Preoperative Warming Versus no Preoperative Warming for Maintenance of Normothermia in Women Receiving Intrathecal Morphine for Cesarean Delivery: A Single-Blinded, Randomized Controlled Trial

Finger cuff versus invasive and noninvasive arterial pressure measurement in pregnant patients with obesity

BACKGROUND

Pregnant patients with obesity may have compromised noninvasive blood pressure (NIBP) measurement. We assessed the accuracy and trending ability of the ClearSight™ finger cuff (FC) with invasive arterial monitoring (INV) and arm NIBP, in obese patients having cesarean delivery.

METHODS

Participants were aged ≥18 years, ≥34 weeks gestation, and body mass index (BMI) ≥ 40 kg m-2. FC, INV, and NIBP measurements were obtained across 5-min intervals. The primary outcome was agreement of FC measurements with those of the reference standard INV, using modified Bland-Altman plots. Secondary outcomes included comparisons between FC and NIBP and NIBP versus INV, with four-quadrant plots performed to report discordance rates and evaluate trending ability.

RESULTS

Twenty-three participants had a median (IQR) BMI of 45 kg m-2 (44-48). When comparing FC and INV the mean bias (SD, 95% limits of agreement) for systolic blood pressure (SBP) was 16 mmHg (17, -17.3 to 49.3 mmHg), for diastolic blood pressure (DBP) -0.2 mmHg (10.5, -20.7 to 20.3), and for mean arterial pressure (MAP) 5.2 mmHg (11.1, -16.6 to 27.0 mmHg). Discordance occurred in 54 (26%) pairs for SBP, 41 (23%) for DBP, and 41 (21.7%) for MAP. Error grid analysis showed 92.1% of SBP readings in Zone A (no-risk zone). When comparing NIBP and INV, the mean bias (95% limits of agreement) for SBP was 13.0 mmHg (16.7, -19.7 to 29.3), for DBP 5.9 mmHg (11.9, -17.4 to 42.0), and for MAP 8.2 mmHg (11.9, -15.2 to 31.6). Discordance occurred in SBP (84 of 209, 40.2%), DBP (74 of 187, 39.6%), and MAP (63 of 191, 33.0%).

CONCLUSIONS

The FC and NIBP techniques were not adequately in agreement with INV. Trending capability was better for FC than NIBP. Clinically important differences may occur in the setting of the perfusion-dependent fetus.

Prewarming Parturients for Cesarean Section Does Not Raise Wound Temperature But Body Heat and Level of Comfort: A Randomized Trial

PURPOSE

Prewarming before cesarean section lowers the rates of surgical site infections (SSIs). We hypothesized that this effect is explained due to a higher core temperature resulting in a higher wound temperature.

DESIGN

We conducted an open-labeled randomized study with on-term parturients scheduled for elective cesarean section under spinal anesthesia. Participants were randomized into an intervention group (prewarming) and a control group.

METHODS

Core and wound temperature, comfort level, and examination results were taken at defined times until discharge from the postanesthesia care unit (PACU). There was a follow-up visit and interview 1 day after the procedure. The primary outcome was a difference in wound temperature. The secondary outcomes were differences in core temperature, patient comfort, blood loss, SSI, and neonatal outcome.

FINDINGS

We randomized a total of 60 patients, 30 per group. Prewarming lead to a significantly higher core temperature. Additionally, patient comfort was significantly higher in the prewarming group even after discharge from PACU. We did not find a difference in wound temperature, SSI, neonatal outcome, or blood loss.

CONCLUSIONS

Prewarming before cesarean section under spinal anesthesia maintains core temperature and improves patient comfort but does not affect wound temperature.

The effectiveness of warming approaches in preventing perioperative hypothermia: Systematic review and meta-analysis

AIM

To assess if experimental warming interventions are superior to routine warming interventions in preventing perioperative hypothermia.

BACKGROUND

Perioperative hypothermia is a critical issue for the complications of surgery. There are various kinds of perioperative warming interventions, including experimental and routine warming interventions.

METHODS

We performed a systematic literature review and meta-analysis for the randomized clinical trials of experimental warming interventions vs. routine warming interventions in the perioperative period.

