Effects of Clonidine on the Requirements of Dopamine Used as a Concomitant Drug of Amrinone in Coronary Artery Bypass Surgery (CABG) / 대한마취과학회지

BACKGROUND: Clonidine premedication has many beneficial effects in patients undergoing CABG surgery. Amrinone, having the ability to increase cardiac performance without increasing myocardial O2 consumption, is a valuable drug in postoperative management after cardiopulmonary bypass (CPB). The use of amrinone with a catecholamine is also important clinically because the cathecholamines support perfusion pressure and the combined use exerts synergistic or additive effects. We performed this study to examine whether clonidine premedication could change the amount of dopamine used concomitantly with amrinone for management after CPB. METHODS: Nineteen patients for elective CABG were allocated to two groups according to their premedication; a placebo (Group 1, n = 13) or clonidine 4 microgram/kg p.o. (Group 2, n = 6). All patients arrived in the operating room with infusion of isosorbide dinitrate (ID). Anesthesia was performed with standard techniques. Before initiation of CPB, significant lowering of BP or HR was treated with phenylephrine or atropine respectively. Amrinone was given bolus (0.75 mg/kg) and infusion (10 microgram/ kg/min) was begun instead of ID at the release of aortic cross-clamp. Dopamine infusion (3 microgram/kg/min) was started at 35degree C (rectal) and its rate was adjusted for maintaining acceptable hemodynamics. We compared the amount of infused dopamine within 90 mins after CPB between the two groups. We also compared systolic BP, HR and CVP before induction, 10 mins after induction and 60 mins after CPB. RESULTS: Systolic BP and HR before induction and HR 10 mins after induction were significantly lower in Group 2 (P < 0.05), but they were all within normal range. The proportion of patients who needed phenylephrine or atropine before CPB was not significantly different in the two groups. The amount of infused dopamine was significantly larger in Group 2 (P < 0.05). Hemodynamics were acceptable after CPB although HR 60 min after CPB was significantly lower within the normal range in Group 2 (P < 0.05). Weaning time from CPB was not significantly different in the two groups. No significant adverse effect was observed throughout this study. CONCLUSIONS: Clonidine, used as premedication, increases the need of catecholamine which is concomitantly administered with amrinone for weaning from CPB. But this method provides clinically effective result without jeopardizing hemodynamics in CABG.

The Effects of Clonidine and Midazolam to Prevent Vomiting after Strabismus Surgery in Childeren / 대한마취과학회지

BACKGROUND: Postoperative vomiting is a troublesome problem in pediatric patients undergoing strabismus surgery. We compared the effect of clonidine and midazolam to prevent vomiting in a randomized, single-blind, placebo-controlled study of 60 healthy children undergoing surgical correction of strabismus. METHODS: The children, aged 3~15 years, were randomly allocated into three groups. The children in group 1 received clonidine 4 microgram/kg per oral about 90 min before induction of anaesthesia. Those in group 2 received midazolam 75 microgram/kg intravenously after induction before surgery. Those in group 3 received a placebo. Anaesthesia consisted of enflurane, nitrous oxide in oxygen, vecuroniun and thiopental. RESULTS: There was no difference among the groups with respect to age, gender, weight, duration of anaesthesia and recovery room time. The data showed that clonidine 4 microgram/kg per oral before induction of anaesthesia was significantly effective in preventing vomiting (P<0.017). But there was no significant difference between the midazolam group and the placebo group. CONCLUSION: We recommend the prophylactic administration of clonidine 4 microgram/kg per oral to children 3~15 years old because it decreases postoperative vomiting. It also provides preoperative sedation, postoperative analagesia, perioperative hemodynamic stability and a reduction in the volatile anesthetic requirement.

