Incidence Of Inadvertent Perioperative Hypothermia Research Articles

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

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. 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. 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.

Importance of Preventing Inadvertent Perioperative Hypothermia During Liver Transplant

Inadvertent perioperative hypothermia (IPH) leads to a series of deleterious effects that can be especially in complex procedures such as liver transplant. The implementation of a protocol is key to ensure the patient's normothermia. A cohort of 209 patients who underwent liver transplant in a tertiary hospital in a period between January 2016 and December 2018 was retrospectively analyzed. The patients were divided into 2 groups: group 1, patients with normothermia (core body temperature ≥ 36°C) and group 2, patients with hypothermia (core body temperature < 36°C). Mortality between both groups at 1 month, 1 year, and 3 years is compared. Postoperative morbidity is also compared. The incidence of IPH is 21.5%. Patients with normothermia present with statistical significance: a lower mortality at 1 year; a lower need for transfusion of platelets, plasma, fibrinogen consumption, or massive polytransfusion; and lower primary graft dysfunction, graft and surgical complications, rejection, hemodynamic complications, and metabolic and surgical reintervention. No significant differences were found in mortality at 1 month or 3 years in the need for prolonged mechanical ventilation; hospital readmission; length of stay in the intensive care unit or in hospital stay; rate of red blood cell transfusion; vascular, biliary, respiratory, or digestive complications; refractory ascites; or neurologic, kidney, hematological, endocrine, thrombotic, nutritional, or infectious issues. The incidence of IPH is relatively low in our patients, based on what is described in the literature, and in most cases it is mild. There is a reduction in complications fundamentally related to the consumption of blood products and the graft.

Incidence of inadvertent perioperative hypothermia in pediatric laparoscopic surgery: a prospective observational single-center study.

Abstract&#x0D; Objective&#x0D; The pediatric age group is in the risk group for Inadvertent perioperative hypothermia (IPH) due to insufficient subcutaneous adipose tissue and underdeveloped thermoregulatory responses.&#x0D; We aimed to determine the frequency of IPH in the pediatric age group undergoing laparoscopic surgery.&#x0D; Methods&#x0D; The study is prospective observational.&#x0D; Pediatric patients (1-18 years old) who underwent laparoscopic surgery under general anaesthesia were evelueted. The tympanic membrane temperature measurements of the patients (°C) were recorded before anaesthesia induction (T0) and then every 15 minutes during the surgery.&#x0D; Results&#x0D; A total of 100 patients were evaluated. The frequency of inadvertent perioperative hypothermia was detected 13 (13%). Frequency of IPH on elective surgery patients was higher than emergency surgery (

Using a Normothermia Bundle With Perioperative Prewarming to Reduce Patient Hypothermia

PurposeTo determine if implementing a normothermia bundle, which includes preoperative forced-air warming blankets, reduces incidence of inadvertent perioperative hypothermia (IPH). DesignIntervention study using retrospective chart review. MethodsPatients received a preoperative forced-air warming blanket and temperature management with the normothermia bundle. Temperature status data was collected from patient charts to evaluate the incidences of IPH and findings from this data analysis was used to measure improvement in perioperative temperature management. FindingsOf 200 patients, 63 (31.5%) remained normothermic, 37 (18.5%) had at least one documented hypothermic temperature, and 100 (50%) had no documented temperature during the intraoperative phase of care. Although compliance with intraoperative temperature monitoring decreased by 13% postintervention, the incidence of documented IPH in reviewed records was decreased by 3.6-fold. ConclusionImplementing a normothermia bundle that includes a preoperative forced-air warming blanket may lower the incidences of IPH, especially in surgical cases lasting over 120 minutes.

