Hypothermia In Patients Research Articles

Hypothermia and Influence of Rewarming Rates on Survival Among Patients Admitted to Intensive Care with Bloodstream Infection: A Multicenter Cohort Study.

Although critically ill patients with bloodstream infections (BSIs) who present with hypothermia are at the highest risk for death, it is not known how rewarming rates may influence the outcomes. The objective of this study was to identify the occurrence and determinants of hypothermia among patients admitted to intensive care units (ICUs) with BSI and assess how the rate of temperature correction may influence 90-day all-cause case-fatality. A cohort of 3951 ICU admissions associated with BSI was assembled. The lowest temperature measured within the first 24 hours of admission was identified, and among those who were hypothermic (<36°C), the rewarming rate [(time difference between lowest and subsequent first temperature ≥36°C) divided by hypothermia severity (difference between lowest measured and 36°C)] was determined. Within the first 24 hours of admission to the ICU, 329 (8.4%) and 897 (22.7%) subjects had the lowest temperature measurements ranging <34.9°C and 35-35.9°C, respectively. Patients with lower temperatures were more likely to be admitted to tertiary care ICUs, have more comorbid illnesses, have greater severity of illness, and have a higher need for organ-supportive therapies. The 90-day all-cause case-fatality rate was 22.9% overall and was 45.3%, 24.8%, and 19.6% for those with the lowest 24 hours temperatures of <35°C, 35-35.9°C, and ≥36°C, respectively (p < 0.001). Among 1133 hypothermic patients with documented temperatures corrected to the normal range while admitted to the ICU, the median rate of temperature increase was 0.24 (interquartile range, 0.13-0.45)oC/hour. After controlling for the severity of illness and comorbidity, a faster rewarming rate was associated with significantly lower 90-day case-fatality. Hypothermia is a significant risk factor associated with death among critically ill patients with BSI that faster rates of rewarming may modify.

Distinct immune profiles and clinical outcomes in sepsis subphenotypes based on temperature trajectories.

Sepsis is a heterogeneous syndrome. Identification of sepsis subphenotypes with distinct immune profiles could lead to targeted therapies. This study investigates the immune profiles of patients with sepsis following distinct body temperature patterns (i.e., temperature trajectory subphenotypes). Hospitalized patients from four hospitals between 2018 and 2022 with suspicion of infection were included. A previously validated temperature trajectory algorithm was used to classify study patients into temperature trajectory subphenotypes. Microbiological profiles, clinical outcomes, and levels of 31 biomarkers were compared between these subphenotypes. The 3576 study patients were classified into four temperature trajectory subphenotypes: hyperthermic slow resolvers (N = 563, 16%), hyperthermic fast resolvers (N = 805, 23%), normothermic (N = 1693, 47%), hypothermic (N = 515, 14%). The mortality rate was significantly different between subphenotypes, with the highest rate in hypothermics (14.2%), followed by hyperthermic slow resolvers 6%, normothermic 5.5%, and lowest in hyperthermic fast resolvers 3.6% (p < 0.001). After multiple testing correction for the 31 biomarkers tested, 20 biomarkers remained significantly different between temperature trajectories: angiopoietin-1 (Ang-1), C-reactive protein (CRP), feline McDonough sarcoma-like tyrosine kinase 3 ligand (Flt-3l), granulocyte colony stimulating factor (G-CSF), granulocyte-macrophage colony stimulating factor (GM-CSF), interleukin (IL)-15, IL-1 receptor antagonist (RA), IL-2, IL-6, IL-7, interferon gamma-induced protein 10 (IP-10), monocyte chemoattractant protein-1 (MCP-1), human macrophage inflammatory protein 3 alpha (MIP-3a), neutrophil gelatinase-associated lipocalin (NGAL), pentraxin-3, thrombomodulin, tissue factor, soluble triggering receptor expressed on myeloid cells-1 (sTREM-1), and vascular cellular adhesion molecule-1 (vCAM-1).The hyperthermic fast and slow resolvers had the highest levels of most pro- and anti-inflammatory cytokines. Hypothermics had suppressed levels of most cytokines but the highest levels of several coagulation markers (Ang-1, thrombomodulin, tissue factor). Sepsis subphenotypes identified using the universally available measurement of body temperature had distinct immune profiles. Hypothermic patients, who had the highest mortality rate, also had the lowest levels of most pro- and anti-inflammatory cytokines.

