Incidence and Consequence of Surgical Site Infections William A. Rutala, PhD, MPH Director, Hospital Epidemiology, Occupational Health and Safety; Professor

Incidence and Consequence of Surgical Site Infections

William A. Rutala, PhD, MPHDirector, Hospital Epidemiology, Occupational Health and Safety;

Professor of Medicine and Director, Statewide Program for Infection Control and Epidemiology

University of North Carolina at Chapel Hill, USA

Disclosure

This presentation reflects the techniques, approaches and opinions of the individual presenter. This Advanced Sterilization Products (“ASP”) sponsored presentation is not intended to be used as a training guide. Before using any medical device, review all relevant package inserts with particular attention to the indications, contraindications, warnings and precautions, and steps for use of the device(s).I am compensated by and presenting on behalf of ASP, and must present information in accordance with applicable FDA requirements.The third party trademarks used herein are trademarks of their respective owners.

TOPICS

• Epidemiology of healthcare associated infections (HAI)

• Review the morbidity, mortality, national initiatives and economic consequences of SSI

• Discuss the risk factors and etiology of SSI• Provide strategies to prevent SSI

HEALTHCARE-ASSOCIATED INFECTIONS IN THE US: IMPACT

• 1.7 million infections per year• 98,987 deaths due to HAI

Pneumonia 35,967 Bloodstream 30,665 Urinary tract 13,088 Surgical site infection 8,205 Other 11,062

• 6th leading cause of death (after heart disease, cancer, stroke, chronic lower respiratory diseases, and accidents)1

1 National Center for Health Statistics, 2004

COST ESTIMATES FOR HEALTHCARE-ASSOCIATED INFECTIONS (HAIs)

HAI Cost per HAI US$

+ SE

Range

Ventilator-associated pneumonia 25,072 + 4,132 8,682-31,316

Healthcare-associated bloodstream infections

23,242 + 5,184 6,908-37,260

Surgical site infections 10,443 + 3,249 2,527-29,367

Catheter-associated urinary tract infections

758 + 41 728-810

Anderson DJ, et al. ICHE 2007;28:767-773Costs based on literature review 1985-2005; adjusted to US 2005 dollars

INCREMENTAL HOSPITAL DAYSDUE TO COMMON HAIs

Days, 13Days, 14

Days, 4

Days, 7

Pneumonia BloodstreamInfections

Urinary TractInfections

Surgical SiteInfectins

Surgical Site Infection

SSIs: IMPACT

• 27,000,000 surgical procedures per year1

• Prevalence 2-5% of surgical patients develop an SSI2

500,000 infections per year2 (~70% superficial, ~30% organ/space)1

SSIs account for ~22% of nosocomial infections: 2nd most common nosocomial infection (after UTIs)1

• Impact Each SSI results in 7-10 additional hospital days2

Patients with SSI have a 2-11 times higher risk of death2

77% of deaths among patients with SSI are directly due to SSI2

~8,000 deaths due to SSI Cost (2007 dollars): $11,874 to $34,670 per infection (total = $3.45-$10 bil)3

1Klevens R, et al. Pub Health Rep 2007;122:160 - 2Anderson D, et al ICHE 2008;29 (Suppl 1):S51 – 3http://www.cdc.gov/ncidod/dhqp/pdf/Scott_CostPaper.pdf

SSI: PATHOGENESIS

Risk of surgical site infections =

Microbial load x Virulence x Tissue injury x Foreign material x Antibiotic resistance

____________________________________________________________

Host resistance x Perioperative antibiotics

SSI: Primary Risk FactorsSSI: Primary Risk Factors

Endogenous microorganisms Skin-dwelling microorganisms

Most common sourceS aureus most common isolateFecal flora (gnr) when incisions are near the perineum or

groin Exogenous microorganisms

Surgical personnel (members of surgical team) OR environment (including air) All tools, instruments, and materials