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

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

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

Unintended perioperative hypothermia, defined as core body temperature less than 36°C, is closely related to many complications such as cardiovascular diseases, peroperative hemorrhagic diathesis and impairment of drug metabolism. Determination of the incidence of perioperative hypothermia and examination of risk factors may help to prevent hypothermia and its complications. We conducted a prospective, observational study of 2015 patients who underwent various operations under general anesthesia, and the risk factors of developing hypothermia were analysed. The incidence of perioperative hypothermia was 78.6%. The incidence of hypothermia within 2hours was 56.6%, and after 2hours, it was 100%. Mean age was 49.36±16.10, and 17.8% were over 65years old. The mean body mass index (BMI) was 27.96±3.94kg/m2 ; 60.8% of the patients had American Society of Anesthesiologists (ASA) I score, 33.4% had ASA II and 5.8% had ASA III; 35.8% of the patients had co-morbidities. Intravenous and irrigation fluids were unwarmed; 99.9% of the patients were warmed passively, and only 0.1% of patients received active heating intraoperatively. The incidence of hypothermia was higher in overweight (BMI≥25kg/m2 ), elderly (>65years) patients and those with co-morbidities. High American Society of Anesthesiologists (ASA) scores, grade 3-4 surgery, endoscopic surgery, duration of anesthesia>2hours, infusion or irrigation>1000mL significantly increased the incidence of hypothermia. The incidence of perioperative hypothermia found was high. Important risk factors were found as prolonged duration of anesthesia and surgery, advanced age, overweight, high ASA scores, major surgeries, endoscopic operations and unwarmed fluid administration. High incidence may be reduced by raising awareness, considering fossible risk factors and following the recommendations of the guidelines on prevention of perioperative hypothermia.

Does the Laminar Airflow System Affect the Development of Perioperative Hypothermia? A Randomized Clinical Trial.

We aimed to compare tympanic membrane temperature changes and the incidence of inadvertent perioperative hypothermia (IPH) in patients undergoing laparoscopic cholecystectomy under general anesthesia in laminar airflow systems (LAS-OR) and conventional turbulent airflow systems (CAS-OR). Different heating, ventilation, and air-conditioning (HVAC) systems are used in the operating room (OR), such as LAS and CAS. Laminar airflow is directed directly to the patient in LAS-OR. Does laminar airflow in ORs cause faster heat loss by convection? This is a prospective, randomized study. We divided 200 patients with simple randomization (1:1), as group LAS and group CAS, and took the patients into the LAS-OR or CAS-OR for the operation. Clinical trial number: IRCT20180324039145N3. The tympanic membrane temperatures of patients were measured (°C) before anesthesia induction (T0) and then every 15 min during surgery (Tn). Changes (Δn) between T0 and Tn were measured. In the first 30 min, there was a temperature decrease of approximately 0.8 °C (1.44 °F) in both groups. Temperature decreases at 45 min were higher in group LAS than in group CAS but not statistically significant, Δ45, respectively, 0.89 (95% confidence interval [CI] [0.77, 1.02]) versus 0.77 (95% CI [0.69, 0.84]; p = .09). IPH occurred in a total of 60.9% (112 of 184) of patients in the entire surgical evaluation period in group LAS and group CAS (58.9% vs. 62.8%, p = . 59). IPH is seen frequently in both HVAC systems. Clinically, the advantage of HVAC systems relative to each other has not been demonstrated during laparoscopic cholecystectomy.