FINDINGS

A total of 15 studies were included with 983 participants allocated to experimental warming interventions and 939 controls with routine warming interventions, who were receiving a variety of surgeries. The focused outcome was the intraoperative and postoperative body temperature. All included studies were randomized clinical trials. Among the participants receiving operations, the meta-analysis showed that routine warming intervention groups experienced lower intraoperative and postoperative body temperatures compared to the experimental warming groups. The meta-analysis results included positive mean differences, significant tests for overall effect and significant heterogeneity in the random-effects model.

CONCLUSIONS

In spite of significant heterogeneity, experimental warming interventions are likely to demonstrate superior warming effects when compared to routine warming interventions, as shown by the current meta-analysis results of randomized clinical trials.

Perioperative hypothermia prevention: development of simple principles and practice recommendations using a multidisciplinary consensus-based approach

OBJECTIVES

To develop a consensus on evidence-based principles and recommendations for perioperative hypothermia prevention in the Australian context.

DESIGN

This study was informed by CAN-IMPLEMENT using the ADAPTE process: (1) formation of a multidisciplinary development team; (2) systematic search process identifying existing guidance for perioperative hypothermia prevention; (3) appraisal using the AGREE II Rigor of Development domain; (4) extraction of recommendations from guidelines meeting a quality threshold using the AGREE-REX tool; (5) review of draft principles and recommendations by multidisciplinary clinicians nationally and (6) subsequent round of discussion, drafting, reflection and revision by the original panel member team.

SETTING

Australian perioperative departments.

PARTICIPANTS

Registered nurses, anaesthetists, surgeons and anaesthetic allied health practitioners.

RESULTS

A total of 23 papers (12 guidelines, 6 evidence summaries, 3 standards, 1 best practice sheet and 1 evidence-based bundle) formed the evidence base. After evidence synthesis and development of draft recommendations, 219 perioperative clinicians provided feedback. Following refinement, three simple principles for perioperative hypothermia prevention were developed with supporting practice recommendations: (1) actively monitor core temperature for all patients at all times; (2) warm actively to keep body temperature above 36°C and patients comfortable and (3) minimise exposure to cold at all stages of perioperative care.

CONCLUSION

This consensus process has generated principles and practice recommendations for hypothermia prevention that are ready for implementation with local adaptation. Further evaluation will be undertaken in a large-scale implementation trial across Australian hospitals.

Effect of early oral carbohydrate intake after elective Cesarean delivery on maternal body temperature and satisfaction: a randomized controlled trial

PURPOSE

Although the Enhanced Recovery After Cesarean Delivery (ERAC) consensus statement provides recommendations for early postoperative drinking and eating, evidence from high-quality clinical research directly addressing parturients is sparse. Our objective was to assess if early oral carbohydrate intake after elective Cesarean delivery improves maternal recovery.

METHODS

In this randomized controlled trial, we enrolled parturients undergoing elective Cesarean delivery under spinal anesthesia with tympanic membrane temperatures ≤ 36.5 °C immediately upon arrival at the postanesthesia care unit. Parturients were randomized to either 100 mL of oral complex carbohydrate intake (group CC) or 10 mL of water (group C). The primary outcome was maternal tympanic membrane temperature. Other outcomes included maternal thermal comfort score, degree of shivering, satisfaction, degree of thirst and hunger, and gastric emptying assessed by ultrasonography.

RESULTS

We included 90 participants in the final analysis. The mean (standard deviation [SD]) maternal body temperature at 120 min after ingestion was 36.7 (0.3) °C in group CC and 36.6 (0.3) °C in group C (difference in means, 0.14 °C; 95% confidence interval, 0.02 to 0.26; P = 0.02). Furthermore, using repeated measure models, the linear trends of temperature changes over time between groups CC and C were significantly different (P = 0.04). The thermal comfort scores at 120 min after ingestion were higher in group CC than in group C (P = 0.02), and the linear trends of shivering score changes over time between groups CC and C also were different (P = 0.003). The mean (SD) visual analogue scale scores for maternal satisfaction were 84 (13) mm in group CC and 47 (20) mm in group C (P < 0.001). Nevertheless, at 90 and 120 min after ingestion, there were no differences between the two groups in the number of participants with a gastric antrum cross-sectional area > 10.3 cm2.

