Utility of Routine Preoperative Laboratory Testing for Low-Risk Patients in Ambulatory Gynecologic Surgery.

Abstract

STUDY OBJECTIVE\nTo examine the current utilization of routine preoperative laboratory testing in low-risk patients undergoing ambulatory gynecologic surgery and to determine if such testing impacts surgical outcomes.\n\n\nDESIGN\nThe American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database was queried for ambulatory gynecologic surgeries between 2015-2018. Low-risk patients included in this study were defined as being American Society of Anesthesiologists (ASA) class 1 or 2.\xa0The rate of preoperative laboratory testing prior to ambulatory gynecologic surgery in low-risk patients was determined and factors associated with testing including patient characteristics and comorbidities were evaluated. NSQIP-defined complications were compared between those with and without preoperative laboratory testing. Preoperative laboratory testing was defined as chemistry, hematology, coagulation, or liver function studies obtained within 30 days preoperatively.\n\n\nSETTING\nNational health systems that participate in the NSQIP.\n\n\nPATIENTS\n19,855 patients who underwent an ambulatory gynecologic procedure.\n\n\nINTERVENTIONS\nPreoperative laboratory testing in low-risk patients prior to ambulatory gynecologic surgery.\n\n\nMEASUREMENTS AND MAIN RESULTS\nOf 19,855 patients studied, 14,258 (71.8%) received preoperative laboratory testing. Statistically significant differences were seen between patients who underwent preoperative testing and patients who did not. The most frequent preoperative test was a complete blood count (70.4%). Among patients who received preoperative testing, 4,053 (28.4%) were found to have at least one abnormal result. No statistically significant difference was seen in overall postoperative complication rate when comparing patients who received preoperative laboratory testing with those who did not (2.5% vs. 2.2%, p=0.30). Specifically, no statistically significant difference was seen among wound complications (1.0% vs. 1.0% p=0.78), major complications (1.0% vs. 0.8% p=0.11), unplanned return to the operating room (0.1% vs. 0.2%, p=0.40), unplanned readmission (0.7% vs. 0.5% p=0.10), or overall morbidity (2.1% vs. 1.9% p=0.38). Chi-squared analyses were performed to compare categorical variables. Continuous variables were compared using unpaired t-tests.\n\n\nCONCLUSION\nThis large study utilizing a reputable national database reveals that despite updated evidence-based guidelines that recommend against the practice, preoperative laboratory testing continues to be performed for the majority of low-risk patients undergoing ambulatory gynecologic surgery. This study also further supports current guidelines in demonstrating no difference in surgical outcomes between low-risk patients who did and did not receive preoperative laboratory testing. Preoperative laboratory testing practices for low-risk patients undergoing ambulatory gynecologic surgery do not follow current evidence-based guidelines and should be re-evaluated.