Effect of Perioperative Active Body Surface Warming Systems on Analgesic and Clinical Outcomes: A Systematic Review and Meta-analysis of Randomized Controlled Trials

A prospective randomized study of the efficacy of continuous active warming in patients undergoing laparoscopic gastrectomy

BACKGROUND

The RCT study on the efficacy of continuous active warming (CAW) in patients undergoing laparoscopic gastrectomy is scarce. The purpose of this research was to determine if a significant difference between continuous active warming (CAW) and active warming when body temperature is below 36 °C (BAW) in terms of incidence of intraoperative hypothermia and clinical rehabilitation in patients undergoing laparoscopic gastrectomy surgery.

METHODS

A prospective, randomized and controlled trial with a sample of 62 patients who underwent elective total laparoscopic radical gastrectomy was conducted. Patients assigned to CAW group were warmed immediately since the surgical incision procedure, the others were warmed while the body bladder temperature dropped to 36 °C. The bladder temperature of the patient was recorded every 30 min during the operation. One-way ANOVA and ANOVA with repeated measures were used for comparisons between multiple groups, independent samples t-test for pair-wise comparisons.

RESULTS

This study included a total of 62 patients, with 31 in each group. Among them, there were 52 males and 10 females, with an age range of 39 to 83 years. The mean age in the CAW group was (62.52 ± 8.15) years, and in the BAW group, it was (62.74 ± 9.20) years. The overall incidence of hypothermia was 16.13% in 62 patients who underwent elective total laparoscopic radical gastrectomy. The incidence of shivering and agitation after operation was both 3.23% in CAW group, and it was 32.26% and 29.03% in BAW group. Time from end of surgery to tracheal extubation in CAW group was significantly lower than BAW group. In addition, continuous active warming could shorten time to first postoperative flatus of patients and relieve postoperative pain.

CONCLUSION

Our study showed that continuous active warming in patients undergoing laparoscopic gastrectomy decreased the incidence of intraoperative hypothermia and contributed to postoperative rehabilitation.

TRIAL REGISTRATION

It was permitted by the Ethics Committee of Xijing Hospital, Air Force Military Medical University, China. No. KY20212024-C-1 25/01/2021 and was registered with the Chinese Clinical Trial Registration Center (11/02/2025) ( www.chictr.org.cn ; registration number: ChiCTR2500097060).

The Effect of Temperature Chain Management Scheme During Robot-Assisted Radical Prostatectomy

The study aimed to explore the effect of the temperature chain management scheme on preventing hypothermia in patients undergoing robot-assisted radical prostatectomy (RARP). The patients were randomized to receive either intraoperative warming only (control group, Group C) or the temperature chain management (experimental group, Group T). We compared the core temperature, inadvertent perioperative hypothermia (IPH) rates, the incidence of shivering, and thermal comfort between the two groups. The perioperative core temperature of the Group T was higher than that of the Group C, and the incidence of IPH, the incidence of shivering in the postanesthesia care unit (PACU), and the length of stay in PACU were lower than those of the control group. The thermal comfort of Group T scored higher than that of Group C when leaving the PACU, all above have a statistically significant difference (p < 0.05). The temperature chain management scheme could decrease the IPH rates and reduce postoperative complications in RARP patients. The Clinical Trials Registration number is 2023IIT034.

Warming with a composite warming strategy reduces intraoperative hypothermia in patients undergoing open hepatectomy for liver cancer: A randomized controlled study

BACKGROUND

This study investigated the application of a composite warming strategy in the perioperative care of patients who underwent open hepatectomy for liver cancer. The clinical efficacy of the composite warming strategy was observed and analyzed, and the factors causing hypothermia were discussed.

METHODS

From January 2020 to December 2021, 80 patients were selected for the study. The control group adopted perioperative forced-air warming measures, while the experimental group implemented a composite warming strategy. The clinical data of the 2 groups of patients were compared, and the factors influencing intraoperative hypothermia were explored.

RESULTS

The incidence of hypothermia in the composite warming strategy group was significantly lower than that in the forced-air warming group (P = .015). There were no significant differences in sex, age, BMI, stage of liver cancer, presence of liver cirrhosis, chronic hepatitis, history of alcohol consumption, PLT, PT, pain score, length of hospital stay, etc, between the 2 groups (P > .05). However, there were significant differences in intraoperative fluid volume, anesthesia time, intraoperative blood loss, and PACU observation time (P < .05). Multivariate analysis revealed that intraoperative blood loss, intraoperative fluid replacement volume, and operation time were factors influencing intraoperative hypothermia (P < .05).

CONCLUSION

The composite warming strategy plays a role in preventing hypothermia during open hepatectomy for liver cancer. The occurrence of hypothermia during open hepatectomy for liver cancer patients is related to intraoperative blood loss, intraoperative fluid replacement volume, and anesthesia time.

Implementing Guidelines for hypothermia prevention with Local adaptation to keep periOperative patients Warm (GLOW): protocol of a stepped-wedge cluster randomised hybrid type II effectiveness-implementation study

INTRODUCTION

Perioperative hypothermia is a common and preventable complication of surgery. Systems level change that enables perioperative teams to integrate hypothermia prevention into practice in ways that are contextually appropriate is needed. The purpose of this trial is to evaluate the effectiveness and implementation of perioperative hypothermia prevention guidance with local adaptation on clinical, implementation and economic outcomes. Our objective is to decrease the risk of patients developing perioperative hypothermia.

METHODS AND ANALYSIS

A hybrid type II effectiveness-implementation study. An incomplete stepped-wedge cluster randomised controlled trial design will be used, with a 6-month transition period for implementation. Perioperative departments from five major public hospitals in South East Queensland, Australia, will participate over 27 months. The co-primary outcomes are (effectiveness) hypothermia on arrival to the post anaesthetic care unit (PACU) and (implementation) extent of temperature monitoring and active warming. Secondary clinical effectiveness outcomes include hypothermia at any perioperative time point, PACU and hospital length of stay, intraoperative or post-anaesthetic adverse events, blood transfusions and surgical site infection. Secondary implementation outcomes include pre-transition measures of adoptability and implementability, and post-transition measures of adoption, fidelity of implementation strategy and site team learning. Cost-effectiveness will evaluate implementation costs and quality-adjusted life years. Based on the number and unequal sizes of clusters, we used a constrained randomisation approach for sample size determination to minimise the imbalance between control and intervention period sample sizes. Generalised linear mixed models will be used to analyse primary and secondary outcomes.

ETHICS AND DISSEMINATION

Ethical approval was obtained with a waiver of consent to access clinical records (reference: HREC/2023/MNHB/94571). Informed consent will be sought from patients completing surveys. Consent will be implied from clinicians participating in implementation evaluation. Findings will be disseminated through journal publications and conference presentations. Practice and policy recommendations will be collaboratively developed with partner organisations.

TRIAL REGISTRATION NUMBER

Prospective registration of the trial was obtained on 28 July 2023 on the Australia and New Zealand Clinical Trials Registry Network: ACTRN12623000814673.

Hypothermia: Pathophysiology and the propensity for infection

Hypothermia in combination with infection presents a complex challenge in clinical and battlefield medicine. Multifaceted physiological and immunological consequences of hypothermia drastically change the risk, progression, and treatment of a concomitant infection. Managing hypothermia and infection in extreme cold settings is particularly relevant in an era with increased risk of military operations in Polar climates. Here, we discuss the elevated instance of infection during accidental and therapeutic hypothermia and speculate how a compromised immune system may contribute. We focus on skin and soft tissue infections and sepsis, which are among the serious infectious complications of hypothermia and battlefield injuries. We also present the challenges associated with treating infections under hypothermic conditions. Finally, we advocate for a renewed focus on identifying causal relationships between hypothermia and infection risk and assessing established infection treatment regiments in hypothermic patients to enhance trauma management and survival outcomes in hypothermia-related injuries.

