Prevention of Surgical Site Infections

Sinil Nair, CIC Infection Control Expert Clinical Quality and Healthcare Accreditation Department, MOHAP Background

a) The second most common (20%) of all HAIs in hospitalized patients. b) Occurs in 2%–5% of patients undergoing inpatient . c) One of the most preventable HAIs.

a) Up to 60% of SSIs are preventable by using evidence-based guidelines. d) Each SSI is associated with ≈ 7–11 additional hospital-days. Background

e) 3% Mortality

f) Patients with an SSI have a 2–11-times higher risk of death compared with operative patients without an SSI.

g) 77% of deaths in patients with SSI are directly attributable to SSI.

h) The most costly HAI

i) Long term disabilities Types of SSI NHSN Definitions 1. Superficial incisional SSI

Must meet the following criteria: a) Infection occurs within 30 days after any operative procedure (where day 1 = the procedure date) AND a) involves only skin and subcutaneous tissue of the incision AND c) patient has at least one of the following: i. purulent drainage from the superficial incision. ii. organisms identified from an aseptically-obtained specimen from the superficial incision or subcutaneous tissue by a culture or non-culture based microbiologic testing method which is performed for purposes of clinical diagnosis or treatment (e.g., not Active Surveillance Culture). iii. superficial incision that is deliberately opened by a surgeon, attending physician or other designee and culture or non-culture based testing is not performed. AND patient has at least one of the following signs or symptoms: pain or tenderness; localized swelling; erythema; or heat. A culture or non- culture based test that has a negative finding does not meet this criterion. iv. diagnosis of a superficial incisional SSI by the surgeon or attending physician or other designee. NHSN Definitions…

 There are two specific types of superficial incisional SSIs: a) 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 CABG) b) 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 CABG) NHSN Definitions…

2. Deep incisional SSI Must meet the following criteria: a) Infection occurs within 30 or 90 days after the operative procedure (where day 1 = the procedure date) AND b) involves deep soft tissues of the incision (e.g., fascial and muscle layers) AND c) patient has at least one of the following: i. purulent drainage from the deep incision. ii. a deep incision that spontaneously dehisces, or is deliberately opened or aspirated by a surgeon, attending physician or other designee and organism is identified by a culture or non-culture based microbiologic testing method which is performed for purposes of clinical diagnosis or treatment (e.g., not Active Surveillance Culture) or culture or non-culture based microbiologic testing method is not performed AND iii. patient has at least one of the following signs or symptoms: fever (>38°C); localized pain or tenderness. A culture or non-culture based test that has a negative finding does not meet this criterion. iv. an abscess or other evidence of infection involving the deep incision that is detected on gross anatomical or histopathologic exam, or imaging test. NHSN Definitions…

There are two specific types of deep incisional SSIs: a) Deep Incisional Primary– 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 CABG) b) Deep Incisional Secondary – 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 CABG) NHSN Definitions… Organ/Space SSI Must meet the following criteria: a) Infection occurs within 30 or 90 days after the operative procedure (where day 1 = the procedure date). AND b) infection involves any part of the body deeper than the fascial/muscle layers, that is opened or manipulated during the operative procedure AND c) patient has at least one of the following: i. 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) ii. organisms are identified from an aseptically-obtained fluid or tissue in the organ/space by a culture or non-culture based microbiologic testing method which is performed for purposes of clinical diagnosis or treatment (e.g., not Active Surveillance Culture). iii. an abscess or other evidence of infection involving the organ/space that is detected on gross anatomical or histopathologic exam, or imaging test AND d) meets at least one criterion for a specific organ/space infection site listed in next slide. Organ/Space SSI

Specific Sites of an Organ/Space SSI

http://www.cdc.gov/nhsn/PDFs/pscManual/17pscNosInfDef_current.pdf SSI- Factors Influencing Pathogenesis a) Microbial characteristics (eg, degree of contamination, virulence of pathogen) b) Patient characteristics (eg, immune status, comorbid conditions); and c) Surgical characteristics (eg, type of procedure, introduction of foreign material, amount of damage to tissues) SSI- Sources of Pathogens:

1. Endogenous

a) Patient flora

i. – skin

ii. – mucous membranes

iii. – GI tract

b) Seeding from a distant focus of infection

2. Exogenous

a) Surgical Personnel (surgeon and team)

i. – Soiled attire

ii. – Breaks in aseptic technique

iii. – Inadequate hand hygiene

b) OR physical environment and ventilation

c) Tools, equipment, materials brought to the operative field Organisms Causing SSI (CDC January 2006-October 2007)