Implementasi Hot Pack Untuk Peningkatan Suhu Tubuh Pada Pasien Hipotermi Pasca Operasi

Introduction: As a kind of therapy, surgery involves cutting into the patient in order to reach the targeted location of the body. The risk of hypothermia is a potential consequence of anesthesia. A dangerous drop in core temperature, below 36 degrees Celsius, causes hypothermia. One way to alleviate cold symptoms is using a warm compress. An alternative to using hot packs to raise core temperature is a warm compress. Hot packs have many advantages over buli-buli, the most notable of which is that they can be reused and never run out of steam. Objective: This community service activity is to implement hot packs on hypothermic patients. Method: As part of their community service, volunteers take patients' temperatures using electronic thermometers. Including thirty individuals who were found to have hypothermia. Result: Impact of Volunteer Work Hypothermia after administration of a hot pack, with a pre-package average temperature of 35.20 degrees Celsius Average core temperature before administration of the hot pack: 36.50 °C Body temperature values ranged from 34.10C before implementation to 36.70C thereafter, with a low value of 35.10C and a high value of 35.90C before and after, respectively. Conclusion: This proves that there is an increase in body temperature in hypothermic patients after implementing Hot packs.

Case Study of Severe Accidental Hypothermia with Rapid Cooling, Preserved Shivering, and Consciousness with a Summary of Similar Case Reports.

We describe a case of severe accidental hypothermia of a kayaker with preserved consciousness and shivering despite a rectal temperature of 22.9°C following a 50-min immersion in 3°C water with an estimated core temperature cooling rate of 10.6°C/h. Based on survival at sea prediction curves and cooling rates from physiology studies, cold water (eg, 0-5°C) immersion is expected to drop core temperature by 2 to 4°C/h. Furthermore, accidental hypothermia classification systems predict that severely hypothermic patients are usually unconscious and not shivering. The patient in this report rewarmed rapidly at 3.6°C/h with only minimally invasive measures and was discharged fully neurologically intact. In 41 similar cases of survival in moderate to severe hypothermia with core temperatures <32°C due to cold water immersion, cold air exposure, or avalanche burial, mean cooling rates were 4.3±3.3°C/h (range 0.4-10.6°C/h). Including the current patient, shivering was reported in only four cases. We found several other cases of rewarming from moderate to severe hypothermia with only minimally invasive measures. The current and summarized cases lead us to conclude that patients may be at risk of severe hypothermia in <60 min of cold water immersion and that it is possible for severely hypothermic patients to have preserved consciousness, close to normal vital signs, and shivering. Minimally invasive or noninvasive rewarming of patients with severe hypothermia is also possible, especially in those who continue to shiver. Hypothermia management should not necessarily be guided by classification systems or core temperature alone but rather by a careful consideration of the entire clinical picture.

Prognostic thresholds of outcome predictors in severe accidental hypothermia.

