Active Warming Research Articles

Utility of Perioperative Warming for the Prevention of Surgical Site Infection and Patient Rehabilitative Complications: A Systematic Review

Overview: Surgical site infection (SSI) is a leading cause of postoperative complication, rehospitalisation, and patient mortality after invasive clinical interventions. Surgical risks compounded by SSI introduce greater medical, economic, and quality-of-life challenges for both patients and providers alike, and to better inform clinical practice, empirical evaluation of modern surgical warming techniques is relevant. This systematic review and meta-analysis qualitatively examined the efficacy of both active and passive perioperative warming interventions upon SSI presentation versus standardised (i.e., non-warming) care. Methods: This review analysed available literature on active and passive warming application across general anaesthesia procedures, containing longitudinal data on patient outcomes and SSI. The primary outcome studied was occurrence of post-surgical SSI; secondary outcomes included rehabilitative length of stay, attributable SSI-related mortality, and incidence of re-admittance. Results: Meta-analysis demonstrated a significantly reduced risk ratio for SSI in patients receiving any surgical warming intervention (odds ratio: 0.36; 95% confidence interval: 0.18–0.87; p<0.01) compared to individuals treated under standard care conditions, with limited further data supporting improved active warming effect in contrast with passive implementation. Secondary postoperative outcomes, including length of rehabilitative stay or wound healing score (ASEPSIS), correspondingly demonstrated greater outcomes for surgical patients receiving perioperative warming. Introduction of warming interventions consistently correlated with reduced patient-reported pain experiences (p<0.05) and downstream care expenditures (p<0.01). Conclusion: The present review identified evidence supporting a statistically significant correlation between both active and passive perioperative warming interventions to SSI prevention. These findings strongly support the recommendation of standardised perioperative warming implementation with continued investigation of relative efficacy contrasting active and passive methodologies, and across more diverse and substantial patient population sizes.

Perioperative measurement of core body temperature using an unobtrusive passive heat flow sensor.

Clinicians strive to maintain normothermia, which requires measurement of core-body temperature and may necessitate active warming of patients. Monitoring temperature currently requires invasive probes. This work investigates a novel foam-based flexible sensor worn behind the ear for the measurement of core body temperature. This observational study uses the device prototype and clinical data to compare three methods for calculating the temperature from this sensor: a basic heat-flow model, a new dynamic model that addresses changing surrounding temperatures and one that combines the dynamic model with a correction for adhesive quality. Clinical validation was performed with 21 surgical patients (average length of surgery 4.4 h) using an esophageal temperature probe as reference. The operative period was divided into four segments: normal periods (with stable surrounding temperatures), surrounding temperatures increasing due to the use of the Bair Hugger™, stable periods during Bair Hugger™ use and surrounding temperatures decreasing due to its removal. The error bias and limits of agreement over these segments were on average of - 0.05 ± 0.28 °C (95% limits of agreement) overall. The dynamic model outperformed the simple heat-flow model for periods of surrounding temperature changes (12.7% of total time) while it had a similar, high, performance for the temperature-stable periods. The results suggest that our proposed topical sensor can replace invasive core temp sensors and provide a means of consistently measuring core body temperature despite surrounding temperature shifts.

Prewarming Followed by Active Warming is Superior to Passive Warming in Preventing Hypothermia for Short Procedures in Adult Rats (Rattus norvegicus) Under Isoflurane Anesthesia.

General anesthesia is a common procedure in laboratory rats; however, it impairs thermoregulation, rapidly leading to hypothermia as warm core blood is distributed to the cooler periphery. The protective strategy of prewarming before the onset of anesthesia delays hypothermia, but only for a short period. This prospective, randomized, cross-over, experimental study in adult male and female SD rats (n = 8) was designed to compare passive (fleece blanket) and active (temperature controlled heating pad) warming. Initial treatment order was randomized, with a cross-over after a minimum 5 d washout period. Both groups underwent a period of prewarming in a warming box to increase core temperature by 1% (median 0.4 °C). At completion of prewarming, general anesthesia was induced and maintained for 30 min with isoflurane carried in oxygen. Core temperature was monitored for a further 30 min after anesthesia. Active warming resulted in higher core temperatures during anesthesia. During passive warming, hypothermia occurred after approximately 30 min of anesthesia and continued into recovery. In contrast, active warming prevented hypothermia. Prewarming followed by passive warming delayed hypothermia for approximately 30 min, but active warming was more effective at maintaining normothermia both during and after general anesthesia.

