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 III : 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).
@ES The results are as follows:
@EN 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).
Group III : The systolic and diastolic blood pressure, heart rate and rato-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 resuits, it can be concluded that clonidine inhibits cardiovascular stimuolating 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.
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