Comparison of meperidine and pancuronium for the treatment of shivering after cardiac surgery

Comparison of dexmedetomidine and meperidine for the prevention of shivering following coronary artery bypass graft: study protocol of a randomised controlled trial

INTRODUCTION

Shivering is a common complication in the postoperative period. The incidence of shivering has been reported to range from 5% to 65% under general anaesthesia and as 33% during epidural anaesthesia. Shivering can increase perioperative risk in patients. Both dexmedetomidine and meperidine are effective agents for the prevention of postanaesthetic shivering. However, few studies have compared the anti-shivering effects of different agents following coronary artery bypass graft (CABG). This study aims to compare the effects of dexmedetomidine and meperidine on the incidence of shivering in patients undergoing CABG.

METHODS AND ANALYSIS

A total of 180 patients aged 18-75 years, with an American Society of Anesthesiologists (ASA) grade of II-IV, undergoing elective CABG will be enrolled and randomly assigned to the dexmedetomidine, meperidine and control groups (placebo) in an intended 1:1:1 allocation ratio. The patients will be followed up for 7 days after surgery. The primary outcome is the incidence of shivering within 24 hours postoperatively. The secondary outcomes are the number of remedial drugs used after surgery, the incidence of postoperative hypotension and bradycardia, sedation scores, endotracheal extubation time, intensive care unit length of stay, incidence of postoperative delirium within 7 days after surgery, incidence of postoperative arrhythmias, incidence of postoperative nausea and vomiting, average hospital length of stay and mortality rate 30 days after surgery.

ETHICS AND DISSEMINATION

The study protocol was approved by the ethics committee of The First Affiliated Hospital of Shandong First Medical University on 20 January 2021 (YXLL-KY-2021(002)) and registered at ClinicalTrials.gov. The results of this study will be presented at national and international scientific meetings and conferences. We plan to publish the data in peer-reviewed international scientific journals.

TRIAL REGISTRATION NUMBER

NCT04735965.

Clinical Practice Guidelines for Sustained Neuromuscular Blockade in the Adult Critically Ill Patient

OBJECTIVE

To update the 2002 version of "Clinical practice guidelines for sustained neuromuscular blockade in the adult critically ill patient."

DESIGN

A Task Force comprising 17 members of the Society of Critical Medicine with particular expertise in the use of neuromuscular-blocking agents; a Grading of Recommendations Assessment, Development, and Evaluation expert; and a medical writer met via teleconference and three face-to-face meetings and communicated via e-mail to examine the evidence and develop these practice guidelines. Annually, all members completed conflict of interest statements; no conflicts were identified. This activity was funded by the Society for Critical Care Medicine, and no industry support was provided.

METHODS

Using the Grading of Recommendations Assessment, Development, and Evaluation system, the Grading of Recommendations Assessment, Development, and Evaluation expert on the Task Force created profiles for the evidence related to six of the 21 questions and assigned quality-of-evidence scores to these and the additional 15 questions for which insufficient evidence was available to create a profile. Task Force members reviewed this material and all available evidence and provided recommendations, suggestions, or good practice statements for these 21 questions.