Staphylococcus aureus 30.0% Coagulase-negative staphylococci 13.7% Enterococcus spp. 11.2% Escherichia coli 9.6% Pseudomonas aeruginosa 5.6% Enterobacter spp 4.2% Klebsiella pneumoniae 3.0% Candida spp. 2.0% Klebsiella oxytoca 0.7% Acinetobacter baumannii 0.6% Risk Factors

Patient Related 6. Coexistent infections at a 1. Age remote body site 2. Nutritional status 7. Colonization with 3. Diabetes pathogens 4. Smoking 8. Altered immune response 5. Obesity 9. Length of preoperative stay

Risk Factors

Procedure Related 1. Preoperative shaving 7. OR ventilation 2. Duration of surgical 8. Inadequate sterilization scrub of instruments 3. Skin antisepsis 9. Foreign material in surgical site and drains 4. Preoperative skin prep 10. Hypothermia 5. Duration of procedure 11. Surgical technique 6. Antimicrobial prophylaxis 1. Poor hemostasis 2. Failure to obliterate dead space 3. Tissue trauma

Surgical Wound Classification Emerging Challenges

1. Challenges in detecting SSIs a) Lack of standardized methods for post- discharge/outpatient surveillance i. Increased number of outpatient ii. Shorter postoperative inpatient stays 2. Antimicrobial Prophylaxis b) Increasing trend toward resistant organisms may undermine the effectiveness of existing recommendations for antimicrobial prophylaxis Important Modifiable Risk Factors

1. Antimicrobial prophylaxis a) Inappropriate choice (procedure specific) b) Improper timing (pre-incision dose) c) Inadequate dose based on body mass index, procedures >3h, or increased blood loss 2. Skin or site preparation ineffective a) Removal of hair with razors 3. Colorectal procedures a) Inadequate bowel prep/antibiotics b) Improper intraoperative temperature regulation Additional Modifiable Risk Factors

1. Excessive OR traffic 2. Inadequate wound dressing protocol 3. Improper glucose control 4. Colonization with preexisting microorganisms 5. Inadequate intraoperative oxygen levels Strategies To Detect SSI

Surveillance: a) A measure of the magnitude of the problem. b) Identify and investigate trends. c) Guide the identification of improvement actions d) Evaluate the effectiveness of these interventions. e) Decrease SSI rates from the feedback f) Investigation of why SSI rates are higher than the benchmark g) Prompt local initiatives to improve performance.

Methods for Surveillance of SSI

A. The direct method: daily observation of the surgical site starting 24–48 hours postoperatively is the most accurate method.

B. The indirect method: a combination of,

1. Review of microbiology reports and patient medical records.

2. Surgeon and/or patient surveys.

3. Screening for readmission and/or return to the operating room.

4. Other information, such as coded diagnoses, operative reports, or antimicrobials ordered.

C. The indirect method of SSI surveillance is both reliable (sensitivity, 84%–89%) and specific (specificity, 99.8%) compared with direct surveillance.

Post-discharge Surveillance

1. Superficial incisional SSIs are most commonly detected and managed in the outpatient setting

2. Deep incisional and organ/space infections typically require readmission for management.

3. SSI rates will be underestimated without post discharge surveillance.

4. No standardized or reliable method for post- discharge surveillance has been established.

Post-discharge Surveillance

 In the Netherlands, the proportion of deep SSIs identified after discharge from the hospital ranged from 6% for colon resections to 88% for knee arthroplasties (the duration of post-discharge surveillance was 30 days versus 1 year for an implant- related procedure).  A pilot study in reported that 10.5% of SSIs following colon procedures were identified after discharge from the hospital.  The overall institutional SSI rate typically increases after post-discharge surveillance methods are implemented successfully.

Best Practices for SSI Prevention 1. Antimicrobial Prophylaxis

1. Administer antimicrobial prophylaxis according to evidence-based standards and guidelines

a) Begin administration within 1 hour before incision to maximize tissue concentration.

i. 2 hours are allowed for the administration of vancomycin and fluoroquinolones.

ii. Antimicrobials should be infused prior to inflation of tourniquets in procedures using “bloodless” techniques.

b) Administering agent closer than 1 hour is effective.

1. Antimicrobial Prophylaxis cont… c) Select appropriate agents on the basis of

i. the surgical procedure,

ii. the most common pathogens causing SSIs for the specific procedure, and

iii. published recommendations. d) Discontinue the prophylactic antimicrobial agent within 24 hours after surgery (dis-continuation within 48 hours is allowable for adult cardiothoracic procedures).

i. There is no evidence that agents given after closure contribute to efficacy.

ii. They do contribute to increased resistance and

iii. The risk of Clostridium difficile disease.

