AORN Journal
Volume 89, Issue 5 , Pages 830-832, May 2009

Reducing surgical patient fasting times

  • Ruth E. Wachtel, PhD, MBA (Associate professor)

      Affiliations

    • Department of Anesthesia, University of Iowa, Iowa City, IA
    • ,
  • Franklin Dexter, MD, PhD (Professor)

      Affiliations

    • Departments of Anesthesia and Health Management & Policy, University of Iowa, Iowa City, IA

Article Outline

 

We commend authors Crenshaw and Winslow1 for their study showing that the revised American Society of Anesthesiologists' guidelines on fasting times before surgery are being implemented gradually at their institution (“Preoperative fasting duration and medication instruction,” Vol 88, No 6). Their review of the supporting literature was clearly presented and unequivocal.

According to the article, in spite of educational programs, staff members were reluctant to tell patients that they could have a light meal eight hours before surgery and clear liquids two hours before surgery. Staff members continued to instruct patients to remain NPO after midnight. Crenshaw and Winslow explain that some reluctance of staff members to implement the new guidelines could be because there is potential for procedures to be moved to earlier time slots. A surgeon may be ready to start a procedure earlier than scheduled, but the procedure cannot start and may have to be delayed or canceled if the patient is not NPO.

We have developed a method2 that uses historical data to determine the earliest time each procedure might begin. Our method obviates the need to have patients fast longer that necessary, with the assurance they would be ready 95% of the time, even if the procedure is moved to an earlier time slot.

As part of a quality improvement project conducted two years ago, we collected data on patient fasting times. At the beginning of April 2006, patients at our institution fasted before their scheduled start times an average of 12 hours 11 minutes ± 11 minutes for solids and 7 hours 6 minutes ± 13 minutes for liquids (N = 382). During the first week in October 2006, patients fasted an average of 11 hours 55 minutes ± 14 minutes for solids and 6 hours 13 minutes ± 15 minutes for liquids (N = 281). The fasting times for solids are comparable to those found by Crenshaw and Winslow. Our patients abstained from liquids for slightly shorter periods than their patients, but the difference seems clinically unimportant.

About 20% of our procedures started at least 20 minutes earlier than scheduled during these two time periods, by an average of 1 hour 14 minutes and 1 hour 21 minutes, respectively. These values are greater than those reported by Crenshaw and Winslow; however, we find that 54% of procedures start earlier than scheduled, consistent with the expectations of scientific case scheduling.3, 4 Thus, our institution has an even greater problem with balancing the issue of requiring patients to fast longer than necessary with that of ensuring patients will be NPO if surgeons are ready to start early.

We recently published a paper2 that addresses this issue of patient readiness before scheduled start times. By taking into account the extent to which procedures start early based on surgical service and day of the week (as a surrogate for “surgeon”), calculations determine the earliest possible time a procedure might start in 95% of cases. Only 5% of procedures would exceed this start time. Information on the anticipated duration of previous procedures in the same room is not necessary.

Only three months to one year of historical data on scheduled and actual start times are needed. Using this statistical method, projected start times can be used for NPO calculations and determination of the times patients should check in to the surgery center, without the worry that a procedure may have to be canceled if surgeons are ready to start early and the patient has not arrived or is not NPO. This method can easily be implemented at any hospital with historical data to determine appropriate NPO guidelines for each patient. In the paper, we describe our experience with our institution, which automatically performs this calculation on the surgery schedule to obtain recommended times each patient should stop eating and drinking, given surgical service and day of the week.

Back to Article Outline

References 

  1. Crenshaw JT , Winslow EH . Preoperative fasting duration and medication instruction: are we improving? . AORN J . 2008;88(6):963–976
  2. Wachtel RE , Dexter F . A simple method for deciding when patients should be ready on the day of surgery without procedure-specific data . Anesth Analg . 2007;105(1):127–140
  3. Dexter F , Ledolter J . Bayesian prediction bounds and comparisons of operating room times even for procedures with few or no historic data . Anesthesiology . 2005;103(6):1259–1267
  4. Dexter F , Macario A , Ledolter J . Identification of systematic underestimation (bias) of case durations during case scheduling would not markedly reduce overutilized operating room time . J Clin Anesth . 2007;19(3):198–203

PII: S0001-2092(09)00263-4

doi:10.1016/j.aorn.2009.04.005

AORN Journal
Volume 89, Issue 5 , Pages 830-832, May 2009

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