The incidence of inadvertent perioperative hypothermia in patients undergoing general anesthesia and an examination of risk factors

Inadvertent Hypothermia in the Perspective of Operating Room Nurses: A Phenomenological Qualitative Study

PURPOSE

The aim of the study was to reveal the awareness and perceptions of operating room nurses concerning inadvertent hypothermia, as well as their experiences and recommendations for its prevention.

DESIGN

The study employed a phenomenological qualitative approach.

METHODS

This study was conducted with 17 nurses working in the operating room of a university hospital in Konya, Turkey. Data were collected face to face between 15 August and 30 September 2022 using the in-depth individual interview method. The data were subjected to inductive content analysis. Written permission was obtained from the hospital, the ethics committee, and the participants to conduct the study.

FINDINGS

The mean age of the nurses was 28.4 years and the majority were female. The nurses were graduates of a four-year health vocational high school, a two-year nursing associate degree program, or a four-year nursing bachelors' degree program. Their operating room experience ranged from 1 to 22 years. All the nurses were aware of inadvertent hypothermia, and all but one encountered hypothermia and applied preventive measures. The data analysis revealed 263 codes, 12 categories, and 4 themes on the awareness and perceptions of operating room nurses about inadvertent hypothermia and their experiences and recommendations for its prevention.

CONCLUSIONS

The findings showed that the majority of the participants were aware of inadvertent hypothermia and its risk factors, and frequently encountered inadvertent hypothermia despite implementing preventive measures.

Barriers and facilitators to evidence-based perioperative hypothermia management for orthopaedic patients: A systematic review

AIM

To assess barriers and facilitators to the implementation of guidelines for the prevention of inadvertent perioperative hypothermia in orthopaedic patients.

DESIGN

Systematic review.

DATA SOURCES

Nine databases: PubMed, Embase, CINAHL, Cochrane CENTRAL, PsycINFO, ProQuest Dissertations and Theses, Scopus, Web of Science and Trip Clinical Evidence Database.

METHODS

Primary studies published in English between January 2008 to July 2022 were screened. Study selection, quality assessment, and data extraction were completed independently by researchers. Data were extracted using the Consolidated Framework for Implementation Research and mapped to the Expert Recommendations for Implementing Change strategies.

RESULTS

Eighty-seven studies were included in the review. The most frequently reported barriers and facilitators related to evidence strength, relative advantage, and cost of implementing perioperative hypothermia prevention guidelines. The top four ERIC strategies were: Identify and prepare champions; Conduct educational meetings; Assess for readiness and identify barriers and facilitators; and Inform local opinion leaders.

CONCLUSION

This review provides synthesized evidence regarding barriers and facilitators to perioperative hypothermia guidelines for patients undergoing orthopaedic surgery.

IMPLICATIONS FOR THE PROFESSION AND PATIENT CARE

Our work provides theory guided strategies to promote implementation of perioperative hypothermia prevention to assist nurses caring for patients undergoing orthopaedic surgery.

IMPACT

Findings provide professionals caring for patients undergoing orthopaedic surgery with theory-informed strategies to improve perioperative hypothermia prevention. Reducing perioperative hypothermia will improve outcomes for patients undergoing orthopaedic surgery.

REPORTING METHOD

The review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020.

NO PATIENT OR PUBLIC CONSULTATION

Due to the study design, no patient or public consultation took place.

The Effect of Prewarming on Perioperative Hypothermia: A Systematic Review and Meta-analysis of Randomized Controlled Studies

PURPOSE

One of the methods for maintaining perioperative normothermia is prewarming. This study was conducted to investigate the effect of a preoperative prewarming intervention on perioperative body temperature.

DESIGN

Systematic review and meta-analysis.

METHODS

A literature review was conducted using PubMed, CINAHL, Cochrane Central, Science Direct, Springer Link, Scopus, Web of Science, and Ovid databases. Randomized controlled trials that investigate the effect of prewarming on body temperature in the prevention of perioperative hypothermia were included. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines. Methodological quality was assessed using the Cochrane Collaboration "risk of bias" tool. Meta-analysis was performed with Comprehensive Meta-Analysis, version 2. Moderator analysis and publication bias assessment were performed. Funnel plots were analyzed using Orwin's fail-safe N, Trim, and Fill test method to investigate the source of heterogeneity.

FINDINGS

A total of 907 studies were found. The systematic review included 27 studies. Of these, 23 were included in the intraoperative meta-analysis, and 16 were included in the postoperative meta-analysis. According to the meta-analysis results, the prewarming intervention was effective in maintaining normothermia in the intraoperative (Hedge's g = 0.972, 95% confidence intervaI = 0.674 to 1.270) and postoperative (Hedge's g = 0.818, 95% confidence intervaI = 0.520 to 1.114) periods.

CONCLUSIONS

The findings of this systematic review and meta-analysis showed that preoperative prewarming played a significant role in providing and maintaining perioperative normothermia.

Construction of risk prediction model for hypothermia during pancreaticoduodenectomy

Purpose

To investigate the factors influencing hypothermia during pancreaticoduodenectomy and establish and verify a prediction model.

