Ondansetron does not reduce the shivering threshold in healthy volunteers

A comparison of prophylactic antiemetic therapy with palonosetron and dexamethasone as single-agents or in combination in adult patients undergoing laparoscopic surgery: A randomized trial

Background

The incidence of postoperative nausea and vomiting (PONV) is quite high after laparoscopic surgeries. This study endeavors to compare the efficacy of the combination of palonosetron and dexamethasone with that of either drug alone in the prevention of PONV in patients undergoing laparoscopic surgeries.

Methods

This randomized, parallel-group trial was done on ninety adults of American Society of Anesthesiologists Grade I and II patients aged 18-60 years undergoing laparoscopic surgeries under general anesthesia. The patients were randomly divided into three groups of thirty patients each. Group P (n = 30) received palonosetron 0.075 mg intravenously (iv), Group D (n = 30) received dexamethasone 8 mg iv and Group P + D (n = 30) received palonosetron 0.075 mg and dexamethasone 8 mg iv. The primary outcome was incidence of PONV in 24 h, and the secondary outcome was a number of rescue antiemetics required. To compare the proportions in the groups, unpaired t-test, Mann-Whitney U-test, Chi-square test, or Fisher's exact test was applied.

Results

We found that the overall incidence of PONV was 46.7% in Group P, 50% in Group D, and 43.3% in Group P + D during the first 24 h. Rescue antiemetic was required in 27% of the patients in Group P and Group D compared to 23% of the patients in Group P + D and twice in 3% of the patients in Group P, 7% of the patients in Group D, and none in Group P + D which were not significant.

Conclusions

The combination therapy of palonosetron plus dexamethasone did not significantly reduce the incidence of PONV when compared with either drug alone.

5-HT3 receptor antagonists for the prevention of postoperative shivering: a meta-analysis

Objective

We evaluated the efficacy of 5-HT3 receptor antagonists for the prevention of postoperative shivering.

Methods

We searched PubMed, the Cochrane Library, EMBASE and Web of Knowledge to find randomized controlled trials (RCT) of 5-HT3 receptor antagonists for the prevention of postoperative shivering. Two researchers independently screened studies, extracted data, and assessed quality in accordance with the inclusion and exclusion criteria, and then conducted a meta-analysis using RevMan 5.2.

Results

Ultimately, 14 RCTs that included 980 patients were included in the analysis. We found that: 1) the incidence of shivering was significantly lower in 5-HT3 groups than placebo groups (relative risk, [RR] = 0.48, 95% confidence interval [CI] 0.40 – 0.58); 2) there was no significant difference in the incidence of shivering between 5-HT3 groups and meperidine groups (RR = 0.89, 95% CI 0.60 – 1.34).

Conclusion

5-HT3 receptor antagonists appear to prevent postoperative shivering, with a broadly comparable efficacy to meperidine.

Perioperative thermoregulation and heat balance

Core body temperature is normally tightly regulated to within a few tenths of a degree. The major thermoregulatory defences in humans are sweating, arteriovenous shunt vasoconstriction, and shivering. The core temperature triggering each response defines its activation threshold. General anaesthetics greatly impair thermoregulation, synchronously reducing the thresholds for vasoconstriction and shivering. Neuraxial anaesthesia also impairs central thermoregulatory control, and prevents vasoconstriction and shivering in blocked areas. Consequently, unwarmed anaesthetised patients become hypothermic, typically by 1-2°C. Hypothermia results initially from an internal redistribution of body heat from the core to the periphery, followed by heat loss exceeding metabolic heat production. Complications of perioperative hypothermia include coagulopathy and increased transfusion requirement, surgical site infection, delayed drug metabolism, prolonged recovery, shivering, and thermal discomfort. Body temperature can be reliably measured in the oesophagus, nasopharynx, mouth, and bladder. The standard-of-care is to monitor core temperature and to maintain normothermia during general and neuraxial anaesthesia.

Preventative effect of ondansetron on postanesthesia shivering in children undergoing caudal anesthesia: a randomized double-blinded clinical trial

BACKGROUND

Ondansetron has been shown to decrease postanesthesia shivering in adults, but this effect has never been studied in children. This study aimed to determine whether ondansetron decreases postanesthesia shivering in children undergoing caudal anesthesia.

