|Year : 2012 | Volume
| Issue : 3 | Page : 180-183
A study on clonidine as a premedicant and its effects on perioperative hemodynamic in normotensive patients
N Ratan Singh, Gojendra Rajkumar, S Sarat Singh, Pradip Jamatia, T Hemjit Singh, Th Rupendra Singh
Department of Anaesthesiology, Regional Institute of Medical Sciences, Imphal, India
|Date of Web Publication||10-Jun-2013|
Department of Anaesthesiology, Regional Institute of Medical Sciences, Imphal
Source of Support: None, Conflict of Interest: None
DOI: 10.4103/0972-4958 .113244
Background: Hemodynamic instability is one of the most imminent conditions during general anesthesia (GA), especially, during laryngoscopy and intubation. The aim of the study was to study the perioperative hemodynamic effect of clonidine in normotensive patients undergoing elective surgery under GA. Materials and Methods: A randomized double blinded placebo controlled study was conducted in the department of Anesthesiology, Regional Institute of Medical Sciences, Imphal on 150 normotensive adult patients of either sex aged 18-60 years (American Society of Anesthesiologist I and II) undergoing elective surgery under GA. The patients were allocated into three groups viz.: Group 1-2 μg/kg clonidine; group II-3 μg/kg clonidine; and group III - placebo/normal saline. The test drug was administered 30 min before the induction of anesthesia. Upon arrival at theatre, the following data were recorded viz.: (1) Visual analogue score of anxiety, (2) loss of consciousness, and (3) dryness of mouth. Pre-induction heart rate (HR) and blood pressure (BP) were recorded 5 min after resting on the operating table. HR and BP were recorded during the time of intubation every 8 min and ½ h after intubation during the intraoperative period (post-intubation). Postoperative BP and HR on arrival at the post-anesthetic care unit and then every ½ h for 3 h were recorded. Any episodes of nausea and vomiting, shivering and analgesic requirements were noted. Results: Clonidine 2 μg/kg and 3 μg/kg both significantly controlled the perioperative hemodynamics. The hemodynamic changes were statistically significant at all times intervals except at preoperative, at 8 min post-intubation to 1 h post-intubation period. Conclusion: Clonidine is useful as a premedicant in controlling the perioperative hemodynamics changes in normotensive patients undergoing operative procedures under GA.
Keywords: Clonidine, General anesthesia, Hemodynamics, Premedicant
|How to cite this article:|
Singh N R, Rajkumar G, Singh S S, Jamatia P, Singh T H, Singh T. A study on clonidine as a premedicant and its effects on perioperative hemodynamic in normotensive patients. J Med Soc 2012;26:180-3
|How to cite this URL:|
Singh N R, Rajkumar G, Singh S S, Jamatia P, Singh T H, Singh T. A study on clonidine as a premedicant and its effects on perioperative hemodynamic in normotensive patients. J Med Soc [serial online] 2012 [cited 2020 Oct 31];26:180-3. Available from: https://www.jmedsoc.org/text.asp?2012/26/3/180/113244
| Introduction|| |
Laryngoscopy and tracheal intubation are mandatory for most patients undergoing operation under general anesthesia (GA), which is associated with certain cardiovascular changes such as tachycardia or bradycardia, rise in blood pressure (BP) and a wide variety of cardiac arrythmias. These effects are deleterious in susceptible individuals culminating in perioperative myocardial ischemia, acute heart failure, and cerebrovascular accidents. Clonidine, an imidazoline, when used as adjuvants in GA because of α2 adrenergic agonist action, reduces minimum alveolar anesthetic concentration and the standard clinical measure of anesthetic depth. It also has nonopiate antinociceptive properties, which might be an alternative for postoperative analgesia free of opiate induced site effects. Even though the clonidine has perioperative beneficial effects as an analgesic,  hypnotic, it has dose and route dependent effects on the preoperative hemodynamics.  Therefore, this study is designed with an attempt to study the preoperative hemodynamics effect of IV clonidine in normotensive patients.
| Materials and Methods|| |
After obtaining approval of the institutional Ethics Committee and written informed consent of the patients, a randomized double-blind placebo controlled study was conducted in the Department of Anesthesiology, Regional Institute of Medical Sciences on 150 normotensive patients aged between 18 and 60 years, with American Society of Anesthesiologist physical status I and II, undergoing elective surgery under GA. They were randomly allocated into three groups:
Group I: 2 μg/kg clonidine;
Group II: 3 μg/kg clonidine;
Group III: Placebo/normal saline.
