Clinical utilization of a sous vide device in the acute rewarming of frostbitten extremities.

The current standard of care for acute frostbite rewarming is the use of a circulating warm water bath at a temperature of 37 °C to 39 °C. There is no standardized method to achieve this. Manual management of a warm water bath can be inefficient and time consuming. This case describes the clinical use of a sous vide cooking device to create and maintain a circulating warm water bath to rewarm acute frostbite. A 34 year-old male presented to the emergency department with acute frostbite. Each of the patient's feet were placed in a water bath with a sous vide device attached to the side of the basin and set to 38 °C. Temperatures were recorded every 2 m from 2 thermometers. Once target temperature was achieved, the extremities were rewarmed for 30 m. The water baths required an average of 25 m to reach target temperature and maintained the target temperature within ±1 °C for the duration of the rewarming. The extremities were clinically thawed in one session and there were no adverse events. The patient was seen by plastic and vascular surgery and admitted to the hospital for conservative management. He was discharged on hospital day 3 and did not require any amputations. A sous vide device can be used clinically to heat and maintain a water bath and successfully rewarm frostbitten extremities in one 30 m cycle. No adverse events were reported and providers rated this as a convenient method of water bath management.

Reduction of Renal Preservation/Reperfusion Injury by Controlled Hyperthermia During Ex Vivo Machine Perfusion.

The possible reno-protective effect of a controlled brief heat-shock treatment during isolated ex vivo machine perfusion of donor grafts prior to reperfusion should be investigated in a primary in vitro study. Porcine kidneys (n = 14) were retrieved after 20 minutes of cardiac standstill of the donor and subjected to 20 hours of static cold storage in University of Wisconsin solution. Prior to reperfusion, kidneys were subjected to 2 hours of reconditioning machine perfusion with gradual increase in perfusion temperature up to 35°C. In half of the kidneys (n = 7), a brief hyperthermic impulse (10 minutes perfusion at 42°C) was implemented in the machine perfusion period. Functional recovery of the grafts was observed upon normothermic reperfusion in vitro. Hyperthermic treatment resulted in a 50% increase of heat shock protein (HSP) 70 and HSP 27 mRNA and was accompanied by ~ 50% improvement of tubular re-absorption of sodium and glucose upon reperfusion, compared with the controls. Furthermore, renal loss of aspartate aminotransferase was significantly reduced to one-third of the controls as was urinary protein loss, evaluated by the albumin to creatinine ratio. It is concluded that ex vivo heat-shock treatment seems to be an easily implementable and promising option to enhance renal self-defense machinery against reperfusion injury after preservation that merits further investigation in preclinical models.

Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: A systematic review.

Prolonged cardiac arrest (CA) may lead to neurologic deficit in survivors. Good outcome is especially rare when CA was unwitnessed. However, accidental hypothermia is a very specific cause of CA. Our goal was to describe the outcomes of patients who suffered from unwitnessed hypothermic cardiac arrest (UHCA) supported with Extracorporeal Life Support (ECLS). We included consecutive patients' cohorts identified by systematic literature review concerning patients suffering from UHCA and rewarmed with ECLS. Patients were divided into four subgroups regarding the mechanism of cooling, namely: air exposure; immersion; submersion; and avalanche. A statistical analysis was performed in order to identify the clinical parameters associated with good outcome (survival and absence of neurologic impairment). A total of 221 patients were included into the study. The overall survival rate was 27%. Most of the survivors (83%), had no neurologic deficit. Asystole was the presenting CA rhythm in 48% survivors, of which 79% survived with good neurologic outcome. Variables associated with survival included the following: female gender (P < .001); low core temperature (P = .005); non-asphyxia-related mechanism of cooling (P < .001); pulseless electrical activity as an initial rhythm (P < .001); high blood pH (P < .001); low lactate levels (P = .003); low serum potassium concentration (P < .001); and short resuscitation duration (P = .004). Severely hypothermic patients with unwitnessed CA may survive with good neurologic outcome, including those presenting as asystole. The initial blood pH, potassium, and lactate concentration may help predict outcome in hypothermic CA.

