Methemoglobinemia presenting in a circumcised baby following application of prilocaine: a case report.

INTRODUCTION: Local anesthesia with prilocaine has become a routine part of ambulatory circumcision procedures. Methemoglobinemia is a rare but potentially lethal complication of local anesthetics. CASE PRESENTATION: We report the case of a 40-day-old Turkish boy who presented with cyanosis after receiving local anesthesia with prilocaine. His methemoglobin level revealed severe methemoglobinemia (methemoglobin = 44%). His cyanosis resolved after intravenous administration of methylene blue. CONCLUSION: Although the association between prilocaine use and methemoglobinemia has generally restricted the use of prilocaine in babies, it is still widely used in ambulatory procedures, especially during circumcision in the neonatal period. Prilocaine should not be used in babies who are less than 3 months old because of the risk of methemoglobinemia; other local anesthetics may be used for this age group. Furthermore, general anesthesia by mask ventilation may be favored for babies less than 3 months of age instead of local anesthetics.

The influence of timing of systemic ketamine administration on postoperative morphine consumption.

STUDY OBJECTIVE: To determine the influence of timing of systemic ketamine administration on postoperative morphine consumption. DESIGN: Prospective randomized study. SETTING: Operating rooms, postanesthesia care unit, and gynecology service of a university hospital. PATIENTS: Forty-five patients undergoing laparotomy for benign gynecologic pathologies were randomized into 3 groups. INTERVENTIONS: In Group 1, before surgical incision, patients received 0.5 mg/kg ketamine IV, followed by normal saline infusion and normal saline IV at wound closure in group 1 (n = 15). In group 2 (n = 15), patients received 0.5 mg/kg ketamine IV before surgery, followed by ketamine infusion 600 mug . kg(-1) . h(-1), until wound closure and normal saline IV at that time. In the other group (group 3, n = 15), patients received normal saline IV before surgery, followed by saline infusion and then 0.5 mg/kg ketamine IV at wound closure. In the postoperative period, patient-controlled analgesia IV morphine was used for postoperative pain relief. First requested analgesic medication time was recorded. Postoperative pain was assessed by measuring morphine consumption at 0 to 2, 0 to 4, and 0 to 24 hours and visual analog scale (VAS) pain scores in response to cough at 2nd, 4th, and 24th hours and during rest at 0 to 2, 0 to 4, and 0 to 24 hours after surgery. MEASUREMENT AND MAIN RESULTS: First requested analgesia was shorter in group 1 than the others (P < .01). Mean VAS pain scores in response to cough at 24th hour in groups 2 and 3 were significantly lower than in group 1 (P < .001 and P < .01, respectively). Mean VAS pain scores during rest at 0 to 24 hours in groups 2 and 3 were significantly lower than in group 1 (P < .01 and P < .05, respectively). Morphine consumption was lower in groups 2 and 3 at 0 to 2 hours (P < .001 and P < .01). Moreover, morphine consumption at 0 to 4 hours in group 2 was significantly lower (P < .01). CONCLUSIONS: Lower pain scores and morphine consumption in groups 2 and 3 may be related to higher plasma ketamine concentrations caused by the higher doses and later administration. Our findings suggest that a single preoperative dose of ketamine provided less analgesia compared with other dosing regimens that included intraoperative infusions or postoperative administration.