Method

The clinical data of patients undergoing pancreaticoduodenectomy in Hunan People's Hospital between January 1, 2022 and October 15, 2022 were analysed. The patients were divided into a hypothermia group (n = 302) and a non-hypothermia group (n = 164) according to whether hypothermia occurred during surgery. A binary logistic regression model was used to analyse the independent risk factors for hypothermia in patients undergoing pancreaticoduodenectomy. A risk prediction model was established, and R software was used to plot a column graph. The predictive value of the model was evaluated using the receiver operating characteristic (ROC) curve.

Results

Among the 466 patients undergoing pancreaticoduodenectomy, 302 (64.81 %) had hypothermia, including 154 men and 148 women, with a median age of 58.6 (38-86) years. The binary logistic regression analysis showed that low body mass index (BMI), room temperature at the time of entry, intraoperative flushing fluid volume and peritoneal flushing fluid temperature were independent risk factors for intraoperative hypothermia in patients undergoing pancreaticoduodenal surgery (P < 0.05). A multivariate logistic regression analysis (backward logistic regression) was used to establish the prediction model. The area under the ROC curve was 0.927, P ≤ 0.001, the sensitivity was 0.921 and the specificity was 0.848, indicating good differentiation by the prediction model.

Conclusion

The nomogram constructed using four independent risk factors: BMI, room temperature at the time of entry, intraoperative peritoneal flushing fluid volume and intraoperative peritoneal flushing fluid temperature, has good predictive efficacy and good clinical application value for predicting intraoperative hypothermia in patients undergoing pancreaticoduodenectomy.

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.

Perioperative hypothermia in robotic-assisted thoracic surgery: Incidence, risk factors, and associations with postoperative outcomes

OBJECTIVE

Inadvertent perioperative hypothermia has been associated with poor surgical outcomes. The purpose of this study was to evaluate the incidence and associated postoperative complications of inadvertent perioperative hypothermia in patients undergoing robotic-assisted thoracic surgery lung resections.

METHODS

This was a single-center, retrospective cohort study evaluating all consecutive patients who underwent robotic-assisted thoracic surgery lung resection between January 1, 2021, and November 30, 2022. Temperatures were measured at 5 time points: preprocedure unit, anesthesia induction, 30 minutes postinduction, extubation, and recovery room arrival. Temperature changes were calculated at each interval. Adjusted and unadjusted comparison was performed between those who experienced varying levels of inadvertent perioperative hypothermia (Hypothermia I: <36 °C, Hypothermia II: <35.5 °C, and Hypothermia III: <35 °C) and those who did not.

RESULTS

A total of 313 patients were included, and 201 (64.2%) lobectomies, 50 (16.0%) segmentectomies, and 62 (19.8%) wedge resections were performed. Across all patients, 291 (93.0%) had a temperature less than 36 °C, 195 (62.3%) had a temperature less than 35.5 °C, and 100 (31.9%) had a temperature less than 35.0 °C. Patients experienced significant temperature change at all intervals (P < .001), with the greatest loss occurring during the preprocedure interval (between leaving preprocedure unit and anesthesia induction). On adjusted analysis, patients who experienced inadvertent perioperative hypothermia less than 35.5 °C were older (odds ratio, 1.03; 95% CI, 1.01-1.05), had lower body mass index (odds ratio, 0.95; 95% CI, 0.87-0.98), and had increasing operative time (odds ratio, 1.00; 95% CI, 1.00-1.01). Patients who experienced inadvertent perioperative hypothermia had higher risk-adjusted rates of overall morbidity and infectious postoperative complications.

CONCLUSIONS

The majority of patients undergoing robotic-assisted thoracic surgery lung resections experience some degree of inadvertent perioperative hypothermia and have associated increased rates of 30-day morbidity. Structured and interval-specific interventions should be implemented to decrease rates of inadvertent perioperative hypothermia and subsequent complications.

Intraoperative hypothermia in patients with laparoscopic surgery: Influencing factors and prevention strategies

Background

Effective body temperature management is crucial for the favorable prognosis of patients undergoing surgery. The purpose of this study is to explore the risk factors of intraoperative hypothermia and to develop a risk prediction model to provide basis for clinical treatment.

Methods

Patients who underwent laparoscopic surgery in a tertiary hospital in China from February 1, 2023 to January 31, 2024 were included. The body temperature characteristics of patients in hypothermia group and non-hypothermia group were collected and evaluated. Univariate and Logistic regression analysis were used to evaluate the influencing factors. Based on the regression coefficients of risk factors, a risk prediction model of hypothermia was established. The model was assessed by Hosmer's Lemeshow (H- L) test and receiver working characteristic (ROC) curve.

Results

In 216 patients undergoing laparoscopic surgery, the incidence of hypothermia was 52.78 %. BMI≤23 kg/m2(OR = 2.061, 95%CI: 1.413-3.263), basal body temperature≤36.1 °C (OR = 3.715, 95%CI: 3.011-4.335), operating room temperature≤22 °C (OR = 2.481, 95%CI: 1.906-3.014), length of surgery≥120 min (OR = 2.228, 95%CI: 1.925-2.981) were the risk factors of hypothermia in patients undergoing laparoscopic surgery (all P < 0.05). The P value of H-L test was 0.098, the area under ROC curve and 95%CI were 0.806 (0.746-0.869). The sensitivity and specificity of the model in this study were good.