The efficacy of HBOC-201 in ex situ gradual rewarming kidney perfusion in a rat model.

Gradual rewarming from hypothermic to normothermic is a novel perfusion modality with superior outcome to sudden rewarming to normothermic. However, the identification of an oxygen carrier that could function at a temperature range from 4 to 7°C or whether it is necessary to use oxygen carrier during kidney rewarming, remains unresolved. This study was designed to test the use of a hemoglobin-based oxygen carrier (HBOC) during gradual kidney rewarming as an alternative to simple dissolved oxygen. In this study, 10 rat kidneys were randomly divided into the control and the HBOC group. In the control group, no oxygen carrier was used during rewarming perfusion and the perfusion solution was oxygenated only by applying diffused carbogen flow. The protocol mimicked a donor after circulatory death (DCD) kidney transplantation, where after 30 minutes warm ischemia and 120 minutes cold storage in University of Wisconsin solution, the DCD kidneys underwent gradual rewarming from 10 to 37°C during 90 minutes with or without HBOC. This was followed by 30 minutes of warm ischemia in room temperature to mimic the anastomosis time and 120 minutes of reperfusion at 37°C to mimic the early post-transplant state of the graft. The HBOC group demonstrated superior kidney function which was highlighted by higher ultrafiltrate production, better glomerular filtration rate and improved sodium reabsorption. There was no significant difference between the 2 groups regarding the hemodynamics, tissue injury, and adenosine triphosphate levels. In conclusion, this study suggests better renal function recovery in DCD kidneys after rewarming with HBOC compared to rewarming without an oxygen carrier.

Human Responses to 5 Heated Hypothermia Wrap Systems in a Cold Environment.

INTRODUCTION: We compared the effectiveness of 5 heated hypothermia wrap systems. METHODS: Physiologic and subjective responses were determined in 5 normothermic subjects (1 female) for 5 heated hypothermia wraps (with vapor barrier and chemical heat sources) during 60 min of exposure to a temperature of -22°C. The 5 systems were 1) user-assembled; 2) Doctor Down Rescue Wrap; 3) hypothermia prevention and management kit (HPMK); 4) MARSARS Hypothermia Stabilizer Bag; and 5) Wiggy's Victims Casualty Hypothermia Bag. Core and skin temperature, metabolic heat production, skin heat loss, and body net heat gain were determined. Subjective responses were also evaluated for whole body cold discomfort, overall shivering rating, overall temperature rating, and preferential ranking. RESULTS: The Doctor Down and user-assembled systems were generally more effective, with higher skin temperatures and lower metabolic heat production; they allowed less heat loss, resulting in higher net heat gain (P<0.05). HPMK had the lowest skin temperature and highest shivering heat production and scored worse than the other 4 systems for the "whole body cold discomfort" and "overall temperature" ratings (P<0.05). CONCLUSIONS: The user-assembled and Doctor Down systems were most effective, and subjects were coldest with the HPMK system. However, it is likely that any of the tested systems would be viable options for wilderness responders, and the choice would depend on considerations of cost; volume, as it relates to available space; and weight, as it relates to ability to carry or transport the system to the patient.

Successful Field Rewarming of a Patient with Apparent Moderate Hypothermia Using a Hypothermia Wrap and a Chemical Heat Blanket.

Hypothermia is a common problem encountered by search and rescue teams. Although mildly hypothermic patients can be rewarmed in the field and can then self-evacuate, the Wilderness Medical Society hypothermia guidelines suggest that a moderately hypothermic patient in the wilderness requires warming in a medical facility. The hypothermia prevention and management kit, developed by the US military, consists of a chemical heat blanket (CHB) and a heat-reflective shell. We present a case in which a hypothermia wrap and the CHB from a hypothermia prevention and management kit were used successfully to rewarm a patient with apparent moderate hypothermia in the field. We are unaware of previous reports of successful field rewarming of a patient with moderate hypothermia. We believe the use of the CHB in conjunction with a hypothermia wrap made field rewarming possible. We recommend that a CHB, along with the components of a hypothermia wrap, be carried by search and rescue teams when a hypothermic patient might be encountered. Although there were no documented core temperatures, we believe this case is consistent with the hypothesis that if a hypothermic patient who is found lying down and shivering is allowed to stand or walk before insulation is applied and before there has been an additional period of 30 min during which the patient continues to shiver, there may be increased afterdrop with deleterious results.

