Shivering and Neuraxial Anesthesia:

Intrathecal dexmedetomidine as an adjuvant to plain ropivacaine for spinal anesthesia during cesarean section: a prospective, double-blinded, randomized trial for ED50 determination using an up-down sequential allocation method

BACKGROUND

Intrathecal dexmedetomidine, as an adjuvant to local anesthetics, has been reported to improve the quality of spinal anesthesia and reduce the required local anesthetic dose. However, the optimal dosage regimen for intrathecal dexmedetomidine combined with plain ropivacaine for cesarean section (CS) remains undetermined. The present study aimed to determine the median effective dose (ED50) of intrathecal dexmedetomidine as an adjuvant to plain ropivacaine for spinal anesthesia during CS.

METHODS

Sixty parturients undergoing CS were randomly assigned to either group: plain ropivacaine 8 mg (Group Rop8) or plain ropivacaine 10 mg (Group Rop10). The initial dosage of intrathecal dexmedetomidine in each group was 5 µg. The effective dose was defined as a bilateral sensory block at the level of T6 or above to pinprick attained within 10 min after intrathecal injection, without the need for supplementary intraoperative epidural anesthesia. Effective or ineffective responses were determined, followed by a 1 µg increment or decrement in the dose of intrathecal dexmedetomidine for the next parturient using up-down sequential allocation. ED50 were calculated using probit regression.

RESULTS

The ED50 of intrathecal dexmedetomidine with plain ropivacaine was 5.9 µg (95% confidence interval [CI], 4.9-7.4 µg) in Group Rop8 and 3.1 µg (95% CI, 0.1-4.8 µg) in Group Rop10 (P < 0.05). Hemodynamic stability, side effects, patient satisfaction and neonatal outcomes were comparable between the two groups.

CONCLUSIONS

The present data suggested that the ED50 of intrathecal dexmedetomidine as an adjuvant to 8 mg and 10 mg plain ropivacaine in spinal anesthesia during cesarean section was approximately 6 µg and 3 µg, respectively.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, identifier: ChiCTR2200055928.

The Effect of Prophylactic Steroids on Shivering in Adults Undergoing Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials

BACKGROUND

Shivering is common following anesthesia and surgery. Corticosteroids (steroids) have been tried to reduce the risk of shivering, but the evidence in favor of their use is uncertain. The primary objective of this review was to evaluate the effect of steroids on the risk of perioperative (intra- and postoperative) shivering versus controls (placebo and active controls). Additional objectives were to assess the risk of severity of shivering, patient satisfaction with shivering prophylaxis, quality of recovery (QoR), and the risk of steroid-related adverse effects.

METHODS

PubMed, Embase, Cochrane Central Registry of Trials, Google Scholar, and preprint servers were searched from inception until November 30, 2022. Randomized controlled trials (RCTs) published in the English language were retrieved, provided they reported on shivering either as a primary or secondary outcome following steroid prophylaxis in adult patients undergoing surgery under spinal or general anesthesia.

RESULTS

A total of 3148 patients from 25 RCTs were included in the final analysis. The steroids used in the studies were either dexamethasone or hydrocortisone. Dexamethasone was administered intravenously or intrathecally, while hydrocortisone was administered intravenously. Prophylactic administration of steroids reduced the risk of overall shivering (risk ratio [RR], 0.65 [95% confidence interval {CI}, 0.52-0.82]; P = .0002; I2 = 77%) as well as the risk of moderate to severe shivering (RR, 0.49 [95% CI, 0.34-0.71]; P = .0002; I2 = 61%) in comparison to controls. Administration of intravenous dexamethasone (RR, 0.67 [95% CI, 0.52-0.87]; P = .002; I2 = 78%) and hydrocortisone (RR, 0.51 [95% CI, 0.32-0.80]; P = .003; I2 = 58%) were effective in shivering prophylaxis. For intrathecal dexamethasone (RR, 0.84 [95% CI, 0.34-2.08]; P = .7; I2 = 56%), the null hypothesis of no subgroup difference was not rejected ( P = .47), preventing definitive conclusions about the efficacy of this route of administration. The prediction intervals for both overall shivering risk (0.24-1.70) and risk of severity of shivering (0.23-1.0) precluded generalization of results in future studies. Meta-regression analysis was used to further explore heterogeneity. Factors like the dose and timing of administration of steroids or the type of anesthesia were not found to be significant. Patient satisfaction and QoR were higher in the dexamethasone groups versus placebo. No increased risk of adverse events of steroids was noted versus placebo or controls.

CONCLUSIONS

Prophylactic steroid administration may be beneficial in reducing the risk of perioperative shivering. However, the quality of evidence in favor of steroids is very low. Further well-designed studies are needed for establishing generalization.

Intraoperative phenylephrine infusion to reduce perioperative shivering in lower segment caesarean section: A randomised controlled study

BACKGROUND

Shivering is described as an involuntary, repetitive activity of the skeletal muscles that can have deleterious effects on anaesthetized patients. This study aimed to evaluate the effectiveness of phenylephrine infusion in preventing perioperative shivering in patients undergoing lower segment cesarean section under spinal anesthesia and to observe the change in the patient's core temperature between the study and control groups.

METHODS

A total of 118 patients scheduled for elective lower segment cesarean section under spinal anesthesia were recruited for this prospective, double-blind, randomized controlled study. The patients were randomized into 2 groups with 59 patients per group. The phenylephrine Group received phenylephrine infusion at a rate of 0.5 mcg/kg/minutes, while the Control Group received normal saline at an equivalent rate. Systolic and diastolic blood pressure, heart rate, core temperature, and the presence and intensity of shivering were recorded before induction and every 15 minutes intraoperatively and postoperatively.

RESULTS

The incidence of intraoperative shivering was significantly lower in the Phenylephrine Group compared to control group (29.1% vs 47.5% respectively; P = .044). Postoperatively, the Phenylephrine Group also had a lower incidence of shivering (34.5% vs 42.4%), but the difference was not statistically significant (P value = 0.391). There were no significant differences in the intensity of shivering between the 2 groups perioperatively, as well as in the systolic and diastolic blood pressure and core temperature. The phenylephrine Group showed a significantly lower heart rate at 15, 30, and 45 minutes after spinal block (P value = .005, .000, and .008, respectively), and at 0 and 30 minutes (P value = .004 and .020 respectively) in the recovery room. There were no significant differences in perioperative adverse events such as hypotension, hypertension, and bradycardia.