RESULTS

The Task Force developed a single strong recommendation: we recommend scheduled eye care that includes lubricating drops or gel and eyelid closure for patients receiving continuous infusions of neuromuscular-blocking agents. The Task Force developed 10 weak recommendations. 1) We suggest that a neuromuscular-blocking agent be administered by continuous intravenous infusion early in the course of acute respiratory distress syndrome for patients with a PaO2/FIO2 less than 150. 2) We suggest against the routine administration of an neuromuscular-blocking agents to mechanically ventilated patients with status asthmaticus. 3) We suggest a trial of a neuromuscular-blocking agents in life-threatening situations associated with profound hypoxemia, respiratory acidosis, or hemodynamic compromise. 4) We suggest that neuromuscular-blocking agents may be used to manage overt shivering in therapeutic hypothermia. 5) We suggest that peripheral nerve stimulation with train-of-four monitoring may be a useful tool for monitoring the depth of neuromuscular blockade but only if it is incorporated into a more inclusive assessment of the patient that includes clinical assessment. 6) We suggest against the use of peripheral nerve stimulation with train of four alone for monitoring the depth of neuromuscular blockade in patients receiving continuous infusion of neuromuscular-blocking agents. 7) We suggest that patients receiving a continuous infusion of neuromuscular-blocking agent receive a structured physiotherapy regimen. 8) We suggest that clinicians target a blood glucose level of less than 180 mg/dL in patients receiving neuromuscular-blocking agents. 9) We suggest that clinicians not use actual body weight and instead use a consistent weight (ideal body weight or adjusted body weight) when calculating neuromuscular-blocking agents doses for obese patients. 10) We suggest that neuromuscular-blocking agents be discontinued at the end of life or when life support is withdrawn. In situations in which evidence was lacking or insufficient and the study results were equivocal or optimal clinical practice varies, the Task Force made no recommendations for nine of the topics. 1) We make no recommendation as to whether neuromuscular blockade is beneficial or harmful when used in patients with acute brain injury and raised intracranial pressure. 2) We make no recommendation on the routine use of neuromuscular-blocking agents for patients undergoing therapeutic hypothermia following cardiac arrest. 3) We make no recommendation on the use of peripheral nerve stimulation to monitor degree of block in patients undergoing therapeutic hypothermia. 4) We make no recommendation on the use of neuromuscular blockade to improve the accuracy of intravascular-volume assessment in mechanically ventilated patients. 5) We make no recommendation concerning the use of electroencephalogram-derived parameters as a measure of sedation during continuous administration of neuromuscular-blocking agents. 6) We make no recommendation regarding nutritional requirements specific to patients receiving infusions of neuromuscular-blocking agents. 7) We make no recommendation concerning the use of one measure of consistent weight over another when calculating neuromuscular-blocking agent doses in obese patients. 8) We make no recommendation on the use of neuromuscular-blocking agents in pregnant patients. 9) We make no recommendation on which muscle group should be monitored in patients with myasthenia gravis receiving neuromuscular-blocking agents. Finally, in situations in which evidence was lacking or insufficient but expert consensus was unanimous, the Task Force developed six good practice statements. 1) If peripheral nerve stimulation is used, optimal clinical practice suggests that it should be done in conjunction with assessment of other clinical findings (e.g., triggering of the ventilator and degree of shivering) to assess the degree of neuromuscular blockade in patients undergoing therapeutic hypothermia. 2) Optimal clinical practice suggests that a protocol should include guidance on neuromuscular-blocking agent administration in patients undergoing therapeutic hypothermia. 3) Optimal clinical practice suggests that analgesic and sedative drugs should be used prior to and during neuromuscular blockade, with the goal of achieving deep sedation. 4) Optimal clinical practice suggests that clinicians at the bedside implement measure to attenuate the risk of unintended extubation in patients receiving neuromuscular-blocking agents. 5) Optimal clinical practice suggests that a reduced dose of an neuromuscular-blocking agent be used for patients with myasthenia gravis and that the dose should be based on peripheral nerve stimulation with train-of-four monitoring. 6) Optimal clinical practice suggests that neuromuscular-blocking agents be discontinued prior to the clinical determination of brain death.

Continuous infusion versus intermittent bolus dosing of vecuronium in patients receiving therapeutic hypothermia after sudden cardiac arrest

STUDY OBJECTIVE

To compare the effects of vecuronium administered as an intravenous continuous infusion versus intermittent bolus doses in patients treated with therapeutic hypothermia after sudden cardiac arrest (SCA). Design. Retrospective medical record review.

SETTING

Cardiac care unit of a university-affiliated, level I trauma center.

PATIENTS

Of 123 adults treated with therapeutic hypothermia after SCA, 80 received continuous-infusion vecuronium 0.8 μg/kg/minute started 2 hours after cooling began or if shivering occurred (January 1, 2004-December 31, 2007), and 43 received intermittent boluses of vecuronium 0.05 mg/kg every 2 hours (January 1, 2008-September 30, 2009).

MEASUREMENTS AND MAIN RESULTS

The degree of neuromuscular blockade was measured with a train-of-four (TOF) test. Primary outcomes evaluated were time to achieve goal TOF response and percentage of time the TOF response was maintained at goal. Secondary outcomes included total daily dose of vecuronium, the vecuronium dose needed to achieve goal TOF response, percentage of TOF measurements above or below goal, and time to return of spontaneous respirations and time to extubation after the last dose of vecuronium. The goal TOF response was achieved significantly earlier in the bolus group than the continuous-infusion group (mean 5.9 vs 11.3 hrs, p=0.008). The mean total daily dose of vecuronium administered in the bolus group was significantly lower than that in the continuous-infusion group (51.7 vs 76.9 mg, p=0.002). The mean percentage of TOF measurements above goal was higher in the continuous-infusion group (33% vs 16%, p<0.0001), and the mean percentage of TOF measurements below goal was higher in the bolus group (43% vs 29%, p<0.0001). The median time to return of spontaneous respirations (6 vs 11 hrs, p=0.017) and time to extubation (29.5 vs 89.5 hrs, p<0.0001) were significantly shorter in the continuous-infusion group than the bolus group.