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

BackgroundInadvertent perioperative hypothermia (< 36 °C) occurs frequently during elective cesarean delivery and most institutions do employ perioperative active warming. The purpose of this retrospective observational cohort study was to determine if the addition of preoperative forced air warming in conjunction with intraoperative underbody forced air warming improved core temperature and reducing inadvertent perioperative hypothermia during elective repeat elective cesarean delivery with neuraxial anesthesia.MethodsWe evaluated the addition of perioperative active warming to standard passive warming methods (preheated intravenous/irrigation fluids and cotton blankets) in 120 parturients scheduled for repeat elective cesarean delivery (passive warming, n = 60 vs. active + passive warming, n = 60) in a retrospective observational cohort study. The primary outcomes of interest were core temperature at the end of the procedure and a decrease in inadvertent perioperative hypothermia (< 36 °C). Secondary outcomes were surgical site infections and adverse markers of neonatal outcome.ResultsThe mean temperature at the end of surgery after instituting the active warming protocol was 36.0 ± 0.5 °C (mean ± SD, 95% CI 35.9–36.1) vs. 35.4 ± 0.5 °C (mean ± SD, 95% CI 35.3–35.5) compared to passive warming techniques (p < 0.001) and the incidence of inadvertent perioperative hypothermia at the end of the procedure was less in the active warming group - 68% versus 92% in the control group (p < 0.001). There was no difference in surgical site infections or neonatal outcomes.ConclusionsPerioperative active warming in combination with passive warming techniques was associated with a higher maternal temperature and lower incidence of inadvertent perioperative hypothermia with no detectable differences in surgical site infections or indicators of adverse neonatal outcomes.

The Effectiveness of Four Intervention Methods for Preventing Inadvertent Perioperative Hypothermia During Total Knee or Total Hip Arthroplasty.

Inadvertent perioperative hypothermia (IPH) occurs when a patient experiences a core temperature below 36° C (96.8° F) in perioperative settings and is a preventable risk factor for anesthesia- and surgery-related complications. Forced-air warming is an effective method to maintain normothermia. This study compared four interventions for preventing IPH for 120 patients undergoing primary elective unilateral total knee or total hip arthroplasty. The study was based on a time series nonequivalent comparison group design to investigate whether the incidence of IPH differed among treatment groups. We also sought to determine whether the patients' preoperative perceptions of warmth or cold correlated with core body temperatures. Patients receiving convective warming and prewarming appeared to experience fewer IPH events than patients in the other study groups. This study suggests that hypothermia is a common issue for patients undergoing total knee or total hip arthroplasty and that it may be possible to reduce its frequency.

Research progress of risk assessment about inadvertent perioperative hypothermia

Inadvertent perioperative hypothermia (IPH) is one of the most common complications of perioperative patients, and induces some other complications such as cardiovascular adverse events, chills, blood coagulation dysfunction, infections of incision with high probability. It is also associated with a substantial economic burden, primarily due to delay of recovery and prolonged hospitalization. Therefore, previous assessment and identification of IPH risk factors is crucial to reduce the incidence of IPH and its adverse effects. This paper will review the following three aspects of IPH’s risk assessment: high-risk groups, tools and effect. Key words: Perioperative; Hypothermia; Risk assessment; Review

Inadvertent Perioperative Hypothermia During Orthopedic Surgery.

Inadvertent perioperative hypothermia is a significant problem in patients undergoing either emergency or elective orthopedic surgery, and is associated with increased morbidity and mortality. Though in general the incidence of inadvertent perioperative hypothermia in postoperative recovery rooms has been decreasing over the last 2 decades, it still remains a significant risk in certain specialty practices, such as orthopedic surgery. This review article summarizes the currently available evidence on the incidence, risk factors, and complications of inadvertent perioperative hypothermia. Also, the effective preventive strategies in dealing with inadvertent perioperative hypothermia are reviewed and essential clinical guidelines to be followed are summarized.

Prewarming according to the AWMF S3 guidelines on preventing inadvertant perioperative hypothermia 2014 : Retrospective analysis of 7786 patients