The Effect of Oral Clonidine Premedication on Changes in Respiratory System Mechanics by Tracheal Intubation / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the influence of oral clonidine premedication on respiratory mechanics by tracheal intubation in smokers. METHODS: Thirty male smoker patients were randomly divided into 3 groups. For group 1 (n = 10), l microgram/kg of clonidine was premedicated. For group 2 (n = 10), 2 microgram/kg of clonidine was premedicated. Group 3 (n = 10, control group) was the no premedication group. After anesthetic induction, CMV was applied with a Siemens Servo 900C ventilator, and anesthetic gases were supplied via the low pressure inlet of the ventilator. Tidal volume (10 ml/kg) was fixed during measurements for each patient. End-inspiratory occlusion was applied for at least 3 seconds and tracheal pressure was measured at the distal end of the endotracheal tube. Pressure, flow and volume were monitored and recorded with a Bicore CP-100 pulmonary monitor. Data were measured after 2 (100% O2) and 5 (1.5 vol% enflurane with 50% N2O) minutes of tracheal intubation. Data were transferred to PC and analyzed by processing software (ANADAT). Total respiratory (Rrs), airway (Raw) and tissue (Rve) resistances, along with static (Cstat), dynamic (Cdyn) compliances were calculated. RESULTS: There were no significant differences for Rrs, Raw, Rve, Cstat and Cdyn in the three groups. CONCLUSIONS: Oral clonidine premedication in dosages up to 2 microgram/kg do not affect the changes of respiratory mechanics caused by tracheal intubation in smokers.

The Effect of Oral Clonidine Premedication on Changes in Respiratory System Mechanics by Tracheal Intubation / 대한마취과학회지

BACKGROUND: The aim of this study was to evaluate the influence of oral clonidine premedication on respiratory mechanics by tracheal intubation in smokers. METHODS: Thirty male smoker patients were randomly divided into 3 groups. For group 1 (n = 10), l microgram/kg of clonidine was premedicated. For group 2 (n = 10), 2 microgram/kg of clonidine was premedicated. Group 3 (n = 10, control group) was the no premedication group. After anesthetic induction, CMV was applied with a Siemens Servo 900C ventilator, and anesthetic gases were supplied via the low pressure inlet of the ventilator. Tidal volume (10 ml/kg) was fixed during measurements for each patient. End-inspiratory occlusion was applied for at least 3 seconds and tracheal pressure was measured at the distal end of the endotracheal tube. Pressure, flow and volume were monitored and recorded with a Bicore CP-100 pulmonary monitor. Data were measured after 2 (100% O2) and 5 (1.5 vol% enflurane with 50% N2O) minutes of tracheal intubation. Data were transferred to PC and analyzed by processing software (ANADAT). Total respiratory (Rrs), airway (Raw) and tissue (Rve) resistances, along with static (Cstat), dynamic (Cdyn) compliances were calculated. RESULTS: There were no significant differences for Rrs, Raw, Rve, Cstat and Cdyn in the three groups. CONCLUSIONS: Oral clonidine premedication in dosages up to 2 microgram/kg do not affect the changes of respiratory mechanics caused by tracheal intubation in smokers.

Prevention of Hypokalemia before Induction of Anesthesia by Clonidine or Midazolam / 대한마취과학회지

BACKGROUND: Selective 2-agonists cause decrease in serum K+ concentration. Midazolam is an anxiolytic, sedative, and amnestic drug. Premedication of midazolam prevents increase of catecholamine with anxiety. Clonidine, alpha 2-adrenergic receptor agonist, supresses sympathetic outflow from central nervous system. So we can expect that premedication of clonidine or midazolam will prevent hypokalemia before induction of anesthesia. METHODS: Twenty two patients received 300 mcg clonidine per oral, 22 patients 0.05 mg/kg midazolan IM and 22 patients had no premedication. We measured serum K+ level at out-patient Department (T1), at 11:00 P.M. of the day before surgery (T2) and immediately before induction of anesthesia (T3). RESULTS: Serum K+ levels at T2 decreased compared to serum K+ level at T1 in all groups. Serum K+ levels T3 decreased compared to serum K+ level at T2 in control and midazolam groups but clonidine group did not decrease in serum K+ level. CONCLUSIONS: We can not prevent decrease of serum K+ level with premedication of midazolam but we can prevent decrease of serum K+ level with premedication of clonidine. So premedication of clonidine is more effective than midazolam in prevention of hypokalemia before induction of anesthesia.