Premedication drug was prepared by anesthesiologist not involved in research. The test drug was given 30 min before induction.  All the assessments in the operation theatre (OT) as well as during anesthesia were conducted by a blinded anesthesiologist. Upon arrival in OT, the following data were recorded:
Visual analogue score (VAS) for anxiety:
0 = completely calm.
100 = the worst possible anxiety.
Heart rate (HR) and BP (pre-induction) were recorded 5 min after resting on OT table. Pre-oxygenation was given with 100% O 2 for 3-4 min; then, anesthesia was induced with thiopentone 5 mg/kg given in a minute, 1 min after which HR and BP were recorded (post-induction) and laryngoscopy and intubation were facilitated by succinylcholine at a dose of 1.5 mg/kg along with i.v. Tramadol 2 mg/kg. After ventilation with O 2 for 3-4 min, tracheal intubation was performed with a cuffed polyvinyl chloride (PVC) endotracheal tube. HR and BP were recorded during the time of intubation, and 8 min after intubation (post-intubation).
Following intubation, anesthesia was maintained with O 2 , N 2 O, isoflurane, vecuronium. HR, BP were recorded every ½ h after intubation (intraoperative). Any episodes of hypertension (>30% of pre-induction level), hypotension (<90 mm Hg systolic), tachycardia (>30% of pre-induction HR), bradycardia (<50 bpm) were also noted. Postoperative recording was done for BP, HR on arrival at the post-anesthetic care unit and every ½ h for 3 h. Episodes of nausea/vomiting, shivering and analgesic requirement were also noted. The findings were recorded and statistically analyzed using analysis of variance test and unpaired 't' test by using Statistical Package for the Social Sciences (SPSS-version 15 (SPSS Inc; 233 South Wacker Drive, 11 th Floor; Chicago, IL 60606-6412.), and the interpretation was made accordingly.
| Results|| |
[Table 1] shows the distribution of demographic profiles of patients in the three groups. The age, weight, and sex were comparable and statistically insignificant. The female preponderance in the present study was due to the fact that the majority of selected participants were posted for cholecystectomy which is common amongst the female population.
[Table 2] and [Figure 1] show the distribution and comparison of HR in the three groups at different time intervals. In all the three groups the HR increased from its baseline/preoperative value to a maximum at the intubation time and receded to approach its baseline value. In the two clonidine groups, the HR achieved a minimum fall at 1 h post-intubation intraoperative; whereas the lowest was recorded at 3 h postoperatively. However, in the control group the rate of fall is comparatively slower in the perioperative period and was recorded higher than in the postoperative period. These trends of changes in the HR in the three groups were statistically significant at all time-intervals except at 8 min post-intubation intraoperative.
The systolic blood pressure (SBP), as shown in [Table 2] and [Figure 2] began to rise from its baseline value to a maximum at intubation time and decreased slowly thereafter in all the three groups. These changes in SBP were significant in all the time intervals except at 8 min post-intubation to 1 h postoperatively in all the three groups.
|Figure 2: Systolic blood pressure, diastolic blood pressure, and mean arterial pressure at different time intervals|
Click here to view
Like the SBP, in all the three groups, the diastolic blood pressure (DBP) rose to a maximum value at intubation time and thereafter receded towards the baseline value, as shown in [Table 2] and [Figure 2]. These changes in DBPs were statistically significant and comparable at all time-intervals except at 8 min post-intubation, thereafter till 1 h post-intubation where the variations were not significant.
As with SBP and DBP, the mean arterial pressure (MAP), as shown in [Table 2] and [Figure 2], rose to maximum value at intubation time and receded slowly to approach the baseline value. These changes were statistically significant at all time-intervals, except at 8 min post-intubation to 1 h post-intubation where the differences were not significant.
