| JOURNAL HOME | CME HOME | THIS MONTH | PAST ISSUES | ETOC | COLLECTIONS |
| AUTHORS | REVIEWERS | EDITORIAL BOARD | FEEDBACK | RSS | HELP |
 
|
|
|
||
|
|
© 2001 International Anesthesia Research Society
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
Abstract |
|---|
 Top Abstract IntroductionMethodsResultsDiscussionReferences |
|---|
Postanesthetic shivering can be treated with many types of drugs. We compared the effects of meperidine, clonidine, and urapidil on postanesthetic shivering. Sixty patients shivering during recovery from general anesthesia were treated in a randomized, double-blinded fashion with 25 mg meperidine IV, 0.15 mg clonidine IV, or 25 mg urapidil IV in three separate groups of 20 patients each. If shivering did not stop within 5 min, the treatment was repeated once; clonidine was replaced with saline for the second dose. Rectal temperature, arterial blood pressure, heart rate, SaO2 and vigilance were monitored. Clonidine stopped shivering in all 20 patients. A single dose of meperidine stopped the shivering in 18 of 20 patients, with the other 2 patients needing a second dose. Urapidil was less effective: the first dose stopped the shivering in only six patients; the second dose was effective in another six; the drug was ineffective in 8 of 20 patients. Meperidine and clonidine were both nearly 100% effective in treating postanesthetic shivering without negative side effects. By comparison, urapidil was only effective in 60% of patients treated (P <0.01).
Implications: Patients shivering during recovery from general anesthesia were treated in a randomized double-blinded fashion with meperidine, clonidine, or urapidil. Meperidine and clonidine were both very effective, whereas urapidil was only effective in 60% of patients treated.
|
Introduction |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
The occurrence of involuntary muscle tremor is a common problem in the recovery room. The incidence of postanesthetic shivering in former studies varies between 5% and 65%, depending on the definition of shivering (1). Shivering should be treated because it is associated with a significant increase in oxygen consumption, lactic acidosis, and increased carbon dioxide production, which may be harmful to patients with cardiopulmonary disease. Sometimes the tremor may interfere with monitoring such as electrocardiogram. Furthermore, shivering is very uncomfortable for the patient.
Postoperative shivering can be treated in various ways: active warming is very effective, although postanesthetic shivering is not always an attempt at thermoregulation, because the core temperature is not low in every patient who starts shivering during recovery from anesthesia (2,3). The use of drugs is a common treatment of shivering: meperidine is very effective, but there are some possible specific side effects including sedation, pruritus, and nausea (4,5). Therefore, clonidine is frequently used (6). Urapidil, another central-acting antihypertensive drug, stopped shivering in healthy subjects and patients (7–9). The aim of this study was to compare, for the first time, the effect of urapidil, meperidine, and clonidine on postanesthetic shivering in patients.
|
Methods |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
The study was approved by the Ethics Committee of the Friedrich-Schiller-University, Jena. Patients gave their written informed consent before participating. One hundred and forty-nine patients (ASA physical status I and II) without cardiovascular diseases and without diseases impairing thermoregulation were included. They were scheduled for elective laparoscopic or orthopedic surgery. The patients were premedicated with 25–50 mg clorazepate dipotassium PO the evening before surgery. Droperidol 2.5 mg and 7.5–15 mg piritramide were administered IM 1 h before surgery. Anesthesia was induced with thiopental (3–5 mg/kg) IV and fentanyl (1.5 µg/kg) IV. Rocuronium IV (0.6 mg/kg) was used to facilitate endotracheal intubation. Anesthesia was maintained with 70% nitrous oxide in oxygen, isoflurane (MAC 1.0 ± 0.3), rocuronium (0.2 mg/kg), and fentanyl (1 µg/kg) as needed. The ventilator settings of a semiclosed circle system at a 3 L/min fresh gas flow were adjusted to keep end-tidal CO2 at 30–36 mm Hg. Antibiotics were administered on surgeon’s request and atropine was given when necessary to treat bradycardia. Isotonic saline solution, stored at operating room temperature, was infused at a rate of 10–15 mL · kg-1 · h-1. The patients were covered up to the shoulders with a single blanket but were not actively warmed. The ambient temperature in the operating room was maintained at 22°C. The tracheas were extubated when the train-of-four-ratio >70% was achieved. All patients were administered 1 g methamizol IV at the end of surgery. As a result of the efficacy of methamizol, no patients in this study had to be treated with piritramide during recovery. Beyond those mentioned above, no other drugs were used between premedication and the last evaluation in the recovery room.