Barriers and Solutions in Implementing Evidence-Based Recommendations to Prevent Intraoperative Inadvertent Hypothermia: A Qualitative Study

In this study, it was aimed to understand the barriers and solutions for operating room (OR) nurses and anesthesiologists to implement evidence-based recommendations to prevent intraoperative inadvertent hypothermia (IIH). A qualitative, inductive, and descriptive study was conducted. This qualitative interview study was conducted face-to-face with 19 participants working in OR units between February and March 2023. The interviews were analyzed using qualitative content analysis. The COREQ checklist was followed. Two main themes and five sub-themes were identified as a result of content analysis. According to the participants, barriers to IIH prevention interventions are caused by individual and organizational inefficiencies and personal opinions, and the main solution is education. Participants reported many factors that hinder IIH prevention practices. The individual characteristics of OR staff and the opinions and behavior of the institution are very important for IIH prevention.

Inadvertent perioperative hypothermia and surgical site infections after liver resection

BACKGROUND

In the overall surgical population, inadvertent perioperative hypothermia has been associated with an increased incidence of surgical site infection (SSI). However, recent clinical trials did not validate this notion. This study aimed to investigate the potential correlation between inadvertent perioperative hypothermia and SSIs following liver resection.

METHODS

This retrospective cohort study included all consecutive patients who underwent liver resection between January 2019 and December 2021 at the First Affiliated Hospital, Zhejiang University School of Medicine. Perioperative temperature managements were implemented for all patients included in the analysis. Estimated propensity score matching (PSM) was performed to reduce the baseline imbalances between the normothermia and hypothermia groups. Before and after PSM, univariate analyses were performed to evaluate the correlation between hypothermia and SSI. Multivariate regression analysis was performed to determine whether hypothermia was an independent risk factor for postoperative transfusion and major complications. Subgroup analyses were performed for diabetes mellitus, age > 65 years, and major liver resection.

RESULTS

Among 4000 patients, 2206 had hypothermia (55.2%), of which 150 developed SSI (6.8%). PSM yielded 1434 individuals in each group. After PSM, the hypothermia and normothermia groups demonstrated similar incidence rates of SSI (7.0% vs. 6.3%, P = 0.453), postoperative transfusion (13.7% vs. 13.3%, P = 0.743), and major complications (10.1% vs. 9.0%, P = 0.309). Univariate regression analysis revealed no significant effects of hypothermia on the incidence of SSI in the group with the highest hypothermia exposure [odds ratio (OR) = 1.25, 95% confidence interval (CI): 0.84-1.87, P = 0.266], the group with moderate exposure (OR = 1.00, 95% CI: 0.65-1.53, P = 0.999), or the group with the lowest exposure (OR = 1.11, 95% CI: 0.73-1.65, P = 0.628). The subgroup analysis revealed similar results. Regarding liver function, patients in the hypothermia group demonstrated lower γ-glutamyl transpeptidase (37 vs. 43 U/L, P < 0.001) and alkaline phosphatase (69 vs. 72 U/L, P = 0.016). However, patients in the hypothermia group exhibited prolonged activated partial thromboplastin time (29.2 vs. 28.6 s, P < 0.001).

CONCLUSIONS

In our study of patients undergoing liver resection, we found no significant association between mild perioperative hypothermia and SSI. It might be due to the perioperative temperature managements, especially active warming measures, which limited the impact of perioperative hypothermia on the occurrence of SSI.

Effects of Active Heating Methods on Body Temperature, Shivering, Thermal Comfort, Pain, Nausea and Vomiting During General Anesthesia: A Randomized Controlled Trial

To investigate the effect of forced-air warming and heated intravenous (IV) and irrigation fluids alone and in combination on body temperature, shivering, thermal comfort, pain, nausea and vomiting in adult patients undergoing surgery under general anesthesia in a prospective, four-group, randomized controlled trial. After induction of anesthesia, 120 patients were divided into the following groups: patients warmed with forced-air warming (n = 30), patients receiving warmed IV and irrigation fluid (n = 30), patients receiving warmed IV and irrigation fluid with forced-air warming (n = 30), and the control group without any intervention (n = 30). Body temperature, shivering, thermal comfort, pain, nausea and vomiting were monitored in the first 24 hours after surgery. The general characteristics of the groups, mean body temperature, length of stay, ambient temperature, and duration of surgery in the preoperative waiting unit were similar (p > 0.05). Compared with the other groups, patients in the control group had a significant decrease in body temperature from the 30th minute during surgery (p < 0.001), lower body temperature in the first 2 hours and thermal comfort in the first three hours after surgery (p < 0.01), and higher shivering levels in the first hour after surgery (p < 0.01). There was no significant difference between the groups in terms of postoperative pain, nausea and vomiting (p > 0.05). The study findings showed that normothermia was maintained in all three intervention groups during the surgery and in the first 24 hours after surgery. Moreover, postoperative thermal comfort increased and shivering levels decreased compared with the control group, but pain, nausea and vomiting levels were not affected. The study was registered on ClinicalTrials.gov (NCT04907617).

Effectiveness of accelerated rehabilitation surgical nursing on perioperative outcomes in patients with calcaneal fractures

This study aims to evaluate the impact of accelerated rehabilitation nursing on perioperative outcomes in patients with calcaneal fractures. A total of 101 patients with calcaneal fractures admitted from December 2020 to December 2022 were included in this study. Patients were randomly assigned to an observation group (OG) of 51 patients receiving accelerated rehabilitation surgical nursing and a control group (CG) of 50 patients receiving conventional surgical nursing. Outcomes assessed included patient satisfaction, visual analog scale (VAS) scores before and after surgery, swelling reduction time, and complication rates. The satisfaction rate in the OG was 96.07%, significantly higher than the 80.00% observed in the CG. Post-operative VAS scores at day 4 and 6 were significantly lower in the OG compared to the CG. Swelling reduction time was shorter in the OG (152.56 ± 25.22 hours) compared to the CG (170.76 ± 22.51 hours). Additionally, the complication rate in the OG was significantly lower at 7.84% compared to 24.00% in the CG (P < .05).the implementation of accelerated rehabilitation nursing significantly shortened the average length of hospital stay for patients in the observation group. In contrast, patients in the control group, who received conventional nursing care, had a relatively longer hospital stay. In the perioperative treatment of calcaneal fractures, accelerated rehabilitation surgical nursing can significantly improve patient satisfaction, reduce pain, shorten the time for swelling to subside, and lower the incidence of complications. Additionally, it can shorten the hospital stay for patients, demonstrating its efficacy and potential for broader clinical application.

Perioperative Patient Blood Management (excluding obstetrics): Guidelines from the French National Authority for Health

The French National Authority for Health (HAS) recently issued guidelines for patient blood management (PBM) in surgical procedures. These recommendations are based on three usual pillars of PBM: optimizing red cell mass, minimizing blood loss and optimizing anemia tolerance. In the preoperative period, these guidelines recommend detecting anemia and iron deficiency and taking corrective measures well in advance of surgery, when possible, in case of surgery with moderate to high bleeding risk or known preoperative anemia. In the intraoperative period, the use of tranexamic acid and some surgical techniques are recommended to limit bleeding in case of high bleeding risk or in case of hemorrhage, and the use of cell salvage is recommended in some surgeries with a major risk of transfusion. In the postoperative period, the limitation of blood samples is recommended but the monitoring of postoperative anemia must be carried out and may lead to corrective measures (intravenous iron in particular) or more precise diagnostic assessment of this anemia. A "restrictive" transfusion threshold considering comorbidities and, most importantly, the tolerance of the patient is recommended postoperatively. The implementation of a strategy and a program for patient blood management is recommended throughout the perioperative period in healthcare establishments in order to reduce blood transfusion and length of stay. This article presents an English translation of the HAS recommendations and a summary of the rationale underlying these recommendations.