Too Cool? Hip Fracture Care and Maintaining Body Temperature

Introduction:Patients with hip fractures can become cold during the perioperative period despite measures applied to maintain warmth. Poor temperature control is linked with increasing complications and poorer functional outcomes. There is generic evidence for the benefits of maintaining normothermia, however this is sparse where specifically concerning hip fracture. We provide the first comprehensive review in this population.Significance:Large studies have revealed dramatic impact on wound infection, transfusion rates, increased morbidity and mortality. With very few studies relating to hip fracture patients, this review aimed to capture an overview of available literature regarding hypothermia and its impact on outcomes.Results:Increased mortality, readmission rates and surgical site infections are all associated with poor temperature control. This is more profound, and more common, in older frail patients. Increasing age and lower BMI were recognized as demographic factors that increase risk of hypothermia, which was routinely identified within modern day practice despite the use of active warming.Conclusion:There is a gap in research related to fragility fractures and how hypothermia impacts outcomes. Inadvertent intraoperative hypothermia still occurs routinely, even when active warming and cotton blankets are applied. No studies documented temperature readings postoperatively once patients had been returned to the ward. This is a point in the timeline where patients could be hypothermic. More studies need to be performed relating to this area of surgery.

A prospective observational study to evaluate the magnitude of temperature changes in children undergoing elective MRI under general anesthesia.

Context:Induction of general anesthesia and mandatory low-ambient temperature in the magnetic resonance imaging (MRI) suite renders the pediatric patient prone to fall in core temperature. Previously done studies have shown mixed results with core temperature showing both rise and fall.Aims:The aim of this study is to evaluate which effect, hypothermia or hyperthermia, predominates in children anesthetized for MRI. Is the change in temperature the same across age groups and for different MRI scanners?.Settings and Design:Prospective, observational study in a tertiary care teaching hospital.Subjects and Methods:Two hundred and fifty children of age between 1 month and 16 years scheduled for MRI under propofol-based total intravenous anesthesia (TIVA) were recruited. A baseline core temperature (pre-scan) was recorded with the pediatric nasopharyngeal temperature probe after induction of anesthesia and also after the scan in the recovery room.Results:The study shows that there is a significant fall in temperature of 1.022°C (CI = 0.964, 1.081) following MRI (P < 0.001) but the difference across different age groups and type of MRI scanner used are not significant. There is a significant correlation between duration in the MRI room and a decrease in temperature (P value = 0.003). Using simple linear regression analysis, it is found that if there is a 1-min increase in the duration of MRI, there is a decrease of 0.006°C in temperature.Conclusion:Vigilant temperature preservation strategies have to be maintained during the time the anesthetized child is present in the MRI suite. MRI compatible active warming devices are warranted especially in high turnover centers.

Breast Cancer Cryoablation: Assessment of the Impact of Fundamental Procedural Variables in an In Vitro Human Breast Cancer Model.

