Related Experiment Video
Updated: Aug 22, 2026

Laparoscopic Anatomical Resection of the Right Anterior Lobe Based on the Laennec Capsule Technique
Published on: May 2, 2025
Clinical skills: an evidence-based approach to preoperative fasting
1Alexandra Hospital, Redditch, Worcestershire.
Insights
Preoperative fasting guidelines are often longer than evidence supports, increasing patient discomfort without clear benefit. This review examines evidence for optimal fasting times to reduce risks like Mendelson's syndrome during anesthesia.
Area of Science:
- Anesthesiology
- Patient Safety
Background:
- Prolonged preoperative fasting is a traditional practice to prevent aspiration pneumonitis (Mendelson's syndrome) during general anesthesia.
- Aspiration occurs when gastric contents move from the stomach to the lungs due to depressed pharyngeal and laryngeal reflexes during anesthesia induction.
- This can lead to serious lung inflammation, though it is a rare complication.
Purpose of the Study:
- To review current evidence regarding preoperative fasting durations.
- To investigate reasons behind the continued practice of prolonged preoperative fasting.
- To provide evidence-based recommendations for optimizing preoperative fasting protocols.
Main Methods:
- Literature review of current evidence on preoperative fasting times.
- Analysis of historical practices and their justification.
- Examination of risk factors and complications associated with fasting.
Main Results:
- Current evidence suggests patients are fasted for longer periods than necessary.
- Traditional practices may not align with the latest scientific findings on aspiration risk.
- Prolonged fasting can lead to increased patient discomfort and potentially other adverse effects.
Conclusions:
- Preoperative fasting times should be guided by current evidence rather than tradition.
- Optimizing fasting protocols can enhance patient comfort and safety.
- Recommendations are proposed to align clinical practice with scientific evidence.
Abstract:
The procedure of fasting from midnight until induction of anaesthesia arose from concern that patients could regurgitate during induction of general anaesthesia when the pharyngeal and laryngeal refluxes are depressed. In this situation, the contents of the stomach do not come out of the patient's mouth, but go up into the oesophagus and trachea and are drawn back down into the lungs. This can damage the lungs, causing chemical inflammation, a condition referred to as aspiration pneumonitis or Mendelson's syndrome, a serious although rare complication of general anaesthesia. For many years, preoperative fasting has been a traditional practice for reducing this risk, but patients are being fasted for considerably longer than the evidence indicates is necessary. This article considers the current evidence for preoperative fasting times and examines why patients are still being subjected to prolonged preoperative fasting. Based on the evidence presented, recommendations are made regarding this aspect of care.
Related Concept Videos
Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...
Cardiomyopathy VII: Pre and Post Operative Nursing Management
Kidney Transplant II: Surgical Procedure
Pre-Procedural Guidelines for Assessing Blood Pressure
Endoscopic Procedures V: ERCP
Patient...