Feasibility of Anesthesiologists Giving Nurse Anesthetists 30-Minute Lunch Breaks and 15-Minute Morning Breaks at a University's Facilities

Abstract

Background Managers of an anesthesia department sought an estimation of how often each anesthesiologist can give lunch breaks and morning breaks to nurse anesthetists to plan staff scheduling. When an anesthesiologist supervising the nurse anesthetists can give a break, it would be preferred because fewer extra nurse anesthetists would be scheduled to facilitate breaks. Methodology Our methodological development used retrospective cohort data from the three surgical suites of a single anesthesia department. Surgical times were estimated using three years of data from October 2016 through September 2019, with 95,146 cases. Comparison was made with the next year from October 2019 through September 2020, with 30,987 cases. The 5% lower prediction bounds for surgical time were estimated based on two-parameter, log-normal distributions. The times when two and three sequential rooms had overlapping lower prediction limits were calculated. Sequential rooms were used because that was how anesthesiologists' assignments were made at the studied department, when feasible given constraints. Percentages of cases were reported with 15 minutes available starting sometime between 9:00 and 10:30 and 30 minutes starting sometime between 11:15 and 12:45, times characteristic for the studied department. At the studied university's facilities, the nurse anesthetists were independent practitioners (e.g., an anesthesiologist supervising two nurse anesthetists each with a long case could give a break to one of the two rooms). Results The percentage of days for which an anesthesiologist could give a lunch break (11:15-12:45) was close to the percentage of cases when an anesthesiologist could give the same-length break anytime throughout the workday. In other words, the length of the break was important, not the time of the day of the break. The absolute percentages also depended on how many rooms the anesthesiologist supervised, the duration of cases, and facility. For example, among anesthesiologists at the adult surgical suite supervising three nurse anesthetists, a lunch break could be given by the anesthesiologist on at most one-third of the days without affecting workflow. Conclusions Our results show that the feasibility of an anesthesiologist clinically supervising one, two, or three rooms to give lunch breaks to the nurse anesthetists in the rooms depends principally on how many rooms are supervised, the duration of the break, and the facility's percentage of cases with surgical times longer than that duration. The specific numerical results will differ among departments. Our methodology would be useful to other departments where anesthesiologists are clinically supervising independent practitioners, sometimes during cases long enough for a break, and there is anesthesiologist backup help. Such departments can use our methodology to plan their staff scheduling for additional nurse anesthetists to give the remaining breaks.

Keywords: anesthesiology; industrial engineering; operating room management; staff assignment; surgical times.

Figure 1. Association between characteristics of the facility and results by the facility.

The factors important for the percentages of days for which an anesthesiologist could give lunch break were the number of cases being supervised, duration of the break, and facility. The figure explores the generalizability of the results. Along the vertical axis are plotted values for single cases in Table 2 (blue dots), Table 1 (red dots), and Table 3 (red dots). Along the horizontal axis are the facility’s percentages of surgical cases during the selected time of day that were at least 30 minutes (for 15-minute breaks) and 45 minutes (for 30-minute breaks). The data deliberately were not jittered. The data are nearly monotonic, as shown by the Spearman rank correlation coefficients being 0.950 and 0.943, respectively. Yet, linear correlation matters from the perspective of understanding the facility as a covariate. The Pearson correlation coefficients were 0.996 and 0.995, respectively. The implication is that, to the extent discernable from the N = 15 combinations of the facility and the time of day, the characteristic of facility affecting results is the percentage of cases with surgical time at least as long as that of the break, plus the 15 minutes used at the start for patient stabilization, positioning, finishing documentation, etc. [4]. The figure also highlights that the percentage of cases when an anesthesiologist supervising just one room can give a lunch break (and have both present waking up the patient) is less than the percentage of cases at the facility with surgical times at least of the length of the break. For example, from the last row of Table 1 and the end of the red line in the figure, for a nurse anesthetist to have a near 50:50 chance of receiving a 30-minute lunch break between 11:15 and 12:45, the facility needs to have overall 83% or more cases with surgical times of 45 minutes or longer. The reason the percentage probabilities along the vertical axis are smaller is that the true duration of surgical time is known only in retrospect.