METHODS

Fifty-nine 8- to 13-y-old children undergoing both intravenous and caudal anesthesia were included. As soon as anesthetization and caudal block were complete, children were given intravenous injections of 4 mg ondansetron or an equal volume of normal saline. Heart rate, blood pressure, oxygen saturation (SpO2), and body temperature were recorded just before application of general anesthesia to children and immediately upon entry into the recovery room after awakening from anesthesia. The shivering score was assessed, using a 4-point scale of severity, immediately upon entry into the recovery room after awakening from anesthesia, 15 min after entry into the recovery room, and 30 min after entry into the recovery room.

RESULTS

Treatment with ondansetron was associated with decreased odds of postanesthesia shivering symptoms compared to the control group. There was also a significant decrease in shivering score with time after anesthesia.

CONCLUSION

Ondansetron decreases postanesthesia shivering in children receiving caudal block after intravenous anesthesia.

Dexmedetomidine Reduces Shivering during Mild Hypothermia in Waking Subjects

Background and Purpose

Reducing body temperature can prolong tolerance to ischemic injury such as stroke or myocardial infarction, but is difficult and uncomfortable in awake patients because of shivering. We tested the efficacy and safety of the alpha-2-adrenergic agonist dexmedetomidine for suppressing shivering induced by a rapid infusion of cold intravenous fluids.

Methods

Ten subjects received a rapid intravenous infusion of two liters of cold (4°C) isotonic saline on two separate test days, and we measured their core body temperature, shivering, hemodynamics and sedation for two hours. On one test day, fluid infusion was preceded by placebo infusion. On the other test day, fluid infusion was preceded by 1.0 μg/kg bolus of dexmedetomidine over 10 minutes.

Results

All ten subjects experienced shivering on placebo days, with shivering beginning at a mean (SD) temperature of 36.6 (0.3)°C. The mean lowest temperature after placebo was 36.0 (0.3)°C (range 35.7-36.5°C). Only 3/10 subjects shivered on dexmedetomidine days, and the mean lowest temperature was 35.7 (0.4)°C (range 35.0-36.3°C). Temperature remained below 36°C for the full two hours in 6/10 subjects. After dexmedetomidine, subjects had moderate sedation and a mean 26 (13) mmHg reduction in blood pressure that resolved within 90 minutes. Heart rate declined a mean 23 (11) bpm after both placebo and dexmedetomidine. Dexmedetomidine produced no respiratory depression.

Conclusion

Dexmedetomidine decreases shivering in normal volunteers. This effect is associated with decreased systolic blood pressure and sedation, but no respiratory depression.

Comparison of ondansetron and meperidine for treatment of postoperative shivering: a randomized controlled clinical trial

Background:

The involved neurotransmitter pathways in the postoperative shivering (POS) are poorly understood. Recently, 5-hydroxytryptamine 3 (5-HT3) receptor antagonists have been reported to prevent POS. We investigated the effect of ondansetron, a 5-HT3 antagonist that is used to treat postoperative nausea and vomiting, on shivering.

Objectives:

This study aimed to compare the efficacy of ondansetron and meperidine in the treatment of shivering after general anesthesia.

Patients and Methods:

In this double-blinded randomized clinical trial, 83 patients (age range, 18-60 years) who had shivering after general anesthesia were randomly allocated to any of these three groups: Group A, (number = 27) received 4 mg of intravenous ondansetron, Group B, (number = 27) received 8 mg of intravenous ondansetron, and Group C, (number = 29) received 0.4 mg/kg of intravenous meperidine at recovery room. The surface temperatures and the incidence as well as intensity of shivering were recorded.

Results:

Shivering was controlled in 16 patients (59%) in Group A, 22 (81%) in Group B, and 25 (86%) in Group C (P = 0.01). Within each group, there were no significant differences among the surface temperature in recovery room. Patients in groups A and B had significantly lower incidence of nausea and vomiting than group C (P = 0.01).

Conclusions:

Ondansetron and meperidine have similar effects on shivering. We concluded that 8 mg of intravenous ondansetron can control shivering and this is the dose of choice, especially in patients with POS with nausea and vomiting.

Efficacy and safety of ondansetron in preventing postanesthesia shivering: a meta-analysis of randomized controlled trials

BACKGROUND

Shivering is a very common complication in the postanesthesia period. Increasing studies have reported ondansetron may be effective in prevention of postanesthesia shivering (PAS). However, the results remained controversial; hence we conducted a meta-analysis of randomized controlled trials to evaluate the efficacy and safety of ondansetron on the prevention of postanesthesia shivering.

