Abdominal pain after ERCP is common, and although it is frequently nonspecific and self-limited, it may provoke concern for complications and thus distress both patients and physicians. Carbon dioxide (CO₂) insufflation during ERCP may reduce abdominal distension in comparison to insufflation of air, resulting in less pain.

To compare the incidence and severity of post-ERCP pain in patients receiving CO₂ versus air insufflation during ERCP.

Randomized, double-blind, controlled trial.

University medical center.

This study involved consecutive patients presenting for ERCP, excluding those with significant preprocedure pain or obstructive lung disease.

Randomization to insufflation with air or CO₂; all other care was identical.

Pre-ERCP and post-ERCP pain and nausea were assessed by using a 0 to 10 visual analogue scale. Patient waist circumferences were measured before and after procedures.

One hundred patients (82 outpatients, 51 women, mean age 54.4 years, 50 randomized to CO₂) completed the study. The CO₂ and air groups were similar in regard to demographics, indication for ERCP, and procedure duration. The mean pain score 1 hour post-ERCP was higher with air than with CO₂ insufflation (1.9 vs 0.7, P = .01). Similarly, the incidence of any pain at 1 hour post-ERCP was higher with air than with CO₂ (48% vs 28%, P = .04). The mean increase in waist circumference was greater with air than with CO₂ (2.1 cm vs 0.3 cm, P = .003). Adverse events were infrequent and did not differ by group. No serious cardiopulmonary complications occurred.

Single-center, selected patient population.

Insufflation of CO₂ during ERCP reduces postprocedure pain and abdominal distension in comparison to insufflation of air. The use of CO₂ in deeply sedated, prone patients appears to be safe.