Estimation of the difference between peritoneal microenvironment and core body temperature during laparoscopic surgery - a prospective observational study

Maintaining patients' temperature during surgery is beneficial since hypothermia has been linked with perioperative complications. Laparoscopic surgery involves the insufflation of carbon dioxide (CO2) into the peritoneal cavity and has become the standard in many surgical indications since it is associated with better and faster recovery. However, the use of cold and dry CO2 insufflation can lead to perioperative hypothermia. We aimed to assess the difference between intraperitoneal and core temperatures during laparoscopic surgery and evaluate the influence of duration and CO2 insufflation volume by fitting a mixed generalized additive model. In this prospective observational single-center cohort trial, we included patients aged over 17 with American Society of Anesthesiology risk scores I to III undergoing laparoscopic surgery. Anesthesia, ventilation, and analgesia followed standard protocols, while patients received active warming using blankets and warmed fluids. Temperature data, CO2 ventilation parameters, and intraabdominal pressure were collected. We recruited 51 patients. The core temperature was maintained above 36 °C and progressively raised toward 37 °C as pneumoperitoneum time passed. In contrast, the intraperitoneal temperature decreased, thus creating a widening difference from 0.4 [25th-75th percentile: 0.2-0.8] °C at the beginning to 2.3 [2.1-2.3] °C after 240 min. Pneumoperitoneum duration and CO2 insufflation volume significantly increased this temperature difference (P < 0.001 for both parameters). Core vs. intraperitoneal temperature difference increased linearly by 0.01 T °C per minute of pneumoperitoneum time up to 120 min and then 0.05 T °C per minute. Each insufflated liter per unit of time, i.e. every 10 min, increased the temperature difference by approximately 0.009 T °C. Our findings highlight the impact of pneumoperitoneum duration and CO2 insufflation volume on the difference between core and intraperitoneal temperatures. Implementing adequate external warming during laparoscopic surgery effectively maintains core temperature despite the use of dry and unwarmed CO2 gases, but peritoneal hypothermia remains a concern, suggesting the importance of further research into regional effects.Trial registration: Clinicaltrials.gov: NCT04294758.

A retrospective cohort study on enhanced recovery after surgery (ERAS) in patients with diabetic foot ulcer

Enhanced recovery after surgery (ERAS) has been successfully integrated into a diverse array of surgical fields to improve the quality and efficacy of treatment intervention. Nonetheless, the application of the ERAS protocol for patients with diabetic foot ulcer (DFU) subsequent to undergoing surgical procedures has not been previously explored. Therefore, this study aimed to investigate the effect of an enhanced recovery protocol on perioperative outcomes in patients with DFU following surgical procedures. A retrospective analysis was conducted on 112 patients with DFU who underwent surgery between January 2020 and December 2021 at a tertiary referral care center. In total, 57 patients received standard perioperative care (the non-ERAS group), and 55 patients received ERAS care (the ERAS group). The primary outcomes included the length of stay (LOS), wound healing time, patient satisfaction, and costs, serving as the basis for assessing the effectiveness of the two approaches. Secondary outcomes included preoperative anxiety (APAIS score), nutritional status (PG-SGA), pain (NRS score), the incidence of lower-extremity deep vein thrombosis (DVT), the reduction in lower-limb circumference, and the activity of daily living scale (Barthel Index). The ERAS group exhibited significantly shorter LOS (11.36 vs. 26.74 days; P < 0.001) and lower hospital costs (CNY 62,165.27 vs. CNY 118,326.84; P < 0.001), as well as a higher patient satisfaction score and Barthel Index score (P < 0.05). Additionally, we found a lower APAIS score, incidence of DVT, and circumference reduction in lower limbs in the ERAS group compared to the non-ERAS group (P < 0.05). In comparison, the wound healing time, nutritional status, and pain levels of participants in both groups showed no significant difference (P > 0.05). By reducing the LOS and hospital costs, and by minimizing perioperative complications, the ERAS protocol improves the quality and efficacy of treatment intervention in patients with DFU who underwent surgical procedures.Trial registration number: ChiCTR 2200064223 (Registration Date: 30/09/2022).

Understanding Obstetrical Surgical Planning for the Pediatrician

Cesarean deliveries are common in the United States, occurring in approximately one-third of deliveries in 2021. Given this high rate of cesarean deliveries, it is important for all clinicians caring for the pregnant person-infant dyad to be educated about cesarean deliveries. In this review, we describe the indications for cesarean delivery, the evidence-based practices of preoperative planning to ensure safe deliveries, and the clinical decision-making behind various cesarean incisions. In addition, we discuss the most common complications of cesarean deliveries for the pregnant person-infant dyad.

The effect of inadvertent systemic hypothermia after mechanical thrombectomy in patients with large-vessel occlusion stroke

Background and aims

Postinterventional hypothermia is a frequent complication in patients with large-vessel occlusion strokes (LVOS) after mechanical thrombectomy (MT). This inadvertent hypothermia might potentially have neuroprotective but also adverse effects on patients' outcomes. The aim of the study was to determine the rate of hypothermia in patients with LVOS receiving MT and its influence on functional outcome.

Methods

We performed a monocentric, retrospective study using a prospectively derived databank, including all LVOS patients receiving MT between 2015 and 2021. Predictive values of postinterventional body temperature and body temperature categories (hyperthermia (≥38°C), normothermia (35°C-37.9°C), and hypothermia (<35°C)) on functional outcome were analyzed using multivariable Bayesian logistic regression models. Favorable outcome was defined as modified Rankin Scale (mRS) ≤3.

Results

Of the 480 included LVOS patients with MT (46.0% men; mean ± SD age 73 ± 12.9 years), 5 (1.0%) were hyperthermic, 382 (79.6%) normothermic, and 93 (19.4%) hypothermic. Postinterventional hypothermia was significantly associated with unfavorable functional outcome (mRS > 3) after 90 days (OR 2.06, 95% CI 1.01-4.18, p = 0.045). For short-term functional outcome, patients with hypothermia had a higher discharge NIHSS (OR 1.38, 95% CI 1.06 to 1.79, p = 0.015) and a higher change of NIHSS from admission to discharge (OR 1.35, 95% CI 1.03 to 1.76, p = 0.029).

Conclusion

Approximately a fifth of LVOS patients in this cohort were hypothermic after MT. Hypothermia was an independent predictor of unfavorable functional outcomes. Our findings warrant a prospective trial investigating active warming during MT.

Effect of Prewarming on Postoperative Hypothermia, Vital Signs, and Thermal Comfort: A Randomized Controlled Trial

This study aimed to determine the effects of preoperative active and passive warming on postoperative hypothermia, vital signs, and perception of thermal comfort in patients scheduled to undergo elective open abdominal surgery. This was a randomized controlled study. The study sample comprised 90 patients (30 in the active warming group, 30 in the passive warming group, and 30 in the control group) who agreed to participate and met the research criteria. According to the comparison of patients' vital signs, a statistically significant difference was observed in terms of patients' preoperative body temperature values (χ2 = 56.959; p = 0.000). A comparison of the patients' postoperative thermal comfort perception scores yielded a statistically significant difference (χ2 = 39.693; p = 0.000). Postoperative comfort scores in the active warming group were significantly higher than those in the passive warming and control groups. In conclusion, warming methods are effective in preventing undesirable postoperative hypothermia. The time to reach normothermia after surgery was shorter, vital signs were at a desirable level, and thermal comfort perceptions were higher in patients who were prewarmed. ClinicalTrials.gov (Identifier: NCT04997694).

