Does a patient need to be Nil Per Os (NPO) for a pleural tap?

NPO Status for Pleural Tapping

Patients do not need to be NPO (nil per os) for pleural tapping procedures. 1

Evidence-Based Rationale

The British Thoracic Society (BTS) guidelines for pleural disease, which represent the most recent and comprehensive guidance on this topic, do not include any NPO requirements before pleural procedures including thoracentesis (pleural tapping) 1. This is significant because these guidelines provide detailed recommendations for the preparation, performance, and aftercare of pleural procedures, yet make no mention of fasting requirements.

Clinical Considerations

Why NPO is Not Required

1. Non-sedated procedure: Pleural tapping is typically performed under local anesthesia without sedation, eliminating the primary concern of aspiration risk associated with sedation or general anesthesia.

2. Outpatient compatibility: The BTS guidelines specifically mention that procedures like pleural fluid aspiration can be performed in outpatient settings 1, which implies that NPO status is not a prerequisite.

3. Procedural urgency: For suspected pleural infections or symptomatic effusions, diagnostic pleural fluid aspiration should be performed promptly 1, and unnecessary NPO requirements could delay essential care.

Special Circumstances

• If sedation is planned: In rare cases where procedural sedation is required for anxious patients or complex procedures, standard pre-procedural sedation guidelines may apply, which typically allow clear liquids up to 2 hours before the procedure 1, 2.

• Critically ill patients: For patients in the ICU or with severe respiratory compromise, clinical judgment regarding NPO status should be exercised, though this is related to their overall condition rather than the pleural procedure itself.

Practical Approach

1. Standard pleural tapping: No NPO requirement

   • Proceed with the procedure regardless of when the patient last ate or drank
   • Focus instead on proper positioning, ultrasound guidance, and sterile technique

2. Emergency situations: Do not delay pleural drainage for NPO considerations

   • For pneumothorax or infected pleural effusions, immediate drainage takes priority 1

3. Ultrasound guidance: Always use ultrasound to guide pleural procedures 1, 3

   • This significantly improves safety and success rates regardless of NPO status

Common Pitfalls to Avoid

1. Unnecessary fasting: Requiring NPO status without evidence can lead to:

   • Patient discomfort and dehydration
   • Procedural delays
   • Extended hospital stays

2. Confusing with other procedures: Unlike endoscopy or surgery, pleural procedures do not carry the same aspiration risks that would necessitate NPO status 4, 5.

3. Outdated practices: The traditional "NPO after midnight" approach has been challenged even for procedures requiring sedation 4, 2, and is completely unnecessary for non-sedated pleural procedures.

In conclusion, patients undergoing pleural tapping do not need to be NPO. Focus should instead be on proper procedural technique, ultrasound guidance, and appropriate post-procedure monitoring.