
left open but the skin is closed, this is considered a nonprimary closure since the incision was not closed at all
tissue levels. Wounds that are “closed secondarily” at
some later date, or described as “healing by secondary
intention” should also be classified as having nonprimary closure. Wounds with non-primary closure may
January 2014

32

SSI

Data Field

Instructions for Data Collection
or may not be described as "packed” with gauze or other
material, and may or may not be covered with plastic,
“wound vacs,” or other synthetic devices or materials.

Surgeon code: Optional. Enter code of the surgeon who performed the
principal operative procedure.
CSEC: Duration of labor

Conditionally required. If operative procedure is CSEC,
enter number of hours the patient labored in the hospital
from beginning of active labor to delivery of the infant,
expressed in hours. The documentation of active labor
can be supplied in the chart by a member of the
healthcare team or physician. Active labor may be
defined by the individual facility’s policies and
procedures, but should reflect the onset of regular
contractions or induction that leads to delivery during
this admission.
If a patient is admitted for a scheduled CSEC and has not
yet gone into labor, the duration of labor would be 0.
Hours should be rounded in the following manner: ≤30
minutes round down; >30 minutes round up.

Circle one: FUSN RFUSN

January 2014

Conditionally required. If operative procedure is FUSN
or RFUSN, circle the procedure that was done.

33

SSI

Data Field
FUSN/RFUSN: Spinal level

Instructions for Data Collection
Conditionally required. If operative procedure is FUSN
or RFUSN, check appropriate spinal level of procedure
from list.

Atlas-Axis – C1 and/or C2 only

Atlas-Axis/Cervical – C1-C7 (any combination
excluding C1 and/or C2 only)

Cervical – C3-C7 (any combination)

Cervical/Dorsal/Dorsolumbar – Extends from any
cervical through any lumbar levels

Dorsal/Dorsolumbar – T1 – L5 (any combination
of thoracic and lumbar)

Lumbar/Lumbosacral – L1-S5 (any combination
of lumbar and sacral)
If more than one level is fused, report category in which
the most vertebra were fused.

FUSN/RFUSN: Approach/Technique

HPRO:

Conditionally required. If operative procedure is FUSN
or RFUSN, check appropriate surgical approach or
technique from list.
Conditionally required. If operative procedure is HPRO,
select TOT (Total), HEMI (Hemi), or RES
(Resurfacing) from the list.
If Total HPRO, select TOTPRIM (Total Primary),
TOTREV (Total Revision), or PARTREV (Partial
Revision)
If Hemi HPRO, select PARTPRIM (Partial Primary),
TOTREV (Total Revision) or PARTREV (Partial
Revision)
If Resurfacing HPRO, select TOTPRIM (Total Primary),
TOTREV (Total Revision), PARTPRIM (Partial
Primary) or PARTREV (Partial Revision)
NOTE: When hardware is inserted for the first time, use
the “primary” designation; otherwise, indicate that the
procedure was a revision.

January 2014

34

SSI

Data Field
KPRO:

Instructions for Data Collection
Conditionally required. If operative procedure is KPRO,
select TOT – Primary (Total) or HEMI - Hemi from list.
If Total KPRO, select TOTPRIM (Total Primary),
TOTREV (Total Revision), or PARTREV (Partial
Revision)
If Hemi KPRO, select PARTPRIM (Partial Primary),
TOTREV (Total Revision) or PARTREV (Partial
Revision)
NOTE: When hardware is inserted for the first time, use
the “primary” designation; otherwise, indicate that the
procedure was a revision.

If total or partial revision, was the
revision associated with prior infection
at index joint?

Conditionally required If operative procedure is an
HPRO or a KPRO. Check Y if operative procedure was
performed on a joint with a prior history of infection,
otherwise check N.

Custom Fields

Optional. Up to 50 fields may be customized for local or
group use in any combination of the following formats:
date (MMDDYYY), numeric, or alphanumeric.
NOTE: Each Custom Field must be set up in the
Facility/Custom Options section of NHSN before the
field can be selected for use. Data in these fields may be
analyzed.

January 2014

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