PATHOGENS ASSOCIATED WITH SSIs: NHSN, 2006-2007

0% 5% 10% 15% 20% 25% 30% 35%

Other

A. baumannii

K. oxytoca

Candida

K. pneumoniae

Enterobacter

P. aeruginosa

E. coli

Enterococcus

CoNS

S. aureus

Hidron AI, et al. ICHE 2008;29:996-1011

TOPICS




SSI: Intrinsic/Patient Risk Factors

Age-extremes Nutritional status-poor Diabetes-controversial;

increased glucose levels in post-op period ↑ risk

Smoking-nicotine delays wound healing ↑ risk

Obesity>20% ideal body weight

Remote infections ↑ risk Endogenous mucosal

microorganisms Preoperative nares S.

aureus- CT patients Immunosuppressive

drugs may ↑ risk Preoperative stay-

surrogate for severity of illness

SSI: OPERATION-RELATEDRISK FACTORS

Surgical wound classification Intraoperative microbial

contamination Antimicrobial prophylaxis Preoperative shaving Preoperative skin preparation Thoroughness of surgical scrub Duration of surgical procedure Surgical attire Sterile draping Traffic-minimize

Surgical technique: Poor hemostasis Failure to obliterate dead space Tissue trauma

Low abdominal operative site Prolonged hospital admission prior

to operation Foreign material Operating room ventilation Instrument sterilization Surgical drains

SSI RISK AS A FUNCTION OF WOUND CLASSIFICATION

Wound Classification Risk of Infection

Clean 1.3-2.9%

Clean-contaminated 2.4-7.7%

Contaminated 6.4-15.2%

Dirty and infected 7.1-40.0%

NATIONAL HEALTHCARE SAFETY NETWORK SSI RISK STRATIFICATION

• NHSN surgery stratification: Scale from -1 to 3 (operation specific) 1 point for ASA score >3 1 point for duration of operation >75th percentile 1 point for contaminated or dirty wound -1 point for surgery done via a laparoscope

• ASA classification 1 = normal healthy patient 2 = patient with mild systemic disease 3 = patient with severe systemic disease 4 = patient with severe systemic disease that is life threatening 5 = patient not expected to survive without the operation 6 = declared brain dead patient whose organs are being removed for donation

SSI RATE, NHSN DATA, 2006-2007Surgical Procedure Risk Category Pooled MeanSpinal fusion 0 0.72Spinal fusion 1 1.95Spinal fusion 2,3 4.13Open Fx reduction 0 1.07Open Fx reduction 1 1.69Open Fx reduction 2,3 2.66Hip prosthesis 0 0.75Hip prosthesis 1 1.68Hip prosthesis 2,3 2.97Knee prosthesis 0 0.68Knee prosthesis 1 1.12Knee prosthesis 2,3 1.82Laminectomy 0 0.73Laminectomy 1 1.11Laminectomy 2,3 2.44

TOPICS




STRATEGIES TO PREVENT SSIsSurgical IP Collaborative-6 Performance Measures

• CMS – Surgical Infection Prevention Collaborative (2002) Deliver antibiotic prophylaxis within 1 hour (2 hours for

vancomycin/quinolones) Use an antibiotic with known effectiveness Discontinue antibiotics within 24 hours (48 hours for cardiac

surgery)

• CMS - Surgical Care Improvement Project (2003) Proper hair removal (clip immediately before surgery) Control blood glucose post-op days 1 and 2 (<200 mg/dL) Maintain perioperative normothermia for patients undergoing

colorectal surgery

Anderson D, et al. ICHE 2008;29(suppl 1):S51-S61

To Reduce the Risk of Surgical Site To Reduce the Risk of Surgical Site InfectionInfection

A simple but realistic approach must be applied with the awareness that the risk of SSIs is influenced by

characteristics of the patient, operation, personnel and hospital

Mangram AJ, et al. Infect Control Hosp Epidemiol. 1999;20(4):250-278.