The Effect of Oral Clonidine on the Duration of Vecuronium / 대한마취과학회지

BACKGROUND: As of alpha2-agonist, clonidine reduces generalized sympathetic outflow in nervous system and also reduces acetylcholine release at cholinergic terminals presynaptically. So clonidine premedication is possibly able to decrease muscle contraction and prolong the duration of neuromuscular blockers. Therefore, the aim of our current study is to investigate the effect of oral clonidine on the duration of vecuronium. METHODS: Forty patients (ASA I or II) sheduled for elective low abdominal or extrimities operation were randomly divided into 2 groups. Clonidine group (n=20) received 5 microgram/kg oral clonidine at 90 min before operation. Control group (n=20) received nothing. Neuromuscular transmission was measured with relaxograph. After injection of vecuronium 0.1 mg/kg, we measured onset time (the time from injection of vecuronium to decrease to the 25% of baseline value, duration 1 (the time interval between injection and recovery of the first twitch to 25% of the baseline value), and duration 2 (the time interval between second injection of 0.02 mg/kg vecuronium and recovery of the first twitch to 25% of the baseline value). RESULTS: There were no statistical differences between control and clonidine group in onset time (2.6 +/- 0.6 min vs 2.7 +/- 0.5 min), duration 1 (37.5 +/- 8.9 min vs 40.3 +/- 8.6 min) and duration 2 (22.0 +/- 6.8 min vs 24.4 +/- 6.1 min). CONCLUSIONS: Five microgram/kg of oral clonidine premedication did not prolong the duration of vecuronium.

Responses of Pro-Inflammatory and Anti-Inflammatory Cytokines with Clonidine Premedication in Patients Undergoing Spinal Surgery / 대한마취과학회지

BACKGROUND: As immune mediators, cytokines are thought to regulate many biological functions. Changes in cytokine response were found in stressful conditions including surgery. Our aim was to study the effects of oral clonidine premedication on the proinflammatory and antiinflammatory cytokines in patients undergoing spinal fusion. METHODS: Thirty patients (ASA I and II) were selected and randomly assigned to one of the three groups. Group 1, 2, and 3 received no premedication, clonidine 0.15 mg and 0.3 mg orally, respectively. Blood concentrations of proinflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), Interleukin-1beta (IL-1beta), IL-6, and antiinflammatory cytokines IL-10, IL-13 were determined as following intervals: before induction, immediate, 1 h, 3 h and 5 h after incision. For cytokines assay, commercially available ELISA kits were used. RESULTS: Compared to baseline values, TNF-alpha , IL-6 and IL-10 concnetrations at 3 h and 5 h after incision increased significantly in all the individual groups. IL-1beta increased significantly at 3 h and 5 h after incision in group 1 and 3, and at immediate, 1 h and 3 h after incision in group 2. At the same times sampled, TNF-alpha, IL-1beta, IL-6, IL-13 concentrations were not statistically different among three groups. However, IL-10 concentration increased significantly at 5 h after incision in group 2 and 3 compared to group 1. In addition, IL-10 level at 5 h after incision in group 2 was significantly different from group 3. CONCLUSIONS: Oral clonidine premedication increased release of antiinflammatory cytokine IL-10 significantly during spinal fusion surgery.

The Effect of Clonidine Premedication on Blood Pressure and Heart Rate during Endotracheal Intubation / 대한마취과학회지

BACKGREOUND: The endotracheal intubation for inhalational anesthesia induces hypertension and tachycardia and these hemodynamic changes cause many cardiovascular complications. Propofol has hemodynamic stability compared with thiopental sodium as an induction agent of general anesthesia. Clonidine, an 2-adrenergic receptor agonist, blunts hemodynamic changes when administered as premedicant. We evaluated the hemodynamic stability during endotracheal intubation after clonidine premedication and each induction with thiopental sodium or propofol. METHODS: The 40 male and 40 female patients who scheduled for elective surgery, were randomly assigned in 4 groups (Group I, II, III and IV). In Group II and IV, the patients were administered 150 microgram of oral clonidine 90 minutes before induction of general anesthesia. Thiopental sodium was used as induction agents in Group I and II, propofol in Group III and IV. We measured systolic blood pressure, diastolic blood pressure, mean arterial pressure and heart rate at ward before administration of oral clonidine premedication (baseline value), before induction, after administration of induction agent, just after intubation, 1, 2, 3 and 5 minutes after endotracheal intubation. RESULTS: The systolic, diastolic and mean arterial pressure and heart rate were increased significantly in all 4 groups (P<0.05) when compared to baseline value of each group but lower in Group IV (P<0.05) compared to Group I, II, III. CONCLUSION: Clonidine 150 microgram premedication and induction of general anesthesia with propofol blunts hemodynamic changes induced by endotracheal intubation.

