Intravenous Low Dose Ketamine versus Lidocaine versus Placebo in Suppressing Fentanyl Induced Cough: A Comparative Study

Intravenous Low Dose Ketamine versus Lidocaine versus Placebo in Suppressing Fentanyl Induced Cough: A Comparative Study
Rozh M. Abdulrahman^1*, Amir M. K. Boujan², Rekout F. Mohammed³, Wehid I. Seniar⁴
Abstract
Background:
Fentanyl is a preferred narcotic in anesthesia, especially with respect to a pre-induction adjunct agent. It elicit a brief cough in up to 50% of patients when the drug is injected by intravenous bolus which in turn could increase intracranial pressure and intraocular pressure and also could increase heart rate and blood pressure in susceptible patient.
Aim:
We designed this study to compare effectiveness of low dose ketamine and lidocaine in the prevention of fentanyl-induced cough.
Material and Methods:
This prospective double blinded, randomized placebo, control study, was conducted in Erbil public and private general Hospitals. We selected 150 patients, age 18-60 years, who underwent elective operation under general anesthesia; 50 cases of them received ketamine, 50 cases received lidocaine 50 cases received normal saline. Any episodes of cough were classified as coughing and was observed for one minute after fentanyl administration by a blinded observer. Blood pressure, heart rate, and pulse oximetry oxygen saturation (Spo2) were recorded before giving ketamine or lidocaine or 0.9% saline and 1 minute after fentanyl injections.
Results: in this study, 25.3% of the whole sample developed cough after fentanyl injection. However, 42% in the control group developed cough, compared with 26% of patients in the Lidocaine group, and 8% in the Ketamine group (p < 0.001).
Conclusion: Low dose ketamine can effectively suppress fentanyl induced cough and it is a better drug compared to lidocaine

_{Keywords: Fentanyl induced cough, Ketamine, Lidocaine, cough suppression}