SSI: CDC GuidelinesSSI: CDC Guidelines

Patient characteristics

Preoperative issues

Intra-operative issues

Postoperative issues



Patient characteristics/risk factorPreoperative issues




Risk and Prevention in SSIsRisk and Prevention in SSIs

Risk Factor-a variable that has a significant independent association with the development of

SSI after a specific operation

SSI: Intrinsic/Patient Risk Factors

Age-extremes Nutritional status-poor Diabetes- increased

glucose levels in post-op period ↑ risk

Smoking-nicotine delays wound healing ↑ risk

Obesity>20% ideal body weight

Remote infections ↑ risk Endogenous mucosal

microorganisms Preoperative nares S.

aureus- CT patients Immunosuppressive

drugs may ↑ risk Preoperative stay-

surrogate for severity of illness

A More Than Typical Scenario - Total Joint Replacement A More Than Typical Scenario - Total Joint Replacement – What is the Risk?– What is the Risk?

High Risk Patient: Immunosuppressive meds RA Diabetes Advanced age Prior surgery to same joint Psoriasis

Obese Malnourished

morbid obesity sAlb<35

low sTransferrin Remote sites of infection Smokers ASA ≥3



Preoperative issues




SSI: Preoperative IssuesSSI: Preoperative IssuesModifiable RisksModifiable Risks

Glucose control-in diabetic patientsPreoperative CHG shower

Appropriate hair removal

Hand hygiene

Skin antisepsis

Antimicrobial prophylaxis

Normothermia-hypo higher risks


5 Million lives. Institute for Healthcare Improvement. Available at:

http://ihi.org/IHI/Programs/Campaign/Campaign.htm. Accessed on February 8, 2007.

Prevention of SSIs

• Preoperative preparation of the patient Preoperative showers with antiseptic agent at least

the night before (IB) Do not remove hair preoperatively unless it will

interfere with the operation (IA) If hair removed, remove just prior to surgery with

electric clippers (IA) Wash and clean at and around incision site prior to

performing antiseptic skin preparation (IB)

Normal Skin Micro-FloraNormal Skin Micro-Flora

Numbers per square centimeter of skin surface (cfu/cm2). Counts on hands range from 3.9x104 to 4.6x106.

Numbers of bacteria that colonize different parts of the body

Microbial Ecology of Skin SurfaceMicrobial Ecology of Skin Surface

• Scalp 6.0 Log10 cfu/cm2

• Axilla 5.5 Log10 cfu/cm2

• Abdomen 4.3 Log10 cfu/cm2

• Forearm 4.0 Log10 cfu/cm2

• Hands 4.0-6.6 Log10 cfu/cm2

• Perineum 7.0-11.0 Log10 cfu/cm2

Surgical Microbiology Research Laboratory 2008 – Medical College of WisconsinSurgical Microbiology Research Laboratory 2008 – Medical College of Wisconsin

0

25

50

75

100

125

150

CH

G C

once

ntra

tion

(PP

M)

CH

G C

once

ntra

tion

(PP

M)

Skin SitesSkin Sites

Left Left ElbowElbow

Right Right ElbowElbow

AbdominalAbdominal Left Left KneeKnee

Right Right KneeKnee

4% Chlorhexidine Gluconate (CHG) Shower - 4% Chlorhexidine Gluconate (CHG) Shower - Mean Skin Surface Concentration (N=60)Mean Skin Surface Concentration (N=60)

MICMIC9090 = 4.8 ppm = 4.8 ppm

Group 2A Group 2A “Morning (AM)”“Morning (AM)”

Group 3A Group 3A

““Both (AM and PM)”Both (AM and PM)”

CHG Shower CHG Shower

Group 1A Group 1A “Evening (PM)”“Evening (PM)”

p p <<0.050.05NSNSP<0.001P<0.001

Edmiston et al, J Am Coll Surg 2008;207:233-239Edmiston et al, J Am Coll Surg 2008;207:233-239




Surgical hand antisepsis

Skin antisepsis






Surgical Hand Antisepsis

• Surgical hand scrubs should: Significantly reduce microorganisms on intact skin Contain a non-irritating antimicrobial preparation Have broad-spectrum activity Be fast-acting and persistent

Surgical Hand Antisepsis

• Studies suggest that neither a brush nor a sponge is necessary to reduce bacterial counts on the hands of surgical personnel to acceptable levels, especially when alcohol-based products are used

• One study (AORN J 2001;73:412) found a brushless application of a preparation of 1% CHG plus 61% ethanol yielded lower bacterial counts on the hands of participants than using a sponge/brush to apply 4% CHG

Perioperative Skin Antisepsis?Perioperative Skin Antisepsis?

