Infection Prevention and Gynecologic Surgery

Shout out to Taylor DeGiulio for today’s episode idea! We’re doing a pretty close reading of ACOG PB 195 if you want to follow along!

SSI represents the most common complication after GYN surgery, however definitions of this may surprise you. The National Surgical Quality Improvement Program (NSQIP) divides SSI up into three broad categories, with their definitions below:

  1. Superficial incisional: occurs within 30 days of surgery, involving only skin or subcutaneous tissue.

  2. Deep incisional: occurs within 30 days of surgery without an implant, or within 1 year of surgery with an implant, and involves deep soft tissues (rectus muscle, fascia).

  3. Organ space: occurs within 30 days of surgery without an implant, or within 1 year of surgery with an implant, and involves any other area manipulated during operative procedure (i.e., osteomyelitis if bone, endometritis or vaginal cuff for GYN, etc.)

  • In addition to satisfying these time and location definitions, an SSI also must have one of the following characteristics present:

    • Purulent drainage from the area of infection.

    • Spontaneous dehiscence or deliberate opening of a wound by the surgeon, with organisms subsequently obtained from an aseptically collected culture; or not cultured, but the patient displays signs/symptoms) of infection (i.e., fever, localized pain or tenderness, redness, etc.).

    • Abscess or other evidence of infection noted on examination.

    • Diagnosis of infection made by surgeon or attending physician.

In GYN surgery, our threats for infection lie primarily from vaginal organisms or skin organisms; however we may also come into contact with fecal content or enteric contents as well. Thinking about the organisms we’re helping to bolster defense against will help in selecting a preventive antibiotic. Thinking about the wound class is a simple way to characterize this:

ACOG PB 195

ACOG also recommends a number of perioperative considerations/techniques to reduce SSI:

  1. Treat remote infections - this one seems pretty obvious. If there’s an infection going on, like a skin infection or a UTI, it’s likely best to postpone surgery in favor of treating the infection!

  2. Do not shave the incision site - Preoperative shaving by patients themselves has actually been shown to be likely harmful, increasing the risk of infection by introducing a nidus for infection remote from surgery. If hair needs to be clipped, it should be done immediately pre-op with electric clippers.

  3. Prevent preop hyperglycemia - blood glucose should be targeted to < 200 mg/dL for both non-diabetic and diabetic patients before proceeding with surgery. Performing a preoperative random blood sugar prior to major surgery is a practice our hospital has implemented to identify diabetes in our patients, and to prevent SSI.

  4. Advise patients to shower or bathe with full body soap on at least the night before surgery -We found it fairly surprising that no particular soap is recommended over another. Many offices offer patients a chlorhexidine soap for use the night before surgery. The soap significantly reduces risk of cellulitis versus no bathing.

  5. Use alcohol-based preop skin prep, unless contraindicated - chlorhexidine-alcohol combinations have been proven in RCTs and meta-analyses to be superior to povidine-iodine for preoperative skin preparation. For mucosal sites such as the vagina, where high alcohol concentrations should not be used due to irritation risk, povidine-iodine or chlorexidine soap solutions should be used.

  6. Maintain appropriate aseptic technique - Of course, right? But in addition, our surgical technique does matter! Effective hemostasis while preserving vital blood supply, maintaining normothermia and reducing operative time, gentle tissue handling, avoiding inadvertent injuries, using drains when appropriate, and eradicating dead space can all help to reduce risk of SSI.

  7. Minimize OR traffic - safety bundles that have included components to reduce opening of OR doors during cases have been shown to reduce SSI.

  8. For hysterectomy, consider preop screening for bacterial vaginosis - prior to routine use of antibiotic prophylaxis for hysterectomy, use of metronidazole pre-op in patients who screened positive for BV reduced SSI. These studies haven’t been repeated with systematic antibiotic prophylaxis, but given the data, ACOG does state that screening is reasonable at the preop visit.