CONCLUSION

Intermittent boluses of vecuronium were more effective in reaching a goal TOF response earlier compared with continuous-infusion vecuronium in patients treated with therapeutic hypothermia. The two dosing strategies were equally effective at maintaining a goal TOF response despite patients receiving a significantly lower daily dose of vecuronium in the intermittent-bolus group.

Pharmacological treatment of postoperative shivering: a quantitative systematic review of randomized controlled trials

Shivering is a frequent complication in the postoperative period. The relative efficacy of interventions that are used for the treatment of postoperative shivering is not well understood. We performed a systematic search (MEDLINE, EMBASE, Cochrane Library, hand searching, all languages, to August, 2000) for full reports of randomized comparisons of any pharmacological antishivering intervention (active) with placebo (control) in the postoperative period. Dichotomous data on absence of further shivering after treatment and adverse effects were extracted from original reports. Relative risk (RR) and number-needed-to-treat (NNT) were calculated with 95% confidence interval (CI) using a fixed effect model. Data from 20 trials (944 adults received an active intervention, 413 were controls) were analyzed. Antishivering efficacy depended on the active regimen and the length of follow-up. Efficacy with meperidine 25 mg, clonidine 150 microg, ketanserin 10 mg, and doxapram 100 mg was reported in at least three trials; all were significantly more effective than control. After 1 min, the NNT of meperidine 25 mg for no further shivering compared with placebo was 2.7 (RR, 6.8; 95% CI, 2.5-18.5). After 5 min, the NNT of meperidine 25 mg was 1.3 (RR, 9.6; 95% CI, 5.7-16), the NNT of clonidine 150 microg was 1.3 (RR, 6.8; 95% CI, 3.3-14.2), the NNT of doxapram 100 mg was 1.7 (RR 4.0; 95% CI, 2.4-6.5), and the NNT of ketanserin 10 mg was 2.3 (RR 3.1; 95% CI, 1.9-5.1). After 10 min, the NNT of meperidine 25 mg was 1.5 (RR 4.0; 95% CI, 2.5-6.2). After 15 min, the NNT of ketanserin 10 mg was 3.3 (RR 1.5; 95% CI, 1.2-1.9). Long-term outcome data were lacking. There were not enough data for alfentanil, fentanyl, morphine, nalbuphine, lidocaine, magnesium, metamizol, methylphenidate, nefopam, pentazocine, and tramadol to draw meaningful conclusions. Reporting of adverse drug reactions was sparse. Fewer than two shivering patients need to be treated with meperidine 25 mg, clonidine 150 microg, or doxapram 100 mg for one to stop shivering within 5 min who would have continued to shiver had they all received a placebo.

IMPLICATIONS

Less than two shivering patients need to be treated with meperidine 25 mg, clonidine 150 microg, or doxapram 100 mg for one to stop shivering within 5 min who would have continued to shiver had they all received a placebo.

The effects of forced-air warming on postbypass central and skin temperatures and shivering activity

STUDY OBJECTIVE

To test the hypothesis that forced-air skin-surface warming used prophylactically after hypothermic cardiopulmonary bypass (CPB) would: (1) decrease the incidence and severity of postbypass shivering, (2) rapidly increase skin-surface temperatures when compared with standard warmed cotton blankets, and (3) not contribute to excessive central temperature elevation.

DESIGN

Prospective, randomized, nonblinded comparison of two rewarming techniques.

SETTING

Multidisciplinary intensive care unit at a tertiary care, private teaching hospital.

PATIENTS

Following hypothermic CPB, 47 patients underwent postoperative rewarming by using either conduction (warmed cotton blankets) or convection (forced-air cover) techniques.

MEASUREMENTS AND MAIN RESULTS

Central and skin temperatures were measured at 30-minute intervals for 5.5 hours postoperatively. Four lead electromyographic recordings were used to objectively document shivering activity. Antihypertensives, opioids, sedatives, and muscle relaxants were administered per patient need and recorded. The forced-air cover markedly decreased the overall incidence, duration, and magnitude of significant shivering compared with the warmed cotton blankets. Forced-air therapy produced clinically significant increases in skin surface temperatures, but avoided excessive central temperature elevation when compared with passive rewarming with cotton blankets.

