The effect of a new NPO policy on operating room utilization

J Clin Anesth. 2000 Feb;12(1):48-51. doi: 10.1016/s0952-8180(99)00139-7.


Study objectives: To prospectively assess the impact of a liberalized preoperative fasting policy on operating room (OR) utilization.

Study design: Prospective cohort study involving data collection before and after a change in nil per os (NPO) policy.

Setting: Academic teaching hospital.

Patients: 5,420 consecutive outpatients and AM admissions.

Interventions: Data collection was done on all adult patients who presented to our OR suite over two 15-week periods. During the first 15-week period, patients were instructed to drink no liquids after midnight (control group, n = 2,646). In the second 15-week period, patients were allowed to consume unlimited clear fluids until 2 to 3 hours prior to surgery (study group, n = 2,774).

Measurements and main results: We found no difference between the control and study groups in the number of cases cancelled (0 in each group) or delayed (8 vs. 9; relative risk [RR] = 1.07, 95% confidence interval [CI] = 1.000 to 1.148) due to noncompliance with fasting guidelines. There was no difference between the groups in the number of cases of aspiration (0 in each group). In the control group, significantly more episodes of regurgitation were noted (12 vs. 9; RR = 0.715, 95% CI = 0.535 to 0.955) and more rapid-sequence/awake intubations were performed (119 vs. 51; RR = 0.409, 95% CI = 0.306 to 0.546) than in the study group.

Conclusions: Liberalizing a preoperative fasting policy and allowing patients to consume unrestricted clear fluids up until 3 hours before their scheduled time of surgery did not affect their compliance with fasting requirements. No increase in cancellations or delays of surgical procedures due to inappropriate oral intake was observed.

MeSH terms

  • Adult
  • Ambulatory Surgical Procedures
  • Anesthesia, General
  • Cohort Studies
  • Confidence Intervals
  • Drinking
  • Fasting*
  • Foreign Bodies / etiology
  • Gastroesophageal Reflux / etiology
  • Hospitals, Teaching / organization & administration
  • Humans
  • Intubation, Intratracheal
  • Operating Rooms / statistics & numerical data*
  • Patient Admission
  • Policy Making*
  • Prospective Studies
  • Risk Factors
  • Time Factors
  • Trachea
  • Treatment Refusal