Conclusions

Patients undergoing laparoscopic surgery are at a high risk of developing hypothermia, a condition influenced by a multitude of factors. This model is designed to be integrated into clinical practice, enabling healthcare providers to identify patients with a higher risk and to implement targeted preventive measures.

The Effect of Brief Warming during Induction of General Anesthesia and Warmed Intravenous Fluid on Intraoperative Hypothermia in Patients Undergoing Urologic Surgery

Background and Objectives: Transurethral urologic surgeries frequently lead to hypothermia due to bladder irrigation. Prewarming in the preoperative holding area can reduce the risk of hypothermia but disrupts surgical workflow, preventing it from being of practical use. This study explored whether early intraoperative warming during induction of anesthesia, known as peri-induction warming, using a forced-air warming device combined with warmed intravenous fluid could prevent intraoperative hypothermia. Materials and Methods: Fifty patients scheduled for transurethral resection of the bladder (TURB) or prostate (TURP) were enrolled and were randomly allocated to either the peri-induction warming or control group. The peri-induction warming group underwent whole-body warming during anesthesia induction using a forced-air warming device and was administered warmed intravenous fluid during surgery. In contrast, the control group was covered with a cotton blanket during anesthesia induction and received room-temperature intravenous fluid during surgery. Core temperature was measured upon entrance to the operating room (T0), immediately after induction of anesthesia (T1), and in 10 min intervals until the end of the operation (Tend). The incidence of intraoperative hypothermia, change in core temperature (T0-Tend), core temperature drop rate (T0-Tend/[duration of anesthesia]), postoperative shivering, and postoperative thermal comfort were assessed. Results: The incidence of intraoperative hypothermia did not differ significantly between the two groups. However, the peri-induction warming group exhibited significantly less change in core temperature (0.61 ± 0.3 °C vs. 0.93 ± 0.4 °C, p = 0.002) and a slower core temperature drop rate (0.009 ± 0.005 °C/min vs. 0.013 ± 0.004 °C/min, p = 0.013) than the control group. The peri-induction warming group also reported higher thermal comfort scores (p = 0.041) and less need for postoperative warming (p = 0.034) compared to the control group. Conclusions: Brief peri-induction warming combined with warmed intravenous fluid was insufficient to prevent intraoperative hypothermia in patients undergoing urologic surgery. However, it improved patient thermal comfort and mitigated the absolute amount and rate of temperature drop.

Development and Validation of a Predictive Model for Intraoperative Hypothermia in Elderly Patients Undergoing Craniocerebral Tumor Resection: A Retrospective Cohort Study

OBJECTIVE

Timely identification of elderly patients who are at risk of developing intraoperative hypothermia (IH) is imperative to enable appropriate interventions. This study aimed to develop a nomogram for predicting the risk of IH in elderly patients undergoing resection of craniocerebral tumor, and to validate its effectiveness.

METHODS

Elderly patients who underwent craniocerebral tumor resection at a large tertiary hospital in eastern China between January 2019 and December 2022 were included (n = 988). The study population was divided into a training set and a validation set by time period. Risk factors identified through the Least Absolute Shrinkage and Selection Operator method and logistic regression analysis were used to establish the nomogram. The model was validated internally by Bootstrap method and externally by validation set through receiver operating characteristic curve analysis, Hosmer-Lemeshow test, and decision curve analysis.

RESULTS

A total of 273 (27.6%) patients developed IH. Duration of anesthesia (P < 0.001), blood loss (P < 0.001), preoperative temperature (P < 0.001), tumor location (P < 0.001), age (P < 0.05), and mean arterial pressure (P < 0.05) were identified as independent risk factors for IH. A nomogram integrating these 6 factors was constructed. The area under the curve was 0.773 (95% confidence interval: 0.735-0.811) (70.5% specificity and 75.0% sensitivity), indicating good predictive performance. The decision curve analysis demonstrated the clinical benefit of using the nomogram.

CONCLUSIONS

Our model showed good performance in identifying elderly patients who are at high risk of developing IH during craniocerebral tumor resection. The nomogram can help inform timely preventive interventions.

Perioperative Health Care Professionals' Knowledge of Evidence-Based Inadvertent Perioperative Hypothermia Management

PURPOSE

To evaluate the perioperative health care professionals' knowledge of evidence-based inadvertent perioperative hypothermia management.

DESIGN

A descriptive, cross-sectional study.

METHODS

The research sample consisted of 219 perioperative nurses and anesthesia technicians working in the university hospital and participating in perioperative care. Data were collected by the researchers using a questionnaire that included descriptive characteristics of health care professionals and inadvertent perioperative hypothermia management between March and April 2021. Descriptive statistics, Shapiro-Wilk normality, Kruskal Wallis, Mann Whitney U, and Spearman correlation test were used to analyze the data.