Intravascular Cooling Device Versus Esophageal Heat Exchanger for Mild Therapeutic Hypothermia in an Experimental Setting.

BACKGROUND: Targeted temperature management is a standard therapy for unconscious survivors of cardiac arrest. To date, multiple cooling methods are available including invasive intravascular cooling devices (IVDs), which are widely used in the clinical setting. Recently, esophageal heat exchangers (EHEs) have been developed providing cooling via the esophagus that is located close to the aorta and inferior vena cava. The objective was to compare mean cooling rates, as well as differences, to target temperature during maintenance and the rewarming period of IVD and EHE. METHODS: The study was conducted in 16 female domestic pigs. After randomization to either IVD or EHE (n = 8/group), core body temperature was reduced to 33°C. After 24 hours of maintenance (33°C), animals were rewarmed using a target rate of 0.25°C/h for 10 hours. All cooling phases were steered by a closed-loop feedback system between the internal jugular vein and the chiller. After euthanasia, laryngeal and esophageal tissue was harvested for histopathological examination. RESULTS: Mean cooling rates (4.0°C/h ± 0.4°C/h for IVD and 2.4°C/h ± 0.3°C/h for EHE; P < .0008) and time to target temperature (85.1 ± 9.2 minutes for IVD and 142.0 ± 21.2 minutes for EHE; P = .0008) were different. Mean difference to target temperature during maintenance (0.07°C ± 0.05°C for IVD and 0.08°C ± 0.10°C for EHE; P = .496) and mean rewarming rates (0.2°C/h ± 0.1°C/h for IVD and 0.3°C/h ± 0.2°C/h for EHE; P = .226) were similar. Relevant laryngeal or esophageal tissue damage could not be detected. There were no significant differences in undesired side effects (eg, bradycardia or tachycardia, hypokalemia or hyperkalemia, hypoglycemia or hyperglycemia, hypotension, overcooling, or shivering). CONCLUSIONS: After insertion, target temperatures could be reached faster by IVD compared to EHE. Cooling performance of IVD and EHE did not significantly differ in maintaining target temperature during a targeted temperature management process and in active rewarming protocols according to intensive care unit guidelines in this experimental setting.

Clinical practice guideline. Unintentional perioperative hypothermia. / Guía de práctica clínica de hipotermia perioperatoria no intencionada.

The importance of the safety of our patients in the surgical theatre, has driven many projects. The majority of them aimed at better control and clinical performance; mainly of the variables that intervene or modulate the results of surgical procedures, and have a direct relationship with them. The Spanish Society of Anesthesiology, Critical Care and Therapeutic Pain (SEDAR), maintains a constant concern for a variable that clearly determines the outcomes of our clinical processes, "unintentional hypothermia" that develops in all patients undergoing an anesthetic or surgical procedure. SEDAR has promoted, in collaboration with other scientific Societies and patient Associations, the elaboration of this clinical practice guideline, which aims to answer clinical questions not yet resolved and for which, up to now, there are no documents based in the best scientific evidence available. With GRADE methodology and technical assistance from the Ibero-American Cochrane Collaboration office, this clinical practice guideline presents three recommendations (weak in favor) for active heating methods for the prevention of hypothermia (skin, fluid or gas); three for the prioritization of strategies for the prevention of hypothermia (too weak in favor and one strongly in favor); two of preheating strategies prior to anesthetic induction (both weak in favor); and two for research.

"Cold Card" to Guide Responders in the Assessment and Care of Cold-Exposed Patients.