Introduction:Breast cancer is the most prominent form of cancer and the second leading cause of death in women behind lung cancer. The primary modes of treatment today include surgical excision (lumpectomy, mastectomy), radiation, chemoablation, anti-HER2/neu therapy, and/or hormone therapy. The severe side effects associated with these therapies suggest a minimally invasive therapy with fewer quality of life issues would be advantageous for treatment of this pervasive disease. Cryoablation has been used in the treatment of other cancers, including prostate, skin, and cervical, for decades and has been shown to be a successful minimally invasive therapeutic option. To this end, the use of cryotherapy for the treatment of breast cancer has increased over the last several years. Although successful, one of the challenges in cryoablation is management of cancer destruction in the periphery of the ice ball as the tissue within this outer margin may not experience ablative temperatures. In breast cancer, this is of concern due to the lobular nature of the tumors. As such, in this study, we investigated the level of cell death at various temperatures associated with the margin of a cryogenic lesion as well as the impact of repetitive freezing and thawing methods on overall efficacy.Methods:Human breast cancer cells, MCF-7, were exposed to temperatures of −5°C, −10°C, −15°C, −20°C, or −25°C for 5-minute freeze intervals in a single or repeat freeze-thaw cycle. Samples were thawed with either passive or active warming for 5 or 10 minutes. Samples were assessed at 1, 2, and 3 days post-freeze to assess cell survival and recovery. In addition, the modes of cell death associated with freezing were assessed over the initial 24-hour post-thaw recovery period.Results:Exposure of MCF-7 cells to −5°C and −10°C resulted in minimal cell death regardless of the freeze/thaw conditions. Freezing to a temperature of −25°C resulted in complete cell death 1 day post-thaw with no cell recovery in all freeze/thaw scenarios evaluated. Exposure to a single freeze event resulted in a gradual increase in cell death at −15°C and −20°C. Application of a repeat freeze-thaw cycle (dual 5-minute freeze) resulted in an increase in cell death with complete destruction at −20°C and near complete death at −15°C (day 1 survival: single −15°C freeze/thaw = 20%; repeated −15°C freeze/thaw = 4%). Analysis of thaw interval time (5 vs 10 minute) demonstrated that the shorter 5-minute thaw interval between freezes resulted in increased cell destruction. Furthermore, investigation of thaw rate (active vs passive thawing) demonstrated that active thawing resulted in increased cell survival thereby less effective ablation compared with passive thawing (eg, −15°C 5/10/5 procedure survival, passive thaw: 4% vs active thaw: 29%).Conclusions:In summary, these in vitro findings suggest that freezing to temperatures of 25°C results in a high degree of breast cancer cell destruction. Furthermore, the data demonstrate that the application of a repeat freeze procedure with a passive 5-minute or 10-minute thaw interval between freeze cycles increases the minimal lethal temperature to the −15°C to −20°C range. The data also demonstrate that the use of an active thawing procedure between freezes reduces ablation efficacy at temperatures associated with the iceball periphery. These findings may be important to improving future clinical applications of cryoablation for the treatment of breast cancer.

AGROCLIMATIC RESOURCES OF TEMPERATURE AND HUMIDITY, AND THEIR DYNAMICS IN THE TERRITORY OF THE UDMURT REPUBLIC

For assessment of the dynamics of most prominent agroclimatic resources, the dates of the steady temperature transitions through 0, 5, 10, 15 °С and the sums of effective temperatures on the Izhevsk meteorological station over the period 1933-2018 were calculated. The values of the Ped index were determined for the whole territory of the Udmurt Republic according to data of 8 meteorological stations over the period 1961-2018. The dynamics of these parameters was analyzed. It was found out that the duration of the vegetation period increases, and the sum of active temperatures increases, reaching the maximum values in the last decade. At the same time, during the active warming phase, there is a tendency towards the increase of aridity of the vegetation period.

Агрометеорологические условия развития и причины гибели озимых посевов в период активной фазы потепления

Агрометеорологические условия развития и причины гибели озимых посевов в период активной фазы потепления

Costs of inadvertent perioperative hypothermia in Australia: A cost-of-illness study

BackgroundA definitive cost analysis of preventing inadvertent perioperative hypothermia (IPH) in surgical patients in Australia is lacking. Preventing IPH is a common nurse-led initiative in surgery and cost savings represent the value of nursing care. AimThe study aims are twofold. First, we aim to estimate the cost of the current prevalence of IPH in Australian hospitals. Second, is to estimate the potential cost reductions that could be realised by reducing IPH prevalence by using a thermal care bundle. MethodsCost-of-illness analysis measures the economic burden of illness to society. It does so by identifying and measuring all costs of a disease or illness such as IPH. It was undertaken using a prevalence approach and a one-year time horizon. FindingsThe annual costs of IPH to the Australian health system can be estimated to be $1,259,725,856. The annual net benefit of IPH prevention to the Australian health system is $602 million. Using a thermal care bundle to reduce IPH by actively warming 80% of the patients that are not warmed yet could save $657.1 million per year at the expense of $18.4 million. DiscussionPreventing IPH using active warming is estimated to lead to significant cost savings across the Australian health system. It is recommended that a national policy for preventing IPH is needed and guidelines must reflect up-to-date strategies for preventing IPH including active prewarming. ConclusionThe Thermal Care Bundle should be adopted to lower IPH incidence and associated costs in Australia.