CONCLUSION

Phenylephrine infusion reduces the incidence of perioperative shivering in lower segment cesarean sections under spinal anesthesia.

A Study of the Clinical Effects of Sequential Combined Spinal Epidural Anesthesia and Spinal Anesthesia in Patients Undergoing Orthopedic Surgeries

BACKGROUND

In orthopedic surgeries, there has been an increase in the usage of the neuraxial blockade to provide excellent surgical conditions and prolonged postoperative analgesia. The introduction of the sequential combined spinal epidural anesthesia (SCSEA) technique provides benefits for both spinal anesthesia (SA) and epidural anesthesia. The focus of this study was to analyze the time needed to attain a desired level of sensory block, to compare the period of sensory block, and to study the intraoperative hemodynamics in the SCSEA and SA groups.

MATERIALS AND METHODS

The study was conducted on patients admitted for elective lower limb orthopedic surgeries. The sample size for this prospective randomized study is two groups of 67 subjects each. Patients aged between 18 and 65 years, posted for orthopedic surgeries for two to three hours, and of American Society of Anaesthesiologists (ASA) Grades 1 and 2 were included and divided into two groups. Group A patients received SCSEA with an epidural-test dose of 3 ml lignocaine (2%) with adrenaline and spinal bupivacaine (0.5%) of 1.5 ml-7.5 mg + fentanyl .25 mic if the sensory level was below T8. An epidural top-up was given with 2 ml per segment of 0.5% bupivacaine to bring the sensory level to T8. Group B patients received SA with spinal bupivacaine (0.5%) of 3 ml-15 mg + fentanyl .25 mic. Intraoperative hemodynamics, the duration to achieve a sensory level of T8, the time for two-segment regression of sensory block, and the complications that occurred were recorded.

RESULTS

The study included a total of 134 subjects with each group having 67 subjects admitted for lower limb surgery. The mean value (SD) of the time taken to attain sensory block in the SCSEA group was prolonged when compared to the SA group (7.15 ± 0.75 and 5.01 ± 0.88). The time for two-segment regression in the SCSEA group was 86.77 ± 3.60 and the SA group was 106.4 ± 8.01, which indicated that the SA group has a longer and better sensory block. Substantially, the study shows that the SCSEA group (P < 0.05) has better hemodynamics when compared to the SA group.

CONCLUSION

The SCSEA technique has better intraoperative hemodynamic stability with a longer analgesic effect when compared to SA. SA shows a sudden change in hemodynamics but reveals a greater sensory block.

Shivering and changes in body temperature in patients undergoing caesarean section under spinal anaesthesia with bupivacaine vs bupivacaine and fentanyl: A randomized clinical study

Background and Aims

Shivering is common after spinal anesthesia in patients undergoing cesarean section. Various drugs have been used for its prevention. The primary aim of this study was to assess the efficacy of adding a small dose of fentanyl intrathecally (12.5 μg) in reducing the occurrence of intraoperative shivering and hypothermia and note any significant side effects in this subset of patients.

Material and Methods

In this randomized controlled trial, 148 patients undergoing cesarean section under spinal anesthesia were included. In 74 patients, spinal anesthesia was administered with 1.8 mL of hyperbaric bupivacaine (0.5%), and the remaining 74 patients received 12.5 μg of intrathecal fentanyl with 1.8 mL of hyperbaric bupivacaine. Both were compared to find the incidence of shivering and change in nasopharyngeal and peripheral temperature along with the temperature at the onset of shivering and the grade of shivering.

Results

The incidence of shivering was 9.46% in the intrathecal bupivacaine plus fentanyl group, which was significantly less than the group with intrathecal bupivacaine alone (41.89%). The nasopharyngeal and peripheral temperature showed a decreasing trend in both groups but were greater in the plain bupivacaine group.

Conclusion

The addition of 12.5 μg of intrathecal fentanyl to bupivacaine in parturient undergoing cesarean section under spinal anesthesia significantly reduces the occurrence and intensity of shivering without its adverse effects such as nausea, vomiting, and pruritus, etc.

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.

The effect of ketamine versus tramadol on prophylactic post-spinal shivering in those patients undergoing orthopedic surgery: a prospective cohort study design, 2020

BACKGROUND

Post-spinal shivering is a common complication after spinal anesthesia with a high incidence among orthopedic patients. Untreated shivering may predispose to exacerbation of wound pain, increased metabolic demand, oxygen consumption, and hemostatic dysfunction. Various studies have been done on the effectiveness of preventing post-spinal shivering using ketamine and other drugs. However, little information on better prophylactic agents in terms of effectiveness and availability. Therefore, this study was intended to compare 0.25 mg/kg of Ketamine (K) versus 0.5 mg/kg of Tramadol (T) for the prevention of post-spinal shivering.

METHOD

A prospective cohort study design was employed on 516 patients undergoing orthopedic surgery under spinal anesthesia, and they were selected by a consecutive sampling technique. Patients were divided into two groups based on the anesthetist in charge. Patients who received an intravenous prophylactic dose of Ketamine before spinal anesthesia are called Ketamine groups and patients who received Tramadol are called Tramadol groups (control). The severity and incidence of shivering, blood pressure, heart rate, and axillary body temperature were measured and recorded for one hour at 10-min intervals during the intraoperative period. Descriptive statistics, chi-square, independent t-test, and multivariable logistic regression were used. Significance was declared at a p-value lower than 0.05.

RESULTS

The overall incidence of post-spinal shivering was 187 (36.2%), of which it was 74 (28.7%) on ketamine and 113 (43.8%) on tramadol with a p-value of 0.001. The incidence of nausea and vomiting was 157 (60.9%) on tramadol and 8 (3.1%) on ketamine, with a p-value of 0.001. Patients aged 18-35 years (AOR 0.08 (0.02, 0.27), 36-55 years (AOR 0.24, 0.07, 0.81), and those patients with a prolonged duration of surgery (AOR 1.47 (1.37-1.58)) were more likely to experience post-spinal shivering. And Low-dose ketamine has a protective effect against developing post-spinal shivering with an AOR of 0.427 (0.28-0.63).

CONCLUSION

Low-dose ketamine is more effective in reducing the incidence and severity of shivering after spinal anesthesia. Therefore, we recommend using low-dose ketamine to be effective as a prophylactic for post-spinal shivering in those patients undergoing orthopedic surgery under spinal anesthesia.