1. Antimicrobial Prophylaxis cont… e) Adjust dosing on the basis of patient weight; for example:

a) Use 30 mg/kg for pediatric patients, 2 g of cefazolin for patients weighing 80 kg or more, and 3 g for patients weighing 120 kg or more.

b) Vancomycin should be dosed at 15 mg/kg.

c) Gentamicin should be dosed at 5 mg/kg for adult patients and 2.5 mg/kg for pediatric patients.

d) For morbidly obese patients receiving gentamicin, the weight used for dose calculation should be the ideal weight plus 40% of the excess weight.

1. Antimicrobial Prophylaxis cont…

f) Re-dose prophylactic antimicrobial agents for long procedures and in cases with excessive blood loss during the procedure.

a) Prophylactic antimicrobials should be redosed at intervals of 2 half-lives (measured from time the preoperative dose was administered) in cases that exceed this time.

g) Use a combination of parenteral antimicrobial agents and oral antimicrobials to reduce the risk of SSI following colorectal procedures.

a) Mechanical bowel preparation without oral antimicrobials does not decrease the risk of SSI.

Remote Infections

Whenever possible: 1. Identify and treat before elective operation 2. Postpone operation until infection has resolved 2. Appropriate Hair Removal

a) Do not remove hair at the operative site unless the presence of hair will interfere with the operation.

b) Do not use razors

c) If hair removal is necessary, remove hair outside the operating room using clippers or a depilatory agent.

3. Blood Glucose Control a) Control blood glucose during the immediate postoperative period.

a) Measure blood glucose level at 6AM on POD#1and #2

b) Implement perioperative glycemic control using blood glucose target levels ≤ 200 mg/dL in both diabetic and non- diabetic patients.

c) Maintain post-op blood glucose level at 180 mg/dL or lower in the time frame of 18–24 hours after anesthesia end time ) in patients in the time frame of 18–24 hours after anesthesia end time..

d) Intensive postoperative glucose control (targeting levels less than 110 mg/dL) has not been shown to reduce the risk of SSI and may actually lead to higher rates of adverse outcomes, including stroke and death.

4. Maintain Normothermia a) Maintain normothermia (temperature of 35.5°C or more) during the perioperative period. b) Even mild degrees of hypothermia can

a) increase SSI rates.

b) directly impair neutrophil function or impair it indirectly by triggering subcutaneous vasoconstriction and subsequent tissue hypoxia.

c) increase blood loss, leading to wound hematomas or need for transfusion. c) Preoperative and intraoperative warming can reduce SSI rates and reduce intraoperative blood loss. 5. Tissue Oxygenation

a) Optimize tissue oxygenation by administering supplemental oxygen during and immediately following surgical procedures involving mechanical ventilation. b) Administer increased fraction of inspired oxygen (FiO2 ) for intubated patients undergoing general anesthesia with normal pulmonary function. (2017 HICPAC-CDC Guideline for Prevention of Surgical Site Infection) c) Combined with other measures i. Maintenance of normothermia and ii. Appropriate volume replacement d) Perioperative supplemental oxygen lead to a relative risk (RR) reduction of 25% for SSI. (Meta-analysis of 5 studies). 6. Proper Skin Preparation a) Use alcohol-containing preoperative skin preparatory agents if no contraindication exists.

1. Alcohol is highly bactericidal and effective for preoperative skin antisepsis but does not have persistent activity when used alone. Rapid, persistent, and cumulative antisepsis can be achieved by combining alcohol with chlorhexidine gluconate or an iodophor.

2. Alcohol is contraindicated for certain procedures, e.g; procedures in which the preparatory agent may pool or not dry (e.g. involving hair) due to fire risk. Alcohol may also be contraindicated for procedures involving mucosa, cornea, or ear. b) In the absence of alcohol, chlorhexidine gluconate may have advantages over povidone-iodine, including longer residual activity and activity in the presence of blood or serum. Surgical Scrubs

7. Wound Protection

a) Use impervious plastic wound protectors for gastrointestinal and biliary tract surgery.

i. A wound protector is a plastic sheath that lines a wound and can facilitate retraction of an incision during surgery without the need for additional mechanical retractors.