CONCLUSIONS

Early oral carbohydrate intake after Cesarean delivery helped to restore maternal body temperature postoperatively and improve maternal satisfaction. Nevertheless, the clinical importance of these finding is unclear, given that most of the differences were small. In addition, there was no delay in maternal gastric emptying after consumption of a complex carbohydrate beverage in the early post-Cesarean period.

STUDY REGISTRATION

www.chictr.org.cn (ChiCTR2000031085); first submitted 13 November 2022.

The effect of forced-air warming in the cesarean section on maternal hypothermia, shivering, and thermal comfort: A randomized controlled trial

This trial was carried out to investigate the effect of forced air warming in various body areas of women on hypothermia during cesarean delivery. The patients in the study groups (n = 76) were assigned to the full-body warming group, upper-extremity warming group, lower-extremity warming group, and control groups. The intervention groups received forced-air warming 30 min before the surgery and continued until 30 min after surgery. The incidence of hypothermia was significantly higher in the control group than in the other groups at the 60th minute of the operation (p < 0.01). The intervention and control groups showed significant differences in the frequency of shivering at the entrance to the PACU (p = 0.001). Thermal comfort scores have significant difference between the control group and all of the intervention groups (p<.001). It is said that the full-body forced-air warming technique prevents hypothermia, shivering, and thermal discomfort in women Cesarean Section (CS).

Hypothermia With Paradoxical Symptoms: A Case Series of Cesarean Deliveries With Intrathecal Morphine

Women receiving intrathecal morphine for cesarean delivery may experience hypothermia with paradoxical symptoms of sweating, nausea, and shivering. Despite being relatively rare in comparison to commonly experienced symptoms of perioperative hypothermia, hypothermia with paradoxical symptoms affects early maternal recovery and comfort. The cause is undetermined, and treatment approaches vary. Regular active-warming strategies may not be tolerated because of the paradoxical symptoms of sweating and feeling overheated. This case series aims to explore the phenomenon through the evaluation of health care records of women receiving intrathecal morphine for cesarean delivery at a single, tertiary health care institution in Australia from 2015 to 2018. We also summarize published literature to review treatment approaches used in the care of women experiencing profound heat loss while feeling overheated.

Relationship between perfusion index and central temperature before and after induction of anesthesia in laparoscopic gastrointestinal surgery: A prospective cohort study

The perfusion index (PI) cutoff value before anesthesia induction and the ratio of PI variation after anesthesia induction remain unclear. This study aimed to clarify the relationship between PI and central temperature during anesthesia induction, and the potential of PI in individualized and effective control of redistribution hypothermia. This prospective observational single center study analyzed 100 gastrointestinal surgeries performed under general anesthesia from August 2021 to February 2022. The PI was measured as peripheral perfusion, and the relationship between central and peripheral temperature values was investigated. Receiver operating characteristic curve analysis was performed to identify baseline PI before anesthesia, which predicts a decrease in central temperature 30 minutes after anesthesia induction, and the rate of change in PI that predicts the decrease in central temperature 60 minutes after anesthesia induction. In cases with a central temperature decrease of ≥ 0.6°C after 30 minutes, the area under the curve was 0.744, Youden index was 0.456, and the cutoff value of baseline PI was 2.30. In cases with a central temperature decrease of ≥ 0.6°C after 60 minutes, the area under curve was 0.857, Youden index was 0.693, and the cutoff value of the PI ratio of variation after 30 minutes of anesthesia induction was 1.58. If the baseline PI is ≤ 2.30 and the PI 30 minutes after anesthesia induction is at least 1.58-fold the PI ratio of variation, there is a high probability of a central temperature decrease of at least 0.6°C within 30 minutes after 2 time points.

Combined Forced Air Warming and Warm Intravenous Fluid Strategy for Perioperative Hypothermia in Cesarean Delivery: A Systematic Review and Meta-Analysis

PURPOSE

Evaluate the effect of a combined forced-air warming (FAW) and warm intravenous fluid (IVF) modality on maternal and neonatal outcomes in cesarean delivery under neuraxial anesthesia.

