The Relationship between Increasing Patient Body Mass Index and Operating Room Scheduling Inaccuracies at the Time of Hysterectomy

Abstract

<h3>Study Objective</h3> To assess the relationship between patient body mass index (BMI) and operating room (OR) scheduling inaccuracies at the time of hysterectomy. <h3>Design</h3> Retrospective cohort study. <h3>Setting</h3> Academic medical center. <h3>Patients or Participants</h3> Scheduled hysterectomies (n=951) performed from 11/2017 through 02/2020 for any gynecologic indication. <h3>Interventions</h3> Hysterectomy by any route. <h3>Measurements and Main Results</h3> The primary outcome was operating room time scheduling inaccuracy in minutes, defined as the difference between the scheduled and the actual operating room time. The mean scheduling inaccuracy for women with normal weight, overweight, and class I, II, and III obesity was 22.2, 28.4, 33.5, 38.3, and 48.2 minutes, respectively (p<0.001). Multivariable linear regression analysis adjusted for patient age, the presence of major cardiopulmonary comorbidities, ASA category, anesthetic type, abdominal surgical history, number of procedures performed, procedure route, and uterine weight. Normal and overweight women were similarly under-scheduled. Compared with normal-weight women, those with class 1 and 3 obesity were, on average, 12.7 (95% CI 2.1-23.3, p=0.019) and 18.9 (95% CI 4.4-33.3, p=0.010), respectively, more minutes under-scheduled. (The average scheduling inaccuracy of women with class 2 obesity did not differ significantly from women with normal weight.) Obese women whose surgeries were under-scheduled, compared to those who were not, spent a significantly greater proportion of their operating room time in operative time (82.6% vs. 74.6%, p<0.001) as compared to pre-operative positioning time (12.1% vs. 18.3%, p<0.001) or non-operative anesthetic time (15.6% vs. 21.0%, p<0.001). <h3>Conclusion</h3> When adjusted for key factors that may affect operating room time, obese women were significantly more under-scheduled than women of normal weight. Obese women with under-scheduled cases spent proportionally more OR time in operative as opposed to non-operative time. Future studies can assess whether awareness of this tendency helps surgeons more accurately predict operating room time required for hysterectomy for obese women.