Effect of Active Warming on Surgical Site Infections

Effect of Active Warming on Surgical Site Infections

Comparison of efficacy of active forced-air warming for preventing perioperative hypothermia between the elderly and young patients

Objective To observe whether the active forced-air warming has the same efficacy on the prevention of perioperative hypothermia in the elderly as compared with young patients. Methods This was a prospective, randomized, controlled clinical trial.Forty patients scheduled for abdominal surgery under general anesthesia were allocated to two groups: the elderly group and the young group(n=20, each). All patients received active forced-air warming at 20-30 min before induction of anaesthesia till leaving the operation room.Blood products and peritoneal lavage fluids were warmed to 37℃, and other intravenous fluids were at room-temperature.The core temperatures were recorded after entering the operation room(baseline), before induction of anaesthesia, at 15 min intervals after induction of anaesthesia, at the end of surgery and before leaving the operation room.The postoperative shivering and adverse reactions were also recorded. Results The core temperature was lower in elderly patients than in young patients at baseline and at each time points after 30 min of induction of anaesthesia(P<0.05). In elderly patients, the core temperature was significantly lower before leaving operation room than at the baseline(t=2.353, P=0.03), but in young patients, no significant difference was found in the core temperature between at the baseline and before leaving operation room(t=0.233, P=0.818). The incidence of intra-operative hypothermia was higher in elderly patients than in young patients(40.0% or 8/20 vs.5.0% or 1/20, c2=7.025, P=0.008). Conclusions During abdominal surgery under general anesthesia, active forced-air warming cannot effectively prevent perioperative hypothermia in elderly patients as compared with young patients. Key words: Anesthesia, general; Body temperature regulation

Warming strategies for preventing hypothermia and shivering during cesarean section: A systematic review with network meta-analysis of randomized clinical trials.

Hypothermia and shivering are undesirable morbidities that occur commonly during cesarean section. Although some active warming strategies, such as the use of forced-air, mattresses, and fluid warming, can attenuate such adverse events, no studies have yet performed multiple contrast assessments of these strategies. We, therefore, conducted a network meta-analysis to simultaneously assess the effects of various warming strategies for cesarean section and assist clinicians in making informed decisions. We searched databases for randomized clinical trials that investigated the effects of warming strategies during cesarean section, with primary outcomes targeted on shivering and hypothermia. Trial quality was assessed using the Cochrane Risk of Bias Tool. Quantitative synthesis was performed using consistency model and surface under the cumulative ranking curve (SUCRA). Results were presented as risk ratio (RR) with 95% confidence interval (CI). We identified 18 trials wherein 1953 women underwent a cesarean section. These trials performed 11 active warming strategies for 1620 women, and the other 333 women were in the non-active warming group. According to SUCRA, the combination of forced-air, fluids, and warmed gown warming could be a better strategy for reducing shivering rates compared with the other strategies (SUCRA = 88.5), albeit with an insignificant result. Conduction mattress warming (SUCRA = 89.4) and combination of conduction mattress and fluids warming (SUCRA = 80.2) were better strategies than others in reducing hypothermia. No evidence showed inconsistency or small study effects in our results. In clinical practice, forced-air-based warming strategies can be considered to prevent shivering, and conduction mattress-based warming strategies can be used to reduce hypothermia in women undergoing cesarean section.