DESIGN

Systematic Review and Meta-analysis.

METHODS

An extensive search was conducted using PubMed, Cochrane Library, MEDLINE, CINAHL, Google Scholar, and other grey literature. Only randomized controlled trials examining the combined modality on maternal temperatures were included. Risk ratio (RR), mean difference (MD), and standardized mean difference (SMD) were used to estimate outcomes with suitable effect models. Quality of evidence was assessed using the Risk of Bias and GRADE system.

FINDINGS

Nine trials involving 595 patients were included. Combined strategy showed a smaller change in maternal temperature from baseline by 0.42°C (MD, -0.42; 95% CI, -0.62 to -0.22; P < .0001), higher temperature on PACU arrival (MD, 0.46; 95% CI, 0.11-0.82; P = .01), 15 minutes (MD, 0.43; 95% CI, 0.19-0.67; P = .0004) and 30 minutes after surgery (MD, 0.38; 95% CI, 0.12-0.64; P = .005). Combined strategy also reduced the incidence of hypothermia (RR, 0.55; 95% CI, 0.31-0.95; P = .03), and shivering (RR, 0.40; 95% CI, 0.28-0.58; P < .00001) with improvement in maternal comfort score (SMD; 0.38; 95% CI, 0.08-0.69; P = .01). However, there were no differences in clinical indicators of adverse neonatal outcomes. Lack of participants blinding, and substantial heterogeneity were limitations of this review.

CONCLUSION

The use of combined FAW and warm IVF is an effective strategy in mitigating perioperative hypothermia in cesarean delivery under neuraxial anesthesia.

Comparison of the Effect of Forced-air Warming and Warmed Intravenous Fluid on the Comfort and Prevention of Shivering After Spinal Anesthesia in Patients Undergoing Orthopedic Surgery

PURPOSE

This study aimed to compare the effect of forced-air warming and warmed intravenous fluid on the comfort and prevention of shivering after spinal anesthesia in patients undergoing orthopaedic surgery.

DESIGN

Randomized controlled clinical trial.

METHODS

A total of 120 patients were randomly divided into three groups: forced-air warming (38°C), warmed intravenous fluid (37°C), and the control group. Patients' comfort and severity of shivering were measured and recorded five times (immediately and 15 minutes after spinal anesthesia, end of the surgery, time of entrance to the recovery room, and 15 minutes after entering the recovery room), and compared with each other.

FINDINGS

There was a significant difference between the three groups in terms of comfort at all points of evaluation times (P < .001). The comfort score in the control group was significantly higher than the two intervention groups (P < .001). Moreover, the comfort score in the warmed intravenous fluid group was significantly higher than the forced-air warming group (P < .001). In addition, there was a significant difference in shivering severity between the three groups at the end of the surgery, entrance to the recovery room, and 15 minutes after surgery (P < .001). The majority of patients in the forced-air warming group (90%) had no shivering at all three times, while the warmed IV fluid and control groups was 65% and 30% respectively.

CONCLUSIONS

Non-pharmacological methods such as forced-air warming and warmed intravenous fluid can provide comfort and prevent shivering in orthopaedic patients undergoing spinal anesthesia. However, the use of forced-air warming is more effective than warmed intravenous fluid in providing comfort and preventing shivering in these patients. It is recommended that these methods be used in the operating room to provide comfort and prevent shivering in these patients.

Effect of active and passive warming on preventing hypothermia and shivering during cesarean delivery: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Perioperative hypothermia and shivering commonly occur in pregnant women undergoing cesarean section. The warming method is usually used to prevent hypothermia and shivering. However, the effect of active warming (AW) prior to passive warming (PW) on the perioperative outcomes of pregnant women and their offspring remains controversial.

METHODS

This study aimed to investigate the effects of AW and PW on maternal and newborn perioperative outcomes during cesarean delivery. According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses, PubMed, Embase, Scopus, and the Cochrane Library were used to search for randomized controlled trials (RCTs) up to August 7, 2022. The Cochrane risk of bias assessment tool was used to assess articles selected for the systematic review. Continuous data were analyzed using weighted mean differences (WMDs) with 95% confidence intervals (CIs), and categorical data were analyzed by the random-effects model.