Study ResultsStudy Results

• N = 849 surgical patients: 409 Alc-CHG vs 440 PI (ITT)N = 849 surgical patients: 409 Alc-CHG vs 440 PI (ITT)• 1:1 randomization1:1 randomization• Patients monitored for 30 days post-opPatients monitored for 30 days post-op• Overall rate of SSI was significantly reduced in Alc-CHG vs PI Overall rate of SSI was significantly reduced in Alc-CHG vs PI groups: 9.5% vs 16.1%, groups: 9.5% vs 16.1%, p=0.004p=0.004• Significant difference for both superficial incisional site rate: 4.2% Significant difference for both superficial incisional site rate: 4.2% A-CHG vs 8.6% PI (A-CHG vs 8.6% PI (p=0.008p=0.008) and deep incisional: 1% A-CHG vs 3% PI ) and deep incisional: 1% A-CHG vs 3% PI ((p=0.05p=0.05))• No significant adverse events noted during the study in either No significant adverse events noted during the study in either groupgroup• Alc-CHG superior to PI in reducing the risk of SSI in clean-Alc-CHG superior to PI in reducing the risk of SSI in clean-contaminated procedurescontaminated procedures

Darouiche RO, et al. New England Journal of Medicine 2010;362:18-26Darouiche RO, et al. New England Journal of Medicine 2010;362:18-26




Hand hygiene

Skin antisepsis






IDSA GUIDELINE

• Infusion of the first dose within 60 min of surgical incision• Prophylactic therapy should be discontinued within 24 hrs• Provide additional intraoperative doses if surgery extends

beyond 2 half-lives of the initial dose• Provide therapy based on weight (>30% above ideal body

weight) or body mass index• Additional measures

Supplemental oxygen administration, perioperative glucose control, aggressive fluid resuscitation, proper intraoperative temperature control



Preoperative issues




LISTER CARBOLIC ACID SPRAY AS ANTISEPTIC PRECAUTIONLISTER CARBOLIC ACID SPRAY AS ANTISEPTIC PRECAUTIONWood Engraving - William Watson Cheyne, 1882 - National Library of MedicineWood Engraving - William Watson Cheyne, 1882 - National Library of Medicine

OR Environment

• Air Largest source of airborne microbial contamination is

the OR staff Organisms become airborne as a result of

conversation or shedding from the hair or exposed skin Microbial level directly proportional to the number of

people moving about in the room Improved ventilation associated with decreased SSI

Prevention of SSIs

• Intraoperative (Ventilation) Maintain 15 AC/hr (>3 fresh)*, positive pressure (IB) Filter all air through appropriate filters (IB) Introduce air at ceiling and exhaust near floor (IB) Keep OR doors closed as needed for passage of

equipment, personnel, and patients (IB) Limit the number of OR personnel (IB) Consider ultraclean air for orthopedic implants (II)*2010 Guideline (FGI, ASHRAE) is 20 AC/hr (>4 fesh)

OR Environment

• Ventilation Three primary design components act to purify the OR

airHigh-flow ventilation - 15 air changes per hour (3

outside air)High-efficiency filtration 90-99.97%Positive pressure relative to adjacent areas

(prevents contamination from less clean areas) Maintain the temperature (68o-73oF [20-23oC]) and

relative humidity (30-60%)

OR Environment

• Environment as an Exogenous Source of Pathogens Clean environment minimizes the risk of OR

environmental surfaces and floors as a source of infection

Microorganisms isolated from the OR are usually non-pathogens rarely associated with infection

When inanimate sources implicated, the sources have been contaminated solutions, antiseptics, or dressings (not floors, walls or environmental surfaces)

Prevention of SSIs

• Intraoperative (Cleaning/disinfection environmental surfaces) Clean when visibly soiled/contaminated with EPA

approved disinfectant before the next operation (IB) Do not perform special cleaning after contaminated or

dirty surgery (IB) Do not use tacky mats (IB) Cleaning between surgery if no visible contamination

(No recommendation)