Effect of preoperative warming on intraoperative hypothermia and postoperative functional recovery in total hip arthroplasty: a randomized clinical trial

BACKGROUND

Intraoperative hypothermia is associated with increased morbidity and impaired postoperative recovery. Direct anterior-approached total hip arthroplasty (ATHA) may lead to significant thermal loss. We aimed to assess whether preoperative warming had an impact on intraoperative hypothermia and postoperative functional recovery after ATHA.

METHODS

In this prospective randomized controlled clinical trial 40 patients scheduled for ATHA were randomly divided into two groups of 20 patients each. Group W received, prior to the induction of general anesthesia, a 30 minutes 43 °C forced-air preoperative warming. Group C did not receive any preoperative warming. A blinded observer noted the core body temperature at the time of induction and at fixed time points, i.e. every five minutes during the first hour of surgery. The evolution of postoperative patient perceived thermal comfort (TC) and functional recovery (QoR-15) was assessed 24, 48 and 72 hours after surgery. Length of stay in the post-anesthesia care unit (PACU) was noted.

RESULTS

The temperature drop was significantly faster and of higher amplitude in group C than in group W, during first hour of surgery (P<0.001). Evolution of QoR-15 and TC was significantly better in group W than in group C (P<0.001 for QoR-15 and P<0.001 for thermal comfort), with shorter length of stay (median [IQR]) in the PACU (minutes; 73 [61-79] for group C and 98 [83-129] for group W, P<0.001).

CONCLUSIONS

In ATHA, pre-warming delays and reduces intraoperative heat loss, impacting patient comfort and postoperative functional recovery.

A Health Economic Analysis Exploring the Cost Consequence of Using a Surgical Site Infection Prevention Bundle for Hip and Knee Arthroplasty in Germany

Background

According to the European Centre for Disease Prevention and Control, surgical site infections (SSIs) constitute over 50% of all hospital-acquired infections. Reducing SSIs can enhance healthcare efficiency.

Objective

This study explores the cost consequences of implementing an SSI prevention bundle (SPB) in total hip and knee arthroplasty (THKA).

Methods

A health-economic model followed a cohort of THKA patients from admission to 90 days postdischarge. The perioperative process was modeled using a decision tree, and postoperative recovery and potential SSI evaluated using a Markov model. The model reflects the hospital payers' perspective in Germany. The SPB includes antimicrobial incision drapes, patient warming, and negative pressure wound therapy in high-risk patients. SSI reduction associated with these interventions was sourced from published meta-analyses. An effectiveness factor of 70% was introduced to account for potential overlap of effectiveness when interventions are used in combination. Sensitivity analyses were performed to assess the robustness of model outcomes.

Results

The cost with the SPB was €4274.32 per patient, €98.27, or 2.25%, lower than that of the standard of care (€4372.59). Sensitivity analyses confirmed these findings, indicating a median saving of 2.22% (95% credible interval: 1.00%-3.79%]). The SPB also reduced inpatient SSI incidence from 2.96% to 0.91%. The break-even point for the SPB was found when the standard of care had an SSI incidence of 0.938%. Major cost drivers were the cost of inpatient SSI care, general ward, and operating room, and the increased risk of an SSI associated with unintended, intraoperative hypothermia. Varying the effectiveness factor from 10% to 130% did not substantially impact model outcomes.

Conclusions

Introducing the SPB is expected to reduce care costs if the inpatient SSI rate (superficial and deep combined) in THKA procedures exceeds 1%. Research into how bundles of measures perform together is required to further inform the results of this computational analysis.

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.

Changes in coagulation and temperature management in burn patients - A survey of burn centers in Switzerland, Austria and Germany

BACKGROUND

Severely burned patients suffer from both coagulopathy and hypothermia, with a lack of international consensus and appropriate treatment guidelines. This study examines recent developments and trends in coagulation and temperature management in European burn centers.

METHODS

A survey was sent to burn centers in Switzerland, Austria and Germany in 2016 and again in 2021. The analysis was performed using descriptive statistics, with categorical data reported in absolute numbers (n) and percentages (%) and numerical data reported as mean and standard deviation.

RESULTS

The rate of completed questionnaires was 84 % (16 of 19 questionnaires) in 2016 and 91 % (21 of 22 questionnaires) in 2021. The number of global coagulation tests performed has decreased over the observation period in favor of single factor determination and bed-side point-of-care coagulation tests. This has also led to increased administration of single factor concentrates in therapy. Although many centers had a defined treatment protocol for hypothermia in 2016, coverage increased such that in 2021 all centers surveyed had such a protocol. The body temperature was measured more consistently in 2021; thus, hypothermia was more actively sought, detected and treated.

CONCLUSION

A point-of-care guided, factor-based coagulation management and the maintenance of normothermia have gained importance in the care of burn patients in recent years.

Enhanced perioperative care in emergency general surgery: the WSES position paper

Enhanced perioperative care protocols become the standard of care in elective surgery with a significant improvement in patients' outcome. The key element of the enhanced perioperative care protocol is the multimodal and interdisciplinary approach targeted to the patient, focused on a holistic approach to reduce surgical stress and improve perioperative recovery. Enhanced perioperative care in emergency general surgery is still a debated topic with little evidence available. The present position paper illustrates the existing evidence about perioperative care in emergency surgery patients with a focus on each perioperative intervention in the preoperative, intraoperative and postoperative phase. For each item was proposed and approved a statement by the WSES collaborative group.

Impact of warm saline irrigation, hyperthermic intraperitoneal chemotherapy on postoperative pain in primary ovarian cancer from the KOV-HIPEC-01 randomized trial

BACKGROUND

Hyperthermic intraperitoneal chemotherapy (HIPEC) has emerged as a treatment option at the time of cytoreductive surgery after neoadjuvant chemotherapy. The effect of active warming of HIPEC on postoperative pain needs to be investigated. This study aimed to investigate whether HIPEC reduces postoperative pain.

METHODS

From the KOV-HIPEC-01 trial, a randomized controlled trial of HIPEC for advanced primary ovarian cancer, 184 patients with a residual tumor size <1 cm were randomly assigned to the HIPEC and control groups at a 1:1 ratio. The consumption of analgesics and pain scales were analyzed. Hyperthermic intraperitoneal chemotherapy was administered after cytoreductive surgery. The primary objective was to compare the consumption of opioids measured in morphine milligram equivalents and non-opioids measured as the maximum daily dose between the HIPEC and control groups. The secondary objective was to compare the minimum and maximum pain intensities on numeric rating scales between the two groups using a linear mixed model.

RESULTS

Lesser consumption of non-opioids, with a lower mean maximum daily dose on postoperative days 1 and 2, was observed. The HIPEC group also experienced lower maximum pain intensities on postoperative day 1. No overall differences in the minimum or maximum pain intensities were observed on postoperative day 7.

CONCLUSION

The addition of HIPEC to cytoreductive surgery did not lead to increased postoperative pain, as demonstrated by a reduction in the use of analgesics and lower scores on postoperative pain scales during the early postoperative period.

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.