RESULTS

A total of 1241 participants from twelve RCTs were selected for the final meta-analysis. AW was associated with a lower risk of maternal hypothermia (RR: 0.77, 95% CI: 0.63-0.93, P = 0.007) and shivering (RR: 0.56, 95% CI: 0.37-0.85; P = 0.007). AW was associated with high maternal temperature (WMD: 0.27, 95%CI: 0.14 to 0.40, P < 0.001). No significant difference was observed between AW and PW in terms of hypothermia (RR: 0.60, 95% CI: 0.24-1.51, P = 0.278), temperature (WMD: 0.31, 95% CI: - 0.00 to 0.62; P = 0.050), and umbilical vein PH in newborns (WMD: -0.00; 95% CI: - 0.02 to 0.02, P = 0.710).

CONCLUSIONS

These findings suggested that AW can better prevent maternal hypothermia and shivering than PW. In contrast, no significant effect was observed in newborns. Overall, the quality of the included studies is high due to RCTs, low risk of bias, consistency, and precision. We identified the quality of the overall evidence from the survey to be GRADE I.

Effect of Forced-Air Warming Blanket on Perioperative Hypothermia in Elderly Patients Undergoing Laparoscopic Radical Resection of Colorectal Cancer

The study aimed to evaluate the effect of forced-air warming blanket combined with conventional thermal insulation measures on inadvertent perioperative hypothermia (IPH) in elderly patients undergoing laparoscopic radical resection of colorectal cancer. A total of 70 elderly patients undergoing laparoscopic radical resection of colorectal cancer with general anesthesia were included, and divided into conventional warming treatment (CT) group or forced-air warming treatment (FT) group. In the FT group, based on the conventional warming strategy, patients received prewarming with the forced-air warming blanket (38°C) for ≥20 minutes before induction of anesthesia, and received this treatment continuously during operation. The core body temperature, recovery time from anesthesia, extubating time, and length of stay in the postanesthesia care unit were recorded. The incidence of IPH and postoperative shivering was observed. The incidence of IPH was significantly lower, and average minimum body temperature during the operation was significantly higher in the FT group than that in the CT group (5.7% vs. 22.8% and 36.23°C vs. 35.89°C, respectively). The intraoperative body temperature decreased less (0.32°C vs. 0.69°C), the recovery time from anesthesia was faster (12.8 minutes vs. 17.1 minutes), and the incidence of postoperative shivering was less (2.8% vs. 28.6%) in the FT group than the CT group. In elderly patients undergoing laparoscopic radical resection of colorectal cancer, use of forced-air warming blankets combined with conventional warming measures is more effective to maintain normal body temperature during the perioperative period and reduce the incidence of IPH.

Nurse-Led Randomized Controlled Trials in the Perioperative Setting: A Scoping Review

PURPOSE

Nurses provide care at each phase of the complex, perioperative pathway and are well placed to identify areas of care requiring investigation in randomized controlled trials. Yet, currently, the scope of nurse-led randomized controlled trials conducted within the perioperative setting are unknown. This scoping review aims to identify areas of perioperative care in which nurse-led randomized controlled trials have been conducted, to identify issues impacting upon the quality of these trials and identify gaps for future investigation.

METHODS

This scoping review was conducted in reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews. Searches were conducted in PubMed, Embase, Cumulative Index for Nursing and Allied Health Literature and the Cochrane Central Register of Controlled Trials, with a date range of 2014-19. Sources of unpublished literature included Open Grey, and ProQuest Dissertation and Theses, Clinical Trials.gov and the Australian and New Zealand Clinical Trials Registry. After title and abstract checking, full-text retrieval and data extraction, studies were appraised using the Joanna Briggs Institute Critical Appraisal Checklists for randomized controlled trials. Data were synthesized according to the main objectives. Key information was tabulated.

RESULTS

From the 86 included studies, key areas where nurses have led randomized controlled trials include patient or caregiver anxiety; postoperative pain relief; surgical site infection prevention: patient and caregiver knowledge; perioperative hypothermia prevention; postoperative nausea and vomiting; in addition to other diverse outcomes. Issues impacting upon quality (including poorly reported randomization), and gaps for future investigation (including a focus on vulnerable populations), are evident.