METHODS

PubMed and Embase databases were searched to identify the eligible randomized controlled trials assessing the effect of ondansetron on the prevention of PAS. Results were expressed as risk ratios (RRs) with accompanying 95% confidence intervals (CIs). The meta-analysis was performed with fixed-effect model or random-effect model according to the heterogeneity.

RESULTS

Six trials including 533 subjects were included. Compared with placebo, ondansetron was associated with a significant reduction of PAS (RR 0.43, 95% CI, 0.27-0.70), without an increased risk of bradycardia (RR 0.37, 95% CI, 0.12-1.15). Compared with meperidine, no difference was observed in the incidence of PAS (RR 0.68, 95% CI, 0.39-1.19) and bradycardia (RR 2.0, 95% CI, 0.38-10.64).

CONCLUSIONS

Ondansetron has a preventive effect on PAS without a paralleled side effect of bradycardia.

Effect of palonosetron on postanesthetic shivering after propofol-remifentanil total intravenous anesthesia

PURPOSE

The authors conducted a prospective, randomized, double-blind study to evaluate the anti-shivering efficacy of palonosetron for patients after gynecological laparoscopy under total intravenous propofol-remifentanil anesthesia.

METHODS

Sixty female patients were randomly assigned to one of two groups and administered palonosetron 0.075 mg (palonosetron group, n = 30) or the same volume of normal saline (control group, n = 30) immediately after anesthesia induction. Anesthesia was induced and maintained with propofol and remifentanil, using a target-controlled infusion device. Esophageal and index finger temperatures were measured immediately after anesthesia induction (baseline) and at 15-min intervals until the end of the surgery. Postanesthetic shivering and side effects were assessed in a postanesthetic care unit.

RESULTS

Incidence of shivering was comparable in the control and palonosetron groups (10/30 vs. 8/30, respectively, P = 0.779). No significant intergroup differences were observed between esophageal and index finger temperatures. Compared with baseline values, esophageal temperatures decreased immediately after pneumoperitoneum in the control group and from 30 min after pneumoperitoneum in the palonosetron group.

CONCLUSION

Use of palonosetron (0.075 mg) did not reduce the incidence of postanesthetic shivering after gynecological laparoscopy under propofol-remifentanil anesthesia. Further study including other 5-HT3 antagonists or male patients would elucidate the effect of palonosetron on shivering after propofol-remifentanil anesthesia.

Effects of ramosetron and dexamethasone on postoperative nausea, vomiting, pain, and shivering in female patients undergoing thyroid surgery

PURPOSE

Some antiemetics are effective in the treatment of postoperative pain and shivering, as well as for postoperative nausea and vomiting (PONV). The aim of this study was to investigate the effects of ramosetron and dexamethasone on PONV, pain, and shivering and to determine the correlations between nausea, pain, and shivering.

METHODS

For this study, 123 patients scheduled for thyroid surgery were randomly allocated to one of three groups: the control group (group C, n = 41), dexamethasone group (group D, n = 41), or the ramosetron group (group R, n = 41). The patients were treated intravenously with 2 mL of 0.9 % NaCl, 2 mL of 5 mg/mL dexamethasone, or 2 mL of 0.15 mg/mL ramosetron immediately after anesthesia.

RESULTS

The overall incidence and severity of postoperative nausea and the level of antiemetic consumption were significantly lower in group R compared with group D, and these parameters were significantly lower in groups R and D than in group C. There were significant differences in the incidence and severity of shivering, severity of pain, and analgesic consumption between group C and group R or D, but the incidence of shivering, pain severity, and analgesic consumption did not differ between groups R and D. The severity of shivering was significantly lower in group R than in group D. The correlation coefficients for shivering and pain, shivering and nausea, and pain and nausea were 0.210 (P = 0.010), 0.106 (P = 0.198), and 0.190 (P = 0.035), respectively, in group C.

CONCLUSIONS

Two antiemetic drugs, ramosetron and dexamethasone, significantly reduced the incidence and severity of postoperative nausea and the need for administration of rescue antiemetic drugs. Furthermore, both drugs effectively decreased the severity of pain and shivering. Ramosetron was superior to dexamethasone for reducing nausea, antiemetic consumption, and the severity of nausea, but not for reducing the incidence of shivering. Further studies are required to elucidate the correlations between postoperative nausea, pain, and shivering, as a statistically significant but weak correlation was shown in the present study.