Inadvertent perioperative hypothermia, which is defined as a core body temperature of less than 36.0 °C, can have serious consequences in surgery patients. These include cardiac complications, increased blood loss, wound infections and postoperative shivering; therefore, the scientific evidence that inadvertent perioperative hypothermia should be avoided is undisputed and several national guidelines have been published summarizing the scientific evidence and recommending specific procedures. The German AWMF guidelines were the first to emphasize the importance of prewarming for surgery patients to avoid inadvertant perioperative hypothermia; however, in contrast to intraoperative warming, prewarming is so far not sufficiently implemented in clinical practice in many hospitals. Furthermore, arecent study has questioned the effectiveness of prewarming. The aim of this retrospective investigation was to evaluate the hypothermia rates that can be achieved when prewarming in the anesthesia induction room is introduced into the clinical practice and performed in addition to intraoperative warming. The ethics committee of the Medical Faculty of the Martin Luther University Halle Wittenberg gave approval for data storage and retrospective data analysis from the anesthesia database. According to the existing local standard operating procedure, prewarming with forced air was performed in addition to intraoperative warming in the anesthesia induction room in 3899 patients receiving general anesthesia with aduration of 30 min or longer from January 2015 to December 2016. The results were compared with acontrol group of 3887 patients from July 2012 to August 2014 who received intraoperative warming but were not subjected to prewarming. Tracheal intubation was carried out in all patients and temperature measurements after the induction of anesthesia were performed using esophageal, urinary catheter or intra-arterial temperature probes. The mean duration of prewarming was 25 min in the treatment group. Patients subjected to prewarming showed an intraoperative hypothermia rate of 15.8% and apostoperative hypothermia rate of 5.1%. Patients without prewarming showed an intraoperative hypothermia rate of 30.4% and apostoperative hypothermia rate of 12.4%. This means a52% reduction of the intraoperative hypothermia rate and a41% reduction of the postoperative hypothermia rate for patients who received prewarmimg (p< 0.0001). Multivariate logistic regression revealed that the lack of prewarming was independently associated with intraoperative hypothermia with an odds ratio of 2.5 (95% confidence interval CI 2.250-2.841; p< 0.0001) and postoperative hypothermia with an odds ratio of 2.8 (95% CI 2.316-3.277; p< 0.0001). Prewarming, as recommended in the AWMF guidelines, resulted in a significant and clinically relevant reduction in the incidence of inadvertent perioperative hypothermia; therefore, prewarming can still be regarded as an effective method to avoid perioperative hypothermia. Hypothermia rates of 15.8% intraoperatively and 5.1% postoperatively can be achieved in clinical practice, when prewarming is performed in addition to intraoperative warming in the anesthesia induction room directly before the start of surgical procedures.

Effectiveness of active and passive warming for the prevention of inadvertent hypothermia in patients receiving neuraxial anesthesia: A systematic review and meta-analysis of randomized controlled trials

ObjectivePerioperative hypothermia is a common complication of anesthesia that can result in negative outcomes. The purpose of this review is to answer the question: Does the type of warming intervention influence the frequency or severity of inadvertent perioperative hypothermia (IPH) in surgical patients receiving neuraxial anesthesia? DesignSystematic review and meta-analysis. SettingPerioperative care areas. PatientsAdults undergoing surgery with neuraxial anesthesia. InterventionPerioperative active warming (AW) or passive warming (PW). MeasurementsPubMed, CINAHL, Embase, and Cochrane Central Register of Controlled Trials were searched. Inclusion criteria were: randomized controlled trials; adults undergoing surgery with neuraxial anesthesia; comparison(s) of AW and PW; and temperature measured at end of surgery/upon arrival in the Postanesthesia Care Unit. Exclusion criteria were: no full-text available; not published in English; studies of: combined neuraxial and general anesthesia, warm intravenous or irrigation fluids without using AW, and rewarming after hypothermia. Two independent reviewers screened abstracts and titles, and selected records following full-text review. The Cochrane Collaboration's tool for assessing risk of bias was used to evaluate study quality. A random-effects model was used to calculate risk ratios for dichotomous data and mean differences for continuous data. Main resultsOf 1587 records, 25 studies (2048 patients) were included in the qualitative synthesis. Eleven studies (1189 patients) comparing AW versus PW were included in the quantitative analysis. Meta-analysis found that intraoperative AW is more effective than PW in reducing the incidence of IPH during neuraxial anesthesia (RR=0.71; 95% CI 0.61–0.83; p<0.0001; I2=32%). The qualitative synthesis revealed that IPH continues despite current AW technologies. ConclusionsDuring neuraxial anesthesia, AW reduces IPH more effectively than PW. Even with AW, IPH persists in some patients. Continued innovation in AW technology and additional comparative effectiveness research studying different AW methods are needed.

