Massive intraoperative blood loss (MIBL) is strongly and independently linked to postoperative febrile morbidity following gynecologic laparotomy, according to a retrospective cohort study in the Journal of Obstetrics and Gynaecology Canada (JOGC).
The final sample for the study comprised 711 patients undergoing gynecologic laparotomy at Health Sciences Hospital in Winnipeg, Canada, between January 2012 and December 2016.1
The group exposed to MIBL (n = 298) were patients with either > 1L of blood loss operatively, < 40 g/L drop in hemoglobin by postoperative Day 1, or perioperative blood transfusion.
The group not exposed to MIBL (n = 413) did not meet the criteria for MIBL.
The primary outcome was one or more postoperative infectious complications, defined as a positive wound swab culture, a positive urine culture or systemic inflammatory response syndrome (SIRS).
SIRS is considered as having two or more of the following conditions simultaneously, at any point during the postoperative stay: temperature > 38⁰C; heart rate > 90 beats per minute; respiratory rate > 20 breaths per minute or a PaCO2 < 32 torr; or a leukocyte count > 12,000 or < 4,000 cells/mm3 with > 10% bands.
Composite postoperative febrile morbidity occurred in 48% of surgeries with MIBL (n = 144 of 289) compared with only 12% of surgeries without MIBL (n= 51 of 413) (P < 0.0001).
After adjusting for age, body mass index (BMI), diabetes, immunosuppression, type of procedure and incision type, plus drains left in situ and bowel complications, MIBL was revealed to be robustly and independently associated with infectious outcomes: adjusted odds ratio 7.04; 95% confidence interval: 4.62 to 10.74 (P < 0.0001).
A prior study from the group found the prevalence of MIBL during gynecologic laparotomy was 14% and the frequency of postoperative infectious complications in those with MIBL was 26%.
“The predisposition to infection secondary to massive intraoperative blood loss has many proposed mechanisms including diminished delivery of oxygen to end organs resulting in end-organ dysfunction, diminished delivery of oxygen to the wound, dilution effects of fluid and blood loss on antibiotics given prophylactically and diminished delivery of essential factors and cells involved in wound healing and repair,” wrote the authors.
Blood transfusions administered to manage MIBL may also have immunosuppressive effects postoperatively, secondary to diminished number and function of natural killer and cytotoxic T cells.
The researchers noted that at their institution, it is standard procedure to administer preoperative antimicrobial prophylaxis for gynecologic laparotomies, with the first choice being 1 to 2 g of cefazolin, 15 to 30 minutes before the skin incision.
The most common surgery performed for the current study was total abdominal hysterectomy, comprising 71.1% (n= 212) of the surgeries with MIBL and 75.5% (n = 312) of the selected surgeries without MIBL.
Preoperative antibiotics were given in over 99% of cases in both groups.
Patients that had surgeries with MIBL had lower BMI, lengthier surgery, and a higher frequency of vascular injury, bowel injury, surgical complications, and surgical drains left in situ postoperatively compared with surgeries without MIBL.
“Further prospective research is needed in order to identify interventions that might mitigate the increased risk for postoperative infection associated with MIBL,” the authors concluded.