The effect of intravenous lidocaine on propofol dosage in painless bronchoscopy of patients with COPD

BACKGROUND: We tested the hypothesis that intravenous (IV) lidocaine reduces propofol requirements in painless bronchoscopy in patients with chronic obstructive pulmonary disease (COPD). METHODS: A total of 93 patients who underwent bronchoscopy were included in this randomized placebo-controlled study. The patients were randomly divided into two groups. After the IV doses of nalbuphine, patients were given a bolus of propofol, which was titrated if necessary until loss of consciousness. Then patients were given IV lidocaine (2 mg/kg then 4 mg/kg/h) or the same volume of saline. The primary endpoint was the propofol requirements. Secondary endpoints were the incidence of hypoxemia, the incidence of cough during glottis examination, the systolic blood pressure (SBP) and heart rate (HR) during bronchoscopy procedures, the bronchoscopist's comforts, and the time for wakefulness before recovery. RESULTS: Lidocaine infusion resulted in a significant reduction in propofol requirements (p < .0001), and the incidence of hypoxemia (p = .001) and cough (p = .003) during examination decreased significantly in the lidocaine group. During the examination, the fluctuation of SBP and HR was significantly lower than that in the control group, and the difference was statistically significant (p < .05). Bronchoscopist's comforts were higher in the lidocaine group (p < .001), and time for wakefulness (p < .001) were significantly lower in the lidocaine group. CONCLUSION: In painless bronchoscopy in patients with COPD, IV infusion of lidocaine resulted in a reduction in propofol dose requirements and reduce the incidence of adverse events.