Active perioperative patient warming using a self-warming blanket (BARRIER EasyWarm) is superior to passive thermal insulation: a multinational, multicenter, randomized trial

Study ObjectiveIncidence of inadvertent perioperative hypothermia is still high; therefore, present guidelines advocate “prewarming” for its prevention. Prewarming means preoperative patient skin warming, which minimizes redistribution hypothermia caused by induction of anesthesia. In this study, we compared the new self-warming BARRIER EasyWarm blanket with passive thermal insulation regarding mean perioperative patient core body temperature. DesignMultinational, multicenter randomized prospective open-label controlled trial. SettingSurgical ward, operation room, postanesthesia care unit at 4 European hospitals. PatientsA total of 246 adult patients, American Society of Anesthesiologists class I to III undergoing elective orthopedic; gynecologic; or ear, nose, and throat surgery scheduled for 30 to 120 minutes under general anesthesia. InterventionsPatients received warmed hospital cotton blankets (passive thermal insulation, control group) or BARRIER EasyWarm blanket at least 30 minutes before induction of general anesthesia and throughout the perioperative period (intervention group). MeasurementsThe primary efficacy outcome was the perioperative mean core body temperature measured by a tympanic infrared thermometer. Secondary outcomes were hypothermia incidence, change in core body temperature, length of stay in postanesthesia care unit, thermal comfort, patient satisfaction, ease of use, and adverse events related to the BARRIER EasyWarm blanket. Main ResultsThe BARRIER EasyWarm blanket significantly improved perioperative core body temperature compared with standard hospital blankets (36.5°C, SD 0.4°C, vs 36.3, SD 0.3°C; P<.001). Intraoperatively, in the intervention group, hypothermia incidence was 38% compared with 60% in the control group (P=.001). Postoperatively, the figures were 24% vs 49%, respectively (P=.001). Patients in the intervention group had significantly higher thermal comfort scores, preoperatively and postoperatively. No serious adverse effects were observed in either group. ConclusionsPerioperative use of the new self-warming blanket improves mean perioperative core body temperature, reduces the incidence of inadvertent perioperative hypothermia, and improves patients' thermal comfort during elective adult surgery.

Comparison of resistive heating and forced-air warming to prevent inadvertent perioperative hypothermia

BackgroundForced-air warming is a commonly used warming modality, which has been shown to reduce the incidence of inadvertent perioperative hypothermia (<36°C). The reusable resistive heating mattresses offer a potentially cheaper alternative, however, and one of the research recommendations from the National Institute for Health and Care Excellence was to evaluate such devices formally. We conducted a randomized single-blinded study comparing perioperative hypothermia in patients receiving resistive heating or forced-air warming. MethodsA total of 160 patients undergoing non-emergency surgery were recruited and randomly allocated to receive either forced-air warming (n+78) or resistive heating (n+82) in the perioperative period. Patient core temperatures were monitored after induction of anaesthesia until the end of surgery and in the recovery room. Our primary outcome measures included the final intraoperative temperature and incidence of hypothermia at the end of surgery. ResultsThere was a significantly higher rate of hypothermia at the end of surgery in the resistive heating group compared with the forced-air warming group (P+0.017). Final intraoperative temperatures were also significantly lower in the resistive heating group (35.9 compared with 36.1°C, P+0.029). Hypothermia at the end of surgery in both warming groups was common (36% forced air warming, 54% resistive heating). ConclusionOur results suggest that forced-air warming is more effective than resistive heating in preventing postoperative hypothermia. Clinical trial registrationNCT01056991.

