# Comparison of Lidocaine and Dexmedetomidine in Preventing Fentanyl-induced Cough in Patients Undergoing Elective Surgery: A Blinded Randomized Controlled Trial

## TL;DR

This study compares lidocaine and dexmedetomidine for preventing cough caused by fentanyl in surgery patients, finding both drugs equally effective but with different effects on blood pressure.

## Contribution

The study provides a direct comparison of lidocaine and dexmedetomidine for preventing fentanyl-induced cough, revealing their equal efficacy but differing hemodynamic impacts.

## Key findings

- DEX and LIDO were equally effective in preventing fentanyl-induced cough (7.0% and 10.5% incidence, respectively).
- Both DEX and LIDO were significantly more effective than the saline control group (33.3% incidence).
- DEX caused more pronounced suppression of heart rate and blood pressure compared to LIDO.

## Abstract

Fentanyl-induced cough (FIC) refers to a cough that can occur as a side effect of fentanyl, an opioid analgesic primarily used for pain management. Both lidocaine (LIDO) and dexmedetomidine (DEX) are effective in preventing FIC, but the comparative efficacy of each has not yet been thoroughly investigated.

In this study, we aimed to compare the effect of LIDO versus DEX in preventing FIC in adult patients undergoing elective surgery.

A total of 171 adult patients with American Society of Anesthesiologists (ASA) class I or II undergoing elective surgery were enrolled in this blinded, randomized, placebo-controlled trial. Patients received either 0.5 μg × kg-1 of DEX in 10 mL of isotonic saline, 1.5 mg × kg-1 LIDO, or a matching placebo (equal volume of 0.9% saline) prior to fentanyl injection. The incidence and severity of cough were recorded within the two minutes following fentanyl administration. Hemodynamic parameters were measured at different time intervals. Statistical analysis was performed using SPSS version 18. The incidence of cough among groups was compared using the Pearson chi-square test, while continuous hemodynamic variables were analyzed using one-way ANOVA followed by Tukey’s post-hoc test. A two-tailed P-value < 0.05 was considered statistically significant. The study was registered at the Iranian Registry of Clinical Trials (IRCT20211023052848N1).

The incidence of cough was 7.0%, 10.5%, and 33.3% in the DEX, LIDO, and saline groups, respectively (P < 0.001). There was no significant difference between the DEX and LIDO groups (P = 0.453), but both were significantly more effective than the control group (P < 0.001 for DEX vs. saline; P = 0.002 for LIDO vs. saline; P < 0.001 for DEX reduced heart rate, systolic and diastolic blood pressure).

The results of this study demonstrated that 0.5 μg × kg-1 of DEX and 1.5 mg × kg-1 of LIDO are equally effective in preventing FIC. However, hemodynamic parameters are more markedly suppressed in the DEX group compared to the lidocaine group.