"The magnitude and associated factors of intraoperative shivering after cesarean section delivery under Spinal anesthesia'': A cross sectional study

Background

Shivering is an involuntary, spontaneous, and repetitive contraction of the skeletal muscle and increases patients’ discomfort, oxygen-consuming, wound infection; increased surgical bleeding, and morbid cardiac events. The aim of this study was to determine the magnitude and associated factors of intraoperative shivering after cesarean section delivery

Methodology

An institution-based cross-sectional study was conducted. A total of 326 willing patients were included in the study after obtaining ethical consent and we have used consecutive sampling techniques. Axillary temperature was recorded preoperatively and in the intra-operative period every 5 min. Descriptive statistics, cross-tabs, and binary logistic regression analysis were performed to identify the association shivering and independent variables. The strength of the association was presented using an adjusted odds ratio with a 95% confidence interval and a p-value<0.05 was considered as statistically significant.

Results

The overall incidence of intraoperative shivering after cesarean section delivery under spinal anesthesia was 51.8% (95% CI: 46.3, 57.1). The majority of the patients who developed shivering were after 20 min of spinal anesthesia. In this study body temperature, mean arterial pressure of the patient, and duration of surgery were significantly associated with shivering.

Conclusion

In this study duration of surgery, hypothermia and hypotension were the independent associated risk factors for intraoperative shivering.

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The incidence of post spinal anesthesia shivering after cesarean section delivery was 51.8% in the study area.

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More than 45% patients were developed Grade III shivering.

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Hypothermia, hypotension and duration of surgery were affected shivering.

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Most patients were developed shivering after 20 min of spinal anesthesia.

Ondansetron for Shivering after Spinal Anesthesia in Cesarean Delivery: A Systematic Review and Meta-Analysis

PURPOSE

Evaluate the efficacy of ondansetron in preventing shivering after spinal anesthesia in cesarean delivery.

DESIGN

Systematic review and meta-analysis METHODS: Following the PRISMA statement, PubMed, CINAHL, Cochrane, EMBASE, Google scholar and other grey literature databases were searched for eligible studies.

FINDINGS

The overall incidence of shivering after spinal anesthesia in cesarean delivery is 32%, with 24% in patients who received ondansetron compared to 40% in the placebo group. A total of 19 trials consisting of 1399 patients were evaluated. Compared to placebo, ondansetron is effective in reducing the incidence of shivering (RR, 0.47; 95% CI, 0.29 to 0.78; P = 0.003). The quality of evidence is low due to substantial heterogeneity, imprecision and suspected publication bias. Patients who received ondansetron are less likely to require rescue treatment for shivering (RR, 0.34; 95% CI, 0.15 to 0.76; P = 0.009). Also, ondansetron is associated with a lower incidence of hypotension necessitating vasopressor treatment, and nausea and vomiting with no effects on the incidence of bradycardia.

CONCLUSION

Ondansetron is effective in mitigating shivering after spinal anesthesia in cesarean delivery.

The relationship between core temperature and perioperative shivering during caesarean section under intrathecal anesthesia with bupivacaine and ropivacaine: a randomized controlled study

Purpose

To assess the incidence rate of perioperative shivering for cesarean section and explore the associations between the occurrence of shivering and hypothermia, core temperature change, local anesthetic.

Methods

This is a prospective, randomized, controlled, double-blinded study of 100 patients consenting for caesarean section under intrathecal anesthesia. Parturients with ASA I or II accepted elective caesarean section with combined spinal-epidural anesthesia (SA). 2–2.5 ml of 0.5% bupivacaine or 0.5% ropivacaine was intrathecally injected in group B and group R, respectively.

Results

The intraoperative shivering incidence in group B was significantly higher than that in group R (66.7 vs. 20.5%, Pvalue < 0.001), and shivering intensity in group B was significantly greater than group R (score: 1.4 vs. 0.3, Pvalue < 0.001). The core temperature in both groups gradually decreased with the time after SA. Hypothermia (core temperature < 36.0 ℃) 5–30 min after SA was not associated with shivering. However, changes of temperature at 25 and 30 min after SA, and bupivacaine were statistically associated with shivering, with the odds of 10.77 (95% CI: 1.36–85.21, P value = 0.02), 8.88 (95% CI: 1.29–60.97, P value = 0.03), and 7.78 (95% CI: 2.94–20.59, P value < 0.01), respectively.

Conclusions

In our study, for cesarean section, the occurrence of shivering was associated with the local anesthetics and the change of core temperature after SA, while not the hypothermia.

Preoperative perfusion index as a predictor of post-anaesthetic shivering in caesarean section with spinal anaesthesia

BACKGROUND

Post-anaesthetic shivering is frequently preceded by a decrease in peripheral blood flow. Perfusion index is a fast non-invasive method to assess peripheral blood flow, thus might be correlated with post-anaesthetic shivering.

AIM

To analyse the relationship between preoperative perfusion index and post-anaesthetic shivering in patients undergoing caesarean section with spinal anaesthesia.

METHODS

In this prospective observational study, preoperative perfusion index measurements were performed on 40 participants who were undergoing elective caesarean section under spinal anaesthesia. Spinal anaesthesia was performed using Lidodex (Lignocaine + Dextrose 5%) at vertebrae L4-L5 or L3-L4 interspace. Shivering was observed until 120 minutes according to the Crossley and Mahajan scale. Statistical analysis was performed to examine the correlation and cut-off of preoperative perfusion index as a predictor for post-anaesthetic shivering.

RESULT

There was a significant relationship between preoperative perfusion index with the incidence (p = 0.005) and the degree (p = 0.014) of post-anaesthetic shivering. The preoperative perfusion index cut-off value based on the ROC curve was 4.2 (AUC = 0.762, p = 0.002) with a sensitivity of 73.9% and specificity of 88.2%. Participants with preoperative PI < 4.2 had a greater risk of post-anaesthetic shivering (p < 0.001, RR = 3.13).

CONCLUSION

Preoperative perfusion index less than 4.2 can predict post-anaesthetic shivering in patients undergoing caesarean section with spinal anaesthesia.

Prevalence of aberrant blood pressure readings across two automated intraoperative blood pressure monitoring systems among patients undergoing caesarean delivery

OBJECTIVES

Aberrant automated blood pressure (BP) readings during caesarean delivery may lead to disruptions in monitoring. The present study compared the frequency of aberrant BP readings across two types of commercially available BP monitoring systems in use during caesarean delivery.

