| JOURNAL HOME | CME HOME | THIS MONTH | PAST ISSUES | ETOC | COLLECTIONS |
| AUTHORS | REVIEWERS | EDITORIAL BOARD | FEEDBACK | RSS | HELP |
| ||||||||||||||
| ||||||||||||||
|
|
|
|
||||||||||||
|
||||||||||||||
Department of Anesthesiology, Intensive Care Medicine, and Pain Therapy, Klinikum Kassel, Oberhausen, Germany
Address correspondence and reprint requests to Priv.-Doz. Dr. P. J. Kulka, Department of Anesthesiology and Intensive Care Medicine, Evangelisches Krankenhaus Oberhausen, EKO, Virchowstrasse 20, D-46047 Oberhausen, Germany. Address e-mail to Peter.Kulka{at}ruhr-uni-bochum.de
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
IMPLICATIONS: The recovery from sevoflurane anesthesia may be complicated by the presence of agitation in pediatric patients. Clonidine 2 µg/kg IV after anesthetic induction effectively reduces the incidence of agitation without resulting in clinically relevant bradycardia and hypotension.
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
2-adrenoceptor agonist clonidine has often been proposed as a supplement to general anesthesia in adult and pediatric (8) surgical patients. Clonidine is effective in the prophylaxis and treatment of agitation in adult intensive care patients (9,10). We performed this study to test the hypotheses that treatment with clonidine reduces the incidence and the severity of the early postanesthestic emergence delirium in preschool children undergoing sevoflurane anesthesia. |
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
After fasting for 5 h all the patients received midazolam 0.5 mg/kg orally 30 min before the induction of anesthesia. Anesthesia was induced by a single breath induction method using sevoflurane (8 Vol%) in a mixture of nitrous oxide/oxygen (2:1) at a fresh gas flow of 6 L/min. An IV catheter was then inserted into a forearm vein. After endotracheal intubation end-tidal sevoflurane concentration was adjusted to 1.5 minimum alveolar concentration (11). Fresh gas flow was reduced to 1 L/min. Minute ventilation was adjusted to maintain an end-expiratory CO2-concentration of 35 mm Hg. Before the start of surgery a penile block was performed using bupivacaine 0.5% 0.1 mL/kg and the children received paracetamol 15 mg/kg body weight in suppository form.
Intraoperatively vital signs (heart rate and blood pressure) were recorded every 5 min. Five minutes after the start of surgery, patients received either clonidine (2 µg/kg IV diluted in 5 mL NaCl 0.9% over a time period of 5 min) or a placebo (the same volume of sodium chloride). The anesthesiologist was blinded to the drug. At the end of surgery sevoflurane administration was discontinued. The children’s tracheae were extubated and the children were transferred to the postanesthesia care unit.
The patient evaluation was performed by a second investigator who was blinded to the patient’s treatment schedule. Agitation was defined as unpurposeful movement requiring restraint. If agitated patients could not be easily calmed, the second investigator was allowed to administer midazolam IV at increments of 0.1 mg/kg. These events were defined as severe agitation. Immediately after arrival at the postanesthesia care unit and every 15 min during an observation period of 2 h the patients’ behavior was assessed according to a scale that was composed to evaluate the severity of discomfort and pain in children during the postoperative period (12).
As pain is an important triggering factor for agitation we excluded patients with insufficient regional blockade under certain conditions. When heart rate and blood pressure increased by more than 15% compared with baseline within 5 min after the start of surgery an inadequate penile block was presumed, alfentanil 0.02 mg/kg was administered, and the patient was excluded from the study. All patients who reported pain during the recovery periodwere excluded from the study. Patients in an agitated state in whom agitation could not be improved by 2 boluses of midazolam were excluded, as we considered pain to be a significant triggering factor for agitation in these patients. The intent was to treat these patients with piritramide (0.2 mg/kg body weight) IV.
Throughout the observation period heart rate and blood pressure were measured every 15 min. Bradycardia and hypotension were defined as deviations from the age-related norm by more than 15% (13). Pulse oxymetry was performed continuously to rule out hypoxemia. Warming devices were applied to every child to avoid the occurrence of hypothermia. The discharge criteria included being fully awake, stable vital signs for at least 30 min, no bleeding, no signs of pain or vomiting, and ambulation possible according to age.
A two-way analysis of variance or the Mann-Whitney U-test was performed to compare quantitative data between the two groups. Incidence comparisons were met by using a two-tailed Fisher’s exact test. A P value <0.05 was defined as statistically significant.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Postoperative agitation may be caused by hypoxemia, metabolic disturbances, pain and the effect of drugs (3). The incidence of postsevoflurane agitation is more frequent in younger children (3). In the study of Aono et al. (3) 11.5% of the children with a mean age of 9 ± 1 years and 40% of preschool children developed postoperative agitation. Viitanen et al. (14) reported an incidence of 55% in children 1–3 years of age and an incidence of 39% in patients 0.5 to 6 years of age (15). Various treatments for agitation have been suggested and include IV ketorolac (16), midazolam (1), fentanyl (1, 17), pethidine (14), or small doses of propofol or thiopental (6). Lapin et al. (15) observed an incidence of 67% in unpremedicated patients 0.5 to 6 years of age undergoing myringotomy. An oral premedication with midazolam 0.5 mg/kg reduced the incidence of agitation to 39%. Viitanen et al. (7) investigated children 1–3 years of age undergoing adenoidectomy and found that midazolam did not significantly influence the incidence of agitation but delayed recovery from anesthesia. In patients 1–5 years of age premedicated with nasal midazolam 0.2 mg/kg, the prophylactic administration of the nonsteroidal, nonopioid analgesic ketorolac 1 mg/kg IV on emergence of anesthesia reduced the incidence of agitation from 38% to 14% (16).