Aspects of thermoregulation physiology

PURPOSE OF REVIEW

The review covers the main aspects of thermoregulation physiology and highlights the implications for therapeutic hypothermia trials. Prevention of shivering and other hypothermia side-effects is of key importance because controlling thermoregulatory responses may be essential for demonstrating neuro-protective properties of hypothermia in several pathologic conditions in which its role is still uncertain, such as in traumatic brain injury and stroke.

RECENT FINDINGS

Several recommendations and clinical reviews have been produced in the past 2 years about the application and feasibility of therapeutic hypothermia. Many drugs have been tested in healthy volunteers and anaesthetized patients to abolish shivering but the best protocol for managing side-effects has not yet been defined. A possible strategy might be to simultaneously apply physical methods, such as skin warming, and combination drug therapy. Different drug protocols can be applied, depending on the nature of the care setting.

SUMMARY

During moderate hypothermia treatment, conducted in an intensive care environment, shivering can be treated with sedatives, opioids (meperidine in particular), and α2-agonists, combined with active skin counter-warming. However, new randomized controlled clinical trials in intensive care patients are required to improve our knowledge regarding this treatment.

The effect of altering skin-surface cooling speeds on vasoconstriction and shivering thresholds

BACKGROUND

Both core and skin temperatures contribute to steady-state thermoregulatory control. Dynamic thermoregulatory responses trigger aggressive defenses against rapid thermal perturbations. These responses potentially complicate interpretation of thermoregulatory studies and could slow induction of therapeutic hypothermia. We thus tested the hypothesis that rapid external skin-cooling triggers vasoconstriction and shivering at higher mean skin temperatures than slow or moderate rates of skin cooling.

METHODS

Eleven healthy volunteers were cooled at 3 skin-cooling rates using forced air or/and conductive cooling in random order. One day volunteers received slow (≈2°C/h) skin cooling, and on another day, they received both medium (≈4°C/h) and fast (≈6°C/h) skin cooling. An endovascular heat-exchanging catheter maintained core temperature. Fingertip blood flow ≤0.25 mL/min defined onset of vasoconstriction; sustained ≥25% increase in oxygen consumption defined onset of shivering. Results were evaluated with repeated-measures analysis of variance, with P < 0.05 representing statistical significance.

RESULTS

Volunteers were 25 ± 5 years of age (mean ± SD), 175 ± 7 cm tall, and weighed 63 ± 10 kg. Core temperature remained constant (≈37°C) throughout each study day. At vasoconstriction, mean skin temperatures were 33.2°C (95% confidence interval [CI]: 32.0°C, 34.4°C), 33.5°C (95% CI: 32.3°C, 34.7°C), and 33.0°C (95% CI: 31.4°C, 34.6°C) at slow, medium, and fast skin-cooling rates, respectively. Mean skin temperatures at shivering were also comparable: 31.4°C (95% CI: 30.3°C, 32.5°C), 31.5°C (95% CI: 30.2°C, 32.8°C), and 30.7°C (95% CI: 28.9°C, 32.5°C), respectively.

CONCLUSIONS

Onset of vasoconstriction and shivering occurred at similar mean skin temperatures with all 3 cooling rates. Aggressive surface cooling can thus be used in thermoregulatory studies and for induction of therapeutic hypothermia without provoking dynamic thermoregulatory defenses.

Pharmacologic options for reducing the shivering response to therapeutic hypothermia

Recent literature has demonstrated significant improvements in neurologic outcomes in patients who have received induced hypothermia in the setting of out-of-hospital cardiac arrest. Through multiple metabolic mechanisms, the induction of hypothermia slows the progression and devastation of transient cerebral hypoxia. Despite these benefits, the desired reduction in core temperature is often a challenging venture as the body attempts to maintain homeostasis through the induction of thermoregulatory processes aimed at elevating body temperature. Shivering is an involuntary muscular activity that enhances heat production in an attempt to restore homeostasis. For successful induction and maintenance of induced hypothermia, shivering, as well as other thermoregulatory responses, must be overcome. Several pharmacologic options are available, either used alone or in combination, that safely and effectively prevent or treat shivering after the induction of hypothermia. We conducted a PubMed search (1966-March 2009) to identify all human investigations published in English that discussed pharmacologic mechanisms for the control of shivering. Among these options, clonidine, dexmedetomidine, and meperidine have demonstrated the greatest and most clinically relevant impact on depression of the shivering threshold. More research in this area is needed, however, and the role of the clinical pharmacist in the development and implementation of this therapy needs to be defined.