ii. A recent meta-analysis of 6 randomized clinical trials in 1,008 patients reported that use of a plastic wound protectors was associated with a 45% decrease in SSIs. b) Surgical Wound Dressing: Protect primary closure incisions with sterile dressing for 24-48 hrs post-op 8. Reduce Modifiable Risk Factors a) Optimal preparation and disinfection of the operative site and the hands of the surgical team members. b) Adherence to hand hygiene, including non-surgeon members of the operating team. c) Reduce unnecessary traffic in operating rooms:

i. Keep OR doors closed during surgery except as needed for passage of equipment, personnel, and the patient d) Appropriate care and maintenance of operating rooms, including appropriate air handling and optimal cleaning and disinfection of equipment and the environment. OR Ventilation

20-23◦ Celsius 9. Surgical Safety Checklist

1. Use a checklist based on the World Health Organization (WHO) checklist to ensure compliance with best practices to improve surgical patient safety. 2. Use of the WHO checklist led to lower rates of surgical complications, including SSI and death, in 8 countries.

10. Perform Surveillance for SSI a) Identify high-risk, high-volume operative procedures to be targeted for SSI surveillance. b) Prepare periodic SSI reports and identify trends c) Use updated CDC NHSN definitions for SSI. d) Perform indirect surveillance for targeted procedures. e) Perform postoperative surveillance for 30 days and up to 90 days for certain procedure categories. f) Surveillance should be performed on patients readmitted to the hospital. 10. Perform Surveillance for SSI …

g) Develop a system for routine review and interpretation of SSI rates to detect significant increases or outbreaks and to identify areas where additional resources might be needed to improve SSI rates. h) Provide ongoing feedback regarding SSI rates and rates of compliance with process measures to surgical and perioperative personnel and leadership. i) Implement policies and practices aimed at reducing the risk of SSI that align with evidence- based standards.

11. Educate about SSI Prevention

a) Surgical team members b) Patients and families. i. Provide instructions and information to patients prior to surgery describing strategies for reducing SSI risk. Specifically provide preprinted materials to patients.

12. Special Approaches

a) Screen for Staph aureus and decolonize surgical patients with an anti-staphylococcal agent in the preoperative setting for high-risk procedures, including some orthopedic and cardiothoracic procedures.

b) Perform antiseptic wound lavage.

i. A meta-analysis published in 2010 evaluated 24 randomized controlled trials and concluded that lavage with dilute povidone-iodine decreased the risk of SSI compared with non-antiseptic lavage.

c) Perform an SSI risk assessment using a multidisciplinary team.

12. Special Approaches…

d) Observe and review operating room personnel and the environment of care in the operating room

i. Perform direct observation audits of operating room personnel to assess operating room processes and practices to identify infection control lapses.

ii. Perform direct-observation audits of environmental cleaning practices in the operating room, instrument processing (sterilization), and storage facilities.

iii. Review maintenance records for operating room heating, ventilation, and air conditioning system, including results of temperature and relative humidity testing, and test for maintenance of positive air pressure in the operating room(s).

e) Provide feedback and review infection control measures with operating room and environmental personnel.

12. Special Approaches… f) Observe and review practices in the post- anesthesia care unit, surgical intensive care unit, and/or surgical ward.

i. Hand hygiene practices of direct contact staff

ii. Wound care practices

iii. Environmental cleaning practices g) Provide feedback and review infection control measures with staff in post operative care settings.

12. Special Approaches…

h) patients: a) Mechanically prepare the colon (Enemas, cathartic agents) b) Administer non-absorbable oral antimicrobial agents in divided doses on the day before the operation. Approaches that are Not Recommended Routinely a) Do not routinely use vancomycin for antimicrobial prophylaxis. b) Do not routinely delay surgery to provide parenteral nutrition. c) Do not routinely use antiseptic-impregnated sutures as a strategy to prevent SSIs. d) Do not routinely use antiseptic drapes as a strategy to prevent SSIs. References

1. Centers for Disease Control and Prevention Guideline for the Prevention of Surgical Site Infection, 2017 2. WHO Global Guidelines For The Prevention Of Surgical Site Infection 2016 3. Strategies to Prevent Surgical Site Infections in Acute Care Hospitals: 2014 Update NIH 4. SSI Event 2016 CDC 5. CDC/NHSN Surveillance Definitions for Specific Types of Infections 2016 6. WHO Surgical Safety Checklist 7. SSI Tool Kit 2009 CDC 8. http://www.ashp.org/surgical-guidelines 9. http://www.sign.ac.uk/pdf/sign104.pdf 10. https://www.idsociety.org/uploadedFiles/IDSA/Guidelines- Patient_Care/PDF_Library/2013%20Surgical%20Prophylaxis%20AS HP,%20IDSA,%20SHEA,%20SIS(1).pdf 11. CDC Guidelines for Prevention of Surgical Site Infections 1999