After surgery, patients were transferred to the recovery room. Heart rate, noninvasive arterial blood pressure, and oxygen saturation (SaO2) were recorded every 5 min. We also recorded rectal temperature. The Aldrete Score was used to describe the vigilance of the patients (10). Patients were observed continuously during recovery by a single blinded observer for the presence of postanesthetic shivering. The intensity of shivering was graded as 0 = no shivering, 1= mild shivering, 2 = modest shivering, and 3 = severe shivering. After a 5-min interval of continuous shivering the patients were allocated in a randomized and double-blinded fashion to one of three treatment groups (n = 20 in each group): meperidine 25 mg IV, clonidine 0.15 mg IV, or urapidil 25 mg IV. If shivering did not stop 5 min after treatment, the patient was given a second dose of the same drug, except for clonidine, which was replaced with saline to avoid the side effects of sedation and hypotonia of a larger dosage.
Five min after the second dosage, any patient still shivering was given 25 mg meperidine as a rescue drug. The monitoring was finished 60 min after arrival at the recovery room or 60 min after successful treatment of shivering.
Statistical analyses were performed with Fisher’s exact test, the Mann-Whitney U-test, and the Wilcoxon’s signed-rank test. All data are expressed as mean (± SD) or as number. A P value <0.05 identified statistically significant differences.
|
Results |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Sixty of 149 monitored patients (40.3%) developed shivering during the recovery phase and were allocated to the three treatment groups. There were no significant differences between patients who shivered and those who did not with regard to weight, duration of anesthesia, and Aldrete score during recovery (Table 1). Seventy-six of 149 patients (51%) monitored were male, but 38 of 60 patients (63%) who shivered were men (P <0.05). Patients who shivered were younger (36 vs 42 yr, P <0.01). At the end of surgery the rectal temperature of patients who shivered was 36.2°C (nonshivering patients: 36.1°C); during recovery the rectal temperature of these patients increased to 36.5°C (nonshivering group: 36.2°C). Thus, the patients who shivered tended to be younger and male, but not lower in body temperature (Table 1).
|
The three treatment groups were comparable with regard to sex, body weight, duration of anesthesia, and rectal temperature during recovery. The meperidine group was older than the other treatment groups (P <0.05) (Table 2). The degree of shivering in the treatment groups was comparable, especially the number of patients with severe shivering (Table 3).
|
|
Meperidine and clonidine were more effective in treating the postanesthetic shivering than urapidil (P < 0.01); shivering ceased in all patients treated with a single dose of 0.15 mg clonidine, but in 4 of the 20 patients the effect took more than 5 min to occur. Meperidine (25 mg) stopped shivering in 18 of 20 patients within 5 min, and in the other two, shivering stopped after the second dose of 25 mg (Table 4). The onset of action of both drugs was very fast (clonidine 3.1 ± 2.5 min, meperidine 2.7 ± 1.8 min, not significant).
|
Urapidil was not as effective, as only six patients stopped shivering after the first dose. Another six patients stopped shivering after the second dose (Table 3). The rescue drug (25 mg meperidine) was used with success in all eight patients, who did not stop shivering after the second dose of urapidil.
Mean arterial pressure decreased in the Urapidil Group from 108 ± 14 to 95 ± 14 mm Hg (P < 0.01) and in the Clonidine Group from 108 ± 17 to 97 ± 17 mm Hg (P < 0.01). Meperidine did not decrease mean arterial pressure significantly (109 ± 10 to 105 ± 13 mm Hg). In no group was treatment necessary because of hypotension (mean arterial pressure <60 mm Hg).
SaO2 did not change during recovery in the Urapidil Group (97 ± 2%), but small decreases in SaO2 were observed with the other two drugs. In the Clonidine Group, SaO2 decreased from 98 ± 2% to 96 ± 3% at time of discharge (P < 0.05). In patients treated with meperidine, SaO2 decreased from 97 ± 3% to 95 ± 2% after treatment (P < 0.01), but at time of discharge the SaO2 was back to 96 ± 3%.
Two patients (3.3%) suffered from postoperative nausea and vomiting after treatment with meperidine, but 8 of 94 patients (8.5%) who did not shiver also had postoperative nausea and vomiting during the first hour of recovery from anesthesia.
|
Discussion |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
Our study confirms that 0.15 mg clonidine or 25 mg meperidine are both very effective treatments for postanesthetic shivering. The time to effect (2–6 minutes) of both drugs is comparable. If oxygen is administered during recovery, even the small decrease in SaO2 we found should not occur.
Urapidil was not as effective as meperidine and clonidine. It was first mentioned as a drug to treat shivering in 1996 by Ittner et al. (8,9). Urapidil, a central-acting antihypertensive drug (
-1-receptor-antagonist/5-HT1A-agonist), suppressed shivering produced by infusion of 4°C isotonic saline solution in volunteers. Then, in a brief report, we showed that postanesthetic shivering could be treated successfully by urapidil (7). In our current study, postanesthetic shivering did cease in 60% of the patients treated with urapidil, which is thus more frequent than the success rate of placebo, 20–25% (5–7).