Hemodynamically unstable patients with severe hypothermia and preserved circulation should be transported to dedicated extracorporeal life support (ECLS) centers, but not all are eligible for extracorporeal therapy. In this group of patients, the outcome of rewarming may sometimes be unfavorable. It is, therefore, crucial to identify potential risk factors for death. Furthermore, it is unclear what criterion for hemodynamic stability should be adopted for patients with severe hypothermia. The aim of this study is to identify pre-rewarming predictors of death and their threshold values in hypothermic patients with core temperature ≤ 28°C and preserved circulation, who were treated without extracorporeal rewarming. We conducted a multicenter retrospective study involving patients in accidental hypothermia with core temperature 28°C or lower, and preserved spontaneous circulation on rewarming initiation. The data were collected from the International Hypothermia Registry, HELP Registry, and additional hospital data. The primary outcome was survival to hospital discharge. We conducted a multivariable logistic regression and receiver operating characteristic curve (ROC) analysis. In the multivariate analysis of laboratory tests and vital signs, systolic blood pressure (SBP) adjusted for cooling circumstances and base excess (BE) were identified as the best predictor of death (OR 0.974 95% CI 0.952-0.996), AUC ROC 0.79 (0.70-0.88). The clinically relevant cutoff for SBP was identified at 90mmHg with a sensitivity of 0.74 (0.54-0.89) and a specificity of 0.70 (0.60-0.79). The increased risk of death among hypothermic patients with preserved circulation occurs among those with an SBP below 90mmHg and in those who developed hypothermia in their homes.

Using machine learning to predict bacteremia in urgent care patients on the basis of triage data and laboratory results

BackgroundDespite advancements in antimicrobial therapies, bacteremia remains a life-threatening condition. Appropriate antimicrobials must be promptly administered to ensure patient survival. However, diagnosing bacteremia based on blood cultures is time-consuming and not something emergency department (ED) personnel are routinely trained to do. MethodsThis retrospective cohort study developed several machine learning (ML) models to predict bacteremia in adults initially presenting with fever or hypothermia, comprising logistic regression, random forest, extreme gradient boosting, support vector machine, k-nearest neighbor, multilayer perceptron, and ensemble models. Random oversampling and synthetic minority oversampling techniques were adopted to balance the dataset. The variables included demographic characteristics, comorbidities, immunocompromised status, clinical characteristics, subjective symptoms reported during ED triage, and laboratory data. The study outcome was an episode of bacteremia. ResultsOf the 5063 patients with initial fever or hypothermia from whom blood cultures were obtained, 128 (2.5 %) were diagnosed with bacteremia. We combined 36 selected variables and 10 symptoms subjectively reported by patients into features for analysis in our models. The ensemble model outperformed other models, with an area under the receiver operating characteristic curve (AUROC) of 0.930 and an F1-score of 0.735. The AUROC of all models was higher than 0.80. ConclusionThe ML models developed effectively predicted bacteremia among febrile or hypothermic patients in the ED, with all models demonstrating high AUROC values and rapid processing times. The findings suggest that ED clinicians can effectively utilize ML techniques to develop predictive models for addressing clinical challenges.

The Outcome of Walking Cold Patients with Potential Mild Hypothermia to Safety-A Mountain Rescue Case Series.

Some experts recommend that ambulant hypothermic patients should be rewarmed, fed, and not permitted to exercise for 30 min because of concerns that afterdrop can cause cardiac instability. We investigated the outcome of ambulant hypothermic patients in a case series from mountain rescue teams in Great Britain. A questionnaire was used to collect information on a series of adult patients with a clinical diagnosis of mild hypothermia. All patients were alert on the AVPU scale and evacuated by walking from the mountain. The outcome measures were survival or a change in management because of medical deterioration during evacuation. A series of 108 eligible cases were reported over a 5-year period. When rescuers arrived on the scene, 98 (91%) patients were stationary, and 10 (9%) were still mobile. Thirty-eight (39%) of the stationary cases were walked immediately off the mountain without any on-scene delay. In the remaining 60 (61%) stationary cases, the decision was taken to delay evacuation to provide food, drinks, and additional clothing. In 3 cases, the use of heat packs indicated an intention to actively rewarm. In cases where the on-scene time was reported, 27 (79%) were known to be mobile again within 20 min. All patients survived, and no adverse medical events occurred in all 108 cases. In this study, no adverse events occurred because of immediate mobilization, suggesting that in these cases, there appears to be minimal risk of early activity.