CONCLUSION

Convection warming, when compared with conductive warming with cotton blankets, limited the incidence, magnitude, and duration of shivering following hypothermic cardiac surgery. This suggests an important role of cutaneous thermal input in the mediation of the shivering response. The central tissue compartment is buffered from the effects of skin-surface warming and, thus, forced-air therapy will not lead to excessive central temperature elevation in this patient population when compared with cotton blanket rewarming.

The etiology and management of inadvertent perioperative hypothermia

Mild perioperative hypothermia is a frequent complication of anesthesia and surgery. Core temperature should be monitored during general anesthesia and during regional anesthesia for large operations. Reliable sites of core temperature monitoring include the tympanic membrane, nasopharynx, esophagus, bladder, rectum, and pulmonary artery. The skin surface is not an acceptable site for monitoring core temperature. Anesthetic-induced vasodilation initially rapidly decreases core temperature secondary to an internal redistribution of heat rather than an increased heat loss to the environment. Both general and regional anesthetics impair thermoregulation, increasing the interthreshold range; that is, the range of core temperatures over which no autonomic response to cold or warmth occurs. Preinduction skin surface warming is the only means to prevent this initial redistribution hypothermia. Forced-air warming is the most effective method of rewarming hypothermic patients intraoperatively.

Determinants of postoperative hypothermia after normothermic cardiopulmonary bypass

Inadvertent postoperative hypothermia in the cardiac surgical patient can have various adverse physiologic effects. Previous studies have investigated the relationship of patient, surgical, and anesthetic factors with postoperative hypothermia in patients undergoing noncardiac surgery. This study was designed to assess the relationship between postoperative hypothermia after normothermic cardiopulmonary bypass (CPB) for cardiac surgery and a variety of perioperative and patient factors. Fifty-six patients undergoing daytime elective or urgent cardiac surgery with warm (37 degrees C) CPB were studied. The following patient variables were included: age, weight, height, sex, history of previous cardiac surgery, and prebypass temperature. The following treatment factors were recorded: type of surgery, type and dose of anesthetic, use of airway humidifier, use of an intravenous (i.v.) fluid warmer, total volume of i.v. fluid administered during surgery, net fluid volume administered via CPB, total time spent on CPB, use of nitroglycerin, use of alpha-agonists during surgery, and elapsed time from end of CPB to end of surgery. Core temperature readings, as measured by a pulmonary artery catheter thermistor, were noted as follows: (1) on insertion of the pulmonary artery catheter; (2) after the patient was weaned from CPB; (3) within 30 minutes of intensive care unit (ICU) arrival; (4) 3 to 5 hours after ICU arrival; (5) 7 to 9 hours after ICU arrival; and (6) 11 to 13 hours after ICU arrival. Multiple linear regression and logistic regression for categorical variables with backward elimination were employed to determine the impact of all variables on lowest postoperative temperature. The lowest mean temperature occurred during CPB.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of vecuronium and meperidine on the clinical and metabolic effects of shivering after hypothermic cardiopulmonary bypass

The use of vecuronium and meperidine on the clinical and metabolic effects of shivering in mechanically ventilated patients after hypothermic cardiopulmonary bypass (CPB) was compared. Twenty adult male patients undergoing cardiac surgery were randomized to meperidine, 25 to 75 mg (n = 10), or vecuronium, 0.1 microgram/kg (n = 10), for the treatment of shivering during postoperative rewarming. Vecuronium was continued as an infusion at 1.0 microgram/kg/min for 4 hours. Meperidine abolished shivering in 50% of patients with a 60% recurrence within 2 hours and did not correct acute respiratory acidosis when it occurred. Vecuronium uniformly abolished shivering, corrected acute respiratory acidosis, and improved mixed venous oxygen saturation (20% v 4%), decreased oxygen consumption (-32% v -7%) and decreased end-tidal carbon dioxide (-21% v -5%) significantly more than meperidine (p < 0.005). Meperidine administration caused a significant decline in systolic blood pressure (121.9 +/- 10.6 mmHg to 106.9 +/- 8.5 mmHg, p = < 0.02). The authors conclude that, during rewarming after hypothermic CPB, muscle relaxation with vecuronium reverses both the clinical and metabolic effects of shivering more reliably and effectively than repeated boluses of meperidine, and with greater hemodynamic stability. Control can be maintained by continuous infusion of vecuronium with concomitant sedation for up to 4 hours without prolonging intubation time.