Use of Preoperative Laboratory Testing Among Low-Risk Patients Undergoing Elective Anorectal Surgery

Many low-risk patients receive preoperative laboratory testing (PLT) prior to elective outpatient surgery, with no effect on postoperative outcomes. This has not been studied in patients undergoing anorectal surgery. The aim of this study was to determine if PLT in this population was predictive of perioperative complications.

The 2015-2018 National Surgical Quality Improvement Program (NSQIP) databases were queried for elective ambulatory anorectal surgeries. PLT was defined as chemistry, hematology, coagulation, or liver function studies obtained ≤30 days preoperatively. American Society of Anesthesiologists (ASA) class 1 and 2 patients were included who underwent elective, ambulatory, benign anorectal surgery. Patient demographics, comorbidities, and postoperative outcomes were compared between those who did and did not receive PLT. Postoperative outcomes were defined as wound-related, procedure-related, major complications, unplanned readmission, and death occurring within 30 days. Multivariate regression analysis determined patient characteristics predictive of receiving testing.

Of 3309 patients studied, 48.6% received PLT. On multivariate analysis, older age, female sex, Black race, ASA class 2, and comorbidities were predictive of receiving testing. The complication rates were similar between patients who did and did not receive testing (4.3% versus 3.5%, P = 0.22).

PLT is performed in over half of low-risk patients receiving elective anorectal surgery. There was no difference in the rate of postoperative complications between patients who received testing or not, nor with normal versus abnormal results. PLT can be used more judiciously in this population.