INTRODUCTION: A concise, easy-to-use decision aid "Cold Card" that can be carried in the field by wilderness search and rescue teams or medical responders to advise on assessment and care of cold-exposed patients was created. METHODS: A 2-sided card was designed to summarize the important principles established by the Wilderness Medical Society practice guidelines for hypothermia. The card was continually updated through feedback from several content experts. The card was then distributed for further feedback from members of the Search and Rescue Volunteer Association of Canada and enrollees of the Baby It's Cold Outside web-based educational program. This additional feedback was used to create the final iteration of the card. RESULTS: On the front "ASSESS COLD PATIENT" side, the level of cold exposure or hypothermia is accomplished by evaluating (as either normal or impaired function) consciousness, movement, shivering, and alertness on a series of concentric rings. The important treatment actions are provided for each cold-exposure level. The back "CARE FOR COLD PATIENT" side provides the required elements and principles of use for a hypothermia wrap. The Cold Card is available for free download and unlimited use for education or in-field instruction by any individual or group. The card should be printed on heavy, waterproof stock (13×18 cm) for use in all weather conditions. CONCLUSIONS: Key elements of hypothermia evaluation and field care have been summarized on a small portable card for laypersons, trained rescuers, and first responders.

Numerical simulation for treatment of hypothermia based on vascular interventional direct heating system.

The treatment of hypothermia suffered by naval fighters owing to seawater immersion has been a focus of research in recent years. Currently, the treatment of hypothermia in China is limited to external rewarming, which is of low efficiency and is not effective for patients suffering moderate to severe hypothermia. We thus proposed a vascular interventional heating method which directly heats the blood flow via a minimally invasive heating needle for rewarming. And a numerical simulation using a compartment model based on finite difference method was conducted. A set of whole body heating treatment simulation was also developed. Appropriate treatment parameters and procedures can be set and adjusted based on patient physical parameters. Here temperature response curves of different heating modes were obtained and analyzed. It was demonstrated that the desired thermal response can be achieved by adjusting the heating power and heating time, ensuring controllable accuracy in the treatment of patients with severe hypothermia. The proposed treatment for hypothermia is a new and effective alternative, and further progress is expected in clinical trials.

Use of an intravascular temperature control catheter for rewarming of hypothermic trauma patients with ongoing hemorrhagic shock after combined damage control thoracotomy and laparotomy: A case series.

BACKGROUND: Correction of hypothermia is a key component of the resuscitation of critically injured patients with hemorrhagic shock who require damage control surgery. External rewarming methods may not be sufficient in this population, while extracorporeal techniques lack widespread feasibility. Intravascular catheter-based temperature modulation is increasingly being employed in different critically ill patient populations but has not been described as part of a damage control resuscitation strategy in trauma patients. METHODS: We retrospectively reviewed the medical records of all patients admitted to our multi-trauma intensive care unit from July 1, 2015 - December 31, 2017 in whom an intravascular temperature control catheter (IVTCC) was employed for rewarming from hypothermia during the immediate postoperative resuscitation of continued hemorrhage after undergoing combined damage control thoracotomy and laparotomy for trauma. All patients received baseline treatment with active external rewarming modalities and inline fluid/blood warmers. Core temperature values over the first 24 h of hospital admission were analyzed. Efficacy (rewarming rate) and safety (associated adverse events) of the IVTCC system were determined. RESULTS: Three patients (age 22 ±â€¯4.6, 100% male, 100% torso gunshot wounds with prehospital cardiac arrest) meeting the inclusion criteria were treated with the IVTCC system during the study period. Temperature at the start of rewarming using the IVTCC ranged from 30.1 to 35.5 °C. Despite ongoing severe hemorrhagic shock (24-hour ICU blood product requirement: 104 ±â€¯44 units), a mean rewarming rate of 1.04 ±â€¯0.63°C/hour was achieved. One patient suffered an uncomplicated catheter-associated deep vein thrombosis. Two of the 3 patients survived to hospital discharge with intact cognitive function. CONCLUSIONS: Use of an IVTCC may be a minimally-invasive, practical, and effective method for rewarming critically ill trauma patients with ongoing hemorrhagic shock after multi-cavitary damage control surgery. Further studies are needed to compare this technology with currently available rewarming methods.

Rewarming After Severe Accidental Hypothermia Using the Esophageal Heat Transfer Device: A Case Report.