Thermoregulatory defense mechanisms

Core body temperature is normally tightly regulated by an effective thermoregulatory system. Thermoregulatory control is sometimes impaired by serious illness, but more typically remains intact. The primary autonomic defenses against heat are sweating and active precapillary vasodilation; the primary autonomic defenses against cold are arteriovenous shunt vasoconstriction and shivering. The core temperature triggering each response defines its activation threshold. Temperatures between the sweating and vasoconstriction thresholds define the inter-threshold range. The shivering threshold is usually a full 1 degrees C below the vasoconstriction threshold and is therefore a "last resort" response. Both vasoconstriction and shivering are associated with autonomic and hemodynamic activation; and each response is effective, thus impeding induction of therapeutic hypothermia. It is thus helpful to accompany core cooling with drugs that pharmacologically induce a degree of thermal tolerance. No perfect drug or drug combination has been identified. Anesthetics, for example, induce considerable tolerance, but are rarely suitable. Meperidine-especially in combination with buspirone-is especially effective while provoking only modest toxicity. The combination of buspirone and dexmedetomidine is comparably effective while avoiding the respiratory depression association with opioid administration.

Effects of redecoration of a hospital isolation room with natural materials on stress levels of denizens in cold season

We investigated the effects of redecoration of a hospital isolation room with natural materials on thermoregulatory, cardiovascular and hormonal parameters of healthy subjects staying in the room. Two isolation rooms with almost bilaterally-symmetrical arrangements were used. One room (RD) was redecorated with wood paneling and Japanese paper, while the other (CN) was unchanged (with concrete walls). Seven healthy male subjects stayed in each room for over 24 h in the cold season. Their rectal temperature (T(re)) and heart rate, and the room temperature (T(a)) and relative humidity were continuously measured. Arterial blood pressures, arterial vascular compliance, thermal sensation and thermal comfort were measured every 4 h except during sleeping. Blood was sampled after the stay in the rooms. In RD, T(a) was significantly higher by about 0.4 degrees C and relative humidity was lower by about 5% than in CN. Diurnal T(re) levels of subjects in RD significantly differed from those in CN, i.e., T(re)s were significantly higher in RD than in CN especially in the evening. In RD, the subjects felt more thermally-comfortable than in CN. Redecoration had minimal effects on cardiovascular parameters. Plasma levels of catecholamines and antidiuretic hormone did not differ, while plasma cortisol level was significantly lower after staying in RD than in CN by nearly 20%. The results indicate that, in the cold season, redecoration with natural materials improves the thermal environment of the room and contributes to maintaining core temperature of denizens at preferable levels. It also seems that redecoration of room could attenuate stress levels of isolated subjects.

[Dolasetron and shivering. A prospective randomized placebo-controlled pharmaco-economic evaluation]

BACKGROUND AND GOAL

Forced by the current economical situation, German hospitals have to reconsider their clinical productivity. When caregivers introduce new therapeutic concepts medical quality should either be improved without increasing costs or when reducing costs medical quality should be maintained. In the surgical field postoperative shivering reduces both patient comfort and medical quality. We therefore investigated the clinical pathway prevention of shivering with dolasetron in a prospective, randomized, placebo-controlled analysis of cost-effectiveness.

MATERIAL AND METHODS

After written informed consent we randomized 40 patients scheduled for lumbar disc hernia repair or head and neck surgery into two groups: patients of group D received dolasetron 1 mg/kg body weight during surgery whereas patients of group K received 100 ml saline as placebo. Primary endpoints were the incidence of shivering, the length of stay in the postanesthesia care unit and process-associated costs. Secondary endpoint was the influence on perioperative thermoregulation.

RESULTS

We observed postanesthetic shivering in 5 patients belonging to group D in comparison to 15 patients receiving the placebo (p<0.05). The length of stay in the postanesthesia care unit was shorter in patients allocated to dolasetron (mean+/-SD; group D: 43+/-16 min, group K 62+/-18 min, p<0.05). There was a significant saving in process-associated personnel costs (personnel costs in group D EUR 41.26+/-14, personnel costs in group K EUR 53.15+/-15) but in contrast the process-associated material costs were significantly increased (group D EUR 17.16+/-3, group K EUR 0.73+/-1, p<0.05).

CONCLUSIONS

The optimization of the clinical process and medical quality induced by a prophylaxis against shivering and postoperative nausea and vomiting compensates for the increased use of pharmaceutical resources in our setting.