Piper et al. (11) recently studied the use of these same three drugs to prevent postanesthetic shivering rather than waiting to treat it once it had started. In a dose of 0.2 mg/kg, urapidil did not prevent postanesthetic shivering, whereas clonidine and meperidine were both effective. A larger dosage of 0.3–0.6 mg/kg, as we used to treat shivering in our study, could have improved the performance of urapidil in the prevention of shivering, but clonidine and meperidine are still probably the better choice to prevent it. In our opinion, the emphasis for prevention of shivering should be focused on physical methods to minimize heat loss during anesthesia and the drug therapy should be administered to those who shiver despite such methods. This current study was designed around a basic level of thermal insulation between the patient and the environment. Where available, more elaborate external warming devices are recommend to prevent shivering (2).
In conclusion, both meperidine and clonidine were virtually 100% effective in stopping postanesthetic shivering without negative side effects. They each have secondary effects that may become important. Meperidine, long recognized as a standard therapy for postanesthetic shivering, also has an analgetic effect. Clonidine, however, includes an antihypertensive effect. Although the present data show that urapidil does have some efficacy, we cannot recommend it over clonidine and meperidine as a standard medication to treat postanesthetic shivering.
|
Acknowledgments |
|---|
The authors acknowledge the advice of Don Bredle on the preparation of the manuscript. We would like to thank the staff of the Institut fuer medizinische Statistik, Informatik und Dokumentation for the help with the statistical analysis.
|
References |
|---|
|
TopAbstractIntroductionMethodsResultsDiscussionReferences |
|---|
- Crossley AWA. Perioperative shivering. Anaesthesia 1992; 47: 193–5.[Web of Science][Medline]
- Horn EP, Sessler DI, Standl T, et al. Non-thermoregulatory shivering in patients recovering from isoflurane or desflurane anesthesia. Anesthesiology 1998; 89: 878–86.[Web of Science][Medline]
- Sessler DI, Israel D, Pozos RS, et al. Spontaneous post-anesthetic tremor does not resemble thermoregulatory shivering. Anesthesiology 1988; 68: 843–50.[Web of Science][Medline]
-
Singh P, Dimitriou V, Mahajan RP, Crossley AWA. Double-blind comparison between doxapram and pethidine in the treatment of postanaesthetic shivering. Br J Anaesth 1993; 71: 685–8.
[Abstract/Free Full Text] -
Wrench IJ, Cavill G, Ward JEH, Crossley AWA. Comparison between alfentanil, pethidine and placebo in the treatment of post-anaesthetic shivering. Br J Anaesth 1997; 79: 541–2.
[Abstract/Free Full Text] - Joris J, Banache M, Bonnet F, et al. Clonidine and ketanserin both are effective treatment for postanesthetic shivering. Anesthesiology 1993; 79: 532–9.[Web of Science][Medline]
- Fritz H, Schwarzkopf K, Hoff H, et al. Effect of urapidil on postanesthetic shivering: a double-blind study [abstract]. Br J Anaesth 1999;82:suppl.1; A404.
- Ittner KP, Bucher M, Hoerauf K, et al. Urapidil, ein alpha1-antagonist/5-HT1A-agonist, supprimiert artefiziell induziertes Kaeltezittern [abstract]. Anaesthesist 1996;45:suppl.2; A117.
-
Ittner KP, Bucher M, Riebel K, et al. Urapidil, an 1-adrenergic-antagonist/5-HT1A-agonist, suppresses cold induced shivering in humans [abstract]. Anesthesiology 1996;85:No3A; A170.
- Aldrete JA. The post-anesthesia recovery-score revisited. J Clin Anesth 1995; 7: 89–91.[Web of Science][Medline]
-
Piper SN, Maleck WH, Boldt J, et al. A comparison of urapidil, clonidine, meperidine and placebo in preventing postanesthetic shivering. Anesth Analg 2000; 90: 954–7.
[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
 |
|
  H. G. Fritz, H. Hoff, M. Hartmann, W. Karzai, and K. R. G. Schwarzkopf The Effects of Urapidil on Thermoregulatory Thresholds in Volunteers Anesth. Analg., March 1, 2002; 94(3): 626 - 630. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Kranke, L. H. Eberhart, N. Roewer, and M. R. Tramer Pharmacological Treatment of Postoperative Shivering: A Quantitative Systematic Review of Randomized Controlled Trials Anesth. Analg., February 1, 2002; 94(2): 453 - 460. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. N. Piper, K. D. Rohm, W. H. Maleck, M. T. Fent, S. W. Suttner, and J. Boldt Dolasetron for Preventing Postanesthetic Shivering Anesth. Analg., January 1, 2002; 94(1): 106 - 111. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