Patients with severe accidental hypothermia require active rewarming. External rewarming may not be successful in severe hypothermia, and use of invasive techniques is limited to regional centers and is associated with vascular access site and other complications. We present a patient with severe accidental hypothermia who was successfuly rewarmed using a novel esophageal heat transfer device. A 55-year-old male (175 cm, 71 kg) was admitted with the first recorded temperature 23.3°C. Rewarming using renal replacement therapy circuit was unsuccessful because of severe hypotension. We inserted the esophageal heat transfer device and rewarmed him successfully to target temperature 35-36°C. After rewarming, we maintained his body temperature in the range 35-36°C until accidental removal of the device. We observed no major adverse effects. To conclude, rewarming from severe accidental hypothermia was possible using the esophageal heat transfer device.

Severe Hypothermia Management in Mountain Rescue: A Survey Study.

Podsiadlo, Pawel, Tomasz Darocha, Sylweriusz Kosinski, Kinga Salapa, Miroslaw Zietkiewicz, Tomasz Sanak, Rachel Turner, and Hermann Brugger. Severe hypothermia management in mountain rescue: A survey study. High Alt Med Biol 18:411-416, 2017. INTRODUCTION: Severe hypothermia is a rare but demanding medical emergency. Although mortality is high, if well managed, the neurological outcome of survivors can be excellent. The aim of the study was to assess whether mountain rescue teams (MRTs) are able to meet the guidelines in the management of severe hypothermia, regarding their equipment and procedures. METHODS: Between August and December 2016, an online questionnaire, with 24 questions to be completed using Google Forms, was sent to 123 MRTs in 27 countries. RESULTS: Twenty-eight MRTs from 10 countries returned the completed questionnaire. Seventy-five percent of MRTs reportedly provide advanced life support (ALS) on-site and 89% are regularly trained in hypothermia management. Thirty-two percent of MRTs transport hypothermic patients in cardiac arrest to the nearest hospital instead of an Extracorporeal Life Support facility; 39% are equipped with mechanical chest compression devices; 36% measure core body temperature on-site and no MRT is equipped with a device to measure serum potassium concentration on-site in avalanche victims. CONCLUSIONS: Most MRTs are regularly trained in the treatment of severe hypothermia and provide ALS. The majority are not equipped to follow standard procedural guidelines for the treatment of severely hypothermic patients, especially with cardiac arrest. However, the low response rate-23% (28/123)-could have induced a bias.

A novel thermal compression device for perioperative warming: a randomized trial for feasibility and efficacy.

BACKGROUND: Inadvertent perioperative hypothermia (IPH) leads to surgical complications and increases length of stay. IPH rates are high with the current standard of care, forced air warming (FAW). Our hypothesis is that a prototype thermal compression device that heats the popliteal fossa and soles of the feet, with lower leg compression, increases perioperative temperatures and reduces IPH compared to the current standard of care. METHODS: Thirty six female breast surgery patients, at a tertiary academic hospital, were randomized to the device or intraoperative FAW (stage I) with a further 18 patients randomized to the device with a single heating area only (stage II, popliteal fossa or sole of the feet). Stage I: 37 patients recruited (final 36). Stage II: 18 patients recruited (final 18). INCLUSION CRITERIA: general anesthesia with esophageal monitoring for over 30 min, legs available and able to fit the device and no contraindications to leg heating or compression. The intervention was: Stage I: Investigational prototype thermal compression device (full device group) or intraoperative FAW. Stage II: Device with only a single heating location. Primary outcomes were perioperative temperatures and incidence of IPH. Secondary outcomes were local skin temperature, general and thermal comfort scores and presence of perioperative complications, including blood loss. RESULTS: Mean temperatures in the full device group were significantly higher than the FAW group in the pre-operative (36.7 vs 36.4 °C, p < 0.001), early intraoperative (36.3 vs 35.9 °C, p < 0.001), intraoperative (36.6 vs 36.2 °C, p < 0.001) and postoperative periods (36.8 vs 36.5 °C, p < 0.001). The incidence of IPH in the device group was also significantly lower (16.7% vs 72.0%, p = 0.001). Thermal comfort scores were significantly higher in the full device group and hypothermia associated wound complications were higher in the FAW group. CONCLUSIONS: The thermal compression device is feasible and has efficacy over the FAW. Further studies are recommended to investigate clinically significant outcomes. TRIAL REGISTRATION: clinicaltrials.gov ( NCT02155400 ).

