Perioperative Laboratory Abnormalities in Gynecologic Oncology Surgical Patients

Background: Laboratory blood testing incurs financial costs and the blood draws can increase discomfort, yet minimal data exists regarding routine testing in gynecologic oncology surgical patients. Additionally, an increasing number of gynecologic oncology surgeries are performed via a laparoscopic approach. Thus, further investigation into perioperative laboratory testing for gynecologic oncology patients is warranted. An increasing number of gynecologic oncology surgeries are performed via a laparoscopic approach. Thus, further investigation into perioperative laboratory testing for gynecologic oncology patients is warranted. Objective: The aims of this study were (1) to evaluate the frequency and etiology of perioperative laboratory test abnormalities in patients undergoing laparoscopic and laparotomy surgery in a gynecologic oncology service, and (2) to establish an evidence-based algorithm to reduce unnecessary laboratory testing. Materials and Methods: A single-institution retrospective study was completed, investigating laparoscopic and laparotomic surgeries over 4 years. Information on preoperative and postoperative laboratory data, surgical parameters, perioperative interventions, and patient demographics was collected. Quality-assurance data were reviewed. Data were tabulated and analyzed using Statistical Product and Service Solutions (SPSS) version 22. A Student's t-test was used to test for group differences for continuous variables with equal variance, the Mann-Whitney-U test for continuous variables when unequal variance was detected, and Pearson's χ2 was used to investigate categorical variables of interest. p-Values <0.05 were considered to be statistically significant. Logistic regression was performed to investigate the relationships among multiple predictors and each identified outcome. Results: The study included 481 subjects (168 laparoscopies, 313 laparotomies). Patients undergoing laparoscopy were, on average, younger (53.5 versus 57.4), with lower body mass indexes (29.7 versus 33.0) and lower rates of diabetes (10.7% versus 19.5%), compared to patients undergoing laparotomy. Overall, >98% of patients underwent at least one preoperative and postoperative laboratory test, totaling 8060 preoperative and 5784 postoperative results. The laparoscopy group was significantly less likely to have postoperative metabolic abnormalities or to undergo perioperative blood transfusion. Patients taking an angiotensin-converting-enzyme inhibitor, angiotensin-II-receptor blocker, or diuretic were significantly more likely to have elevated creatinine preoperatively (odds ratio [OR]: 5.0; p < 0.001) and postoperatively (OR: 7.1; p < 0.001), and this remained true for each group when divided by surgical approach. Perioperative complications meeting institutional quality assurance criteria occurred in 1.7% of laparoscopy patients compared to 11.8% of laparotomy patients (p < 0.001); perioperative laboratory testing was not a factor in the diagnosis of these complications. Conclusions: Clinically significant laboratory abnormalities are uncommon and are less likely to be found on routine perioperative testing in gynecologic oncology patients undergoing laparoscopy, compared to patients undergoing laparotomy. This suggests a role for limiting perioperative laboratory blood testing. (J GYNECOL SURG 32:111).