Reducing Implant Infection in Orthopaedics (RIIiO): Results of a pilot study comparing the influence of forced air and resistive fabric warming technologies on postoperative infections following orthopaedic implant surgery

Active warming during surgery prevents perioperative hypothermia but the effectiveness and postoperative infection rates may differ between warming technologies. To establish the recruitment and data management strategies needed for a full trial comparing postoperative infection rates associated with forced air warming (FAW) versus resistive fabric warming (RFW) in patients aged >65 years undergoing hemiarthroplasty following fractured neck of femur. Participants were randomized 1:1 in permuted blocks to FAW or RFW. Hypothermia was defined as a temperature of <36°C at the end of surgery. Primary outcomes were the number of participants recruited and the number with definitive deep surgical site infections. A total of 515 participants were randomized at six sites over a period of 18 months. Follow-up was completed for 70.1%. Thirty-seven participants were hypothermic (7.5% in the FAW group; 9.7% in the RFW group). The mean temperatures before anaesthesia and at the end of surgery were similar. For the primary clinical outcome, there were four deep surgical site infections in the FAW group and three in the RFW group. All participants who developed a postoperative infection had antibiotic prophylaxis, a cemented prosthesis, and were operated under laminar airflow; none was hypothermic. There were no serious adverse events related to warming. Surgical site infections were identified in both groups. Progression from the pilot to the full trial is possible but will need to take account of the high attrition rate.

Peri-operative temperature measurement. Guideline or fantasy?

Introduction Perioperative hypothermia is common but associated with adverse outcomes and is defined as patient core temperature below 36.0°C. During the first 30 to 40 minutes of anaesthesia, a patient's temperature can drop to below 35.0°C. National guidelines advise1: • Temperature to be measured and documented in the hour before patient leaves ward • If • Maintain active warming throughout intraoperative phase • Temperature should be 36.0°C before transfer from/to the ward Additionally it is suggested that: - Induction of anaesthesia should not begin unless temperature is 36.0°C - Intravenous fluids (500 ml or more)/blood products should be warmed to 37°C using a fluid warming device - Warm patients intraoperatively from induction of anaesthesia, using a forced-air warming device if they are undergoing anaesthesia for more than 30 minutes, or anaesthesia for less than 30 minutes but are at higher risk of inadvertent perioperative hypothermia. - The patient's temperature should be measured and documented before induction and every 30 minutes until the end of surgery - Temperature should be measured and documented on admission to the recovery room and then every 15 minutes. If the patient's temperature is Methods The electronic charts of 31 patients undergoing routine thoracic surgery of duration over 30 minutes in a dedicated cardiothoracic unit over a two-week period were reviewed. The use of peri-operative temperature measurement was examined. Results 41% of patients had a temperature measured on arrival in the operating department. At 30 minutes into the procedure only 29% had temperature recorded. In the PACU 11 (32%) of patients had temperature measured, and of these only 6 (19%) had an arrival temperate over 36.0oC. Subsequently 1/31 patient had temperature measured every 15 minutes and just 4/31 patients had temperature recorded every 30 minutes. However 42% of patients had temperature recorded at discharge from the PACU. Discussion These data show a small improvement when compared to a previous audit of a similar cohort of patients (38 patients undergoing elective thoracic surgery over 30 minute duration) as shown below: Temperature recorded 2018 2017 Arrival O R 41% 24% 30 min O R 29% 24% Arrival PACU 32% 24% Leave PACU 42% 5% However no single data point exceeded 50% despite efforts to educate operating department staff on the requirement to record temperature and the benefits of actively warming patients.

Evaluation of the effect of two active warming and humidifying high-flow oxygen therapy systems in patients with tracheotomy.

The present study evaluated the effect of two active warming and humidifying high-flow oxygen therapy systems in patients with tracheotomy, in order to provide a basis for selecting the method of humidification oxygen therapy for tracheotomy. A total of 78 patients with tracheotomy, who underwent surgery between July 2017 and December 2017, were randomly divided into an observation group (39 patients) and a control group (39 patients). Patients in the observation group were treated with artificial airway high-flow humidification oxygen therapy in a closed suction system. Patients in the control group were treated using a respiratory humidification therapy device. Changes of sputum viscosity, pulmonary infection, arterial oxygen partial pressure (PaO2), arterial blood carbon dioxide partial pressure (PaCO2) and arterial oxygen saturation (SaO2) were observed at 0, 48 and 96 h, and 7 days following oxygen therapy. The sputum viscosity and lung infection in the observation group were lower than those in the control group at 48, 96 h and 7 days following oxygen therapy, and the PaO2 and SaO2 were higher in the observation group than in the control group, which was statistically significant (P<0.05). However, there was no statistically significant difference (P>0.05) in PaCO2 between the two groups. In conclusion, the artificial airway high-flow humidification oxygen therapy closed suction system was considered more suitable for long-term oxygen therapy of tracheotomy patients than the respiratory humidification therapy device. It can improve airway humidification and oxygen levels at lower equipment and consumable costs. The effects of treatment aim to reduce lung infections, which have clinical implications to a certain extent.