Guidelines on perioperative optimization protocol for the adult patient 2023

OBJECTIVE

The French Society of Anesthesiology and Intensive Care Medicine [Société Française d'Anesthésie et de Réanimation (SFAR)] aimed at providing guidelines for the implementation of perioperative optimization programs.

DESIGN

A consensus committee of 29 experts from the SFAR was convened. A formal conflict-of-interest policy was developed at the outset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Four fields were defined: 1) Generalities on perioperative optimization programs; 2) Preoperative measures; 3) Intraoperative measures and; 4) Postoperative measures. For each field, the objective of the recommendations was to answer a number of questions formulated according to the PICO model (population, intervention, comparison, and outcomes). Based on these questions, an extensive bibliographic search was carried out using predefined keywords according to PRISMA guidelines and analyzed using the GRADE® methodology. The recommendations were formulated according to the GRADE® methodology and then voted on by all the experts according to the GRADE grid method. As the GRADE® methodology could have been fully applied for the vast majority of questions, the recommendations were formulated using a "formalized expert recommendations" format.

RESULTS

The experts' work on synthesis and application of the GRADE® method resulted in 30 recommendations. Among the formalized recommendations, 19 were found to have a high level of evidence (GRADE 1±) and ten a low level of evidence (GRADE 2±). For one recommendation, the GRADE methodology could not be fully applied, resulting in an expert opinion. Two questions did not find any response in the literature. After two rounds of rating and several amendments, strong agreement was reached for all the recommendations.

CONCLUSIONS

Strong agreement among the experts was obtained to provide 30 recommendations for the elaboration and/or implementation of perioperative optimization programs in the highest number of surgical fields.

Predicting Intraoperative Hypothermia Burden during Non-Cardiac Surgery: A Retrospective Study Comparing Regression to Six Machine Learning Algorithms

BACKGROUND

Inadvertent intraoperative hypothermia is a common complication that affects patient comfort and morbidity. As the development of hypothermia is a complex phenomenon, predicting it using machine learning (ML) algorithms may be superior to logistic regression.

METHODS

We performed a single-center retrospective study and assembled a feature set comprised of 71 variables. The primary outcome was hypothermia burden, defined as the area under the intraoperative temperature curve below 37 °C over time. We built seven prediction models (logistic regression, extreme gradient boosting (XGBoost), random forest (RF), multi-layer perceptron neural network (MLP), linear discriminant analysis (LDA), k-nearest neighbor (KNN), and Gaussian naïve Bayes (GNB)) to predict whether patients would not develop hypothermia or would develop mild, moderate, or severe hypothermia. For each model, we assessed discrimination (F1 score, area under the receiver operating curve, precision, recall) and calibration (calibration-in-the-large, calibration intercept, calibration slope).

RESULTS

We included data from 87,116 anesthesia cases. Predicting the hypothermia burden group using logistic regression yielded a weighted F1 score of 0.397. Ranked from highest to lowest weighted F1 score, the ML algorithms performed as follows: XGBoost (0.44), RF (0.418), LDA (0.406), LDA (0.4), KNN (0.362), and GNB (0.32).

CONCLUSIONS

ML is suitable for predicting intraoperative hypothermia and could be applied in clinical practice.

Comparative effects of warming systems applied to different parts of the body on hypothermia in adults undergoing abdominal surgery: A systematic review and network meta-analysis of randomized controlled trials

STUDY OBJECTIVE

The prevention of perioperative hypothermia after anesthesia induction is a critical concern in patients undergoing abdominal surgery. The effectiveness of various warming systems for preventing hypothermia and shivering when applied to specific areas of the body remains undetermined.

DESIGN

Systematic review and network meta-analysis.

SETTING

Operating room.

INTERVENTION

Five electronic databases were searched, including only randomized control trials (RCTs) reporting the effects of warming systems applied to specific body sites on the intraoperative core temperature and postoperative risk of shivering in adults undergoing abdominal surgery. A multivariate random-effects network meta-analysis with a frequentist framework was implemented for data analysis.

MEASUREMENTS

The primary outcome was the core body temperature 60 and 120 min after anesthesia induction for abdominal surgery. The secondary outcome was the incidence of postoperative shivering.

RESULTS

This review comprised a total of 24 RCTs including 1119 patients. At 60 and 120 min after anesthesia induction, a forced-air warming system applied to the upper body (0.3 °C and 95% confidence intervals = [0.3 to 0.4], 1.0 °C [0.7 to 1.3]), lower body (0.4 °C [0.3 to 0.5], 0.9 °C [0.5 to 1.2]), and underbody (0.5 °C [0.5 to 0.6], 1.2 °C [0.9 to 1.6]) was superior to passive insulation in terms of core body temperature regulation. Compared with passive insulation, the forced-air warming system applied to the lower body (odds ratio = 0.06) or underbody (0.44) and the electric heating blanket to the lower body (0.02) or the whole body (0.07) significantly reduced the risk of shivering.

CONCLUSIONS

The results of this NMA revealed that forced-air warming with an underbody blanket effectively elevates core body temperatures in 60 and 120 min after induction of anesthesia and prevents shivering in patients recovering from abdominal surgery.

Effect of active warming on perioperative cardiovascular outcomes: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

The objective of this study was to provide an updated review on the active warming effects on major adverse cardiac events, 30-day all-cause mortality, and myocardial injury after noncardiac surgery.

METHOD

We systematically searched MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, Web of Science, and Chinese BioMedical Literature Database. We included randomized controlled trials of adult population undergoing noncardiac surgeries that concentrate on the comparison of active warming methods and passive thermal management. Cochrane Collaboration's tool was applied for risk-of-bias assessment. We used trial sequential analysis to evaluate the possibility of false positive or negative results.

RESULTS

A total of 13,316 unique records were identified, of which only 19 with reported perioperative cardiovascular outcomes were included in the systematic review and nine of them were included in final meta-analysis. No statistically significant difference between active warming methods and routine care was found in major adverse cardiac events (RR 0.56, 95% confidence interval (CI) 0.14-2.21, I² = 71%, number of events 59 vs. 70), 30-day all-cause mortality (RR 0.81, 95% CI 0.43-1.54, I² = 0%, number of events 17 vs. 21), and myocardial injury after noncardiac surgery (RR 0.61, 95% CI 0.17-2.22, I² = 79%, number of events 236 vs. 234). Trial sequential analysis suggests that current trials did not reach the minimum information size regarding the major cardiovascular events.

CONCLUSIONS

Compared to routine perioperative care, we found that active warming methods are not necessary for cardiovascular prevention in patients undergoing noncardiac surgery.

Association between intraoperative body temperature and postoperative delirium: A retrospective observational study

STUDY OBJECTIVE

The effect of perioperative body temperature derangement on postoperative delirium remains unclear. This study aimed to evaluate the association between intraoperative body temperature and postoperative delirium in patients having noncardiac surgery.

DESIGN

Single-center retrospective observational study.

SETTING

Tertiary university hospital.

PATIENT

Adult patients who had major noncardiac surgery under general anesthesia for at least two hours between 2019 and 2021.

INTERVENTIONS

Patients were classified into three groups according to their intraoperative time-weighted average body temperature: severe hypothermia (<35.0 °C), mild hypothermia (35.0 °C-36.0 °C), and normothermia (≥36.0 °C) groups.

MEASUREMENTS

The primary outcome was the risk of delirium occurring within seven days after surgery, which was compared using logistic regression analysis. A multivariable procedure was performed adjusting for potential confounders including demographics, history of hypertension, diabetes, atrial fibrillation or flutter, myocardial infarction, congestive heart failure, and stroke or transient ischemic attack, preoperative use of antidepressants and statins, preoperative sodium imbalance, high-risk surgery, emergency surgery, duration of surgery, and red blood cell transfusion. Cox regression analysis was also performed using the same covariates.