Alright, now time for the antibiotics! We dive deeper in the podcast, but PB 195 will give you the quick version here in the tables:

ACOG PB 195

ACOG PB 195

HIV in the Non-Pregnant Patient

We jump back to our STI saga to cover HIV today. ACOG PB 167 and CO 596 make for supplementary reading for this show.

The CDC and USPSTF recommend at least one-time HIV screening in most women. The CDC goes further to recommend up to annual screening in certain high-risk groups, including IV drug users, > 1 sex partner annually or known sex partner with HIV, those who exchange sex for money or goods, and MSM.

Screening is important, because almost 25% of new cases occur in women, and heterosexual intimate contact is the most common form of disease spreading. ACOG subscribes to a philosophy of “opt out” testing, by which HIV screening should be considered routine, with the patient able to opt out. Physicians need to document the reason for this in their notes. Screening tests are broken into rapid and confirmatory. A positive rapid screen should always be followed with a confirmatory test, as the rapid screens have high sensitivity, but lower specificity.

GYN care may vary somewhat with positive HIV status. For Pap smears, PB 167 describes an appropriate algorithm for dealing with initial screening and some positive results:

ACOG PB 167

ACOG PB 167

We spend some time reviewing the treatment of other STIs in the podcast briefly, all of which are reviewed in PB 167 as well. Highlights include:

  • Using 1 week rather than single-dose metronidazole treatment for trichomonal infections

  • Re-testing any positive GC/CT testing result at 3 months, due to high risk of re-infection

  • Screening for most STIs at entry to care for HIV-affected patients.

Birth control is also another important topic for HIV-affected patients. ACOG and the CDC recommend use of dual-contraception — that is, a barrier method and a hormonal method — to prevent viral spread. Certain forms of hormonal contraception may be affected by antiretroviral drugs:

  • CHCs: The NNRTI non nucleoside reverse transcriptase inhibitor efavirenz and certain protease inhibitors (-navir) may decrease efficacy of combined methods by reducing contraceptive hormone levels; however, they are considered US MEC Category 2.

    • The exception to this rule is fosamprenavir, as CHCs also lead to decreased levels of this protease inhibitor (US MEC 3).

  • Etonogestrel implant:  Similarly to CHCs, there are theoretical risks in decreased contraceptive effectiveness for patients on efavirenz; however, the implant remains US MEC 2.

  • DMPA: MEC category 1 for all users, except for those on fosamprenavir; there is limited evidence DMPA decreases fosamprenavir levels like CHCs (US MEC 2).

  • IUDs: MEC category 1 for all users!

  • Emergency contraception: for oral medicatons such as levenorgestrel and ulipristal, these should be offered to HIV-affected women as the benefits of emergency contraception are considered to outweigh the risks in this group. Similarly to CHCs, there is theoretical risk of decreased efficacy of these methods among women taking efavirenz.

Finally, in a preview to our next episode, we talk about preconception counseling for HIV-affected patients. The goal for any patient with HIV is to achieve a negative viral load, and for OB-GYNs, this is important to limit vertical transmission. Efavirenz has been associated with neural tube defects, so should be avoided in pregnancy if possible.

Conceiving is safest through artificial insemination. However, if natural conception is desired. OB-GYNs should discuss limiting unprotected intercourse to ovulatory times, and using pre-exposure prophylaxis for the patient, or her partner, in serodiscordant couples. This generally involves a daily regimen of tenofovir/emtricitabine (Truvada) for 1 month prior to, and 1 month after, conception. Risk reduction is estimated to be somewhere between 63-75%, and the best-available data suggests this is likely safe.

Gonorrhea and Chlamydia

Though CREOGs are over, we hope you continue to study with us! On today’s episode we tackle chlamydia and gonorrhea.

The most helpful resource we mention on today’s episode comes from the CDC’s 2015 STD Treatment Guidelines. They even have a free smartphone app, which is very handy for use in your emergency department or clinic/office setting.

Gonorrhea is caused by the gram negative diplococcus Neisseria gonorrhoeae. Chlamydia is an obligate intracellular gram negative pathogen. Below we’ve created our own guides to treatment based on the CDC recommendations. Happy listening!