Effectiveness of Underbody Forced-air Warming System in Preventing Hypothermia in Patients Undergoing Major Surgeries.

Objective To compare the effectiveness of the forced-air warming system and the conventional warming care practice in preventing hypothermia in patients undergoing major surgeries.Methods A total of 62 patients were enrolled in this study. Patients of both sexes,aged≥18 years,and with an ASA physical status Ⅰ-Ⅲ were included and allocated randomly into intervention group(n=30)or control group(n=32). Patients in the intervention group were provided forced-air warming,either prior to induction or during the surgery procedure depending on core temperature monitoring results. In the control group,patients were warmed with conventional warming care without any intervention. Core temperature was measured by Spot-On sensor and tympanic membrane thermometer,blood pressure,the electrocardiogram,heart rate,pulse oxygen staturation,and partial pressure of end-tidal CO2 were also monitored continuously in the two groups.Crystalloid,colloid,and allogeneic blood were also recorded by strict protocol. Results Intraoperative hypothermia monitored with tympanic thermometer was observed in 23 patients(71.87%)in the control group,which was significantly higher than that (0) in the intervention group(P=0.00). In addition,the incidence of hypothermia monitored by Spot-On sensor was 81.25%(n=26)in control group and 13.33%(n=4)in intervention group(P=0.00). Conclusion Compared with the conventional warming care,forced-air warming system is more effective in preventing hypothermia during major surgeries.

[Severe accidental hypothermia : Treatment using an intravascular temperature management catheter]. / Schwere akzidentelle Hypothermie : Behandlung mithilfe eines intravaskulären Katheters zum Temperaturmanagement.

Different techniques have been reported for the treatment of severe accidental hypothermia. In this case, we successfully used an intravascular catheter temperature management system which has been developed to induce reversible therapeutic hypothermia in patients following resuscitation. In our patient, the initial core temperature was 26.7 °C, and the temperature management system allowed for successful rewarming without complications with a maximum rate of about 1 °C/h.

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

STUDY OBJECTIVE: Incidence 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. DESIGN: Multinational, multicenter randomized prospective open-label controlled trial. SETTING: Surgical ward, operation room, postanesthesia care unit at 4 European hospitals. PATIENTS: A 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. INTERVENTIONS: Patients 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). MEASUREMENTS: The 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 RESULTS: The 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. CONCLUSIONS: Perioperative 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.

Perioperative warming with a thermal gown prevents maternal temperature loss during elective cesarean section. A randomized clinical trial / O aquecimento no perioperatório com avental cirúrgico térmico impede a perda de temperatura materna durante a cesariana eletiva. Estudo clínico randômico

Abstract Background and objectives: Decrease in body temperature is common during general and regional anesthesia. Forced-air warming intraoperative during cesarean section under spinal anesthesia seems not able to prevent it. The hypothesis considers that active warming before the intraoperative period avoids temperature loss during cesarean. Methods: Forty healthy pregnant patients undergoing elective cesarean section with spinal anesthesia received active warming from a thermal gown in the preoperative care unit 30 min before spinal anesthesia and during surgery (Go, n = 20), or no active warming at any time (Ct, n = 20). After induction of spinal anesthesia, the thermal gown was replaced over the chest and upper limbs and maintained throughout study. Room temperature, hemoglobin saturation, heart rate, arterial pressure, and tympanic body temperature were registered 30 min before (baseline) spinal anesthesia, right after it (time zero) and every 15 min thereafter. Results: There was no difference for temperature at baseline, but they were significant throughout the study (p < 0.0001; repeated measure ANCOVA). Tympanic temperature baseline was 36.6 ± 0.3 °C, measured 36.5 ± 0.3 °C at time zero and reached 36.1 ± 0.2 °C for gown group, while control group had baseline temperature of 36.4 ± 0.4 °C, measured 36.3 ± 0.3 °C at time zero and reached 35.4 ± 0.4 °C (F = 32.53; 95% CI 0.45-0.86; p < 0.001). Hemodynamics did not differ throughout the study for both groups of patients. Conclusion: Active warming 30 min before spinal anesthesia and during surgery prevented a fall in body temperature in full-term pregnant women during elective cesarean delivery.