MAIN RESULTS

Among 27,674 patients analyzed, 5.5% experienced postoperative delirium. The incidence rates of delirium were 6.2% (63/388) in the severe hypothermia group, 6.4% (756/11779) in the mild hypothermia group, and 4.6% (712/15507) in the normothermia group. Compared with the normothermia group, the risk of delirium was significantly higher in the severe hypothermia (adjusted odds ratio, 1.43; 95% confidence interval, 1.04-1.97) and mild hypothermia (1.15; 1.02-1.28) groups. The mild hypothermia group also had a significantly increased risk of cumulative development of delirium than the normothermia group (adjusted hazard ratio 1.14; 95% confidence interval, 1.03-1.26).

CONCLUSIONS

Intraoperative hypothermia (even mild hypothermia) was significantly associated with an increased risk of postoperative delirium.

A qualitative study of nurse-perceived barriers to body temperature management in postoperative patients

Although evidence-based practices exist for preventing hypothermia in patients during surgery, few studies have focused on this concern in postoperative patients. The aim of this qualitative study was to explore the most challenging issues experienced by surgical ward nurses while managing the body temperature of adult surgical patients. To address this research gap, this study used a qualitative descriptive design to document barriers to body temperature management as reported by a sample of 16 perioperative nurses. The semi-structured, face-to-face interviews were digitally recorded, transcribed verbatim and analysed using inductive content analysis. The main barriers fell into three categories: professional nursing ability limitations, unfavourable working conditions and management of human resources. The eight subcategories were disadvantageous professional views, professional knowledge limitations, low motivation to provide nursing care, non-standard treatment environment, inadequate equipment and care protocols, heavy nursing care loads, inadequate staff training and ineffective staff supervision. These findings highlighted the importance of adequate resources, proper education and evidence-based care protocols in the effective delivery of body temperature management to postoperative patients.

The Effectiveness of Active External Warming of Patient Concurrently With Ice Application on the Incision Site on Post-Thoracotomy Pain and Analgesic Consumption

The aim of study is to investigate the effects of active external warming of patient concurrently with application of ice to incision site on thoracotomy pain and analgesic consumption. The research is a quasi-experimental design with control and study groups. The study was conducted in 2018 and 2019. A total of 70 patients were included in the study: 35 in the control group and 35 in the study group. The mean verbal pain scale values were significantly lower in the intervention group (2.85 point) than in the control group (4.57 point; p < .001). Opioid consumption rate was high in control group patients (77.1% tramadol 30 mg; 45.7% morphine sulfate 5 mg) In contrast, the rate of opioid consumption was lower in patients in the intervention group (40% tramadol 30 mg; 17% morphine sulfate 5 mg). Active external warming and ice application on the incision area, could reduce the intensity of thoracotomy pain.

Incidence of postoperative hypothermia and shivering and risk factors in patients undergoing malignant tumor surgery: a retrospective study

BACKGROUND

Perioperative hypothermia and shivering are common and can cause adverse outcomes. The aim of this study was to investigate the incidence of postoperative hypothermia and shivering and their risk factors in patients undergoing malignant tumor surgery.

METHODS

This retrospective study collected data from patients with American Society of Anesthesiologists physical status (ASA) I or II who underwent scheduled surgery from November 2020 to March 2021 at Fudan University Shanghai Cancer Center. Each patient's core body temperature was measured at three time points: time point 1 (arrival at the postanesthesia care unit (PACU)), time point 2 (after 30-min care in the PACU), and time point 3 (at discharge from the PACU). At time point 1, if the patient's body temperature was below 36 ℃, we provided an active forced-air warmer. At time point 2, if it was still below 36 ℃, the forced-air warmer was still applied until the patient was discharged from the PACU. If it reached 36 ℃, the forced-air warmer would be switched off. Univariate and multivariate logistic regression combined with stepwise methods and linear regression were used to explore risk factors for postoperative hypothermia and shivering.

RESULTS

The numbers (percentage) of 202 patients who developed postoperative hypothermia at the different time points were 52 (25.7%), 37 (18.3%) and 28 (13.9%). Eight patients (4.0%) experienced shivering. Multivariate logistic regression showed that high weight (OR = 0.923, 95% CI: 0.884 to 0.964, P = 0.0003) and low estimated blood loss (OR = 0.252, 95% CI: 0.115 to 0.550, P = 0.0005) were protective factors against hypothermia, while long surgical duration (OR = 3.339, 95% CI: 1.675 to 6.655, P = 0.0006) was an independent risk factor for hypothermia at time point 1. There was no risk factor associated with the occurrence of shivering (P > 0.05). There was a significant difference between the hypothermia and normothermia groups in the median length of stay in the PACU (59.0 vs. 49.0 min, P = 0.0123).

CONCLUSIONS

Postoperative hypothermia occurred frequently. Weight, estimated blood loss and surgical duration were significantly associated with hypothermia on arrival at the PACU.

Evaluation of Postoperative Warming Care Protocol for Thermal Comfort and Temperature Management Immediately After Surgery: Nonrandomized Controlled Trial

PURPOSE

This study aimed to determine the effects of a warming care protocol (WCM) on temperature control and thermal comfort perception in hypothermia following major abdominal surgery.

DESIGN

A prospective nonrandomized controlled trial.

METHODS

A total of 54 patients undergoing major abdominal surgery were assigned to receive routine care (control group, 27 patients) or the WCM (intervention group, 27 patients). The body temperature (core and peripheral) was measured, and physical symptoms were monitored every hour for 4 hours after arriving at the ward and then every 4 hours for up to 12 hours.

FINDINGS

The temperature gap, calculated as the difference between the core and skin temperatures, was similar between the control and intervention groups at the end of surgery. However, the temperature gap in the intervention group decreased within 3 hours after arrival at the ward and remained lower than that in the control group. The visual analog scale score for postoperative thermal discomfort was significantly lower in the intervention group than in the control group, indicating achievement of higher comfort with the warming intervention.

CONCLUSIONS

Patients were warmed using active warming methods under the WCM, which in turn increased the thermal comfort perception with the body temperature. Postoperative patients often require warming care for thermal comfort, which may be improved by proper observation and management within 1 to 2 hours postoperatively. Our results indicate that nurses could effectively warm the patient to maintain normal body temperature following surgery not only to improve thermal comfort, but also to prevent shivering and possibly various postoperative complications.

Desenvolvimento de protocolo clínico assistencial para prevenção e tratamento da hipotermia perioperatória

Objetivo: desenvolver um protocolo de prevenção e tratamento da hipotermia perioperatória. Método: pesquisa do tipo desenvolvimento tecnológico em saúde, desenvolvida em três etapas: Revisão de diretrizes clínicas sobre fatores de risco para desenvolvimento de hipotermia perioperatória; Identificação da ocorrência de hipotermia perioperatória e dos fatores de risco associados ao seu desenvolvimento em um centro cirúrgico e Elaboração do protocolo de prevenção de hipotermia perioperatória. Resultados: os fatores de risco identificados nas diretrizes foram categorizados em características clínicas (idade, Índice de Massa Corporal, comorbidades, temperatura corporal) e anestésico-cirúrgicas (tipo e duração da anestesia e cirurgia, temperatura da sala cirúrgica). Na segunda etapa, 90 pacientes cirúrgicos foram avaliados. A ocorrência de hipotermia foi de 28,9% na admissão cirúrgica, 77,8% na admissão da Sala de Recuperação Pós-Anestésica e 45,6% alta do centro cirúrgico. Houve associação estatisticamente significativa entre ocorrência de hipotermia e índice ASA (p=0,049), idade (p=0,037), comorbidades (p=0,031), hipotermia pré-operatória (p=0,015). Conclusão: para elaboração do protocolo foram considerados os fatores de risco descritos na literatura, os resultados de estudo local e acesso às tecnologias disponíveis na instituição. As ações incluíram avaliação de fatores de risco e de situações desencadeantes, monitorização e registro da temperatura e outros parâmetros, aquecimento passivo para pacientes normotérmicos, aquecimento ativo para pacientes hipotérmicos, infusão de soluções endovenosas aquecidas e suporte de oxigênio para pacientes hipotérmicos.