Clonidine is an 2 adrenoceptor agonist that has been used for premedication in adult and pediatric patients. Clonidine is effective by the stimulation of pre- and postsynaptic 2 adrenoceptors in many areas of the central nervous system leading to sedation, analgesia, and reduction of sympathetic tone (18). In adult intensive care patients, clonidine is used in the treatment of agitation associated with withdrawal syndromes (9,10,19). We therefore assumed clonidine to be a promising drug for the treatment of agitation after sevoflurane anesthesia. We chose 2 µg/kg body weight, as this was the smallest dose to be effective in adult patients undergoing anesthesia (20,21).
Clonidine administration may have decreased sevoflurane requirements because it decreases minimum alveolar concentration (8). We therefore used a fixed concentration of 1.5 minimum alveolar concentration sevoflurane in all patients. Intraoperative blood pressure and heart rate were not different between groups. During the recovery period heart rate and mean arterial pressure were lower in patients treated with clonidine but there were no episodes of hypotension or bradycardia during and after anesthesia.
Clonidine significantly decreased the pain and discomfort scores in our study. Because of its analgesic properties, clonidine could have influenced the scores by an improved pain therapy. However, the design of our study negated the presence of pain in the postoperative period by the use of regional blockade. Therefore, we believe that the scores obtained in our study are a reflection of the severity of agitation rather than of pain. We cannot eliminate the possibility that patients treated with clonidine were more sedate in the postoperative period. Furthermore, we did not investigate whether clonidine influenced the "discharged ready" times. However, clonidine administration did not delay the discharge of our patients after the observation period of 2 hours.
In summary, our study has demonstrated that clonidine 2 µg/kg body weight IV significantly decreases the incidence and severity of postoperative agitation in children undergoing sevoflurane anesthesia. The IV administration of clonidine is safe and does not lead to an increased incidence of side effects.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  N. Tazeroualti, F. De Groote, S. De Hert, A. De Ville, A. Dierick, and P. Van der Linden Oral clonidine vs midazolam in the prevention of sevoflurane-induced agitation in children. A prospective, randomized, controlled trial Br. J. Anaesth., May 1, 2007; 98(5): 667 - 671. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. P. Vlajkovic and R. P. Sindjelic Emergence Delirium in Children: Many Questions, Few Answers Anesth. Analg., January 1, 2007; 104(1): 84 - 91. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
U. Lankinen, R. Avela, and P. Tarkkila The prevention of emergence agitation with tropisetron or clonidine after sevoflurane anesthesia in small children undergoing adenoidectomy. Anesth. Analg., May 1, 2006; 102(5): 1383 - 1386. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. J. Dalens, A. M. Pinard, D.-R. Letourneau, N. T. Albert, and R. J. Y. Truchon Prevention of emergence agitation after sevoflurane anesthesia for pediatric cerebral magnetic resonance imaging by small doses of ketamine or nalbuphine administered just before discontinuing anesthesia. Anesth. Analg., April 1, 2006; 102(4): 1056 - 1061. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. Constant, Y. Leport, P. Richard, M.-L. Moutard, and I. Murat Agitation and changes of Bispectral IndexTM and electroencephalographic-derived variables during sevoflurane induction in children: clonidine premedication reduces agitation compared with midazolam{dagger} Br. J. Anaesth., April 1, 2004; 92(4): 504 - 511. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. Ibacache, H. R. Munoz, V. Brandes, and A. L. Morales Single-Dose Dexmedetomidine Reduces Agitation After Sevoflurane Anesthesia in Children Anesth. Analg., January 1, 2004; 98(1): 60 - 63. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. P. Cravero, M. Beach, B. Thyr, and K. Whalen The Effect of Small Dose Fentanyl on the Emergence Characteristics of Pediatric Patients After Sevoflurane Anesthesia Without Surgery Anesth. Analg., August 1, 2003; 97(2): 364 - 367. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Voepel-Lewis, S. Malviya, and A. R. Tait A Prospective Cohort Study of Emergence Agitation in the Pediatric Postanesthesia Care Unit Anesth. Analg., June 1, 2003; 96(6): 1625 - 1630. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Bock, P. Kunz, R. Schreckenberger, B. M. Graf, E. Martin, and J. Motsch Comparison of caudal and intravenous clonidine in the prevention of agitation after sevoflurane in children{dagger} Br. J. Anaesth., June 1, 2002; 88(6): 790 - 796. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Mikawa, K. Nishina, and M. Shiga Prevention of Sevoflurane-Induced Agitation with Oral Clonidine Premedication Anesth. Analg., June 1, 2002; 94(6): 1675 - 1676. [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
