Effect of intravenous lidocaine on the ED50 of propofol for inserting gastroscope without body movement in adult patients: a randomized, controlled study.

BACKGROUND: Circulatory and respiratory depression are common problems that occur in propofol alone sedation during gastroscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during Endoscopic retrograde cholangiopancreatography (ERCP) or colonoscopy. However, it is still unknown the median effective dose (ED50) of propofol when combined with lidocaine intravenously. This study aimed to compare the ED50 of propofol with or without intravenous lidocaine for inserting gastrointestinal endoscope successfully. METHODS: Fifty nine patients undergoing gastroscopy or gastrointestinal (GI) endoscopy were randomly divided into control group (Group C, normal saline + propofol) or lidocaine group (Group L, lidocaine + propofol). Patients were initially injected a bolus of 1.5 mg/kg lidocaine in Group L, whereas equivalent volume of 0.9% saline in Group C. Anaesthesia was then induced with a single bolus of propofol in all subjects. The induction dose of propofol was determined by the modified Dixon's up-and-down method, and the initial dose was 1.5 mg/kg in both groups. The primary outcome was the ED50 of propofol induction dose with or without intravenous lidocaine. The secondary outcomes were the induction time, the first propofol bolus time (FPBT: from MOAA/S score ≤ 1 to first rescue bolus propofol), and adverse events (AEs: hypoxemia, bradycardia, hypotension, and body movements). RESULTS: Totally, 59 patients were enrolled and completed this study. The ED50 of propofol combined with lidocaine was 1.68 ± 0.11 mg/kg, significantly reduced compared with the normal saline group, 1.88 ± 0.13 mg/kg (P = 0.002). There was no statistical difference in induction time (P = 0.115) and the FPBT (P = 0.655) between the two groups. There was no significantly difference about the AEs between the two groups. CONCLUSION: The ED50 of propofol combined with intravenous lidocaine for successful endoscope insertion in adult patients, was 1.68 ± 0.11 mg/kg significantly reduced compared with the control group. TRIAL REGISTRATION: Chinese Clinical Trial Registry, No: ChiCTR2200059450. Registered on 29 April 2022. Prospective registration. http://www.chictr.org.cn .

Effects of intravenous lidocaine on hypoxemia induced by propofol-based sedation for gastrointestinal endoscopy procedures: study protocol for a prospective, randomized, controlled trial.

BACKGROUND: Oxygen-desaturation episodes, blood pressure drops, and involuntary body movement are common problems that occur in propofol-based sedation in the procedure of painless gastrointestinal (GI) endoscopy. As a widely used analgesic adjuvant, intravenous lidocaine can reduce the consumption of propofol during ERCP or colonoscopy. However, it is still unknown how lidocaine affects the incidence of oxygen-desaturation episodes and cardiovascular events, and involuntary movement during painless GI endoscopy. Therefore, we aimed to assess the effectiveness and safety of intravenous lidocaine in propofol-based sedation for GI endoscopy. METHODS: We will conduct a single-center, prospective, randomized, double-blind, saline-controlled trial. A total number of 300 patients undergoing painless GI procedures will be enrolled and randomly divided into the lidocaine group (Group L) and the control group (Group C). After midazolam and sufentanil intravenous injection, a bolus of 1.5 mg/kg lidocaine was immediately injected and followed by a continuous infusion of 4 mg/kg/h in the lidocaine group, whereas the same volumes of saline solution in the control group. Then, propofol was titrated to produce unconsciousness during the procedure. The primary outcome will be the incidence of oxygen-desaturation episodes. Secondary outcomes will be the incidence of involuntary body movement, discomfort symptoms, propofol consumption, endoscopist, and patient satisfaction. DISCUSSION: Propofol-based deep sedation without intubation is widely used in painless GI endoscopy. However, adverse events such as hypoxemia often occur clinically. We expect to assess the effect of lidocaine on reducing the incidence of oxygen-desaturation episodes, cardiovascular events, and involuntary body movement. We believe that the results of this trial will provide an effective and safe method for painless GI endoscopy. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR2100053818. Registered on 30 November 2021.