Prevention of Perioperative Surgical Infections

Michael A. West, MD, PhD, FACSDepartment of Surgery

University California San FranciscoSan Francisco, CA, USA

Michael A. West, MD, PhD, FACSDepartment of Surgery

University California San FranciscoSan Francisco, CA, USA

Surgical Site Infections (SSI)2-5% of operated patients will develop SSI

40 million operations annually in the U.S.

⇒ 800,000 – 2,000,000 SSI’s annually in U.S.!!SSI increases LOS in hospital

average 7.5 days

Excess cost per SSI:*$5,739-51,191 (adjusted to 2009 USD)US national costs: $250 million – $1.7 billion/year

*Jarvis, Infect Control HospEpidemiol. 1996;17.

Opportunity to Prevent Surgical Infections

An estimated 40-60% of SSIs are preventable

Overuse, underuse, improper timing, and misuse of antibiotics occurs in 25-50% of operations

Risk Factors for Risk Factors for InfectionInfection

Wound ClassificationI. Clean: uninfected, no inflammation, no mucosal

surface transected: Mastectomy, Thyroidectomy

II. Clean/Contaminated: mucosal-lined lumen entered in controlled conditions. Cholecystectomy, Colectomy, Whipple, Laryngectomy, Urologic procedures.

III. Contaminated: Open accidental wounds, break in sterile conditions, spillage, stomas. Appendicitis, Diverticulitis, Small bowel GSW.

IV. Dirty/ Infected*: Infection, perforation, devitalized tissue. Abscess, Peritonitis, Enteric fistulas, Remove infected implant.

<2%

5-15%

15-30%

> 30%

Risk of SSI

Nichols RL - Amer J Surg 1996; 172: 68-74

* Dirty wounds ≈

infection - antibiotics indicated as therapy

Medical Conditions Increasing Risk of Surgical Site Infection (SSI)

Extremes of ageUnder-nutritionObesityDiabetesPrior site irradiation

HypoxemiaRemote infectionCorticosteroid therapyRecent operationChronic inflammation

Antibiotic prophylaxis may be indicated in clean cases when associated conditions increase infection risk

NNIS Risk Index as a Predictor of Risk of Infection

2.8%13.0%6.8%2.9%1.5%All

7.1%12.8%8.1%3.1%NADirty

6.4%13.2%6.6%3.4%NAContaminated

3.3%NA9.5%4.0%2.1%Clean/Contam

2.1%NA5.4%2.3%1.0%CleanAll3210Traditional Class

NNIS Risk Index

Nichols RL, Martone WJ. Surgery 2000; 128: S2-S13

13.2%

5.4%

6.4%

NNIS Risk Index as a Predictor of Risk of Infection

2.8%13.0%6.8%2.9%1.5%All

7.1%12.8%8.1%3.1%NADirty

6.6%3.4%NAContaminated

3.3%NA9.5%4.0%2.1%Clean/Contam

2.1%NA2.3%1.0%CleanAll3210Traditional Class

NNIS Risk Index

Nichols RL, Martone WJ. Surgery 2000; 128: S2-S13

Preventing Preventing InfectionInfection

New(er) Developments in SSIAttention to problemNew surgical techniques.Better systems for administration of

prophylactic antibioticsDuration of antibioticsRecognition of environmental factors that

aggravate SSITechnical factors in wound management

Mechanisms to Prevent SSIMinimize (or eliminate) bacteria in wound at

time of surgery. - skin decontamination - excellent surgical technique - peri-operative prophylactic antibiotics

Maximize delivery (and effectiveness) of host defenses. - pre-op nutritional state. - adequate oxygentation. - excellent perfusion of wound.

Influence of Shaving on SSINo Hair

Group Removal Depilatory Shaved

Number 155 153 246

Infection rate 0.6% 0.6% 5.6%

Seropian. Am J Surg 1971; 121: 251

Greif R: Supplemental perioperative oxygen to reduce the incidence of surgical-wound infection. Outcomes Research Group. N Engl J Med 2000 Jan 20;342(3):161-7

500 patients, randomized, double-blind protocolcolorectal resectionSubjects received 30% or 80% inspired O2 during operation

and for 2 hours post-op.Wounds evaluated dailyInfection = “Culture-positive” pus

Impact of Oxygen on SSI

30% O2 80% O2 p-valueNumber of Subjects 250 250 O2 Saturation 98% 99% N.S.Wound Infection 28 (11.2%) 13 (5.2%) 0.01

