Preoperative fasting times: Prescribed and actual fasting times at Universitas Hospital Annex, Bloemfontein, South Africa

Abstract

Background. Guidelines recommend a preoperative fasting period of 6 hours for solid food and 2 hours for clear fluids. Because of fixed meal times and imprecise operation starting times, patients often fast for an extended period of time.

Objective. To investigate the prescribed preoperative fasting times, and the actual duration of fasting, compared with the internationally accepted fasting times for solid food and clear fluids.

Methods. Patients (N=105) aged 14 - 60 years, who were scheduled for elective surgery in the morning session (list starting time 07h00), were included in this prospective study. On arrival in theatre, all patients were asked when they last ate and drank. Anaesthetic records were used to determine the prescribed fasting times and operation starting times.

Results. For solids, patients were most frequently prescribed to start fasting from 22h00 to 00h00 (53.3% and 39.1%, respectively). No patient fasted <8 hours. The median duration of fasting was 14 hours and 45 minutes (range 9 hours and 45 minutes - 19 hours and 5 minutes). For fluids, patients were most frequently prescribed to start fasting from 05h00 (46.7%), 00h00 (27.6%) and 22h00 (7.6%). In practice, no patient ingested fluids after 22h30 or <9 hours preoperatively. The median fasting time for oral fluids was 13 hours and 25 minutes (range 9 hours and 37 minutes - 19 hours and 5 minutes).

Conclusion. Most patients started fasting too early preoperatively, consequently withholding food and oral fluids for longer than recommended. An increased awareness regarding complications of unnecessarily long fasting times, and interventions to correct this problem, is required.