CONCLUSION

Nurse-led randomized controlled trials in the perioperative setting have focused on key areas of perioperative care. Yet, opportunities exist for nurses to lead experimental research in other perioperative priority areas and within different populations that have been neglected, such as in the population of older adults undergoing surgery.

Altered Thermoregulatory Responses Following Spinal Morphine for Caesarean Delivery: a Case Report

OBJECTIVE

Spinal anaesthesia interferes with physiological thermoregulatory responses, potentially leading to peri-operative hypothermia. Spinal morphine can further compound this by a paradoxical clinical presentation leading to poor patient outcome.

CASE REPORT

Following an uneventful caesarean delivery (CD) under spinal anaesthesia with intrathecal morphine for post-operative analgesia, a parturient presented in the recovery room with increasing somnolence, excessive sweating and a sensation of feeling hot. She was haemodynamically stable, but her temperature was 34.5°C. Active warming measures were implemented, and normothermia was achieved in 3 hours.

CONCLUSION

Spinal morphine can alter the clinical presentation of hypothermia by manifesting as excessive sweating and subjective sensation of warmth. Teams involved in the perioperative care of parturients should be aware of (a) the possibility of spinal anaesthesia causing perioperative hypothermia, (b) intrathecal morphine masking the clinical presentation of hypothermia and (c) the importance of monitoring temperature of patients who have received spinal anaesthesia with added morphine.

Improving intraoperative temperature management in elective repeat cesarean deliveries: a retrospective observational cohort study

Background

Inadvertent perioperative hypothermia (< 36 °C) occurs frequently during elective cesarean delivery and most institutions do employ perioperative active warming. The purpose of this retrospective observational cohort study was to determine if the addition of preoperative forced air warming in conjunction with intraoperative underbody forced air warming improved core temperature and reducing inadvertent perioperative hypothermia during elective repeat elective cesarean delivery with neuraxial anesthesia.

Methods

We evaluated the addition of perioperative active warming to standard passive warming methods (preheated intravenous/irrigation fluids and cotton blankets) in 120 parturients scheduled for repeat elective cesarean delivery (passive warming, n = 60 vs. active + passive warming, n = 60) in a retrospective observational cohort study. The primary outcomes of interest were core temperature at the end of the procedure and a decrease in inadvertent perioperative hypothermia (< 36 °C). Secondary outcomes were surgical site infections and adverse markers of neonatal outcome.

Results

The mean temperature at the end of surgery after instituting the active warming protocol was 36.0 ± 0.5 °C (mean ± SD, 95% CI 35.9–36.1) vs. 35.4 ± 0.5 °C (mean ± SD, 95% CI 35.3–35.5) compared to passive warming techniques (p <  0.001) and the incidence of inadvertent perioperative hypothermia at the end of the procedure was less in the active warming group - 68% versus 92% in the control group (p <  0.001). There was no difference in surgical site infections or neonatal outcomes.

Conclusions

Perioperative active warming in combination with passive warming techniques was associated with a higher maternal temperature and lower incidence of inadvertent perioperative hypothermia with no detectable differences in surgical site infections or indicators of adverse neonatal outcomes.

Effects of preoperative warming on the occurrence of surgical site infection: A systematic review and meta-analysis

OBJECTIVE

To determine whether preoperative warming can reduce the risk of surgical site infection (SSI) after surgery.

BACKGROUND

Intraoperative hypothermia is a risk factor for the occurrence of SSI in patients after surgery. However, the effectiveness of preoperative warming in reducing the incidence of the condition remains unclear.

MATERIALS AND METHODS

A systematic review was conducted using Medline, EMBASE, and the Cochrane Library to identify randomized controlled trials (RCTs) that evaluated the risk of SSI after surgery with and without the use of a preoperative warming protocol. The primary outcome measure was the diagnosis of SSI within 10-90 days of surgery. The pooled risk ratio was estimated with a fixed-effect meta-analysis. Sensitivity analyses were performed to examine the impact of the structural design of preoperative warming on the pooled risk of SSI.

