From the Guidelines
Patients should have no food by mouth for 4 hours and clear fluids by mouth up to 2 hours before bronchoscopy. This recommendation is based on the British Thoracic Society guidelines on diagnostic flexible bronchoscopy 1. The guidelines emphasize the importance of verbal and written patient information to improve tolerance of the procedure.
Key Points to Consider
- The NPO requirement is a safety precaution to prevent aspiration, which can cause serious complications like pneumonia.
- Having food or liquid in the stomach increases the risk of vomiting and subsequent aspiration during sedation or anesthesia.
- Patients should be advised not to drive, sign legally binding documents, or operate machinery for 24 hours after the procedure if they have been sedated 1.
- The recovery time for the return of an adequate gag reflex will vary between patients, and return of the gag reflex and the ability to swallow clear fluids safely should be established before discharge from hospital 1.
Recommendations for Patient Care
- Patients should be given some idea of what the next stage of management will be, an appointment for follow up, and a brief written explanation that they have had a bronchoscopy 1.
- Day case patients who have been sedated should be accompanied home, and higher risk patients such as the elderly and those who have had transbronchial biopsies should have someone to stay with them at home 1.
- Patients who undergo a bronchoscopy are fearful of a malignant diagnosis and need individualized care, which should be provided in an empathic and caring way 1.
From the Research
NPO Requirements for Bronchial Procedures
- The need for NPO (nil per os) before bronchial procedures is a topic of discussion, with some studies suggesting that the risk of aspiration is low 2.
- Current guidelines support reduced fasting durations before procedures requiring anesthesia or sedation, but many health systems still use NPO past midnight 2.
- A quality improvement initiative at a single academic health system in Southeast Texas aimed to reduce NPO usage by 50% within 6 months and was successful in removing NPO requirements from 70% of existing diagnostic imaging and therapeutic orders 2.
Aspiration Risk and NPO
- Aspiration is a syndrome with variable respiratory manifestations, and diagnostic testing is limited 3.
- The leading mechanism for microaspiration is thought to be gastroesophageal reflux disease (GERD), which can cause damage to airway epithelium and lead to inflammation 4.
- The detection of pepsin and bile acids in bronchoalveolar lavage fluid and exhaled breath condensate may be useful in identifying patients with GERD-induced aspiration 5.
Preoperative Fasting Guidelines
- Preoperative fasting guidelines are often generalized and do not distinguish between ambulatory and inpatient settings 6.
- Prolonged preoperative fasting is common, but may result in adverse effects such as intraoperative hemodynamic instability and postoperative delirium 6.
- Liberal approaches to clear fluid fasting, such as allowing clear fluids up to 1 hour prior to anesthesia, have shown no increase in adverse events among children and may be beneficial for adults as well 6.