M. Dekock et al., EPIDEMIOLOGY OF THE ADVERSE HEMODYNAMIC EVENTS OCCURRING DURING CLONIDINE ANESTHESIA - A PROSPECTIVE OPEN TRIAL OF INTRAOPERATIVE, Journal of clinical anesthesia, 7(5), 1995, pp. 403-410
Study Objective: Determine the hemodynamic consequences of intraoperat
ive clonidine during major abdominal surgery. Design: Prospective open
trial. Setting: Teaching hospital. Patients: 402 consecutive patients
scheduled for major abdominal surgery. Interventions: 350 consecutive
patients received intravenous (IV) clonidine (loading dose of 4 mu g/
kg in 20 minutes at anesthesia induction, followed by a continuous inf
usion of 2 mu g/kg/h until the end of surgery). Fifty-two additional p
atients served as controls. Anesthetic technique consisted of balanced
anesthesia (isoflurane, fentanyl, atracurium). ECG, invasive arterial
blood pressure (BP), expiratory PCO2 and pulse oximetry were continuo
usly recorded. Hemodynamic events (HEs) were defined as moderate for a
20% reduction of the baseline systolic blood pressure (SBP) or a hear
t rate (HR) decreasing between 50 beats per minute (bpm) and 40 bpm. A
30% reduction of the baseline SBP or a HR below 40 bpm was considered
an important HE. The rate and duration of these events were recorded
from induction to recovery. HEs requiring a specific treatment were no
ted. Central venous pressure, volume of fluid infused, and urinary out
put were also recorded. Measurements and Main Results: 21% of control
patients and 31% of clonidine patients had no adverse HEs. A moderate
reduction of the baseline BP was the most common episode in both group
s. The incidence of the HEs (moderate and important) was similar in bo
th groups but the duration HEs was significantly longer in the clonidi
ne patients (p < 0.05). 40% of the control patients and 13% of the clo
nidine patients required specific management for their HEs (p < 0.05),
the most common of which was hypotension without bradycardia. Neither
coexisting pathology nor preoperative medications influenced the inci
dence of HEs. Conclusion: IV clonidine can be used routinely during an
esthesia for major abdominal surgery.