Hypothermia and the Global War on Terror: 18 Years of Minimal Progress.

The association between hypothermia, coagulopathy, and acidosis in trauma is well described. Hypothermia mitigation starts in the prehospital setting; however, it is often a secondary focus after other life-saving interventions. The deployed environment further compounds the problem due to prolonged evacuation times in rotary wing aircraft, resource limitations, and competing priorities. This analysis evaluates hypothermia in combat casualties and the relationship to resuscitation strategy with blood products. Using the data from the Department of Defense Joint Trauma Registry from 2003 to 2021, a retrospective analysis was conducted on adult trauma patients. Inclusion criteria was arrival at the first military treatment facility (MTF) hypothermic (<95ºF). Study variables included: mortality, year, demographics, battle vs non-battle injury, mechanism, theater of operation, vitals, and labs. Subgroup analysis was performed on severely injured (15 < ISS < 75) hypothermic trauma patients resuscitated with whole blood (WB) vs only component therapy. Of the 69,364 patients included, 908 (1.3%) arrived hypothermic; the vast majority of whom (N = 847, 93.3%) arrived mildly hypothermic (90-94.9°F). Overall mortality rate was 14.8%. Rates of hypothermia varied by year from 0.7% in 2003 to 3.9% in 2014 (P <0.005). On subgroup analysis, mortality rates were similar between patients resuscitated with WB vs only component therapy; though base deficit values were higher in the WB cohort (-10 vs -6, P < 0.001). Despite nearly 20 years of combat operations, hypothermia continues to be a challenge in military trauma and is associated with a high mortality rate. Mortality was similar between hypothermic trauma patients resuscitated with WB vs component therapy, despite greater physiologic derangements on arrival in patients who received WB. As the military has the potential to conduct missions in environments where the risk of hypothermia is high, further research into hypothermia mitigation techniques and resuscitation strategies in the deployed setting is warranted.

Incidence of hypothermia in critically ill patients receiving continuous renal replacement therapy in Siriraj Hospital, Thailand.

Hypothermia is a relatively common complication in patients receiving continuous renal replacement therapy (CRRT). However, few studies have reported the factors associated with hypothermia. A retrospective cohort study was performed in five intensive care units (ICUs) to evaluate the incidence of hypothermia and the predictive factors for developing hypothermia during CRRT, with hypothermia defined as a time-weighted average temperature <36 °C. From January 2020 to December 2021, 300 patients were enrolled. Hypothermia developed in 23.7% of them within the first 24 hours after CRRT initiation. Compared to non-hypothermic patients, hypothermic patients were older and had lower body weight, more frequent acidemia, and higher ICU and 30-day mortality rates. In the multivariate analysis, age >70 years (odds ratio [OR], 2.59; 95% CI, 1.38-4.98; P=0.004), higher positive fluid balance on the day before CRRT (OR, 1.11; 95% CI, 1.02-1.22; P=0.02), and CRRT dose (OR, 1.003; 95% CI, 1.00-1.01; P=0.04) were significantly associated with hypothermia. Conversely, a higher body weight was independently associated with mitigated risk of hypothermia (OR, 0.89; 95% CI, 0.81-0.97; P=0.01). Moreover, a higher coefficient of variance of temperature was associated with greater ICU mortality (OR, 1.41; 95% CI, 1.13-1.78; P=0.003). Hypothermia during CRRT is a relatively common occurrence, and factors associated with hypothermia onset in the first 24 hours include older age, lower body weight, higher positive fluid balance on the day before CRRT, and higher CRRT dose. Greater temperature variability was associated with increased ICU mortality.