The effects of a resistive warming mattress during caesarean section: a randomised, controlled trial

BackgroundThe adverse effects of inadvertent perioperative hypothermia in the surgical population are well established. The aim of this study was to investigate whether a resistive warming mattress would reduce the incidence of inadvertent perioperative hypothermia in patients undergoing elective caesarean section. MethodsA total of 116 pregnant women booked for elective caesarean section were randomised to either intraoperative warming with a mattress or control. The primary outcome was the incidence of inadvertent perioperative hypothermia, defined as a temperature <36.0°C on admission to the recovery room. Shivering in the perioperative period, severity of shivering and the need for treatment, total blood loss, fall in haemoglobin, incidence of blood transfusion, immediate health of baby, and length of hospital stay were also recorded. ResultsThe incidence of inadvertent perioperative hypothermia in the mattress-warmed group was significantly lower than in the control group (5.2% vs. 19.0%, P=0.043); mean temperatures differed between the two groups, 36.5°C and 36.3°C, respectively (P=0.046). There was also a significantly lower mean (± SD) haemoglobin change in the mattress-warmed group at −1.1±0.9 g/dL versus −1.6±0.9 g/dL in the control group (P=0.007). There was no difference in shivering (P=0.798). ConclusionsA resistive warming mattress reduced the incidence of inadvertent perioperative hypothermia and attenuated the fall in haemoglobin. The use of resistive mattress warming should be considered during caesarean section.

Effect of Pre-warming on Reducing the Incidence of Inadvertent Peri-operative Hypothermia for Patients Undergoing General Anaesthesia: A Mini-review

AbstractObjective:This mini-review aims to assess the effect pre-warming has on reducing the incidence of inadvertent peri-operative hypothermia for patients undergoing general anaesthesia.Method:A search of the MEDLINE and EMBASE databases, as well as hand-searching through the reference lists of key articles, was undertaken. Articles were included on the basis that the studies were randomised controlled trials, undertaken on patients who were undergoing surgery under general anaesthesia and were pre-warmed for 60 minutes using forced-air warming systems. This resulted in two articles being critically appraised and reviewed using guidelines based on those given in Greenhalgh and Donald (2000).Findings:The results for both of these studies showed that statistically significant differences were seen in core body temperature, with analysis of variance used to test for the significant differences between the sample means. The findings were also clinically significant, as a small drop in temperature as a result of anaesthesia and surgery can lead to IPH, and with pre-warming this can be avoided.Conclusion:The studies that were used in this review both reported that pre-warming patients for 60 minutes pre-operatively had both a statistically significant and clinically significant effect. This means that patients should receive a period of pre-warming before surgery in addition to being warmed peri-operatively, in order to reduce any drop in potential temperature that can lead to IPH.

Effect of prewarming on post-induction core temperature and the incidence of inadvertent perioperative hypothermia in patients undergoing general anaesthesia

BackgroundInadvertent perioperative hypothermia (IPH) occurs in many patients because warming techniques are insufficient to counteract thermal redistribution resulting from the ablation of thermoregulatory vasoconstriction associated with anaesthesia. We tested the efficiency of a preoperative forced-air warming (FAW) device (Bair Paws®) in preventing IPH. MethodsSixty-eight adult patients undergoing spinal surgery under general anaesthesia were randomized to receive either normal care or prewarming for 60 min, at 38°C, using the Bair Paws® system. All patients received routine FAW intraoperatively. ResultsThirty-one patients were prewarmed and 37 patients were in the control group. There was a 0.3°C smaller decrease in mean core temperature in the prewarmed group at 40, 60, and 80 min post-induction (P≤0.05). Temperature was maintained above the hypothermic threshold of 36°C in 21 (68%) patients in the prewarmed group, compared with 16 (43%) patients in the control group (P<0.05). ConclusionsPreoperative warming using the Bair Paws® system results in smaller decreases in core temperature intraoperatively and less IPH in patients undergoing spinal surgery under general anaesthesia.