NPO Guidelines Before Bronchoscopy
Patients should have no solid food for 4 hours and may have clear fluids up to 2 hours before bronchoscopy. 1
Evidence-Based Fasting Recommendations
The British Thoracic Society provides clear guidance on preoperative fasting for bronchoscopy that balances aspiration risk with patient comfort 1:
- Solid food: Nothing by mouth for 4 hours before the procedure 1
- Clear fluids: Permitted up to 2 hours before bronchoscopy 1
This represents a liberalized approach compared to traditional overnight fasting protocols, which are unnecessarily conservative and cause patient discomfort without added safety benefit 2.
Physiologic Rationale
The differential fasting times are based on gastric emptying physiology 2:
- Clear liquids empty from the stomach in 1-2 hours 2
- Solid food may take more than 6 hours to empty completely 2
Studies demonstrate that clear liquid ingestion up to 2 hours before anesthesia induction is safe in healthy patients without risk factors, and longer fluid fasting does not provide additional protection against pulmonary aspiration 2.
Clinical Outcomes
The incidence of clinically significant aspiration during elective procedures is extremely low at 1.4-6.0 per 100,000 anesthetics 2. Application of these liberalized guidelines has not resulted in increased aspiration, morbidity, or mortality, but instead has decreased patient irritability, anxiety, thirst, and hunger in the perioperative period 2.
Essential Procedural Safeguards
Beyond NPO timing, several critical safety measures must be implemented 1:
- Intravenous access should be established before bronchoscopy begins (and before sedation if given) and maintained through the recovery period 1
- Continuous pulse oximetry monitoring is mandatory during the procedure 1
- Oxygen supplementation should achieve oxygen saturation ≥90% to reduce arrhythmia risk 1
High-Risk Patient Considerations
Certain patients require modified approaches 3, 2:
- Elevated baseline CO₂: Avoid sedation, as this can precipitate respiratory failure 3
- Severe hypoxemia (SaO₂ <93%): Requires close monitoring and oxygen supplementation 3
- Risk factors for aspiration: Including gastroesophageal reflux, increased intra-abdominal pressure, impaired consciousness, or extremes of age may warrant more conservative fasting 2
Common Pitfalls to Avoid
- Do not impose overnight fasting for routine bronchoscopy—this is outdated practice that causes unnecessary patient suffering 2
- Do not withhold clear fluids beyond 2 hours—this provides no additional safety and worsens patient experience 1, 2
- Do not proceed without IV access—this must be established before starting the procedure 1