Surgical Site Infections:The Foundation

What Are We Doing Together Over the Next Two Months

• Talk about ways to prevent surgical site infections and venous thromboembolism in surgical patients.

• Webinars every two-weeks where we will discuss methods that appear in the literature and that are “low-hanging fruit”.

• The topics that we discuss are things that:– will make the most difference to your patients– have clear evidence– are things that you can put into place in your ORs

We Will Not Go Into Step-By Step Instructions On How To Put These Methods Into Place

Today’s Topics• Brief History of Infection Prevention Techniques• Prophylactic Antibiotic Administration• Weight Based Dosing• Re-dosing• Discontinuing Antibiotics

Common Sense Science• Bacteria cause infection• Bacteria are everywhere• It is a battle against the bacteria

Ignaz Semmelweiss Joseph ListerLouis Pasteur

Brief History of Infection Prevention

Surgery – 1969Postoperative Wound Infection:

A Prospective Study of Determinant Factors and Prevention

Polk HC Jr, Lopez-Mayor JF

Surgical Technique, Prophylactic Antibiotics and SSI

Polk. Surgery 1969;66:97-103

Different Ways of Preventing SSI’s

• Pre-operative screenings• Proper Hair Removal• Skin Prep• Hair Prep• Hand Hygiene• Prophylactic Antibiotics• Surgical Technique• Glucose Control• Hyperoxia

• OR Traffic• Bowel Prep• Temperature Control• Transfusion• Maintenance of

hemostasis and perfusion• Wound Protectors• Communication• Teamwork

Preventing SSI’sPre-Incision Incision/Surgery Post Op

Patient

• Basics of Skin Prep

• Showers• Skin Wipes

• Hair Removal• Weight Based

Dosing• MRSA Screening • Glucose Control

• Glucose Control• Hyperoxia

• Wound care• Dressings

Operation

• Antibiotic• Bowel Prep

• Re-dosing• Operating Time• Use of Tourniquet• Surgical Technique• Wound protectors

Environment

• Basics of Sterility• Instrument Sterility• Hand Hygiene• Temperature

Control• Teamwork• Culture

• Basics of Sterility• Instrument Sterility• Hand Hygiene• OR Traffic• Temperature Control• Teamwork• Culture

• Discontinue antibiotics

• Teamwork• Culture

Rates of Surgical Site Infection and Benefit From Prophylactic Antibiotics

•

Operation Antibiotic Yes

Antibiotic No

Number Needed to Treat

Colon 4-12% 24-48% 3-5

Other (mixed) GI 4-6% 15-29% 4-9

Vascular 1- 4% 7-17% 10-17

Cardiac 3-9% 44-49% 2-3

Hysterectomy 1-16% 18-38% 3-6

Craniotomy 0.5-3% 4-12% 9-29

Spinal Operation 2.2% 5.9% 27Total Joint

Replacement 0.5-1% 2-9% 12-100

Breast & Hernia Operation 3.5% 5.2% 58

Dellinger, Patchen 2013. Hospital Engagement Network

Common Sense Science: Timing of Antibiotics

• In order for antibiotics to be effective they need to be in the tissue at the time that the incision is made.

• It can take more time to reach some tissues than others.

• Antibiotics can’t get to tissue that has no blood flow.

Classen. NEJM. 1992;328:281.

Perioperative Prophylactic Antibiotics

Timing of AdministrationIn

fect

ions

(%)

Hours From Incision

14/369

5/6995/10092/180

1/81

1/411/47

15/441

Common Sense Science:Weight Based Dosing

• Larger patients have more tissue and larger blood volumes.

• Standard antibiotics doses given to larger patients will result in lower blood and tissue levels of antibiotics.

• The dose of prophylactic antibiotic should be adjusted for larger patients.

Obesity Map

Prophylactic Antibiotics:Size of Patient and Size of Dose

• Morbidly obese patients having bariatric surgery have higher infection rates.

• Cefazolin levels are lower in obese patients than in non-obese patients at same dose.

• Cefazolin dose changed from 1 g to 2 g:– Infection rate at 1g: 16.5%– Infection rate at 2g: 5.6%

Forse RA. Surgery 1989;106:750

Ancef• Pediatric Dosing:

– 25 – 50 mg/kg/day divided into three doses• 70kg x 50 = 3500• 3500/3 = ~1000 or 1 gram• 100kg x 50 = 5000• 5000/3 = ~ 1700 or 2 grams

Recommended Adult Dosing• < 80 kg -------- 1 gram• > 80 kg -------- 2 grams

Common Sense Science: Antibiotic Re-dosing

• The blood level of all antibiotics decreases with time.

• When the level falls enough, the infections “fighting power” of the antibiotic is no longer effective.

• A second [or third] dose of antibiotics should be given to prevent surgical site infection.

Results When You Re-Dose Antibiotics

How Long Between Re-Dosing?• It turns out that if antibiotics are re-dosed

they can remain clinically effective.• There is probably some variability in this

[different surgical procedures can change drug metabolism].

• Other factors can decrease this interval.

Common Sense Science: Discontinuing Prophylactic

Antibiotics• The primary effect of giving antibiotics during

surgery comes from the initial dose given before the incision and additional doses given while the incision is open.

• That is when most of the bacteria contamination occurs.

• Additional doses of antibiotics given after the wound is closed have minimal or no effect on the development of surgical site infections.

Antibiotic Resistance is a Big Problem

NEJM: Pallares et al. Vol. 333:474-480.

Staphylococcus Aureus

Emerging Infectious Diseases: Vol.7 No. 2. Chambers, H.F.

Vancomycin

Take Home Messages• This is hard.• The GREATER GOOD.• My patient.

?Questions

Upcoming Calls• Thursday, May 16th 2:00-2:45: The Impact

of Communication, Teamwork, and Culture on SSI’s.

• Thursday, May 30th 2:00-2:45: Preventing SSI’s When Preparing Our Patients for Surgery

Office Hours:Wednesday 2:00-3:00

Resources

Website:www.safesurgery2015.org

Email: safesurgery2015@hsph.harvard.edu