Resumo Justificativa e objetivos: A redução da temperatura corporal é comum durante a anestesia tanto geral quanto regional. O sistema de ar forçado aquecido no intraoperatório durante a cesariana sob anestesia peridural não parece conseguir impedi-la. A hipótese considera que o aquecimento ativo antes do período intraoperatório evita a perda de temperatura durante a cesariana. Métodos: Quarenta pacientes grávidas, saudáveis, submetidas à cesariana eletiva com anestesia espinal receberam aquecimento ativo de um avental térmico na unidade de cuidados pré-operatórios 30 minutos antes da anestesia e durante a cirurgia (Go, n = 20) ou nenhum aquecimento ativo a qualquer momento (Ct, n = 20). Após a indução da anestesia espinhal, o avental térmico foi colocado sobre o tórax e os membros superiores e mantido durante o estudo. Temperatura ambiente, saturação de hemoglobina, frequência cardíaca, pressão arterial e temperatura corporal timpânica foram registradas 30 minutos antes (fase basal) da anestesia espinhal, logo após a anestesia (tempo zero) e a cada 15 minutos subsequentemente. Resultados: Não houve diferença de temperatura na fase basal, mas as diferenças foram significativas ao longo do estudo (p < 0,0001; Ancova de medida repetida). A temperatura timpânica na fase basal foi de 36,6 ± 0,3 °C, mediu 36,5 ± 0,3 °C no tempo zero e atingiu 36,1 ± 0,2 °C no grupo avental, enquanto a temperatura basal do grupo controle foi de 36,4 ± 0,4 °C, mediu 36,3 ± 0,3 °C no tempo zero e atingiu 35,4 ± 0,4 °C (F = 32,53; IC de 95% 0,45-0,86, p < 0,001). A hemodinâmica não diferiu ao longo do estudo em ambos os grupos de pacientes. Conclusão: O aquecimento ativo 30 minutos antes da anestesia espinhal e durante a cirurgia evitou a queda da temperatura corporal em mulheres grávidas a termo durante a cesariana eletiva.

Perioperative warming with a thermal gown prevents maternal temperature loss during elective cesarean section. A randomized clinical trial.

BACKGROUND AND OBJECTIVES: Decrease in body temperature is common during general and regional anesthesia. Forced-air warming intraoperative during cesarean section under spinal anesthesia seems not able to prevent it. The hypothesis considers that active warming before the intraoperative period avoids temperature loss during cesarean. METHODS: Forty healthy pregnant patients undergoing elective cesarean section with spinal anesthesia received active warming from a thermal gown in the preoperative care unit 30min before spinal anesthesia and during surgery (Go, n=20), or no active warming at any time (Ct, n=20). After induction of spinal anesthesia, the thermal gown was replaced over the chest and upper limbs and maintained throughout study. Room temperature, hemoglobin saturation, heart rate, arterial pressure, and tympanic body temperature were registered 30min before (baseline) spinal anesthesia, right after it (time zero) and every 15min thereafter. RESULTS: There was no difference for temperature at baseline, but they were significant throughout the study (p<0.0001; repeated measure ANCOVA). Tympanic temperature baseline was 36.6±0.3°C, measured 36.5±0.3°C at time zero and reached 36.1±0.2°C for gown group, while control group had baseline temperature of 36.4±0.4°C, measured 36.3±0.3°C at time zero and reached 35.4±0.4°C (F=32.53; 95% CI 0.45-0.86; p<0.001). Hemodynamics did not differ throughout the study for both groups of patients. CONCLUSION: Active warming 30min before spinal anesthesia and during surgery prevented a fall in body temperature in full-term pregnant women during elective cesarean delivery.