Ranitidine--bolus or infusion prophylaxis for stress ulcer

Area of Science:

• Critical Care Medicine
• Gastroenterology
• Pharmacology

Background:

• Stress ulcers are a significant risk for critically ill patients.
• Maintaining gastric pH above 3.5 is crucial for stress ulcer prophylaxis.
• Histamine H2 receptor antagonists offer a convenient method for pH control.

Purpose of the Study:

• To evaluate the efficacy of ranitidine in controlling gastric pH in mechanically ventilated, critically ill patients.
• To compare the effectiveness of ranitidine administered via bolus versus continuous infusion.

Main Methods:

• Critically ill, ventilated patients received ranitidine as 50-mg boluses every 6 hours or continuous infusion at 125 or 250 micrograms/kg/hour.
• Gastric pH was monitored throughout the study period.
• The presence of occult blood in gastric aspirates was assessed.

Main Results:

• All ranitidine regimens reduced the percentage of gastric samples with pH less than 4.
• pH control was achieved more rapidly with the bolus administration of ranitidine.
• No significant difference in pH control was observed between the different ranitidine dosing groups.
• Occult blood in gastric juice did not correlate with gastric pH or respond to ranitidine therapy.

Conclusions:

• Ranitidine is effective in maintaining gastric pH above 3.5 for stress ulcer prophylaxis in critically ill patients.
• While both bolus and infusion regimens are effective, bolus administration offers faster pH control.
• Continuous infusion of ranitidine requires a loading dose for optimal efficacy.
• Ranitidine does not appear to affect the presence of occult blood in gastric secretions.