Topical anesthesia for line insertion in very low birth weight infants.

OBJECTIVE This pilot study was designed to assess the impact of topical lidocaine and prilocaine cream on the pain response of very low birth weight infants undergoing percutaneous central venous line insertion. STUDY DESIGN Infants were randomly assigned to receive 1 to 1.25 gm of the topical anesthetic or to receive zinc oxide placebo 1 hour before line insertion. Investigators blinded to treatment group assignment obtained serial measurements of heart rate, respiratory rate, systolic blood pressure, and oxygen saturation by pulse oximetry. Toxicity from lidocaine was assessed by clinical parameters, and toxic effects from prilocaine were assessed by methemoglobin levels (normal range 0% to 4%). RESULTS Hearts rates increased significantly during line insertion in controls (n = 6) but not in treated patients (n = 7). Respiratory rates and blood pressure values increased significantly during line insertion in both groups. Oxygen saturation did not change significantly in either group. The percent of increase in heart and respiratory rates from baseline was attenuated in the treated patients compared with controls. Methemoglobin levels were 0.3% to 2.0% for the treated group and 0.3% to 0.7% for controls. CONCLUSION The topical lidocaine and prilocaine cream application attenuated the lability of vital signs during line insertion in very low birth weight infants, with no evidence of toxicity.