Comparison Between Intravenous Nalbuphine and Lidocaine in Reducing Propofol-Induced Injection Pain During Gastroscopy: A Randomized Controlled Trial

INTRODUCTION: Intravenous propofol anesthesia is widely used in painless endoscopy. However, propofol injection pain is a common adverse effect. This study investigated the effects of nalbuphine and lidocaine in reducing propofol-induced injection pain. METHODS: In this double-blind, randomized study, 330 patients were randomly divided into three groups by using a random number table: the nalbuphine group (N), lidocaine group (L), and control group (C). The N, L, and C groups received either 0.1 mg/kg nalbuphine, 0.5 mg/kg lidocaine, or an equivalent volume of normal saline, respectively, as pretreatment drug. Then propofol was manually injected. The primary outcome of this study was the incidence of propofol-induced injection pain, and secondary outcomes included the severity of propofol-induced injection pain, vital signs, and adverse events, including hypotension, bradycardia (< 50 beats/min), hypoxemia (SpO(2) < 90%), drowsiness, physical movement, and cough. RESULTS: The percentages of patients with propofol injection pain were higher in group C than in group N and group L (64, 34, and 27%, respectively, p < 0.05). The percentage of patients with severe pain after propofol injection was significantly higher in group C than in group N and group L (12, 1, and 0%, respectively, p < 0.05). The doses of propofol in group C and group L were significantly higher than that in group N. More patients suffered hypoxemia in group N than in group C and group L. Then, less patients got physical movement and cough in group N. CONCLUSIONS: Pretreatment with nalbuphine 0.1 mg/kg was effective in reducing propofol-induced injection pain and propofol consumption. Propofol combined with nalbuphine can be safely and effectively used during gastroscopy. TRIAL REGISTRATION: Chinese Clinical Trial Registry; ChiCTR1900025438.