OR Environment

• Disinfection OR environment (furniture, lights, equipment) should be

damp-dusted with a germicide on a scheduled basis Exogenous microorganisms can contaminate surgical

practice setting Disinfection is essential to reduce the risk of cross-

infection Disinfection of these surfaces will control airborne

microorganisms that might travel on dust and lint

OR Environment

• Disinfection Floors should be cleaned with a low-level disinfectant For end-of-use cleaning, necessary to clean a 3-to-4 ft

perimeter around the operative site (extended as necessary by contamination)

Important to re-establish a clean environment after each operation

For terminal daily cleaning, entire floor is cleaned Same cleaning procedures performed whether clean

or contaminated case

OR Environment

• Disinfectants Low-level disinfectants are used for non-critical (skin

contact) surfaces/furniture/lightsPhenolicsQuaternary ammonia compoundsChlorine (1:10 dilution of 5.25% sodium hypochlorite-

blood spills)

OR Environment

• Reusable Items Noncritical-clean (in accordance to manufacturer’s

recommendation)Lower the microbial load (mechanical or manual)Reduces organic and inorganic residual

Disinfect or sterilize based on the risk of infection associated with the use of the item

Critical items (sterile tissue, vascular system) must be sterile

Semicritical (endoscopes) must be high-level disinfected

OR Environment

• Sterilization Inadequate sterilization of surgical instruments has

resulted in SSI Surgical instruments can be sterilized by steam,

ethylene oxide, hydrogen peroxide plasma, vaporized hydrogen peroxide, dry heat or other approved methods

Microbial monitoring of sterilization performance is necessary and can be accomplished by biological indicators

CDC Surgical Site Infection Prevention Guidelines - 1999

Category IA and IB

No prior infections 15 air changes/hr in ORDo not shave in advance Keep OR doors closed Control glucose in D.M. pts Use sterile instrumentsStop tobacco use Wear a maskShower with antiseptic soap Cover hairPrep skin with approp. agent Wear sterile glovesSurgical team nails short Gentle tissue handlingSurgical team scrub hands DPC for heavily contaminated

Exclude I/C surgical team woundsGive prophylactic antibiotics Closed suction drains (when

used)Pos pressure ventilation in OR Sterile dressing x 24-48 hr

SSI surveillance with feedback to surgeons

STRATEGIES TO DETECT SSIs

• Direct method-daily observation of surgical site by physician

• Indirect method Review of microbiology reports and patient medical records Surgeon and/or patient surveys Other information, such as coded diagnoses

• Indirect method is reliable (sensitivity, 84-89%) and specific (specificity, 99.8%)

Surveillance at UNC Hospitals

• Follow certain operations for SSIs and benchmark Abdominal hysterectomy CABG Craniotomy Herniorrhaphy Knee prosthesis Colon surgery Ventricular shunt Laminectomy Peripheral vascular bypass surgery

SSI RATE, NHSN DATA, 2006-2007Surgical Procedure Risk Category Pooled MeanSpinal fusion 0 0.72Spinal fusion 1 1.95Spinal fusion 2,3 4.13Open Fx reduction 0 1.07Open Fx reduction 1 1.69Open Fx reduction 2,3 2.66Hip prosthesis 0 0.75Hip prosthesis 1 1.68Hip prosthesis 2,3 2.97Knee prosthesis 0 0.68Knee prosthesis 1 1.12Knee prosthesis 2,3 1.82Laminectomy 0 0.73Laminectomy 1 1.11Laminectomy 2,3 2.44

TOPICS




Conclusions

• Surgical site infections result in significant patient morbidity and mortality, and increased hospital cost

• Reduction in surgical site infections can be achieved by strict adherence to standard surgical guidelines

• Proper use of surgical prophylaxis crucial to maintaining a low rate of SSIs

THANK YOU!

disinfectionandsterilization.org

SURVEILLANCE OF SSIs

NHSN definitions Superficial incisional SSI Deep incisional SSI Organ/space SSI

Documents

Incidence and Consequence of Surgical Site Infections William A. Rutala, PhD, MPH Director, Hospital Epidemiology, Occupational Health and Safety; Professor