FINDINGS

In this study, only 29.2% of the health care professionals knew that the threshold value for inadvertent perioperative hypothermia was <36 °C. The mean knowledge score of health care professionals on the management of inadvertent perioperative hypothermia was 13.78 ± 3.47. The knowledge score of 79.5% of health care professionals was moderate level. A significant correlation was determined between inadvertent perioperative hypothermia management knowledge score and education status (P = .032), task (P < .001), and mean years in the profession (P = .02).

CONCLUSIONS

The knowledge of the health care professionals working in the perioperative process about evidence-based practices related to inadvertent perioperative hypothermia management was determined to be moderate. We recommend increasing the level of knowledge of health care professionals by providing education on guidelines regarding inadvertent perioperative hypothermia management.

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 (6.3% vs. 7.0%, P = 0.453), postoperative transfusion (13.3% vs. 13.7%, P = 0.743), and major complications (9.0% vs. 10.1%, 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 < 0.01).

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.

Knowledge and practice of nurses with respect to perioperative hypothermia prevention in the Northwest Amhara Regional State Referral Hospitals, Ethiopia: a cross-sectional study

OBJECTIVES

It has been reported that maintaining a normal body temperature among surgical patients can reduce the length of hospitalisation by up to 40%, decrease the risk of surgical site infection by 64% and reduce mortality by fourfold. Nurses are primarily responsible for preventing the occurrence of hypothermia among surgical patients. This study assessed nurses' knowledge and practices with respect to perioperative hypothermia prevention in Northwest Ethiopia, and investigated the factors associated with good knowledge and practice.

DESIGN

Cross-sectional study.

SETTING

Northwest Amhara Regional State Referral Hospitals, Northwest Ethiopia, 25 March-20 May 2021.

PARTICIPANTS

413 nurses working in the perioperative units of five referral hospitals.

OUTCOME MEASURES

Perioperative hypothermia prevention knowledge and practice among nurses.

RESULTS

Nearly three-fifths (59.1%; 95% CI: 54.7% to 63.7%) of respondents had good knowledge and about half (50.4%; 95% CI: 45.5% to 55.0%) had good practice with respect to perioperative hypothermia prevention. Factors associated with nurses' knowledge of prevention of perioperative hypothermia included male sex (adjusted OR (AOR): 1.61, 95% CI: 1.02 to 2.53), having a bachelor's degree (AOR: 2.50, 95% CI: 1.25 to 5.00), having a master's degree (AOR: 4.39, 95% CI: 1.45 to 13.20) and training participation (AOR: 3.68, 95% CI: 2.14 to 6.33). Factors associated with nurses' practice of prevention of perioperative hypothermia included working in recovery (AOR: 2.87, 95% CI: 1.08 to 7.58) and intensive care units (AOR: 2.39, 95% CI: 1.09 to 5.22), training participation (AOR: 2.64, 95% CI: 1.53 to 4.57), being satisfied with their job (AOR: 2.15, 95% CI: 1.34 to 3.43) and having good knowledge (AOR: 2.64, 95% CI: 1.63 to 4.27).

CONCLUSION

Nurses' knowledge and practice of the prevention of perioperative hypothermia were inadequate. Hospital managers need to design and strengthen training programmes and work to enhance job satisfaction.

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.

Construction and validation of a risk prediction model for intraoperative hypothermia in elderly patients undergoing total hip arthroplasty

AIMS

To construct and validate an intraoperative hypothermia risk prediction model for elderly patients undergoing total hip arthroplasty (THA).

METHODS

We collected data from 718 patients undergoing THA in a tertiary hospital from January 2021 to December 2022. Of these patients, 512 were assigned to the modeling group from January 2021 to April 2022, and 206 participants were assigned to the validation group from May 2022 to December 2022. A logistic regression analysis was performed to construct the model. The area under the curve (AUC) was used to test the model's predictive ability.

RESULTS

The incidence rate of intraoperative hypothermia was 51.67%. The risk factors entered into the risk prediction model were age, preoperative hemoglobin level, intraoperative blood loss, postoperative hemoglobin level, and postoperative systolic blood pressure. The model was constructed as follows: logit (P) = - 10.118 + 0.174 × age + 1.366 × 1 (preoperative hemoglobin level) + 0.555 × 1 (postoperative hemoglobin level) + 0.009 × 1 (intraoperative blood loss) + 0.066 × 1 (postoperative systolic blood pressure). Using the Hosmer-Lemeshow test, the P value was 0.676 (AUC, 0.867). The Youden index, sensitivity, and specificity were 0.602, 0.790, and 0.812, respectively. The incidence rates of intraoperative hypothermia in the modeling and validation groups were 53.15% and 48.06%, respectively. The correct practical application rate was 89.81%. This model had good application potential.

CONCLUSIONS

This risk prediction model has good predictive value and can accurately predict the occurrence of intraoperative hypothermia in patients who undergo THA, which provides reliable guidance for clinical work and has good clinical application value.

