EMLA versus nitrous oxide for venous cannulation in children.

We compared EMLA cream with nitrous oxide (N(2)O) for providing pain relief during venous cannulation in children. In a prospective, double-blinded, randomized study, 40 children, 6-11 yr, ASA status I or II, undergoing scheduled surgery received either EMLA cream and inhaled air and oxygen (Group EMLA) or a placebo cream and inhaled 70% N(2)O in oxygen (Group N(2)O) before venous cannulation. Pain was evaluated with a visual analog scale and the Objective Pain Scale. The ease of venous cannulation and the observer's assessment of its efficacy for preventing pain were assessed. Heart rate, blood pressure, respiratory rate, and oxygen saturation were compared before and after venous cannulation. Visual analog scale scores (4.4 +/- 7.5 vs 3.9 +/- 9.3 mm, P = 0.85), Objective Pain Scale scores (median 0 [0-6] vs 0 [0-1], P = 0.61), efficacy (median 0 [0-1] vs 0 [0-1], P = 0.59), and ease of venous cannulation (0 [0-2] vs 0 [0-1], P = 0.84) were not different between EMLA and N(2)O groups, respectively. There was no statistical difference between the groups for the physiologic variables. Minor side effects were significantly more common in the N(2)O group (11 of 20) than in the EMLA group (7 of 20) (P = 0.0248). We conclude that both techniques provided adequate pain relief during venous cannulation, as demonstrated by the low pain scores.