Hypothermia MechanismsImpaired wound perfusion (thermoregulatory vasospasm) Decreased oxygen levels in wound

-impaired collagen synthesis Impaired immune function Decreased delivery of PMNs

Perioperative Normothermia

SSI: 6% normothermia vs. 19% hypothermia

Kurz et al, N Engl J Med 1996

Flores-Maldonado A: Mild perioperative hypothermia and the risk of wound infection. Arch Med Res 2001 May-Jun;32(3):227-31

Prospective-cohort design, 290 surgical patientsNo active study-specific warming interventions.90% follow-up

Impact of Temperature on SSI

Hypothermia Normothermia pNumber Patients 156 105Wound Infection 18 (11.5%) 2 (2%) 0.004Relative risk of SSI 6.3x increased in hypothermia group

Prospective study: 1987-97 2,467 diabetic pts, open heart surgery

Control group (N=968) sliding-scale SQ insulin (SQI)

Study group (N=1,499) continuous iv insulin infusion to maintian glucose ≤

200 mg/dL. 0

0.51

1.52

2.53

3.54

SQIInsulinInfusion

Sternal Wound

Infection (%)

Furnary AP, et al.: Continuous intravenous insulin infusion reduces the incidence of deep sternal wound infection in diabetic patients after cardiac surgical procedures. Ann Thorac Surg 1999 Feb;67(2):352-60

Glucose Control in Diabetics Undergoing Open Heart Surgery

Example Shown: Axiomat ® Guidant Corporation

Minimally Invasive Cardiac Surgery

Minimal access mitral valve replacement D Richens, RS Jutley, M Baker and M Shajarf

J.R.Coll.Surg.Edinb., 47, October 2002, 676-680

Off-Pump CABG

Mitral Valve Replacement

Example Shown: Vasoview 5® Guidant Corporation

Minimally Invasive Surgery Technique for Saphenous Vein Harvest

Crouch JD : Open versus endoscopic saphenous vein harvesting: wound complications and veinquality. Ann Thorac Surg 1999 Oct;68(4):1513-6

568 patients, Non-randomized.Risk factors for wound complication

Open harvesting (p< or =0.001) Diabetes (p< or =0.001) Obesity (p< or =0.02)

Histologic evaluation no difference between the groups

Minimally Invasive Vein Harvest

Open Endoscopic p-valueNumber Patients 388 180Wound Complications 14.2% 5% 0.001

External Bacterial Challenge of Experimental Incisions

NoneNone4 hoursNone301 hour

30700.5 hour80900 hour

Closed withSubcuticular

Closed withStaples

Time of Challenge

Incisions Infected (%)

Stillman, et al. Arch Surg. 1980.

Dellinger EP: Ch 7, Surgical Infections, in, Mulholland et al: Greenfield’s Surgery: Scientific Principles and Practice, 4e. Lippincott, Williams & Wilkins, 2005.

Impact of Prophylactic Antibiotics on SSI Rates

Relation Between Antibiotic Timing and Surgical Wound Rate

0%

1%

2%

3%

4%

5%

6%

>2 2 1 1 2 3 4 5 6 7 8 9 10 >10

Infe

ctio

n R

ate

(%)

Hours before

Incision Hours after incision

Classen DC, et al. NEJM 1992;326:281-285

Operation

Quality Indicators National Surgical Infection Prevention Project

Quality Indicators#1) Receive antibiotics within 1 hour* before surgical incision.

#2) Receive prophylactic antibiotics consistent with current recommendations.

#3) Prophylactic antibiotics discontinued within 24 hours of surgery end.

* Because of the longer required infusion times, vancomycin or fluoroquinolones, when indicated for beta-lactam allergy, may be started within 2 hours before the incision.

Minutes Before or After Incision

Antibiotic Timing Related to IncisionMedicare National Baseline

Bratzler DW, Houck PM, et al. Arch Surg.2005

26.2

10

22.6

6.2 6.32.2 2.7

9.314.5

40.7

50.7

73.379.5

85.8 88 90.7

0

20

40

60

80

100

12 or le

ss

>12-2

4

>24-3

6

>36-4

8

>48-6

0

>60-7

2

>72-8

4

>84-9

6

> 96

Hours After Surgery End Time

Perc

ent

0

20

40

60

80

100

Cum

ulat

ive

Perc

ent

Discontinuation of Antibiotics

Patients were excluded from the denominator of this performance measure if there was any documentation of an infection during surgery or in the first 48 hours after surgery.