RESULTS

Of the 249 studies identified, seven RCTs representing 1086 patients were included in the present meta-analysis. The use of preoperative warming was associated with a significant decrease in SSI (RR = 0.60, 95% CI 0.42-0.87, P = 0.072). Specifically, we defined patients who used forced-air warming (FAW) and integrated measures such as liquid heating and warming blankets as the MIX group and patients who used only FAW as the FAW group. Patients who used MIX methods (temperature set <43 °C and 30-min prewarming) before surgery benefited more from prewarming.

CONCLUSIONS

The results of this study suggest that preoperative warming can reduce rates of SSI after surgery. We, therefore, recommend the application of MIX warming methods before surgery.

Effects of combined warmed preoperative forced-air and warmed perioperative intravenous fluids on maternal temperature during cesarean section: a prospective, randomized, controlled clinical trial

Background

Preventing the frequent perioperative hypothermia incidents that occur during elective caesarean deliveries would be beneficial. This trial aimed at evaluating the effect of preoperative forced-air warming alongside perioperative intravenous fluid warming in women undergoing cesarean sections under spinal anesthesia.

Methods

We randomly allocated 135 women undergoing elective cesarean deliveries to either the intervention group (preoperative forced-air and intravenous fluid warming, n = 69) or the control group (no active warming, n = 66). The primary outcome measure was the core temperature change between groups from baseline to the end of the surgical procedure. Secondary outcomes included thermal comfort scores, the incidences of shivering and hypothermia (< 36 °C), the core temperature on arrival at the post-anesthesia care unit, neonatal axillary temperature at birth, and Apgar scores.

Results

Two-way repeated measures ANOVA revealed significantly different core temperature changes (from the pre-spinal temperature to that at the end of the procedure) between groups (F = 13.022, P < 0.001). The thermal comfort scores were also higher in the intervention group than in the control group (F = 9.847, P = 0.002). The overall incidence of perioperative hypothermia was significantly lower in the intervention group than in the control group (20.6% vs. 51.6%, P < 0.0001).

Conclusions

Warming preoperative forced-air and perioperative intravenous fluids may prevent maternal hypothermia, reduce maternal shivering, and improve maternal thermal comfort for patients undergoing cesarean sections under spinal anesthesia.

Trial registration

The study was registered with the Chinese Clinical Trial Registry (registration number: ChiCTR1800019117) on October26, 2018.

Prospective observational study of the effectiveness of prewarming on perioperative hypothermia in surgical patients submitted to spinal anesthesia

Prewarming has been shown to prevent intraoperative inadvertent hypothermia. Nevertheless, data about optimal prewarming-time from published clinical trials report contradictory results. We conducted this pilot study to evaluate routine clinical practice regarding prewarming and its effect on the prevalence of perioperative hypothermia in patients undergoing transurethral resection (TUR) under spinal anesthesia. This was a prospective, observational, pilot study to examine clinical practice in a tertiary hospital regarding prewarming in 140 consecutive patients. When prewarming (pw) was performed, forced-air warming was provided in the pre-anesthesia room for 15 (pw15), 30 (pw30), or 45 (pw45) min. Tympanic temperature was recorded upon entering the pre-anesthesia room, at the time of initiating surgery, and every 15 min intra-operatively. We also recorded duration of the surgical procedure and length of stay in the Post-Anesthesia Care Unit (PACU). Pw15 was performed in 34 patients, pw30 in 29 patients, and pw45 in 21 patients. Fifty-six patients did not receive pw and 96% of them developed hypothermia at the end of the surgical procedure, compared to 73% of patients in pw15 (p = 0.002), 75% in pw30 (p = 0.006) and 90% in pw45 (p = 0.3). Length of stay in the PACU was markedly shorter in pw15 (131 ± 69 min) and pw30 (123 ± 60 min) than in the non-pw group (197 ± 105 min) (p = 0.015 and p = 0.011, respectively). This difference was not significant in pw45 (129 ± 56 min) compared to non-pw patients. In conclusion, prewarming for 15 or 30 min before TUR under spinal anesthesia prevents development of hypothermia at the end of the surgical procedure.

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.