Inadvertent Perioperative Hypothermia in Ambulatory Surgery Patients: Incidence, Risk Factors, and Prevention Initiatives

PURPOSE

Although the number and complexity of ambulatory surgical interventions has grown considerably over the years, it has not been fully established whether hypothermia still poses a risk for these interventions. In this study, we aimed to determine the incidence, risk factors, and methods applied to prevent perioperative hypothermia in ambulatory surgery patients.

DESIGN

A descriptive research design was used.

METHODS

The study was conducted with 175 patients between May 2021 and March 2022 in the outpatient units of a training and research hospital in Mersin, Turkey. Data were collected using the Patient Information and Follow-up Form.

FINDINGS

The incidence of perioperative hypothermia was 20% in ambulatory surgery patients. Hypothermia developed in 13.7% of the patients at the 0th minute at the PACU, and 96.6% of the patients were not warmed intraoperatively. We noted a statistically significant relationship between perioperative hypothermia and advanced age (≥60 years), high American Society of Anesthesiologists' (ASA) class, and low hematocrit values. In addition, we determined that the female gender, presence of chronic diseases, general anesthesia, and a long operation time were other risk factors for hypothermia in the perioperative period.

CONCLUSIONS

The incidence of hypothermia during ambulatory surgeries is lower than that in inpatient surgeries. The warming rate of ambulatory surgery patients, which is quite low, can be improved by increasing the awareness of the perioperative team and following the guidelines.

Verification of an intravenous fluid warmer: A prospective, two-center observational trial

Objectives

Avoiding inadvertent hypothermia during surgery is important. Intravenous fluid warmers used intraoperatively are critical for maintaining euthermia. We sought to prospectively evaluate the performance of the parylene-coated enFlow™ intravenous fluid warmer in patients undergoing surgery.

Methods

This was a prospective two-center observational clinical trial performed in inpatient surgical services of two large academic hospital systems. After written informed consent, patients were enrolled in the trial. All patients were adults scheduled for a surgery that was expected to last for at least 1 h with the administration of at least 1 L of fluid warmed prior to infusion. Patient temperature was recorded in the preoperative unit, at the induction of anesthesia, and then every 15 or 30 min until the end of surgery. Temperature monitoring continued in the recovery unit. The parylene-coated enFlow™ intravenous fluid warmer was used in addition to the usual patient warming techniques. The primary outcome was the average core temperature, and secondary analyses assessed individual temperature measurements, temperature measurements during specific time periods, and rate of hypothermic events.

Results

In all, 50 patients (29 males) with a mean age of 64 years were included in the analysis. The mean surgical time was 195 min and patients received an average of 1142 mL of fluids. Core temperature dropped by only 0.3°C approximately 60 min after induction and recovered back to the baseline level approximately 60 min later. There was no correlation between flow rate and measured core body temperature.

Conclusions

The parylene-coated enFlow intravenous fluid warmer was able to warm fluids at all flow rates during prolonged surgery. The results showed that enFlow performed as expected.

The Safety Assessment of Irrigation Fluid Management for Shoulder Arthroscopy and Its Effect on Postoperative Efficacy

OBJECTIVE

Fluid extravasation is a potentially dangerous complication associated with shoulder arthroscopy. Most relevant studies have involved respiratory system, while the primary purpose was to reveal the effects of the fluid extravasation on cardiovascular system and postoperative function.

METHODS

The clinical data of 92 patients was retrospective analyzed, in which 84 cases with rotator cuff injury, three cases with shoulder instability, three cases with fractures of the greater tuberosity of the humerus, and two cases with frozen shoulder. All the patients were undergoing shoulder arthroscopy. The relationship between the basic information of the patients and cardiac index (CI) or pulse pressure variation (PPV) were evaluated by linear regression analysis. The change of CI or PPV at different states were evaluated by the one-way analysis of variance. The liquid retention (TR) and postoperative clinical outcomes was analyzed using linear regression.

RESULTS

The preoperative CI was affected by anesthesia status and body position, while PPV was not affected. Multivariate mixed-effects model analysis of CI found that there was a statistically significant difference in groups of older than 55 years old and those with obesity (BMI > 24). After the operation, the retention of irrigation fluid significantly influenced the circumference of the deltoid (P < 0.001 (95%CI: [0.30, 1.00])), but not on the circumference of the deltoid, neck, and arm. The multivariate analysis of the American Shoulder and Elbow Surgery (ASES) scores at 3 and 6 months after surgery showed that the fluid retention volume was correlated with the ASES score at 3 months after surgery, especially when the retention volume was greater than 2 L (P = 0.001 (95%). %CI: [-12.49, -3.22]).

CONCLUSION

The retention of irrigation fluid after shoulder arthroscopic surgery causes swelling of local limbs, and has an effect on peripheral blood vessels, which is mainly reflected in its influence on PPV and the postoperative function. Therefore, surgeons need to improve their surgical technique, shorten the operation time and reduce fluid retention.

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.

