The Effects of Lidocaine and Clonidine Premedication on Cardiovascular Response during Induction of Anesthesia with Ketamine

Lee, Hyun Wha; Kim, Keon Sik; Kang, Hwa Ja; Choi, Young Kyoo; Kwon, Moo Il; Shin, Kwang Il

Abstract

Ketamine may increase blood pressure and heart rate and should be avoided in hypertensive patients. However, in hypovolemic and asthmatic patients, ketamine is used as an induction agent because of its cardiovascular stimulating effect and bronchodilating effect. This study aims to assess the effects of clonidine and lidocaine on the cardiovascular response of intravenous ketamine administration during induction of anesthesia. sixty patients were divided into 3 groups as followed: group I: control ( received no lidocaine or no clonidine) group II: received lidocaine (1.5 mg/kg IV) 3 minutes before intubation group IIl: received clonidine (0.3 mg PO) 90 minutes before induction of anesthesia The changes of blood pressure, heart rate and rate pressure product following intubation were measured at different time interval (before induction,before intubation just after intubation, postintubation 1, 3, 5, 10 min) and compared with the value of control (2 hours before induction of anesthesia). The results are as follows 1) Group I and Group II: The systolic and diastolic blood pressure increased significantly compared to the control value from preinduction to 5 minutes after intubation(p<0.05). It recovered to the control value in 10 minutes, but heart rate and rate-pressure product increased significantly for 10 minutes after intubation(p<0.05) 2) Group III: The systolic and diastolic blood pressure, heart rate and rate-pressure product of preinduction and preintubation values decreased significantly compared to control values but 1 minute after intubation,all values increased significantly(p<0.05). The systolic and diastolic blood pressure and rate-pressure product values recovered to control value in 3 minutes after intubation and heart rate recovered in 5 minutes. Comparing group III with group I and II, it showed significant changes(p<0.05). From the above results, it can be concluded that clonidine inhibits cardiovascular stimulating response by ketamine during induction of anesthesia. the above results, it can be concluded that clonidine inhibits cardiovascular stimulating response by ketamine during induction of anesthesia.