Obgyno Wino Podcast Episode 40 - Prevention of Infection After Gynecologic Procedures
"...the fundamental principles and indispensable postulates of every genuinely productive science are not based on pure logic but rather on the metaphysical hypothesis - which no rules of logic can refute - that there exists an outer world which is entirely independent of ourselves. It is only through the immediate dictate of our consciousness that we know that this world exists." - Max Planck
PB#195 - Published June 2018
Clean your hands, clean the skin, prep the vagina, treat remote infections and keep blood sugars controlled preoperatively to reduce infection rate.
Antibiotic prophylaxis is indicated for all hysterectomies, open surgery, and D&C for abortion, but it's generally not indicated in other procedures unless there's risk of entry into the bowel or a communication made between the abdominal cavity and the vagina.
Evidence is poor for antibiotic prophylaxis for indwelling foley or suprapubic catheters
For patients with penicillin allergy, switch to cephalosporin if allergy is mild, switch to metronidazole (or clindamycin) plus gentamicin (or aztreonam) if allergy is severe or if history of anaphylaxis
Definitions and epidemiology
- surgical site infections are those which develop within 30 days of a procedure (or within a year of an implant)
- incisional infections can be classified as: skin/superficial or involving deeper tissues like muscle or fascia
- skin/superficial incisional infections will either be culture positive, have purulent drainage, or have all of the signs of an infection (erythema, tenderness, or fluctuance) even if culture not performed
- deep incisional infections can be diagnosed the same way but normally require the incision to be opened and found to be culture positive, or if an abscess is found (on visual inspection or imaging), or, in the absence of a culture, fever or pain
- deeper infections involving intra-abdominal organs are diagnosed in the same ways, through imaging and exploration are often staples of your workup
- superficial incisional infections rates are overall lower with laparoscopic gynecologic surgery: <1% for laparoscopic hysterectomy versus ~2.5% for open hysterectomy
- deeper infections result from roughly 1% of hysterectomies by any route
- bugs are usually gram positive cocci (e.g. staph), but may include others given we operate on the vagina/perineum ("clean-contaminated"), such as bugs normally found in the gut (e.g. anaerobes like bacteroides and pepto-/streptococcus; gram negative aerobes like E. coli and proteus)
Risk factors for surgical site infection
- diabetes and impaired glucose control
- poor nutritional status
- remote infection present at time of surgery
- GBS colonization of the vagina or presence of bacterial vaginosis of time of vaginal surgery
- MRSA carrier status
- depth of subcutaneous fat layer
Preoperative prevention measures
- treat remote infections (respiratory, genitourinary, skin, etc.)
- wait until immediately prior to incision to remove hair using an electric clipper (not a razor)
- ensure perioperative serum glucose <200 mg/dL (LEVEL A)
- have the patients wash up with antiseptic soap the night before abdominal surgery
- use 4% chlorhexidine skin prep prior to incision (odds ratio of infection 0.56 with chlorhexidine when compared to providone-iodine; it lasts longer and isn't inactivated by blood or serum proteins) (LEVEL A)
- vaginal prep with 4% chlorhexidine or providone-iodine prior to hysterectomy or vaginal surgery
- recognize and maintain asepsis
- minimize OR traffic
Intraoperative prevention measures
- minimize risk of wound disruption: effective hemostasis while preserving adequate perfusion to tissue, preventing hypothermia, gentle handling of tissues, avoid injuries to bowel, appropriate use of drains and suture, and eradicating dead space
- preoperative antibiotics 1 hour prior to incision, with additional doses considered for obese patients (e.g. ancef 3 g instead of 2 g for patients weighing >120 kg), lengthy procedures (generally >4 hrs), and procedures w/ excessive blood loss
Which procedures require antibiotic prophylaxis?
- hysterectomies: open, laparoscopic, vaginal, robotic, supracervical, in a house, with a mouse (LEVEL A)
- open abdominal surgery: prophylaxis is standard in open abdominal surgery, though data isn't that strong to support it
- other laparoscopy: prophylaxis isn't required in other laparoscopic surgeries in which bowel, vagina, or uterine cavity aren't anticipated
- D&C for abortion: 1x dose of doxycycline 200 mg IV or flagyl as 2nd line (LEVEL A)
- D&C for other indications: nah
- chromopertubation or HSG: prophylaxis is indicated if PID suspected or if hydrosalpinges noted prior to or after procedure (doxy 100 mg BID for 5 days)
- No prophylaxis needed for: sonohysterography, ablation, hysteroscopy, urodynamic studies, IUD insertion (LEVEL A), or cervical procedures
Is antibiotic prophylaxis indicated for indwelling foley or suprapubic catheters postop?
- data is mixed, but probably not useful
- if you, daily prophylactic cipro or macrobid from post-op day 2 until catheter removed
Is it helpful to screen for bacterial vaginosis before hysterectomy?
- maybe, but data is limited.
- Should I treat? If screen is positive, then yes, of course.
- What about prophylactic treatment? It's reasonable to recommend treatment for 5-7 days, including at least four days postoperatively
Should I consider prophylaxis prior to egg retrieval or embryo transfer in IVF?
- during egg retrieval, it's reasonable to consider if history of PID, ruptured appendicitis, or endometriosis based on increased theoretical risk
- not recommended during embryo transfer
Ok. I get it. But how do I modify prophylaxis if the patient is a MRSA carrier?
- add vancomycin at 15 mg/kg
What if they have a penicillin allergy?
- switch to cephalosporin if mild (itchiness, rash)
- if they develop hives, laryngeal edema, shortness of breath, or full blown anaphylaxis: switch to metronidazole (or clindamycin) plus gentamicin (or aztreonam)
- likewise if they have an immediate reaction to PCNs (e.g. Steven Johnsons Syndrome or toxic epidermal necrolysis)