[Postoperative shivering]

A meta-analysis of randomized controlled trials: efficiency and safety of ondansetron in preventing post-anesthesia shivering during cesarean section

OBJECTIVE

Although ondansetron was considered to prevent post-anesthesia shivering during cesarean section, its efficiency remained controversial. Our review was conducted to estimate the efficiency and safety of ondansetron in preventing post-anesthesia shivering during cesarean section.

METHODS

The literature were searched from their inception to October 2020 without restriction of language. All randomized controlled trials investigating the efficacy of ondansetron versus placebo in preventing shivering during cesarean section under neuraxial anesthesia were included. The meta-analysis was conducted using Stata software.

RESULTS

Eleven randomized controlled studies with a total of 748 individuals were finally included in our meta-analysis. Our results manifested that intravenous ondansetron compared with intravenous placebo significantly reduced the incidence of post-anesthesia shivering (PAS) (RR 0.53, 95% CI 0.14-0.68). Subgroup analysis according to doses of ondansetron indicated that the efficacy of 4 mg doses of ondansetron (RR 0.37, 95% CI 0.21-0.64) is equivalent to that of 8 mg doses of ondansetron (RR 0.61, 95% CI 0.47-0.81) in preventing PAS. In addition, the intravenous ondansetron led to a lower incidence of hypotension than intravenous placebo (OR 0.47, 95% CI 0.32-0.70). We could not demonstrate differences in the incidence of bradycardia between intravenous ondansetron and intravenous placebo.

CONCLUSION

Our results found that intravenous ondansetron was effective in preventing shivering during cesarean section under neuraxial anesthesia, and had an advantage in reducing the incidence of hypotension compared with intravenous placebo.

Comparison of the effectiveness of dexmedetomidine, meperidine and ketamine in the prevention of postoperative shivering

OBJECTIVE

To compare the prophylactic effectiveness of dexmedetomidine, meperidine, and ketamine for postoperative shivering.

MATERIALS AND METHODS

A randomized, controlled, double-blind, clinical trial, including 160 patients (ASA I - II) undergoing surgical procedures under general anaesthesia for longer than one hour. They were randomly assigned to four groups to receive a single intravenous dose: Dexmedetomidine 1ug/kg (group A, n=33), meperidine 0.4mg/kg (group B, n=38), ketamine 0.5mg/kg (groupC, n=40), or 0.9% saline solution (group D, n=45), administered 20min before the skin suture. To avoid bias, the anaesthetic induction and maintenance technique, as well as postoperative follow-up was standardised.

RESULTS

For any level of shivering, the greatest incidence was observed in the placebo group (47%) (P<.01). The greatest effect on shivering level 3 and 4 occurred in the placebo group (22% and 18%, respectively). For levels 3 and 4 during follow-up, there was not a single case of shivering at any time in the meperidine group (P<.01). The placebo group (38%) had the highest proportion of patients requiring treatment for post-operative shivering (P<.01).

CONCLUSION

Meperidine given intravenously in a single dose of 0.4mg/kg is a useful means for preventing postoperative shivering.

The Preventive Role of Low-Dose Intravenous Ketamine on Postoperative Shivering in Children: A Placebo Randomized Controlled Trial

Background

Postoperative shivering is a major problem in children undergoing general anesthesia.

Objectives

The aim of the present study was to investigate the role of low-dose intravenous ketamine for prevention of shivering after induction of general anesthesia in children who had undergone tonsillectomy.

Patients and Methods

This was a randomized, double-blinded, placebo-controlled trial including 80 children, of American society of anesthesiologists (ASA) physical status I or II, scheduled for tonsillectomy under general anesthesia who were randomly assigned to an intravenous ketamine (0.5 mg/kg, n = 40; group K) group or matched dose placebo (n = 40; group N) group. Surgical and demographic data, unexpected side effects, and the occurrence of shivering for each child were assessed by a blinded observer at the following time points: T0, in the recovery room; T10, at 10 minutes; T20, at 20 minutes; T30, and at 30 minutes.

Results

With regards to the demographic and surgical data, no significant differences between the two study groups were observed (P ≥ 0.05). Shivering intensity in children who had received ketamine was significantly lower than children who had not received ketamine, at T0, T10, T20, and T30 after arrival (P < 0.05). There were no significant differences in hallucination, nausea, vomiting, hemodynamic dysfunction, blurred vision, and seizure in the K group compared with the N group (P ≥ 0.05).

Conclusions

Administration of intravenous ketamine at a dosage of 0.5 mg/kg immediately after anesthesia induction had a preventive effect on shivering intensity without hemodynamic alterations in children undergoing general anesthesia for tonsillectomy.

[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.

[Perioperative thermal management]

Perioperative hypothermia can influence clinical outcome negatively. It triples the incidence of adverse myocardial outcomes, significantly increases perioperative blood loss, significantly augments allogenic transfusion requirements, and increases the incidence of surgical wound infections. The major causes are redistribution of heat from the core of the body to the peripheral tissues and a negative heat balance. Adequate thermal management includes preoperative and intraoperative measures. Preoperative measures, e.g., prewarming, enhance heat content of the peripheral tissues, thereby reducing redistribution of heat from the core to the peripheral tissues after induction of anesthesia. Intraoperative measures are active skin surface warming of a large body surface area with conductive or convective warming systems. Intravenous fluids should be warmed when large volumes of more than 500-1000 ml/h are required. The body surfaces that cannot be actively warmed should be insulated. Airway humidification and conductive warming of the back are less efficient.

A comparison of nefopam and clonidine for the prevention of postanaesthetic shivering: a comparative, double-blind and placebo-controlled dose-ranging study

Postanaesthetic shivering is a frequent complication following general anaesthesia. The aim of this study was to compare the effectiveness of three doses of nefopam with clonidine and placebo in the prevention of postanaesthetic shivering. We studied 371 patients undergoing abdominal or orthopaedic surgery. Patients were allocated to one of five groups: Group A (n = 73) received 0.2 mg x kg(-1) nefopam, Group B (n = 75) 0.1 mg x kg(-1) nefopam, Group C (n = 76) 0.05 mg x kg(-1) nefopam, Group D (n = 73) 1.5 microg x kg(-1) clonidine, and Group E (n = 74) saline 0.9% as placebo. We found a significant reduction in the incidence of shivering in Group A compared to Group C and clonidine as well as to the placebo group. All active treatments reduced the incidence and the severity of shivering compared to placebo. At 5 min postoperatively clonidine-treated patients showed a significant decrease in MAP and a significantly lower Aldrete score compared to all other groups. No haemodynamic or sedative adverse events were observed in the nefopam-treated patients. The results of our study indicate that nefopam (0.2 mg x kg(-1)) is superior to clonidine (1.5 microg x kg(-1)) in the prophylaxis of postanaesthetic shivering and not accompanied by sedative or haemodynamic side-effects.