The Effects of Oral Clonidine on the Cytokines and Stress Hormone Responses in Patients Undergoing Abdominal Hysterectomy / 대한마취과학회지

BACKGROUND: Surgery cause alterations in immune and neuroendocrine responses. Cytokines and stress hormones are importanat mediators which modulate the various immune reactions. The aim of present study is to investigate whether clonidine premedication can affect on the concentrations of cytokines and stress hormones in abdominal hysterectomy patients. METHODS: Twenty two healthy women undergoing abdominal hysterectomy were randomly allocated to two groups: eleven control patients and eleven clonidine(0.15 mg) pretreated patients. Variations in blood cytokines, Interleukin-1beta(IL-1beta), IL-2, IL-6 and tumor necrosis factor-alpha(TNF-alpha), and stress hormones, cortisol and ACTH were studied. Blood sampling were conducted 4 times in each patient: after induction, after incision, after surgery 1 h and 3 h. Cytokines assays were carried out with commercially available ELISA kits, and cortisol with radioimmunoassay and ACTH with immunoradiometric assay. RESULTS: IL-1beta increased early and the concentrations of IL-1beta in clonidine treated group were significantly lower than control. The mean concentrations of IL-2 at 1 and 3 h after surgery were slightly higher than after induction in clonidine treated group. IL-6 increased significantly at 3 h after surgery in both groups. Clonidine lowered IL-6 during the whole period. TNF-alpha, and cortisol and ACTH concentraitons were not affected by clonidin. CONCLUSIONS: Clonidine pretreatment decreased IL-1beta and IL-6 concentrations, but not stress hormones in response to abdominal hysterectomy.

Effects of Clonidine on Blood pressure and Heart rate, and Anesthetic Requirement During Laparoscopic Cholecystectomy / 대한마취과학회지

BACKGROUND: Laparoscopic cholecystectomy has become popular in the recent year. However, CO2 insufflation and patient's position changes during laparoscopic surgery can create severe hemodynamic changes, and increase anesthetic requirement. The major aim of this study is to assess the effect of oral clonidine on the cardiovascular lability during the operative and post-operative periods and enflurane requirement during operative period. METHODS: 43 patients(ASA I or II) undergoing elective laparoscopic cholecystectomy were selected for this study. The patients were randomly allocated into 3 groups: group 1(n=14) received no clonidine, group 2(n=15) 0.2 mg of clonidine and group 3(n=14) 0.3 mg of clonidine. Blood pressure and heart rate were continuously monitored during both the operative and post-operative periods. The enflurane concentration was also continuously adjusted to maintain blood pressure and heart rate within the range of 20% changes of baseline values. RESULTS: Since enflurane concentration was controlled to maintain systolic blood pressure within 20% of baseline values, there was no statistically significant difference in vital signs in the three groups during anesthesia. However, vital signs including systolic and diastolic blood pressure during their time in PACU (post anesthesia care unit) between the control and the clonidine treated groups were significantly different. The results of the blood pressure for the groups were found as follows. group 1) 134.9 +/-22.3 mmHg and 77.1 +/-12.4 mmHg, group 2) 116.8 +/-11.1 mmHg and 68.9 +/-12.2 mmHg and group 3) 113+/- 9.2 mmHg and 65.9+/- 9.2 mmHg for systolic and diastolic blood pressure respectively. Also, both the clonidine 0.2 mg and 0.3 mg treated groups, showed significantly decreased anesthetic requirement compared with the control group (P<0.05). There were dose dependent changes between 0.2 mg and 0.3 mg clonidine pretreated groups. CONCLUSIONS: Preoperative clonidine administration was effective in decreasing anesthetic supplement during laparoscopic cholecystectomy, and lessening the severity of hemodynamic changes during PACU.