METHODS

This was a retrospective observational study using two comparable patient cohorts that resulted from simultaneous introduction of two types of monitors into a single obstetric surgical center in which similar patients were treated for the same surgical procedure by the same set of clinicians during the same year. Our primary hypothesis was that aberrant readings were significantly associated with the type of monitor being used for BP measurement, controlling for a variety of relevant covariates as specified in the analytic plan.

RESULTS

A total of 1418 cesarean delivery patients met inclusion criteria. Gaps of at least 6 min in machine-captured BP readings occurred in 159 (21.1%) of cases done in the operating room using a Datex-Ohmeda monitor vs. 183 (27.5%) of cases in the operating rooms using Phillips monitors (P = 0.005). In multivariable logistic regression analysis, the relative odds of the occurrence of monitoring gaps was 35% higher in rooms with the Phillips BP monitors as compared to the Datex-Ohmeda monitor while controlling for pre-specified covariates (odds ratio = 1.35, 95% confidence interval = 1.04-1.74, P = 0.02).

CONCLUSION

The present analysis suggests that aberrant BP readings for parturients undergoing caesarean delivery are significantly different between the two types of automated BP monitoring systems used in the operating rooms at our institution.

Low-dose intravenous dexmedetomidine reduces shivering following cesarean delivery: a randomized controlled trial

BACKGROUND

Intravenous dexmedetomidine 30 µg reduces shivering after cesarean delivery but can result in sedation and dry mouth. We hypothesized that prophylactic administration of 10 µg of IV dexmedetomidine would reduce the patient-reported severity of shivering after cesarean delivery, without an increased incidence of side effects.

METHODS

After institutional review board approval and informed written consent, women undergoing scheduled cesarean delivery with spinal or combined spinal-epidural anesthesia were randomized to receive either intravenous normal saline or dexmedetomidine 10 µg immediately after delivery. The primary outcome was a patient-rated subjective shivering score using a 10-cm visual analog scale at 30 and 60 min after arrival in the Post-Anesthesia Care Unit. Secondary outcomes included subjective scores for pain, nausea, itching, dry mouth, and sedation, as well as 24-h medication administration and investigator-rated observations of shivering, vomiting, pruritus, and sedation. Repeated measures ANOVA with Tukey-Kramer multiple-comparison test was applied for primary outcomes.

RESULTS

One hundred patients were enrolled, and 85 completed the study and were included in analysis. The mean ± SD shivering score in the dexmedetomidine group was significantly lower by repeated measures analysis than among controls across the first 60 min (P=0.0002), and individually at both 30 and 60 min (placebo 1.8 ± 2.6 vs. dexmedetomidine 0.6 ± 1.4 at 30 min; 1.2 ± 2.1 vs. 0.3 ± 0.6 at 60 min; both P <0.01). Patient-rated and observer-rated side effects did not significantly differ between groups.

CONCLUSIONS

Prophylactic administration of intravenous dexmedetomidine 10 µg after delivery reduces shivering without notable side effects.

Intravenous dexmedetomidine versus intravenous clonidine for post spinal anesthesia shivering: a meta-analysis of randomized controlled trials

BACKGROUND

Dexmedetomidine and clonidine are the most extensively studied drugs for shivering treatment, because α₂-adrenergic agonists can reduce the shivering threshold. The objective of this meta-analysis was to compare the efficacy and complications of dexmedetomidine with those of clonidine, when used for control of post spinal anesthesia shivering.

METHODS

Electronic databases were searched for randomized controlled trials (RCT) comparing the effect of dexmedetomidine versus clonidine for control of post spinal anesthesia shivering. The endpoints were effective rate of shivering treatment, time to cease shivering, recurrent rate of shivering and complications.

RESULTS

Six studies comprising 340 adult patients were included in this meta-analysis. Dexmedetomidine had higher effective rate of shivering treatment (odds ratio [OR]: 4.11, 95% confidence interval (CI): [1.53, 11.07], P = 0.005), shorter time to cease shivering (Mean differences (MD)=-1.91; 95% CI [-3.66, -0.15], P = 0.03), lower recurrent rate of shivering (OR = 0.30; 95% CI [0.12, 0.75], P = 0.01), compared to clonidine. Dexmedetomidine had a lower rate of hypotension and higher incidence of sedation than clonidine.

CONCLUSIONS

Dexmedetomidine is superior to clonidine when used for shivering treatment after spinal anesthesia, because of higher incidence of effective rate and sedation, faster control of shivering, lower incidence of recurrent rate and hypotention.

Intravenous dexmedetomidine versus tramadol for treatment of shivering after spinal anesthesia: a meta-analysis of randomized controlled trials

Background

Shivering is a frequent complication after spinal anesthesia. Increasing studies have compared the effect of intravenous dexmedetomidine and intravenous tramadol on shivering after spinal anesthesia, hence we performed a meta-analysis of randomized controlled trials to compare dexmedetomidine with tramadol on the treatment of post-spinal anesthesia shivering.

Methods

PubMed, Embase, Cochrane library, Web of Science and Google Scholar were searched to find the eligible studies comparing the effect of dexmedetomidine and tramadol on the treatment of shivering after spinal anesthesia. Mean difference (MD) or risk ratio (RR) along with 95% confidence interval (CI) was used to analyze the outcomes. I² test was conducted to assess the heterogeneity of the included trials. We utilized Review Manager 5.3 to perform statistical analyses.

Results

Thirteen randomized controlled trials including 864 subjects were included. Dexmedetomidine had higher effective rate of shivering control (RR =1.03; 95%CI [1.01, 1.06], P = 0.01, I² = 14%), shorter time to cease shivering (MD = -2.14; 95%CI [− 2.79, − 1.49], P < 0.00001, I² = 98%), lower recurrent rate of shivering (RR = 0.45; 95%CI [0.27, 0.73], P = 0.001, I² = 0%), lower incidences of nausea (RR = 0.10; 95%CI [0.05, 0.19], P < 0.00001, I² = 48%), and vomiting (RR = 0.13; 95%CI [0.06, 0.30], P < 0.00001, I² = 0%), higher incidence of sedation (RR = 2.48; 95%CI [1.32, 4.65], P = 0.005, I² = 82%), hypotension (RR = 2.50; 95%CI [1.24, 5.03], P = 0.01, I² = 0%) and bradycardia (RR = 4.78; 95%CI [1.76, 13.00], P = 0.002, I² = 0%), compared with tramadol.

