Do I need to be nil per os (NPO) for an outpatient procedure (OPMS)?

NPO Requirements for Outpatient Procedures (OPMS)

For most outpatient procedures, you do NOT need to be strictly NPO, but the requirements depend on the type of anesthesia and procedure being performed.

Clear Fluid Guidelines

• Clear fluids are permitted up to 2 hours before elective outpatient surgery under modern guidelines 1, 2
• This 2-hour window for clear fluids has become the standard recommendation across major anesthesiology societies and represents a significant liberalization from traditional "NPO after midnight" policies 2, 3
• Clear fluids include water, clear juices without pulp, black coffee or tea without milk, and carbonated beverages 2

Procedure and Anesthesia-Specific Requirements

Local or Regional Anesthesia Only

• Minimal to no NPO restrictions are required for superficial procedures performed under local or regional anesthesia alone 1
• These patients can often proceed with normal oral intake, as airway protection remains intact 1

General Anesthesia or Deep Sedation

• Standard NPO guidelines apply: clear fluids up to 2 hours, light meals up to 6 hours, and heavy/fatty meals up to 8 hours before the procedure 1, 2
• The procedure should not carry significant risk of serious postoperative complications requiring immediate medical attention 1

Procedural Sedation in Emergency Settings

• NPO status is controversial and not strictly required for emergency procedures with procedural sedation 1
• Current data are insufficient to determine a specific safe NPO duration for emergency sedation 1
• The physician should consider the urgency of the procedure, targeted depth of sedation, risk level of the patient, and timing of most recent solid food intake 1
• Many children receiving procedural sedation in emergency departments have not fasted according to elective guidelines without associated adverse outcomes 1

Essential Medications

You should continue taking essential oral medications with a small sip of water on the morning of your procedure, even if technically NPO 4

• This includes most chronic medications for heart disease, blood pressure, seizures, and pain management 4
• The small amount of water needed for medications is considered safe within the 2-hour clear fluid window 4

Medications to Hold

• Oral hypoglycemic agents and metformin should be withheld the morning of surgery 4
• Specific instructions should be provided by your surgical team for diabetes medications 4

Special Populations

Obstructive Sleep Apnea (OSA)

• Patients with OSA can undergo outpatient procedures when local or regional anesthesia is used 1
• For general anesthesia, superficial procedures are considered equivocal (case-by-case basis), while upper abdominal laparoscopy and airway surgery are not recommended for outpatient settings 1
• OSA patients should be monitored for a median of 3 hours longer than non-OSA patients before discharge 1

Obesity

• Obesity alone is not a contraindication to day surgery or a reason for stricter NPO requirements 1
• Standard NPO guidelines apply, with attention to appropriate resources and equipment 1

Common Pitfalls to Avoid

• Prolonged unnecessary fasting beyond guideline recommendations can cause dehydration, hypoglycemia, patient discomfort, and hemodynamic instability 2, 3
• Fasting periods often exceed intended duration in practice, with some patients fasting 16 hours or more when only 2-6 hours is required 3
• Traditional discharge criteria like "tolerating fluids" are no longer mandatory and may delay discharge unnecessarily 1
• Mandatory oral intake before discharge is not required and may provoke nausea and vomiting 1

Discharge Considerations

• You should be able to resume oral intake within a few hours after surgery 1
• You must have a responsible adult escort you home after general or regional anesthesia 1
• Avoid alcohol, operating machinery, or driving for 24 hours after general anesthesia 1
• Written discharge instructions should include warning signs of complications and contact information 1