Construction of a care protocol following King's Goal achievement theory: experience report

Objective: to report the construction of a Care Protocol for the safe warming of hypothermic patients following Imogene King's Goal Achievement Theory. Method: this is an experience report from an intensive care nurse during the master's and doctorate course, where the protocol was developed, based on Imogene King's Theory. The experience was presented in five thematic axes. Results: In axis 1, there was a lack of monitoring of active heating, a lack of verbal and non-verbal communication, leading to the nursing diagnosis (axis 2) Hyperthermia and Hypothermia. In axis 3, a literature review (scope) was carried out to assess care for hypothermic patients. In axis 4, the content of the protocol was validated with the help of experts in the area and in axis 5, the aim is to evaluate the clinical feasibility of the protocol in everyday hospital settings. Conclusion: the study portrayed the construction of a protocol following Imogene King's Goal Achievement Theory, demonstrating the importance of developing tools to assist nursing in the treatment of hypothermic patients in hospitals.

Intermittent hemodialysis as a rewarming strategy for severe hypothermia in patients without renal failure: a case report

This case report highlights the effective use of intermittent hemodialysis (IHD) in warming a 71-year-old female patient with severe hypothermia who presented with a rectal temperature of 25 °C and signs of hemodynamic instability. The patient, found unconscious after prolonged exposure to cold exacerbated by alcohol consumption, initially showed some improvement in core temperature through active external rewarming methods. However, soon, her temperature plateaued at 27 °C. Patient was deemed unsuitable for extracorporeal membrane oxygenation (ECMO) or cardiopulmonary bypass (CPB) due to her age, and urgent IHD was initiated. This approach resulted in a stable increase in core temperature at approximately 2.0 °C/hr, along with normalization of lactic acidosis, creatinine phosphokinase, and correction of electrolyte imbalances, culminating in her full recovery and discharge after seven days in the hospital.After reviewing this case alongside similar ones from before, this case report highlights the efficacy and safety of IHD as an efficient, readily available, and less invasive method for rewarming moderate to severe hypothermic patients who are hemodynamically unstable patients but do not have cardiac arrest or renal dysfunction. IHD is especially useful when less invasive cooling devices (Artic Sun/ CoolGard) are not available or more invasive extracorporeal life support options (ECMO/ CPB) are either not indicated or unavailable. IHD can also help improve concurrent electrolyte imbalances and/or toxin buildup. The report further emphasizes the necessity of monitoring for potential complications, such as post-dialysis hypophosphatemia and rebound hyperkalemia, following successful rewarming.

Impact of Intraoperative Hypothermia on Incidence of Infection in Implant-Based Breast Reconstruction in Pakistan

Background: Intraoperative hypothermia, an unintentional drop in core body temperature during surgery, poses a significant risk in implant-based breast reconstruction. This condition can weaken immune function, slow blood flow, and increase the risk of postoperative infections. Objective: To evaluate the impact of intraoperative hypothermia on the incidence of infections in patients undergoing implant-based breast reconstruction in Pakistan. Methods: This retrospective cohort study was conducted at Jinnah Sindh Medical University from January 2023 to November 2023. The study included 195 female breast cancer patients aged 18 and above who underwent implant-based breast reconstruction. Patients with pre-existing infections, concurrent chemotherapy or radiotherapy during the perioperative period, and incomplete medical records were excluded. Detailed patient demographics, surgical specifics, and intraoperative temperature control measures were recorded. Patients were categorized into normothermic (core body temperature ≥ 36°C) and hypothermic (core body temperature &lt;36°C) groups. Infection data post-surgery were collected through clinical assessments, blood tests, and imaging techniques. Data were analyzed using SPSS version 25, with descriptive statistics, chi-square tests for categorical variables, and independent t-tests for continuous variables. A p-value of less than 0.05 was considered statistically significant. Ethical approval was obtained, and informed consent was secured from all participants. Results: The mean age of patients was 45.23±3.45 years in the normothermic group and 46.01±2.89 years in the hypothermic group. The hypothermic group had a slightly higher average BMI (25.1 kg/m²) compared to the normothermic group (24.5 kg/m²). Total infections were observed in 26.3% of the hypothermic group versus 10% in the normothermic group. Superficial infections were reported in 12.6% of hypothermic patients compared to 6% of normothermic patients. Deep infections were more prevalent in the hypothermic group at 13.7%, compared to 4% in the normothermic group. The univariate odds ratio (OR) for intraoperative hypothermia was 3.2 (95% CI: 1.5-6.8) and the multivariate OR was 3.0 (95% CI: 1.3-6.5), both with a p-value of less than 0.01. Conclusion: Intraoperative hypothermia significantly increases the risk of postoperative infections in patients undergoing implant-based breast reconstruction. Effective temperature management strategies, such as preoperative warming and the use of intraoperative warming devices, are crucial to reducing infection rates and improving surgical outcomes