Conclusions

Dexmedetomidine is superior to tramadol for shivering treatment, due to higher effective rate of shivering control, earlier onset of action and lesser recurrence of shivering with higher incidence of sedation and lower incidences of nausea and vomiting. However, dexmedetomidine is also associated with higher incidences of hypotension and bradycardia than tramadol.

Risk factors for shivering during caesarean section under spinal anaesthesia. A prospective observational study

BACKGROUND

Shivering during caesarean section (CS) under spinal anaesthesia is a common phenomenon. It could not only alter patient's physiology by increasing oxygen consumption but also affect the parturient's experience of childbirth. Shivering is thought to be associated with intraoperative hypothermia, but the risk factors and exact mechanism remain unclear.

METHODS

We conducted a prospective, observational study to examine the potential risk factors for intraoperative shivering, including anxiety levels. Two hundred patients undergoing elective CS under spinal anaesthesia were recruited. Parturient anxiety levels were evaluated using the State-Trait Anxiety Inventory (STAI) questionnaire. Age, weight, height, BMI, anxiety level, number of previous deliveries, sensory block level, level of education, temperature difference during surgery and American Society of Anesthesiologists score were investigated as potential risk factors. Stepwise logistic regression was used to assess the predictors for shivering.

RESULTS

Data from 155 parturients were analysed. Shivering incidence was 21.9% (34 parturients). The statistical model predicted 8.5% of a shivering incidence variability (R-square Nagelkerke = 0.085). Out of all measured variables, only the number of previous deliveries [(W) = 4.295 Exp(B) = 0.562 P < .05] and STAI-X1 [(W) = 4.127 Exp(B) = 1.052 P < .05] were significant. In our model, the risk of shivering decreased by 44% with every previous delivery and increased by 5.2% with each 1-point increase in STAI-X1.

CONCLUSION

We failed to prove a strong correlation between the measured variables and shivering. Our findings, however, support the hypothesis, that to a limited extent, anxiety promotes shivering during CS.

The Influence of Different Degrees of Temperature of Intrathecal Levobupivacaine on Spinal Block Characteristics in Orthopedic Surgeries: A Prospective Randomized Study

Background and Aims:

The temperature of the local anesthetics may affect the distribution of spinal anesthesia. The aim of the current study is to compare the effects of different degrees of intrathecal levobupivacaine 0.5% on the spinal anesthesia characteristics and shivering in orthopedic surgery.

Materials and Methods:

A randomized, prospective, and controlled trial was conducted on 120 patients aged 40–70 years with American Society of Anesthesiologists Classes I and II and who scheduled for orthopedic surgery; they were randomly distributed into three groups: Group 1 (L 24°C) – levobupivacaine 0.5% warmed to 24°C; Group 2 (L 30°C) – levobupivacaine 0.5% warmed to 30°C; and Group 3 (L 37°C) – levobupivacaine 0.5% warmed to 37°C. Every patient had received 3 mL of 0.5% levobupivacaine intrathecally. Sensory blockade was tested using the loss of pinprick sensation, whereas the motor block was tested using the modified Bromage scale. The onset and grading of shivering after spinal anesthesia were recorded.

Results:

The use of intrathecal levobupivacaine 0.5% warmed to either 30°C or 37°C resulted in a significant acceleration of the onset of either sensory or motor blockade with a significant prolongation in the duration in addition to significant delay in the onset of shivering and the time of the first analgesia requirement in comparison to those of spinal anesthesia with levobupivacaine at room temperature (24°C). Notably, a nonsignificant difference in the spinal block characteristics and shivering was observed between Group L 30°C and Group L 37°C.

Conclusion:

The increasing the temperature of levobupivacaine 0.5% to 30 °C attains more rapid onset of sensory and motor blocks , with prolongation of the onset of shivering. It could be considered as effective equivalent to warming levobupivacaine 0.5%to 37°C in spinal anesthesia.

Comparison of meperidine, tramadol and fentanyl for post-spinal shivering prevention during cesarean delivery: A double-blind randomized controlled trial

AIM

To assess the effects of intravenously administered meperidine, fentanyl and tramadol in reducing the incidence, onset time and severity of the shivering response in parturients during cesarean delivery under spinal anesthesia. Secondary outcomes included patient satisfaction and sedation scores.

METHODS

After Ethics board approval and informed written consent, 350 parturients (ASA physical status I or II), between 20 and 40 years of age, undergoing emergency or elective cesarean delivery under spinal anesthesia were recruited. Parturients were then randomly allocated to seven study groups: normal saline (control), low-dose meperidine (0.5 mg/kg), high-dose meperidine (0.75 mg/kg), low-dose fentanyl (0.5 mcg/kg), high-dose fentanyl (0.75 mcg/kg), low-dose tramadol (0.5 mg/kg) and high-dose tramadol (0.75 mg/kg). The incidence, onset time and severity of shivering, along with patient satisfaction and sedation scores were measured.

RESULTS

All study drugs showed significant reduction in incidence, onset time and severity of shivering and greater satisfaction scores compared to the control group (P < 0.01). Within each drug class, no significant differences in shivering were found between the high-dose and low-dose groups. Among study drugs, low-dose tramadol was superior due to shivering prevention and significantly reduced sedation.

CONCLUSION

Intravenously administered meperidine, fentanyl and tramadol reduce shivering incidence, onset time and severity in parturients undergoing cesarean delivery following spinal anesthesia. Importantly, low-dose intravenous tramadol (0.5 mg/kg) allowed shivering prevention and low sedation scores, thereby offering greater parturient satisfaction and better maternal-newborn bonding.

Effectiveness of Magnesium in Preventing Shivering in Surgical Patients: A Systematic Review and Meta-analysis

BACKGROUND

Clinical trials regarding the antishivering effect of perioperative magnesium have produced inconsistent results. We conducted a systematic review and meta-analysis with Trial Sequential Analysis to evaluate the effect of perioperative magnesium on prevention of shivering.

METHODS

We searched PubMed, EMBASE, Web of Science, Cochrane Central Register of Controlled Trials, and 2 registry sites for randomized clinical trials that compared the administration of magnesium to a placebo or no treatment in patients undergoing surgeries. The primary outcome of this meta-analysis was the incidence of shivering. The incidence of shivering was combined as a risk ratio with 95% CI using a random-effect model. The effect of the route of administration was evaluated in a subgroup analysis, and Trial Sequential Analysis with a risk of type 1 error of 5% and power of 90% was performed. The quality of each included trial was evaluated, and the quality of evidence was assessed using the Grading of Recommendation Assessment, Development, and Evaluation approach. We also assessed adverse events.