Perioperative active warming strategies in children: a protocol for a multicentre, prospective, randomized controlled trial

Introduction

Inadvertent perioperative hypothermia (IPH) refers to a core body temperature lower than 36.0 °C, which can contribute to many adverse events. The special physiological characteristics in children further increase the incidence of IPH. Therefore, it is very important to perform effective perioperative warming measures for children. Traditional passive warming measures with additional layers have limited thermal insulation effects. Active warming measures might be the better choice, and most measures have achieved good effects in adults. This study combines a variety of active warming measures to propose perioperative active warming strategies and aims to verify the feasibility and thermal insulation effects of perioperative active warming strategies in children.

Methods

This study is a multicentre, prospective, randomized controlled trial. From August 2022 to July 2024, 400 paediatric patients undergoing elective surgery will be recruited in four centres and randomly divided into the active warming strategies group and control group at a ratio of 1:1. The primary outcome is the perioperative cumulative hypothermia effect value (Σ ΔTi × Δti, i = 1…, n). Multiple complications covering the anaesthesia recovery period and postoperative hospitalization will be considered as secondary outcomes to comprehensively analyse the prognosis.

Trial registration

ClinicalTrials.gov identifier: ChiCTR2200062168. Registered on July 26th, 2022. Registered with the name of "Perioperative Active Warming Strategies in Children: A multicenter, prospective, randomized controlled trial". URL:http://www.chictr.org.cn/showproj.aspx?proj=172778.

The Effect of Postinduction Blood Glucose on Intraoperative Hypothermia

Background and Objectives: Hypothermia frequently occurs in patients undergoing surgery and is associated with adverse complications. Therefore, this study aimed to investigate the postinduction blood glucose and occurrence of intraoperative hypothermia in patients undergoing laparoscopic surgery. Materials and Methods: This retrospective observational study included 334 patients aged ≥20 years who had undergone elective laparoscopic surgery. The primary outcome of this study was the incidence of intraoperative hypothermia. Stratified analysis revealed differences between patients with and without diabetes. Results: Hypothermia occurred in 200 (59.9%) patients. In multivariate analysis, out-of-range postinduction glucose was independently associated with hypothermia (>150 mg/dL: odds ratio 2.17, 95% confidence interval (1.02, 4.61), p = 0.045; <110 mg/dL: odds ratio 2.02, 95% confidence interval (1.15, 3.55), p = 0.015), whereas preoperative HbA1c >6% was not significantly associated with hypothermia (odds ratio 1.02, 95% confidence interval (0.56, 1.84), p = 0.961). Considering only patients with diabetes, the incidence of hypothermia was lower (p = 0.002), the duration of hypothermia was shorter (p = 0.007), and the minimum temperature was higher (p = 0.006) in those with a postinduction glucose level of 110-150 mg/dL. Conclusions: The postinduction glucose level is independently associated with intraoperative hypothermia. Out-of-range postinduction glucose appeared to have an impact on the development of hypothermia in patients with diabetes, especially those with a postinduction glucose level <110 mg/dL.

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.

Hypothermia and Prolonged Time From Procedure End to Extubation After Endovascular Thoracic Aortic Surgery

OBJECTIVE

Perioperative hypothermia (core temperature <36°C) occurs in 50%-to-80% of patients recovering from thoracic aortic surgery, though its effects have not been described fully in this context. The authors, therefore, sought to characterize the incidence of perioperative hypothermia and its association with time from procedure end to extubation in endovascular aortic surgical patients.

DESIGN

A retrospective cohort study.

SETTING

At a single academic tertiary center.

PARTICIPANTS

Patients recovering from thoracic aortic surgery with lumbar drains.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

A total of 196 patients were included in this study, 55 of whom were hypothermic with temperatures <35.0°C at the end of surgery. Though the unadjusted time to extubation was not statistically different in the hypothermic group (median 8 minutes, IQR 5-13.5 minutes) compared to the normothermic group (median 7 minutes, IQR 4-12 minutes; p = 0.062), multivariate predictors of increased time from procedure end to extubation included hypothermia (p = 0.011), age (p = 0.009), diabetes (p = 0.015), history of carotid disease (p = 0.040), and crystalloid volume (p = 0.019).

CONCLUSIONS

Hypothermia in patients recovering from endovascular aortic surgery was associated with prolonged time from procedure end to extubation. Because of the retrospective observational nature of the authors' analysis, it was not possible to determine the extent to which prolonged mechanical ventilation was influenced by low temperature.

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.