A systematic review of the intervention components, adherence and outcomes of enhanced recovery programmes in older patients undergoing elective colorectal surgery

BackgroundEnhanced recovery programmes (ERPs) aim to attenuate the surgical stress response and accelerate recovery after surgery, but are not specifically designed for older patients. The objective of this study was to review the components, adherence and outcomes of ERPs in older patients (≥65 years) undergoing elective colorectal surgery.MethodsPubmed, Embase and Cinahl were searched between 2000 and 2017 for randomised and non-randomised controlled trials, before-after studies, and observational studies. The methodological quality of the studies was evaluated using the MINORS quality assessment. The review was performed and reported according to the PRISMA guidelines.ResultsTwenty-one studies, including 3495 ERP patients aged ≥65 years, were identified. The ERPs consisted of a median of 13 intervention components. Adherence rates were reported in 9 studies and were the highest (≥80%) for pre-admission counselling, no bowel preparation, limited pre-operative fasting, antithrombotic and antimicrobial prophylaxis, no nasogastric tube, active warming, and limited intra-operative fluids. The median post-operative length of stay was 6 days. The median post-operative morbidity rate (Clavien-Dindo I-IV) was 23.5% in-hospital and 29.8% at 30 days. The in-hospital post-operative mortality rate was 0% in most studies and amounted to a median of 1.4% at 30 days. The median 30-day readmission rate was 4.9% and the median reoperation rate was 5.0%.ConclusionsERPs in older patients were in accordance with the ERP consensus guidelines. Although the number of intervention components applied increased over time, outcomes in earlier and later studies remained comparable. Adherence rates were under-reported. Future studies should explore adherence and age-related factors, such as frailty profile, that could influence adherence.Trial registrationPROSPERO 2018 CRD42018084756.

Efficacy of forced-air warming and warmed intravenous fluid for prevention of hypothermia and shivering during caesarean delivery under spinal anaesthesia: A randomised controlled trial.

Peri-operative hypothermia and shivering are frequent events in patients during caesarean delivery under spinal anaesthesia. We assessed the efficacy of combined pre-anaesthetic forced-air warming in combination with warmed intravenous fluid infusion for preventing hypothermia and shivering during caesarean delivery under spinal anaesthesia. A randomised controlled study. A tertiary care teaching hospital from July 2017 to April 2018. A total of 50 pregnant women, American Society of Anaesthesiologists physical status 2, aged 20 to 45 years, scheduled for caesarean delivery under spinal anaesthesia. Patients were enrolled and randomised into two groups: an active warming group (n = 25), which received combined pre-anaesthetic whole body forced-air warming for 15 min and prewarmed intravenous fluids, and a control group, which received no active warming or warmed fluids (C group; n = 25). Spinal anaesthesia was induced with 10 mg bupivacaine containing fentanyl (10 μg). Tympanic membrane temperature and shivering severity were measured at baseline and every 10 min during surgery, and then every 10 min for 1 h postoperatively. Neonatal outcomes (tympanic membrane temperature at birth, umbilical venous blood pH, Apgar score) were also recorded. The incidences of peri-operative hypothermia (0 vs. 48%, P < 0.001) and shivering (22 vs. 52%, P = 0.031) were significantly lower in the active warming than in the C group. The maximum temperature change was also significantly lower in the active warming than in the C group. Maternal thermal comfort scores were higher in the active warming than in the C group. Neonatal parameters were not significantly different between the groups. The combination of pre-anaesthetic forced-air warming and warmed intravenous fluid infusions appears to be effective for preventing hypothermia and shivering during caesarean delivery under spinal anaesthesia. This trial was registered with Clinical Trials.gov (identifier: NCT03256786).