Bratzler DW, Houck PM, et al. Arch Surg.2005

* Based on medical record abstraction from the charts of patients discharged in the 2nd quarter of 2004. Benchmark rates were calculated for all hospitals in the US based on discharges during April 2003-March 2004 using the Achievable Benchmarks of CareTM methodology (http://main.uab.edu/show.asp?durki=14527).

Surgical Infection Prevention National Baseline Performance

64.3

91

47.6

91.999.1

85.7

0

20

40

60

80

100

Antibiotics w/in 1 hour Correct Antibiotic Antibiotic DC’d in 24 hr

Perc

ent

National Ave.* National Benchmark

Prevention of Surgical Site Infection (SSI)

Importance of Systems

ORRegistration

PreOpHolding

Outpatient ClinicSurgeon Office

Operating Room

Post AnesthesiaRecovery (PAR)

AmbulatorySurgery Room

InpatientHospitaliztion

0630 0730 0900 1030 1400-1 to 30Days

+7-30Days

Outpatient ClinicSurgeon Office

Factors the Surgeon “Controls”What operation is done.

- conduct of operation.When the surgery takes place.

- elective vs. emergent. - adequacy of rescucitation. - monitoring employed.

Antibiotic administration. - choice of agent. - timing of administration. - intra-operative re-dosing.

Blood transfusion.

Project overview available at: www.medqic.org/scip

Inferior performance

Superior performance

NSQIP Annual ReportMortality O/E Ratios for All Operations

Surgical Care Improvement Project (SCIP)

Preventable Complication ModulesSurgical infection preventionCardiovascular complication preventionVenous thromboembolism preventionRespiratory complication prevention

Surgical Care Improvement Project: Why?

Medicare could prevent* up to:13,027 perioperative deaths271,055 surgical complications

* Major surgical cases

There are substantial opportunities toimprove outcomes from surgery!

UCSF SSI Rate After Major Colorectal Surgery

Surgical Site Infection Rate Following Selected Abdominal Surgery Performed by Center for Colorectal Surgery Surgeons

27.6%

3.7%

16.1%

8.7%

25.8%

21.7%

14.3%

37.5%

19.0%16.0%

13.0%

17.4%

12.9%10.3%

7.7%

4.2%

15.0%

22.2%

11.5%

26.1%

4.0%

9.7%

26.7%

19.4%

11.5%

29.6%

22.2%

9.1%

23.3%

0.0%

17.9%

11.8%11.5%

23.1%

5.9%

14.3%

20.7%

9.1%10.0%11.5%

22.6%

3.3%

14.3%14.8%

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

40.0%

Apr '06

May '06Jun '06Jul '0

6Aug '06Sep '06Oct '0

6Nov '06Dec '06Jan '07Feb '07Mar '0

7Apr '0

7May '07Jun '07Jul '0

7Aug '07Sep '07Oct '0

7Nov '07Dec '07Jan '08Feb '08Mar '0

8Apr '0

8May '08Jun '08 *Jul '0

8*Aug '08*Sep '08*Oct '0

8*Nov '08*Dec '08*Jan '09*Feb '09 *Mar '0

9 *Apr '0

9*May '09*Jun '09 *

Jul '09*

Aug '09*Sep '09*

Oct '09

Nov '09*Pe

rcen

tage

monthly rate Linear (monthly rate)

4/06 - 3/07: Implement IHI Bundle 4/07 - 3/08: Monitor IHI Compliance

29 27 31 23 31 23 28 16 21 25 23 23 31 29 26 25 40 27 26 23 25 31 30 36 26 27 36 33 30 29 28 18 26 26 34 35 29 33 40 26 30 30 33 27

n =

4/08 - present: Tighten up Processes

Preventing Surgical Site Infections: Evidence-Based Interventions • Choose Appropriate Antibiotic

• Timely Administration of Antibiotics (30-60 min prior to incision)

• Clip rather than shave operative site.

• Maintain intraoperative O2 saturation.

• Maintain patient body temperature.

• ”Tight” glucose management.

• Infection surveillance.

The EndThe End