Çocuk Hastanesinde Perioperatif Hipotermi Sıklığı ve Predispozan Faktörler

Background/Aim: Perioperative hypothermia is more common in pediatric patients than in adult patients due to increased body surface area/weight ratio and limited subcutaneous fat deposits. Therefore, active and passive warming techniques are used more frequently in the surgeries applied to pediatric patients. This study presents the prevalence of perioperative hypothermia and the predisposing conditions for perioperative hypothermia in pediatric orthopedic surgeries in which active and passive warming techniques are applied. Methods: This cross-sectional, descriptive, and observational study included 102 children admitted to the pediatric orthopedic clinic of a children’s hospital. Temperature measurements were made with a calibrated infrared tympanic thermometer in all cases while they were waiting in the service room, when they entered the operation theater, when they left the operation theater, and when they left the postoperative care unit. Their demographic data, hemogram, and thyroid hormone parameters, preoperative fasting times related to the procedure, and temperature were recorded. Also, the humidity and temperature values of the operating theater, the operation type performed, the anesthesia method applied during the operation, the complications encountered, and the time spent in the operating theater were all recorded in their follow-up forms. Data analysis was done using SPSS V21.0 and was conducted at a 95% confidence interval. Results: Hypothermia was observed in 20,58% of 102 patients included in the study. Predisposing factors were determined for perioperative hypothermia as follows; the patient's American Society of Anesthesiologists risk score is above 1, concomitant diagnosis of cerebral palsy, low hemoglobin level in the preoperative period, fasting longer than 8 hours, the low body temperature of the patient in the service room, long time stayed in the operating room, and different humidity values of the operating theatre. Conclusion: Although active and passive warming techniques are applied during the operation, perioperative hypothermia was observed in 20,58% of pediatric patients who underwent the orthopedic operation. Consideration of predisposing factors together with active and passive warming techniques may reduce the incidence of perioperative hypothermia.

Intraoperative Hypothermia Induces Vascular Dysfunction in the CA1 Region of Rat Hippocampus

Intraoperative hypothermia is very common and leads to memory decline. The hippocampus is responsible for memory formation. As a functional core area, the cornu ammonis 1 (CA1) region of the hippocampus contains abundant blood vessels and is susceptible to ischemia. The aim of the study was to explore vascular function and neuronal state in the CA1 region of rats undergoing intraoperative hypothermia. The neuronal morphological change and activity-regulated cytoskeleton-associated protein (Arc) expression were evaluated by haematoxylin-eosin staining and immunofluorescence respectively. Histology and immunohistochemistry were used to assess vascular function. Results showed that intraoperative hypothermia inhibited the expression of vascular endothelial growth factor and endothelial nitric oxide synthase, and caused reactive oxygen species accumulation. Additionally, the phenotype of vascular smooth muscle cells was transformed from contractile to synthetic, showing a decrease in smooth muscle myosin heavy chain and an increase in osteopontin. Ultimately, vascular dysfunction caused neuronal pyknosis in the CA1 region and reduced memory-related Arc expression. In conclusion, neuronal disorder in the CA1 region was caused by intraoperative hypothermia-related vascular dysfunction. This study could provide a novel understanding of the effect of intraoperative hypothermia in the hippocampus, which might identify a new research target and treatment strategy.

Impact of the Hormonal Status in Women on Intraoperative Hypothermia during Laparoscopic Gynecologic Surgery when Considering the Fresh Gas Flow Rate: A Retrospective Study

Previous studies reported the impact of intrinsic and extrinsic factors on intraoperative hypothermia. However, no clinical study to date has considered the effects of both the phase of the menstrual cycle (an intrinsic factor) and the fresh gas flow rate (FGF) during anesthesia (an extrinsic factor) on the core body temperature and intraoperative hypothermia. This study is aimed at investigatig the effect of the menstrual cycle phase on intraoperative hypothermia when considering the FGF in patients who underwent laparoscopic gynecologic surgery. This study included 667 women aged 19-65 years with menstruation cycles and menopause. The patients were divided into the follicular, luteal, and menopause groups. The primary outcome was the correlations of hormonal status with intraoperative hypothermia. Secondary outcomes included the incidence of intraoperative hypothermia, time to onset of hypothermia, incidence of shivering after anesthesia, and frequency of antishivering drug use in the three groups and risk factors for hypothermia. Overall, the hypothermia incidence was the lowest and the time to onset of hypothermia was the longest in the luteal phase group. At a high FGF, the incidence of hypothermia in the luteal phase group was lower than that in the other two groups (P < 0.05). At a low FGF, the time to onset of hypothermia in the luteal phase group was longer than that in the other two groups (P < 0.05). The female hormonal status had weak positive correlations with hypothermia at low and high FGF rates. A high FGF in univariate and multivariate analyses, follicular phase and menopause in multivariate analysis, and estradiol and progesterone levels in univariate analysis were risk factors for hypothermia. When considering the FGF, the luteal phase is associated with better outcomes concerning intraoperative hypothermia.

The Effects of Intraoperative Hypothermia on Postoperative Cognitive Function in the Rat Hippocampus and Its Possible Mechanisms

Intraoperative hypothermia is a common complication during operations and is associated with several adverse events. Postoperative cognitive dysfunction (POCD) and its adverse consequences have drawn increasing attention in recent years. There are currently no relevant studies investigating the correlation between intraoperative hypothermia and POCD. The aim of this study was to assess the effects of intraoperative hypothermia on postoperative cognitive function in rats undergoing exploratory laparotomies and to investigate the possible related mechanisms. We used the Y-maze and Morris Water Maze (MWM) tests to assess the rats’ postoperative spatial working memory, spatial learning, and memory. The morphological changes in hippocampal neurons were examined by haematoxylin-eosin (HE) staining and hippocampal synaptic plasticity-related protein expression. Activity-regulated cytoskeletal-associated protein (Arc), cyclic adenosine monophosphate-response element-binding protein (CREB), S133-phosphorylated CREB (p-CREB [S133]), α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor 1 (AMPAR1), and S831-phosphorylated AMPAR1 (p-AMPAR1 [S831]) were evaluated by Western blotting. Our results suggest a correlation between intraoperative hypothermia and POCD in rats and that intraoperative hypothermia may lead to POCD regarding impairments in spatial working memory, spatial learning, and memory. POCD induced by intraoperative hypothermia might be due to hippocampal neurons damage and decreased expression of synaptic plasticity-related proteins Arc, p-CREB (S133), and p-AMPAR1 (S831).