Prevalence of low–normal body temperatures and use of active warming in emergency department patients presenting with severe infection

Prevalence of low–normal body temperatures and use of active warming in emergency department patients presenting with severe infection

Implementing a thermal care bundle for inadvertent perioperative hypothermia: A cost-effectiveness analysis

BackgroundActive warming reduces risk of surgical complications. Implementation of a perioperative thermal care bundle increased use of active warming for surgical patients. ObjectiveThis study aimed to determine if implementing a thermal care bundle to prevent inadvertent perioperative hypothermia is cost-effective. DesignA model-based cost-effectiveness analysis was undertaken using Monte Carlo simulations from input distributions to estimate costs and effects. SettingHospitals undertaking between 5,000 and 40,000 surgeries per year, which either implemented or did not implement the thermal care bundle, were modelled. ParticipantsThe decision tree guiding the structure of the model was populated with clinical outcomes (surgical site infection, blood transfusion requirement and morbid cardiac events) of a hypothetical cohort of surgical patients. InterventionsImplementation or non-implementation of the thermal care bundle. Main outcome measuresNet monetary benefit was calculated by multiplying the health benefits (quality-adjusted life years) by the willingness-to-pay threshold minus the cost. We tested a range of values for willingness to pay per quality-adjusted life year thresholds and plotted results for expected incremental benefits and probability of cost-effectiveness. The incremental cost-effectiveness ratio was also calculated. ResultsThermal care bundle implementation simultaneously reduced costs and increased quality-adjusted life years in the majority of simulations (88.1%). The average cost reduction was $689,659 (95% credible intervals spanned from a $2,718,364 decrease in costs to $379,826 increase in costs) and average difference in quality-adjusted life years was 54 (95% CI = 0.4 less to 176 more). This equated to an incremental cost-effectiveness ratio of $12747 saved per quality-adjusted life year gained. ConclusionsIt is likely that increasing use of active warming by implementing the thermal care bundle would generate cost-savings and improve the quality of life for surgical patients. It would be good value for hospitals with similar characteristics to those included in our model to allocate the extra resources required for implementation.

Protocolo de prevención de la hipotermia perioperatoria

La hipotermia perioperatoria es una complicación muy frecuente en nuestro medio que compromete la seguridad de nuestros pacientes quirúrgicos aumentando la morbimortalidad perioperatoria. La hipotermia también aumenta de manera considerable los costes sanitarios por el aumento de las complicaciones y la estancia hospitalaria. Recientemente se ha publicado la guía de práctica clínica de hipotermia perioperatoria no intencionada de la SEDAR. En esta guía se presenta la evidencia científica actual sobre la hipotermia perioperatoria y las recomendaciones sobre su manejo. Basado en esta guía, presentamos el protocolo de prevención de la hipotermia perioperatoria de nuestro centro con una estrategia basada en la monitorización de la temperatura central y en 3 medidas que han demostrado disminuir las complicaciones perioperatorias y ser coste-efectivas: el uso de mantas de aire convectivo, el calentamiento de los fluidos intravenosos y de irrigación, y el calentamiento activo previo a la cirugía. ABSTRACT Protocol for the prevention of perioperative hypothermia Perioperative hypothermia is a very frequent complication that compromises the safety of our surgical patients, increasing perioperative morbidity and mortality. Hypothermia also considerably increases health costs due to the increase in complications and hospital length of stay. Recently, the clinical practice guide for unintentional perioperative hypothermia of the Spanish Society of Anaesthesia (SEDAR) has been published. This guide presents current scientific evidence on perioperative hypothermia and recommendations on its management. Based on this guide, we present the protocol for the prevention of perioperative hypothermia in our institution. This protocol is based on a strategy that includes central temperature monitoring and 3 measures that have shown to reduce perioperative complications and be cost-effective: the use of convective air, warming of intravenous and irrigation fluids, and active warming prior to surgery.