Observation of the effects of lidocaine in painless colonoscopy

Objective To explore the effects of lidocaine on the dosage of propofol and recovery quality during painless colonoscopy. Methods A total of 100 patients undergoing painless colonoscopy in the Affiliated Hospital of Xuzhou Medical University from July 2018 to October 2019 were enrolled. According to the use of lidocaine, the patients were divided into two groups: an observation group (group L) and a blank group (group C). The induction drugs used in group C were remifentanil 20 μg and propofol 1.0-2.5 mg/kg. During the examination, an initial concentration of propofol was adjusted to 5 mg·kg^-1·h^-1. When body movement appeared, 20-50 mg propofol was intravenously given until body movement disappeared, and the concentration of propofol increased by 1 mg·kg^-1·h^-1. Before induction, patients in group L were intravenously infused with 2% lidocaine (1.5 mg/kg) over 1 min, followed by 2 mg·kg^-1·h^-1 lidocaine via a pump until the end of examination. Other anesthesia induction and maintenance procedures were the same as those in group C. Then, the two groups were compared for general information, the induction and total dose of propofol and the number of body movements; the time of recovery, the Visual Analogue Scale (VAS) score immediately after recovery, 5 min after recovery, and 10 min after recovery, and the Observer's Assessment of Alertness/Sedation Scale (OAA/S) scores 5 min and 10 min after withdrawal, and the time of discharge; and adverse reaction rates. Results Compared with group C, patients in group L required decreased doses of propofol for examination, presented relieved abdominal pain, with faster and improved recovery, shortened discharge time, and a reduced incidence of injection pain (P<0.05 or P<0.01). There was no significant difference in the rates of respiratory depression, hypotension, and intraoperative awareness between the two groups (P>0.05). Conclusions Intravenous infusion of 1.5 mg/kg 2% lidocaine followed by pumping of 2 mg·kg^-1·h^-1 lidocaine during the examination, can reduce the dosage of propofol, relieve the pain of patients, and improve the recovery quality.