Implementation of multi-mode nursing insulation program for patients receiving surgery for spine tumor: a propensity score-matched analysis

BACKGROUND

Spinal tumor surgery usually involved long operation time, large area of soft tissue resection and long wound, and was prone to hypothermia during the operation. Therefore, actively promoting insulation and optimizing the intraoperative insulation program have great potential in reducing the incidence of hypothermia and reducing the incidence of postoperative complications. In this study, we compared patients who did not implement multi-mode nursing insulation program (MNIP) with those who implemented MNIP, observing and comparing clinical outcomes, and complications in both groups, with the aim of developing an optimal management plan for the preoperative, intraoperative, and postoperative periods, respectively.

METHODS

We selected 2 periods of 1 year, before (n = 120 patients) and after MINP implementation (n = 120 patients). Data were collected on patient demographics, operative, perioperative details, temperature changes, anesthesia recovery effect, incidence of postoperative wound infection, length of hospital stay and complications. PS analyses were used for dealing with confounding bias in this retrospective observational study.

RESULTS

After PS matching, the outcomes of 120 well-balanced pairs of patients were compared (No-MNIP vs MNIP). There was no significant difference concerning the satisfaction survey. The results indicated that the MNIP had better insulation effect at 90 min, 120 min, 150 min after anesthesia induction and after surgery. There were 16 cases of complications in the No-MNIP group and 5 cases in the MNIP group postoperative, which have significant statistical difference.

CONCLUSION

In this study, the incidence of intraoperative hypothermia was effectively reduced by adopting the multi-mode insulation scheme, thus reducing the incidence of incision infection and shortening the length of hospital stay of patients.

Validation of a Prediction Model for Intraoperative Hypothermia in Patients Receiving General Anesthesia

OBJECTIVES

There have been no fully validated tools for the rapid identification of surgical patients at risk of intraoperative hypothermia. The objective of this study was to validate the performance of a previously established prediction model in estimating the risk of intraoperative hypothermia in a prospective cohort.

METHODS

In this observational study, consecutive adults scheduled for elective surgery under general anesthesia were enrolled prospectively at a tertiary hospital between September 4, 2020, and December 28, 2020. An intraoperative hypothermia risk score was calculated by a mobile application of the prediction model. A wireless axillary thermometer was used to continuously measure perioperative core temperature as the reference standard. The discrimination and calibration of the model were assessed, using the area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow goodness-of-fit test, and Brier score.

RESULTS

Among 227 participants, 99 (43.6%) developed intraoperative hypothermia, and 10 (4.6%) received intraoperative active warming with forced-air warming. The model had an AUC of 0.700 (95% confidence interval [CI], 0.632-0.768) in the overall cohort with adequate calibration (Hosmer-Lemeshow χ ² = 13.8, P=0.087; Brier score = 0.33 [95% CI, 0.29-0.37]). We categorized the risk scores into low-risk, moderate-risk, and high-risk groups, in which the incidence of intraoperative hypothermia was 23.0% (95% CI, 12.4-33.5), 43.4% (95% CI, 33.7-53.2), and 62.7% (95% CI, 51.5-74.3), respectively (P for trend <0.001).

CONCLUSIONS

The intraoperative hypothermia prediction model demonstrated possibly helpful discrimination and adequate calibration in our prospective validation. These findings suggest that the risk screening model could facilitate future perioperative temperature management.

Value of Active Warming Devices for Intraoperative Hypothermia Prevention-A Meta-Analysis and Cost-Benefit Analysis

Purpose: Historically, studies suggested that intraoperative hypothermia (IH) could result in significant resource consumption, but more recent studies have found the opposite. The purpose of this study is to estimate the value of active warming devices for IH prevention based on synthesized evidence. Methods: A cost-benefit analysis was conducted using the effect of active warming versus passive warming devices for intraoperative hypothermia from a meta-analysis. The item-based aggregated treatment cost approach was adopted to estimate the cost of each adverse event, which was then weighted to calculate the total cost of IH. Results: IH was associated with higher risks of bleeding, surgical site infection, and shivering compared with normothermia. The cost of one case of IH was $363.80, and the use of active warming devices might save $152.80. Extra investment in active warming (e.g., $291.00) might only be cost-beneficial when the minimum willingness-to-pay is $150.00. Conclusions: Synthesized evidence showed that the cost of IH might be overestimated. Furthermore, the value of using active warming devices remains uncertain because the willingness to pay may vary between decision-makers. As not enough awareness of hypothermia prevention in some countries, further research into the clinical use of active warming devices during major surgeries is warranted.