RESULTS

Sixty-four trials and 4303 patients (2300 and 2003 patients in magnesium and control groups, respectively) were included. The overall incidence of shivering was 9.9% in the magnesium group and 23.0% in the control group (risk ratio, 0.42; 95% CI, 0.33-0.52). Subgroup analysis revealed that the incidence of shivering was lower with IV (risk ratio, 0.29; 95% CI, 0.29-0.54; Grading of Recommendation Assessment, Development, and Evaluation, moderate), epidural (risk ratio, 0.24; 95% CI, 0.13-0.43; Grading of Recommendation Assessment, Development, and Evaluation, low), and intrathecal administration (risk ratio, 0.64; 95% CI, 0.43-0.96; Grading of Recommendation Assessment, Development, and Evaluation, moderate). Only trials with low risk of bias were included for Trial Sequential Analysis. The Z-cumulative curve for IV magnesium crossed the Trial Sequential Analysis monitoring boundary for benefit even though only 34.9% of the target sample size had been reached. The Z-cumulative curve for epidural or intrathecal administration did not cross the Trial Sequential Analysis monitoring boundary for benefit. No increase in adverse events was reported.

CONCLUSIONS

Perioperative IV administration of magnesium effectively reduced shivering and Trial Sequential Analysis suggested that no more trials are required to confirm that IV magnesium effectively reduces shivering.

Evaluation of Warming Effectiveness on Physiological Indices of Patients Undergoing Laparoscopic Cholecystectomy Surgery: A Randomized Controlled Clinical Trial

PURPOSE

The present study aimed to evaluate the impact of warming on physiological indices of patients undergoing laparoscopic cholecystectomy.

DESIGN

The study was a three-group randomized controlled clinical trial.

METHODS

In the present study, 96 patients were assigned to three groups: forced-air warming system group; warmed intravenous fluid group; and control group. The intervention was performed immediately after the anesthesia induction. Physiological indices (core body temperature, blood pressure, and heart rate) were evaluated at 15-minute intervals, and postoperative shivering was also recorded.

FINDINGS

The mean systolic blood pressure and the mean heart rate were significantly different in each warming group before, during, and after surgery, but the three groups had no significant differences in terms of physiological indices at any time (P > .05). Postoperative shivering was not seen in any group.

CONCLUSIONS

Both interventions had similar effects on physiological indices. Therefore, the recommendation is to use the warming method according to patient's other conditions.

Comparative effectiveness of pharmacologic interventions to prevent shivering after surgery: a network meta-analysis

INTRODUCTION

Although many drugs have been studied to prevent postoperative shivering, their comparative effectiveness is unknown. We attempted to assess the comparative effectiveness of the pharmacologic strategies to prevent shivering after surgery including intravenous (IV) and intrathecal (IT) meperidine, IV and IT dexmedetomidine, IV and IT clonidine, nefopam, tramadol, ketamine, and serotonin receptor antagonists.

EVIDENCE ACQUISITION

We implemented a frequentist network meta-analysis of randomized trials. Random effect model was selected according to deviance information criteria. The incidence of moderate or severe shivering and the overall incidence of postoperative shivering were compared in all patients and subgroups of general and spinal anesthesia.

EVIDENCE SYNTHESIS

Seventy trials with 6062 participants were included. All interventions except clonidine IT and dexmedetomidine IT significantly decreased the incidence of moderate or severe shivering. All interventions except clonidine IT significantly decreased the overall incidence of shivering. Nefopam IV was ranked best regarding both the incidence of moderate or severe shivering (odds ratio [OR] 0.04, 95% confidence interval [CI] 0.04-0.25, SUCRA 86.2, moderate quality-evidence), and the overall incidence of shivering (OR 0.07, 95% CI 0.03 to 0.15, SUCRA 85.7, moderate quality-evidence), which was consistent in the subgroups of anesthesia.

CONCLUSIONS

Nefopam was ranked best regarding both severity and incidence of postoperative shivering. In addition to nefopam, tramadol, meperidine IV and IT, and dexmedetomidine IV were ranked high. However, there was significant heterogeneity regarding the individual drug regimen and surgery type, precluding firm conclusion. Further randomized trials are required to compare the efficacy of the drugs with high rank.

Shivering prevention and treatment during cesarean delivery under neuraxial anesthesia: a systematic review

INTRODUCTION

Perioperative shivering during cesarean sections (CSs) under neuraxial anesthesia (NA) is clinically common but often under-treated. It may prominently increase oxygen consumption, which can be catastrophic for parturients with ischemic cardiovascular disease. Thus, the prevention and treatment of shivering may be of great significance in parturients. The purpose of this systematic review was to investigate the effectiveness of several drugs on shivering prevention and treatment during CSs under NA.

EVIDENCE ACQUISITION

A literature search was carried out using PubMed, EMBASE and the Cochrane Library to identify relevant studies. After literature screening and information extraction, a systematic review was performed.

EVIDENCE SYNTHESIS

Eighteen randomized controlled trials met the inclusion criteria. Intrathecal dexmedetomidine effectively reduced shivering, but effectiveness depended on the dose administered. Intrathecal fentanyl, intrathecal sufentanil, intrathecal meperidine, intravenous ketamine and intravenous tramadol were beneficial for reducing shivering during CSs under NA. MgSO4 administered intrathecally resulted in transient alleviation of shivering, and the effect did not persist. Two trials investigated the antishivering effect of intravenous ondansetron. The medication appeared to be effective in one trial, but ineffective in the other.

CONCLUSIONS

Appropriate use of dexmedetomidine, fentanyl, sufentanil, ketamine, meperidine, tramadol and MgSO4 may effectively reduce the incidence and severity of shivering during CSs under NA, while trials on the effect of intravenous ondansetron reached inconclusive results.

