How to administer lactulose (lactulose) to a patient who is Nil Per Os (NPO)?

Administration of Lactulose in NPO Patients

For patients who are NPO (nil per os), lactulose should be administered as a retention enema consisting of 300 mL lactulose mixed with 700 mL water, given 3-4 times daily until clinical improvement is noted. 1, 2, 3

Rectal Administration Protocol

• Prepare the enema solution by mixing 300 mL of lactulose with 700 mL of water or physiological saline 1, 3
• Administer via a rectal balloon catheter or enema equipment 3
• The solution should be retained in the intestine for at least 30 minutes to ensure maximum effectiveness 1, 3
• May repeat every 4-6 hours as needed, particularly in severe hepatic encephalopathy (HE) cases 3
• Continue until clinical improvement is observed or oral administration becomes possible 1, 3

Clinical Considerations

• This approach is specifically indicated for patients with:

  • Severe HE (West-Haven criteria grade 3 or 4) 1
  • Inability to take medications orally 1
  • Risk of aspiration 2
  • Presence of ileus or abdominal distention 1

• The goal is to achieve the same therapeutic effect as oral administration:

  • Reducing intestinal pH through bacterial degradation to acetic and lactic acids 2
  • Converting ammonia to non-absorbable ammonium ions 2
  • Producing an osmotic laxative effect to eliminate ammonia 2

Monitoring and Adjustments

• Monitor for clinical improvement in mental status 1
• Assess electrolytes regularly to prevent dehydration and hypernatremia 1
• Once the patient improves and can take oral medications, transition to oral lactulose 3
• For oral dosing after improvement, start with 20-30g (30-45 mL) 3-4 times daily, titrated to achieve 2-3 soft stools per day 4, 2

Alternative Approaches

• In patients with ileus, oral lactulose should be held 1
• If a nasogastric tube is in place and there are no contraindications (such as recent variceal band ligation), lactulose can be administered through the nasogastric tube 1, 5
• Polyethylene glycol may be considered as an alternative in patients at risk for ileus or abdominal distention 1

Common Pitfalls and Cautions

• Avoid cleansing enemas containing soap suds or other alkaline agents before lactulose administration 3
• If the enema is evacuated too promptly, it may be repeated immediately 3
• Be vigilant for complications such as dehydration, hypernatremia, and perianal skin irritation 2
• Overuse of lactulose can paradoxically precipitate hepatic encephalopathy 4, 2

Following this protocol ensures effective delivery of lactulose therapy in NPO patients while minimizing potential complications until oral administration becomes possible.