Objectives: Current American Society of Anesthesiologists (ASA) guidelines suggest that healthy, adult patients can ingest clear liquids up to two hours before an elective procedure. However indiscriminate use of nil per os (NPO) hours is still pervasive in current clinical practice. The purpose of this study is to identify the duration of NPO to improve the quality of care.
Methods: This is a retrospective study of adult patients undergoing general surgical procedures from September to November 2023 at our local institute. General surgery procedures were defined as appendectomy, cholecystectomy, hernia repair or intestinal surgery. Patients were categorized as undergoing elective or emergent operations (patients who went to the operating room via admission from the emergency room). NPO was calculated from when the order went into effect to the timeout for surgery. Patients undergoing multiple operations or those with contra-indications for diet (bowel obstruction) were excluded. This is a quality improvement study.
Results: A total of 289 patients were studied. Overall, the NPO hours [median (IQR)] for all patients were 13 (10-16). Patients undergoing emergent [13 (8.25-17)] procedures had similar NPO times compared to patients undergoing elective [13 (11-16)] surgery (p=0.25). Across different surgeries – appendectomy (n=51) [13 (9-17)], cholecystectomy (n=87) [13 (11-16)], hernia repair (n=47) [13 (7-14)], large bowel surgery (n=15) [11 (7.5-13)], small bowel surgery (n=12) [10 (6-15)], and perianal surgery (n=37) [15 (11-17)] there was no statistical difference in NPO hours (p=0.43).
Conclusions: Prolonged pre-operative fasting is an additional stressor on top of the trauma for surgery. Root cause analysis is needed to determine why patients are still subjected to indiscriminate use of NPO hours. The next step in this study is to survey anesthesiologists and administering providers to better understand this phenomenon.
