Intravenous lidocaine suppresses fentanyl-induced cough in Children

Fentanyl-induced cough is usually mild and transitory, but it can be undesirable in patients with increased intracranial pressure, open wounds of the eye, dissecting aortic aneurism, pneumothorax, and reactive airway disease. The aim of this study is to evaluate the efficacy of lidocaine in suppressing fentanyl-induced cough in children during induction in general anesthesia.

One hundred and eighty-six children of both sexes, aged between 4-10 years, ASA physical status I and II, and scheduled for elective surgery, were recruited for the study. Patients with a history of bronchial asthma, obstructive pulmonary disease, or infections of the respiratory tract were excluded. Patients were randomly allocated to three equal groups (n = 62) to receive 1.0 mg/kg lidocaine (Group I), 0.5 mg/kg lidocaine (Group II), or placebo (equal volume of 0.9% saline; Group III). Each was administered over 5 s one minute before intravenous (IV) administration of fentanyl 2-3 μg/kg during induction in general anesthesia. The severity of coughing was graded by counting the number of episodes of cough: mild (1-2), moderate (3-4) or severe (5 or more).

Demographic information was comparable between groups. The most frequent coughing was observed in the placebo group (Group III; 43.5%), of whom 4.8% (three patients) were graded with severe cough. In Group II, 22.6% patients had cough, of which 1.6% (one patient) was graded as severe. In Group I, 16.1% patients had cough, none of whom were graded as severe.

Our results demonstrate that IV lidocaine can markedly suppress fentanyl-induced cough in children, even in doses as low as 0.5 mg/kg.