Perioperative Hypothermia Is Associated With Increased 30-Day Mortality in Hip Fracture Patients in the United Kingdom: Α Systematic Review and Meta-analysis

OBJECTIVES

To undertake a systematic review and meta-analysis to determine the relationship between perioperative hypothermia and mortality after surgery for hip fracture.

DATA SOURCES

A systematic literature search of Medline, EMBASE, CINAHL, and Cochrane CENTRAL databases was performed using the Cochrane methodology for systematic reviews with no publication year limit. Only studies available in the English language were included.

STUDY SELECTION

Predetermined inclusion criteria were patients of any age with a hip fracture, exposure was their body temperature and outcome was mortality rate. Any comparative study design was eligible.

DATA EXTRACTION

The quality of selected studies was assessed according to each study design with the Methodological Index for Non-Randomised Studies (MINORS) used for all the retrospective comparative studies. The GRADE approach was used to assess the quality of evidence.

DATA SYNTHESIS

A meta-analysis was conducted using a random-effects model.

RESULTS

The literature search identified 1016 records. After removing duplicates and those not meeting inclusion criteria, 3 studies measuring 30-day mortality were included. All included studies were carried out in the United Kingdom. The mortality rate was higher in the hypothermic groups as compared with the normothermic group in all the studies, with the difference being significant in 2 of the studies (P < 0.0001). The meta-analysis showed that low body temperature was associated with an increased mortality risk (estimated odds ratio: 2.660; 95% confidence interval: 1.948-3.632; P < 0.001) in patients undergoing surgery for hip fracture.

CONCLUSIONS

This study shows that low body temperature in hip fracture patients is associated with an increased 30-day mortality risk in the United Kingdom. Randomized control trials are required to determine whether the association between perioperative hypothermia in hip fracture patients and mortality is causal. Nevertheless, based on this analysis, we urge the maintenance of normal body temperature in the perioperative period to be included in national hip fracture guidelines.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Aggressive intraoperative warming versus routine thermal management during non-cardiac surgery (PROTECT): a multicentre, parallel group, superiority trial

BACKGROUND

Moderate intraoperative hypothermia promotes myocardial injury, surgical site infections, and blood loss. Whether aggressive warming to a truly normothermic temperature near 37°C improves outcomes remains unknown. We aimed to test the hypothesis that aggressive intraoperative warming reduces major perioperative complications.

METHODS

In this multicentre, parallel group, superiority trial, patients at 12 sites in China and at the Cleveland Clinic in the USA were randomly assigned (1:1) to receive either aggressive warming to a target core temperature of 37°C (aggressively warmed group) or routine thermal management to a target of 35·5°C (routine thermal management group) during non-cardiac surgery. Randomisation was stratified by site, with computer-generated, randomly sized blocks. Eligible patients (aged ≥45 years) had at least one cardiovascular risk factor, were scheduled for inpatient non-cardiac surgery expected to last 2-6 h with general anaesthesia, and were expected to have at least half of the anterior skin surface available for warming. Patients requiring dialysis and those with a body-mass index exceeding 30 kg/m² were excluded. The primary outcome was a composite of myocardial injury (troponin elevation, apparently of ischaemic origin), non-fatal cardiac arrest, and all-cause mortality within 30 days of surgery, as assessed in the modified intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT03111875.

FINDINGS

Between March 27, 2017, and March 16, 2021, 5056 participants were enrolled, of whom 5013 were included in the intention-to-treat population (2507 in the aggressively warmed group and 2506 in the routine thermal management group). Patients assigned to aggressive warming had a mean final intraoperative core temperature of 37·1°C (SD 0·3) whereas the routine thermal management group averaged 35·6°C (SD 0·3). At least one of the primary outcome components (myocardial injury after non-cardiac surgery, cardiac arrest, or mortality) occurred in 246 (9·9%) of 2497 patients in the aggressively warmed group and in 239 (9·6%) of 2490 patients in the routine thermal management group. The common effect relative risk of aggressive versus routine thermal management was an estimated 1·04 (95% CI 0·87-1·24, p=0·69). There were 39 adverse events in patients assigned to aggressive warming (17 of which were serious) and 54 in those assigned to routine thermal management (30 of which were serious). One serious adverse event, in an aggressively warmed patient, was deemed to be possibly related to thermal management.

INTERPRETATION

The incidence of a 30-day composite of major cardiovascular outcomes did not differ significantly in patients randomised to 35·5°C and to 37°C. At least over a 1·5°C range from very mild hypothermia to full normothermia, there was no evidence that any substantive outcome varied. Keeping core temperature at least 35·5°C in surgical patients appears sufficient.

FUNDING

3M and the Health and Medical Research Fund, Food and Health Bureau, Hong Kong.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Effect of prewarming on body temperature in short-term bladder or prostatic transurethral resection under general anesthesia: A randomized, double-blind, controlled trial

Perioperative hypothermia causes postoperative complications. Prewarming reduces body temperature decrease in long-term surgeries. We aimed to assess the effect of different time-periods of prewarming on perioperative temperature in short-term transurethral resection under general anesthesia. Randomized, double-blind, controlled trial in patients scheduled for bladder or prostatic transurethral resection under general anesthesia. Eligible patients were randomly assigned to receive no-prewarming or prewarming during 15, 30, or 45 min using a forced-air blanket in the pre-anesthesia period. Tympanic temperature was used prior to induction of anesthesia and esophageal temperature intraoperatively. Primary outcome was the difference in core temperature among groups from the induction of general anesthesia until the end of surgery. Repeated measures multivariate analysis of covariance modeled the temperature response at each observation time according to prewarming. We examined modeled contrasts between temperature variables in subjects according to prophylaxis. We enrolled 297 patients and randomly assigned 76 patients to control group, 74 patients to 15-min group, 73 patients to 30-min group, and 74 patients to the 45-min group. Temperature in the control group before induction was 36.5 ± 0.5 °C. After prewarming, core temperature was significantly higher in 15- and 30-min groups (36.8 ± 0.5 °C, p = 0.004; 36.7 ± 0.5 °C, p = 0.041, respectively). Body temperature at the end of surgery was significantly lower in the control group (35.8 ± 0.6 °C) than in the three prewarmed groups (36.3 ± 0.6 °C in 15-min, 36.3 ± 0.5 °C in 30-min, and 36.3 ± 0.6 °C in 45-min group) (p < 0.001). Prewarming prior to short-term transurethral resection under general anesthesia reduced the body temperature drop during the perioperative period. These time-periods of prewarming also reduced the rate of postoperative complications.Study Registration Registered at ClinicalTrials.gov (Identifier: NCT03630887).