Preventing shivering with adjuvant low dose intrathecal meperidine: A meta-analysis of randomized controlled trials with trial sequential analysis

The aim of this systematic review and meta-analysis is to evaluate the pros and cons of adjuvant low dose intrathecal meperidine for spinal anaesthesia. We searched electronic databases for randomized controlled trials using trial sequential analysis (TSA) to evaluate the incidence of reduced rescue analgesics, shivering, pruritus, nausea and vomiting when applying adjuvant intrathecal meperidine. Twenty-eight trials with 2216 patients were included. Adjuvant intrathecal meperidine, 0.05-0.5 mg kg-1, significantly reduced incidence of shivering (relative risk, RR, 0.31, 95% confidence interval, CI, 0.24 to 0.40; TSA-adjusted RR, 0.32, 95% CI, 0.25 to 0.41). Intrathecal meperidine also effectively reduced need for intraoperative rescue analgesics (RR, 0.27, 95% CI, 0.12 to 0.64; TSA-adjusted RR, 0.27, 95% CI, 0.08 to 0.91) and the incidence of pruritus was unaffected (RR, 2.31, 95% CI, 0.94 to 5.70; TSA-adjusted RR, 1.42, 95% CI, 0.87 to 2.34). However, nausea and vomiting increased (RR, 1.84, 95% CI, 1.29 to 2.64; TSA-adjusted RR, 1.72, 95% CI, 1.33 to 2.23; RR, 2.23, 95% CI, 1.23 to 4.02; TSA-adjusted RR,1.96, 95% CI, 1.20 to 3.21). Under TSA, these results provided a sufficient level of evidence. In conclusion, adjuvant low dose intrathecal meperidine effectively attenuates spinal anaesthesia-associated shivering and reduces rescue analgesics with residual concerns for the nausea and vomiting.

Intrathecal dexamethasone vs. meperidine for prevention of shivering during transurethral prostatectomy: a randomized controlled trial

BACKGROUND

Shivering is a common complication after spinal anesthesia. Also, during transurethral prostatectomy a large amount of irrigating fluids is used which may cause hypothermia and shivering. We hypothesized that intrathecal dexamethasone could effectively attenuate post-spinal shivering following transurethral prostatectomy as intrathecal meperidine.

METHODS

Ninety male patients, ASA II-III, 50-75 years old were included in this prospective and randomized double-blind study. Patients were divided into three equal groups; Group D received 8 mg dexamethasone, Group M received 0.2 mg/kg meperidine, and Group C received 2 ml of normal saline, each in addition to intrathecal hyperbaric bupivacaine 0.5%. Shivering incidence, intensity and recurrence, dose of IV meperidine required to treat shivering, and adverse events were recorded for 150 min after the start of spinal anesthesia.

RESULTS

The number of patients with shivering was higher in Group C (13) than in Group D (2) and Group M (3) with no differences between Group D and M; P = 0.001. Intensity and recurrence of shivering and dose of IV meperidine used to treat shivering were higher in Group C compared to Group D and Group M; P = 0.01, P = 0.064, and P = 0.004, respectively. Adverse events were not different between groups except sedation and pruritus which occurred only in Group M compared to Group D and Group C; P = 0.005 and P = 0.001, respectively.

CONCLUSION

Intrathecal dexamethasone was as effective as intrathecal meperidine in attenuation of shivering compared to placebo in patients scheduled for prostate surgery under spinal anesthesia with less adverse events.

Comparison of effect of electroacupuncture and nefopam for prevention of postanesthetic shivering in patients undergoing urologic operation under spinal anesthesia

Background

Shivering during spinal anesthesia is a frequent complication and is induced by the core-to-peripheral redistribution of heat. Nefopam has minimal side effects and prevents shivering by reducing the shivering threshold. Electroacupuncture is known to prevent shivering by preserving the core body temperature. We compared the efficacies of electroacupuncture and nefopam for the prevention of shivering during spinal anesthesia.

Methods

Ninety patients scheduled for elective urological surgery under spinal anesthesia were enrolled in the study. Patients were randomly divided into the control group (Group C, n = 30), the electroacupuncture group (Group A, n = 30), and the nefopam group (Group N, n = 30). Groups C and A received 100 ml of isotonic saline intravenously for 30 minutes before spinal anesthesia, while Group N received nefopam (0.15 mg/kg) mixed in 100 ml of isotonic saline. Group A received 30 minutes of electroacupuncture before receiving anesthesia. Shivering scores, mean arterial pressure, heart rate, body temperature and side effects were recorded before, and at 5, 15, 30, and 60 minutes after spinal anesthesia.

Results

The incidence of postanesthetic shivering was significantly lower in Group N (10 of 30) and Group A (4 of 30) compared with that in Group C (18 of 30)(P < 0.017). Body temperature was higher in Group N and Group A than in Group C (P < 0.05). Hemodynamic parameters were not different among the groups.

Conclusions

By maintaining body temperature during spinal anesthesia, electroacupuncture is as effective as nefopam in preventing postanesthetic shivering.

A Prospective Observational Comparison Between Arm and Wrist Blood Pressure During Scheduled Cesarean Delivery

BACKGROUND

Shivering is common during cesarean delivery (CD) under neuraxial anesthesia and may disrupt the measurement of noninvasive blood pressure (BP). BP measured at the wrist may be less affected by shivering. There have been no studies comparing trends in BP measured on the upper arm and wrist. We hypothesized that wrist systolic blood pressure (sBP) would accurately trend with upper arm sBP measurements (agree within a limit of ±10%) in parturients undergoing elective CD under spinal anesthesia or combined spinal-epidural anesthesia.

METHODS

After initiation of spinal anesthesia, BP measurements were obtained simultaneously from the upper arm and wrist on opposite arms. The interval between measurements was 1 to 2 minutes, and data were collected for 20 minutes or until delivery. The primary outcome was agreement in dynamic changes in sBP measurements between the upper arm and the wrist. Bland-Altman plots indicating the levels of agreement between the methods were drawn for baseline measurements, over multiple measurements, and over multiple measurements on percentage change from baseline.

RESULTS

Forty-nine patients were recruited and completed the study. The wrist sBP tended to overestimate the upper sBP for both baseline data (sBP bias = 13.4 mm Hg; 95% confidence interval = +10.4 to +16.4 mm Hg) and data obtained over multiple measurements (sBP bias = 12.8 mm Hg; 95% confidence interval = +9.3 to +16.3 mm Hg). For change in sBP from baseline over multiple measurements, the mean difference between the wrist and the arm sBP was -0.2 percentage points (99% limits of agreement -25 to +25 percentage points).

CONCLUSIONS

The wrist measurement overestimated the reading relative to the upper arm measurement for multiple measurements over time. However, when the time series for each subject was examined for percentage change from baseline, the 2 methods mirrored each other in most cases. Nevertheless, our hypothesis was rejected as the limits of agreement were higher than ±10%. This finding suggests that wrist BP may not be an accurate method of detecting hypotension or hypertension during spinal or combined spinal-epidural anesthesia for CD.

