Lidocaine toxicity after subcutaneous infiltration in children undergoing cardiac catheterization

A comparison between EMLA cream application versus lidocaine infiltration for postoperative analgesia after inguinal herniotomy in children

BACKGROUND

EMLA cream (eutectic mixture of local anesthetics) has been shown to penetrate intact skin and provide analgesia of superficial layers. There are no studies on the effects of topical application of EMLA cream for postoperative pain relief after inguinal hernia repair.

OBJECTIVE

: This randomized, double-blind, placebo-controlled study compared the efficacy of topical application of 5% EMLA cream before surgery, with wound infiltration with 1% lidocaine for postoperative analgesia in children.

METHODS

Ninety children, aged 4 to 12 years, undergoing elective inguinal hernia repair under general anesthesia were enrolled in the study. Patients were randomly assigned to receive either placebo cream (group1), 5% EMLA cream (group 2), or placebo cream followed by 0.5 mL/kg 1% lidocaine (group 3) in the wound after induction of anesthesia. The anesthetic technique and monitoring were standardized, and postoperative pain was assessed using a 10-point objective pain scale. Fentanyl was used as rescue analgesic in immediate postoperative period, and acetaminophen was administered for postoperative pain in surgical ward.

RESULTS

The number of patients requiring fentanyl in the immediate postoperative period was significantly less in the study groups compared with the placebo group. Sixty-seven percent of patients in the placebo group required more than 1 dose of acetaminophen in the first 6 hrs compared with 23% (EMLA group) and 20% (lidocaine group). Four patients (two in the lidocaine group, one in the EMLA group, and one in the control group) developed subcutaneous infection at the site of incision 10 to 15 days postoperatively.

CONCLUSION

Topical application of EMLA (5%) provides postoperative analgesia comparable to infiltration with 1% lidocaine after inguinal hernia repair in children.

Serum lidocaine concentrations after subcutaneous administration in patients undergoing cardiac catheterization in a pediatric institution

OBJECTIVE

We wished to determine serum lidocaine concentrations after subcutaneous injection during cardiac catheterization.

METHOD

Serum lidocaine concentrations were measured in 50 patients during catheterization.

RESULTS

Serum concentration was linearly related to dose per kilogram of body weight. Lidocaine concentrations were therapeutic in 38% of patients.

CONCLUSION

Lidocaine dose must be considered when the drug is used for local anesthesia in children.

Seizures due to lidocaine toxicity in a child during cardiac catheterization

A 17-month-old boy developed grand mal seizures secondary to lidocaine toxicity during balloon dilatation of a congenital pulmonary valve stenosis. Lidocaine at 38 mg/kg (nine times the recommended maximum dose of 4.5 mg/kg) was administered during a 90-min period in order to optimize local anesthesia. This resulted in toxic serum lidocaine levels (8.7 mg/L; therapeutic range, 1.5-5 mg/L) at the time of seizures. Caution should be exercised with local anesthetics during invasive cardiac catheterizations. Hypercarbia (which lowers the seizure threshold to local anesthetics) should be avoided and the temptation to exceed the maximum recommended dose resisted.