Effectiveness of fixed 50% nitrous oxide oxygen mixture and EMLA cream for insertion of central venous catheters in children.

Background: Although the equimolecular mixture of oxygen and nitrous oxide (EMONO) seems a good choice to relieve procedure-related pain in children, it has not been evaluated for insertion of central venous catheters in children. To assess the safety and the effectiveness of this gas mixture for insertion of central venous catheters, we conducted a prospective observational study.

Procedure: This study was performed by the "Centre National de Greffe de Moelle Osseuse." Procedure and inhalation characteristics, as well as pain evaluations and side effects, were reported.

Results: Fifty central venous catheters were inserted in 50 consecutive children. Median age was 7 (range, 4-13) years. An anesthesiologist was responsible for delivering EMONO, and provided constant surveillance throughout the procedure. EMLA cream was applied 2 hr before EMONO inhalation. No associated drugs were used. All catheters were inserted by the same experienced physician in the operating theater. Median inhalation length was 5 min (range, 3-6) before starting catheter's insertion and 12 min (range, 9-25) for the total inhalation. Median procedural pain evaluations were 10 (range, 0-30) for children on a 0-100 visual analog scale (VAS). Minor side effects were observed during eight (16%) inhalations. These side effects were euphoria (14%), deep sedation (4%), nausea and vomiting (2%), hallucinations (2%). All side effects were transient and resolved within 5 min after removing the inhalation device.

Conclusions: This study which shows that EMONO is effective for insertion of central venous catheters in children and represents a simple and safe alternative to general anesthesia.