Older patient perioperative care as experienced via transurethral resection of the prostate (TURP)

This reflective piece takes a holistic approach to an older patient having a transurethral resection of the prostate, commonly known as a TURP. It concentrates on the effects of age and likely comorbidities, and how the care given at each stage--preoperatively, anaesthetically, surgically and postoperatively--by the perioperative team can help to optimise the outcome for the patient. The article offers a critical appraisal of the best evidence available which supports the development of evidence based practitioners.

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.

Study of patient satisfaction and self-expressed problems after emergency caesarean delivery under subarachnoid block

BACKGROUND AND AIMS

Subarachnoid block is one of the common modes of anaesthesia opted for emergency caesarean section, if the maternal and foetal conditions are favourable. Various factors influence the quality of care administered during the procedure. This questionnaire based study was undertaken to look for self-expressed problems in peri-operative period in patients undergoing emergency caesarean surgery under subarachnoid block.

METHODS

All the parturients who underwent emergency caesarean section under subarachnoid block during 6 months period were distributed a questionnaire in post-operative period. They were encouraged to fill and return the form within 15 days. Patient satisfaction and the self-expressed problems were analysed at the end of 6 months.

RESULTS

One hundred and seventy five out of 220 parturients responded. 58.3% of them said that they were explained about the anaesthesia prior to surgery and 85.3% overall remained anxious. With people around them, 93.1% of them felt comfortable and 91.4% expressed that they were made comfortable inside the theatre. The self-expressed problems were shivering (43.4%), breathlessness (21.7%), pain (20%), post-operative headache (15.4%) and backache (19.4%). Parturients who heard their babies cry was 85.1%. After their babies were shown after delivery, 77.1% mothers slept well; 86.9% fed their babies within 4 h of delivery.

CONCLUSION

Pre-operative communication in emergency caesarean section by health personnel did not reduce the anxiety level, which shows that communication was ineffective. Intra-operative psychological support like making the patient comfortable, showing baby to mother and early breast feeding improve bonding between child and mother and essentially contribute to patient satisfaction.

Incidence of shivering after cesarean section under spinal anesthesia with or without intrathecal sufentanil: a randomized study

BACKGROUND AND OBJECTIVES

Shivering is a cause of discomfort and dissatisfaction in patients undergoing cesarean section. The objective of this study paper was to assess the impact of intrathecal administration of sufentanil on the incidence of shivering after cesarean section.

METHOD

In a prospective blinded, randomized clinical trial, pregnant women undergoing cesarean section under spinal anesthesia were enrolled. Pregnant women in labor, febrile, obese, with pregnancy-induced hypertension, anesthetic block failure or surgical complications were excluded. Patients were randomly assigned to two groups. In Group I, 10mg of 0.5% hyperbaric bupivacaine combined with 80 mcg of morphine and 2.5 mcg of sufentanil were administered. In Group II, 10mg of 0.5% hyperbaric bupivacaine combined with 80 mcg of morphine were administered. In the post-anesthesia care unit, patients were evaluated for signs of shivering by an investigator blinded to the patient's group allocation.

RESULTS

The sample consisted of 80 patients. In both groups there was a decrease in axillary temperature of patients after cesarean section (p<0.001). This decrease was not different between groups (p<0.21). In Group I, the incidence of tremor was 32.5% (13/40) and in Group II it was 62.5% (25/40) (p<0.007); RR 0.53 (CI 95% 0.32-0.87).

CONCLUSIONS

It has been suggested that the addition of sufentanil to hyperbaric bupivacaine and morphine during spinal anesthesia for cesarean section provides a decrease in the incidence of shivering in the immediate postoperative period.

Intrathecal Meperidine Plus Lidocaine for Prevention of Shivering during Cesarean Section

Background

Shivering related to spinal anesthesia may interfere with monitoring and is uncomfortable. The aim of the present study was to investigate low-dose intrathecal meperidine for the prevention of shivering after induction of spinal anesthesia in parturients with cesarean section.

Methods

This was a prospective randomized, double-blind, placebo-controlled trial including 100 parturients, of American Society of Anesthesiologists (ASA) physical status I or II, scheduled for elective cesarean section under spinal anesthesia who were randomly assigned to a meperidine (0.2 mg/kg) plus hyperbaric lidocaine (5%, 75 mg, n = 50; group M) group or a placebo plus hyperbaric lidocaine (5%, 75 mg, n = 50; group L) group. Demographic and surgical data, adverse events, and the mean intensity for each parturient were assessed during the entire study period by a blinded observer.

Results

There were no significant differences between the two study groups regarding the demographic and surgical data (P > 0.05). The incidence of shivering during the entire study period significantly decreased in the group of parturients who received intrathecal meperidine (P = 0.04). There were no significant differences in nausea and vomiting between the two groups.

Conclusions

Low-dose intrathecal meperidine (10 mg) is safe and effective in reducing the incidence and severity of shivering associated with spinal anesthesia in parturients with cesarean section.

Prophylactic ondansetron does not prevent shivering or decrease shivering severity during cesarean delivery under combined spinal epidural anesthesia: a randomized trial

OBJECTIVES

Cesarean delivery is commonly performed under regional anesthesia, which is often associated with maternal shivering. This can cause distress and interfere with monitoring. The study objective was to evaluate the antishivering efficacy of ondansetron, which reduces the incidence and severity of shivering in nonobstetric patients. We hypothesized that there would be a significant decrease in the incidence and/or severity of shivering in women who are given intravenous ondansetron 8 mg before combined spinal epidural (CSE) anesthesia, when compared with placebo.

METHODS

This was a randomized, double-blinded, parallel-group, placebo-controlled trial of 118 women scheduled for elective cesarean surgery. Women received either intravenous ondansetron 8 mg (n = 58) or saline (n = 60) before CSE anesthesia (intrathecal hyperbaric bupivacaine 0.5% 2.2-2.5 mL plus fentanyl 15 μg). The incidence and severity of shivering, measured on a validated 5-point scale, and other outcomes, such as nausea, pruritus, headache, or satisfaction, were assessed at 3 time points during the surgery and postoperative period.

RESULTS

The incidence of shivering at any time point did not differ significantly between groups: ondansetron 41% versus placebo 47% (P = 0.54). The incidence of severe shivering at any time was not significantly different: ondansetron 32% versus placebo 33% (P = 0.79). There were no significant differences between the groups for any secondary outcomes.

CONCLUSIONS

Intravenous ondansetron 8 mg before performing CSE anesthesia in women undergoing elective cesarean delivery does not decrease the incidence or severity of shivering.