Resistant fabric warming is a viable alternative to forced-air warming to prevent inadvertent perioperative hypothermia during hemiarthroplasty in the elderly

BACKGROUND

Surgical site infection (SSI) is associated with inadvertent perioperative hypothermia (IPH). This can be prevented by active patient warming. However, results from comparisons of warming techniques are conflicting. They are based mostly on elective surgery, are from small numbers of patients, and are dominated by the market leader, forced-air warming (FAW). Furthermore, the definition of hypothermia is debatable and systematic reviews of warming systems conclude that a stricter control of temperature is required to study the benefits of warming.

AIM

To analyse core temperatures in detail in a large subset of elderly patients who took part in a randomized trial of patient warming following hemiarthroplasty who had received constant zero-flux thermometry to record their temperature.

METHODS

Regression models with a fixed effect for warming group and covariates related to temperature were compared for 257 participants randomized to FAW or resistant fabric warming (RFW) from a prior clinical trial.

FINDINGS

Those in the RFW group were -0.08°C cooler and had a cumulative hypothermia score -1.87 lower than those in the FAW group. There was no difference in the proportion of hypothermic patients at either <36.5°C or <36.0°C.

CONCLUSIONS

This is the first study to provide accurate temperature measurements in patients undergoing a procedure predominantly under regional rather than general anaesthetic. It shows that RFW is a viable alternative to FAW for preventing IPH during hemiarthroplasty. Further studies are needed to measure the benefits of patient warming in terms of clinically important outcomes.

Perioperative Hypothermia-A Narrative Review

Unintentional hypothermia (core temperature < 36 °C) is a common side effect in patients undergoing surgery. Several patient-centred and external factors, e.g., drugs, comorbidities, trauma, environmental temperature, type of anaesthesia, as well as extent and duration of surgery, influence core temperature. Perioperative hypothermia has negative effects on coagulation, blood loss and transfusion requirements, metabolization of drugs, surgical site infections, and discharge from the post-anaesthesia care unit. Therefore, active temperature management is required in the pre-, intra-, and postoperative period to diminish the risks of perioperative hypothermia. Temperature measurement should be done with accurate and continuous probes. Perioperative temperature management includes a bundle of warming tools adapted to individual needs and local circumstances. Warming blankets and mattresses as well as the administration of properly warmed infusions via dedicated devices are important for this purpose. Temperature management should follow checklists and be individualized to the patient's requirements and the local possibilities.

Zero-Heat-Flux and Esophageal Temperature Monitoring in Orthopedic Surgery: An Observational Study

Purpose

Perioperative hypothermia prevention requires regular, accurate, and consistent temperature monitoring. Zero-heat-flux (ZHF) thermometry offers a non-invasive, measurement method that can be applied across all surgical phases. The purpose of this study was to measure agreement between the zero-heat-flux device and esophageal monitoring, sensitivity, and specificity to detect hypothermia and patient acceptability amongst patients undergoing upper and lower limb orthopedic surgery.

Patients and Methods

This prospective, observational study utilized Bland–Altman analysis and Lin’s concordance coefficient to measure agreement between devices, sensitivity and specificity to detect hypothermia and assessed patient acceptability amongst 30 patients between December 2018 and June 2019.

Results

Bias was observed between devices via Bland Altman, with bias dependent on actual temperature. The mean difference ranged from −0.16°C at 34.9°C (where the mean of ZHF was lower than the esophageal device) to 0.46°C at 37.25°C (where the mean of ZHF was higher than esophageal device), with 95% limits of agreement (max) upper LOA = 0.80 to 1.41, lower LOA = −1.12 to −0.50. Seventy-five percentage of zero-heat-flux measurements were within 0.5°C of esophageal readings. Patient acceptability was high; 96% (n=27) stated that the device was comfortable.

Conclusion

ZHF device achieved lesser measurement accuracy with core (esophageal) temperature compared to earlier findings. Nonetheless, due to continuous capability, non-invasiveness and patient reported acceptability, the device warrants further evaluation.

Title Registration

The study was registered at www.ANZCTR.org.au (reference: ACTRN12619000842167).

Inadvertent hypothermia after endovascular therapy is not associated with improved outcome in stroke due to anterior circulation large vessel occlusion

BACKGROUND AND PURPOSE

Hypothermia may be neuroprotective in acute ischemic stroke. Patients with anterior circulation large vessel occlusion (acLVO) are frequently hypothermic after endovascular therapy (EVT). We sought to determine whether this inadvertent hypothermia is associated with improved outcome.

METHODS

We extracted data of consecutive patients (January 2016 to May 2019) who received EVT for acLVO from our prospective EVT register of all patients screened for EVT at our tertiary stroke center. We assessed functional outcome at 3 months and performed multivariate analysis to calculate adjusted risk ratios (aRRs) for favorable outcome (modified Rankin Scale scores = 0-2) and mortality across patients who were hypothermic (<36°C) and patients who were normothermic (≥36°C to <37.6°C) after EVT. Moreover, we compared the frequency of complications between these groups.

RESULTS

Among 837 patients screened, 416 patients received EVT for acLVO and fulfilled inclusion criteria (200 [48.1%] male, mean age = 76 ± 16 years, median National Institutes of Health Stroke Scale score = 16, interquartile range [IQR] = 12-20). Of these, 209 patients (50.2%) were hypothermic (median temperature = 35.2°C, IQR = 34.7-35.7) and 207 patients were normothermic (median temperature = 36.4°C, IQR = 36.1-36.7) after EVT. In multivariate analysis, hypothermia was not associated with favorable outcome (aRR = 0.99, 95% confidence interval [CI] = 0.75-1.31) and mortality (aRR = 1.18, 95% CI = 0.84-1.66). More hypothermic patients suffered from pneumonia (36.4% vs. 25.6%, p = 0.02) and bradyarrhythmia (52.6% vs. 16.4%, p < 0.001), whereas thromboembolic events were distributed evenly (5.7% vs. 6.8%, not significant).

CONCLUSIONS

Inadvertent hypothermia after EVT for acLVO is not associated with improved functional outcome or reduced mortality but is associated with an increased rate of pneumonia and bradyarrhythmia in patients with acute ischemic stroke.

Effects of different thermal insulation methods on the nasopharyngeal temperature in patients undergoing laparoscopic hysterectomy: a prospective randomized controlled trial

Background

This study explored the comparison of the thermal insulation effect of incubator to infusion thermometer in laparoscopic hysterectomy.

Methods

We assigned 75 patients enrolled in the study randomly to three groups: Group A: Used warming blanket; group B: Used warming blanket and infusion thermometer; group C: Used warming blanket and incubator. The nasopharyngeal temperature at different time points during the operation served as the primary outcome.

Results

The nasopharyngeal temperature of the infusion heating group was significantly higher than that of the incubator group 60 min from the beginning of surgery (T3): 36.10 ± 0.20 vs 35.81 ± 0.20 (P<0.001)90 min from the beginning of surgery (T4): 36.35 ± 0.20 vs 35.85 ± 0.17 (P<0.001). Besides, the nasopharyngeal temperature of the incubator group was significantly higher compared to that of the control group 60 min from the beginning of surgery (T3): 35.81 ± 0.20 vs 35.62 ± 0.18 (P<0.001); 90 min from the beginning of surgery (T4): 35.85 ± 0.17 vs 35.60 ± 0.17 (P<0.001). Regarding the wake-up time, that of the control group was significantly higher compared to the infusion heating group: 24 ± 4 vs 21 ± 4 (P = 0.004) and the incubator group: 24 ± 4 vs 22 ± 4 (P = 0.035).

Conclusion

Warming blanket (38 °C) combined infusion thermometer (37 °C) provides better perioperative thermal insulation. Hospitals without an infusion thermometer can opt for an incubator as a substitute.

Trial registration

This trial was registered with ChiCTR2000039162, 20 October 2020.