VAS score for anxiety at the preoperative period were comparable in the three groups, and at the pre-induction time, it was least in the two clonidine groups as compared with the control group where the distribution was highly significant, as shown in [Table 3].
| Discussion|| |
Clonidine, an alpha agonist with antihypertensive, anti-anxiety, antisecretory and analgesic properties seem to be a good choice for counteracting these unwanted perioperative conditions.
In a study by Kulka et al.,  IV clonidine 2, 4, and 6 μg/kg body weights and placebo as control were used. They observed that after induction of anesthesia, HR decreased slightly in all groups. During laryngoscopy and intubation HR increased significantly compared with baseline values in placebo treated patients from 73 ± 8 to 80 ± 11 beat min. In group with clonidine 4 and 6 μg/kg tachycardia was attenuated in all patients. During intubation, mean HR in group clonidine 4 μg/kg (67 ± 12 bpm) and clonidine 6 μg/kg (67 ± 12 bpm) was significantly lower compared with placebo (80 ± 11 bpm). These findings are similar to our study, where the HR in the clonidine groups was significantly lower than the control group during intubation.
Doda et al.,  observed in their study with tab clonidine 0.2 mg for patient < 60 kg or 0.3 mg for patient > 60 kg, and tab diazepam 0.2 mg/kg, that there was no significant difference in BP 1 h after premedication between their two study groups. However, there was significant fall in BP soon after thiopentone administration (clonidine group, 112.6 ± 15.2; diazepam group, 114.7 ± 10.3; P < 0.01), this was followed by significant rise in SBP at intubation (clonidine group, 143.1 ± 20.2; diazepam group, 139 ± 17.6; P < 0.01). These findings are similar to our findings, except, that in our study there was a significant decrease in SBP at pre-induction period (group I, 117.24 ± 11.47; groupII, 116.46 ± 9.25; group III, 128.62 ± 7.58; P = 0.000) which could be due to sedative, anti-anxiety property of clonidine.
In our study, the changes in DBP were significant at all time time-intervals except from 8 min post-intubation to 1 h post-intubation. This is similar to the study conducted by Wright et al.,  where they found significant fall in DBP in pre-anesthetic periods. During intubation, they found significant rise in DBP which receded during post-intubation periods.
Kulka et al.,  in their study with IV clonidine in a dose of 2, 4, or 6 μg/kg and placebo as a control, 30 min prior to induction also found that after administration of the induction with etomidate 0.3 mg/kg, MAP decreased in all groups between 25 and 30 mm Hg below baseline values. During laryngoscopy and intubation, MAP increased significantly to 120 ± 15 mm Hg in placebo group, P < 0.05 (in our study 133.04 ± 7.04 mm Hg). On the other hand, Altan et al.,  studied with IV magnesium sulphate 30 mg/kg over 15 min period before induction of anesthesia and 10 mg/kg h by continuous infusion during operation; group clonidine received 3 μg/kg IV at induction over 15 min period and 2 μg/kg h as maintenance, and normal saline as control and found that MAP with clonidine fell significantly for all measurements with the exception of increased MAP during intubation. They also observed that MAP in the control groups were significantly lower after induction (P < 0.001) and higher after intubation and incision compared with the preoperative value (P < 0.05). The observations of these studies may be compared with the findings of the present study.
VAS for anxiety were almost similar in all the groups in preoperative period (group I, 20.46 ± 0.58; group II, 20.48 ± 0.86; and group III, 20.48 ± 0.89; P = 0.20). However, in the pre-induction period there were statistically significant differences between the clonidine groups and the placebo group (group I, 27.98 ± 0.89; group II, 27.02 ± 0.84; group III, 39.38 ± 0.99; P = 0.000). However, these findings were not similar to the observation done by Doda et al.,  as they could not observe any significant difference between preoperative and pre-induction period. This may be due to the fact that, their control patients were premedicated with tab diazepam preoperatively.
| Conclusion|| |
Clonidine is useful as a pre-medicant in controlling the perioperative hemodynamics in normotensive patients undergoing operative procedures under GA.
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[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3]