Temperature trajectories and mortality in hypothermic sepsis patients

ObjectivesHypothermia is associated with poor outcomes in sepsis patients, and hypothermic sepsis patients exhibit temperature alterations during initial treatment. The objective of this study was to classify hypothermic sepsis patients based on body temperature trajectories and investigate the associations of these patients with 28-day mortality. MethodsThis was a retrospective analysis of prospectively collected data from adult sepsis or septic shock patients who visited three emergency departments between August 2014 and December 2019. Hypothermic sepsis was defined as an initial body temperature <36 °C. delta temperature was calculated by subtracting the 0 h body temperature from the 6 h body temperature. We divided the patients into three groups according to delta temperature: Group A (delta temperature ≤ 0), Group B (0 < delta temperature ≤ 1) and Group C (delta temperature > 1). The primary outcome was 28-day mortality, and a multivariable Cox proportional hazards regression model was generated. ResultsAmong 7344 patients with sepsis or septic shock, 325 hypothermic patients were included in the analysis, and the overall mortality rate was 36%. While initial body temperature was not different between survivors and nonsurvivors, survivors exhibited a higher body temperature at 6 h. The 28-day mortality rates for Groups A, B and C were 53.1%, 36.0%, and 30.0%, respectively, and Group A had significantly higher mortality than Group C did (p < 0.05). Group C demonstrated a 44.2% decrease in 28-day mortality compared to Group A (adjusted hazard ratio of 0.558; 95% confidence interval of 0.330–0.941). ConclusionsIn hypothermic sepsis patients, an increase of 1 °C or more in body temperature after the initial 6 h is associated with a reduced risk of 28-day mortality.

Temperature effect on coagulation function in mild hypothermic patients undergoing thoracic surgeries: thromboelastography (TEG) versus standard tests

PurposeOur previous research has revealed that mild hypothermia leads to excessive bleeding in thoracic surgeries, while the underlying mechanism stayed unrevealed by the standard coagulation tests. The research question in this study was as follows: “How does mild hypothermia impair the hemostatic function in patients receiving thoracic surgeries?”. The purpose was to detect the disturbed coagulation processes by comparing the TEG parameters in patients receiving active vs. passive warming during thoracic surgeries.MethodsStandard coagulation tests and thromboelastography (TEG) were adopted to compare the hemostatic functions in patients receiving active vs. passive warming during thoracic surgeries. Furthermore, blood samples from passive warming group were retested for TEG at actual core body temperatures.ResultsSixty-four eligible patients were included in this study. TEG revealed that mild hypothermia significantly disturbed coagulation by decreasing MA (59.4 ± 4.5 mm vs. 64.2 ± 5.7 mm, p = 0.04) and α angle (70.4 ± 5.2° vs. 74.9 ± 4.4°, p = 0.05) and prolonging ACT (122.2 ± 19.3 s vs. 117.3 ± 15.2 s, p = 0.01) and K time (1.9 ± 1.0 s vs. 1.3 ± 0.4 min, p = 0.02). TEGs conducted under core body temperatures revealed more impaired coagulation than those incubated at 37 °C. Furthermore, postoperative shivering and waking time were significantly increased in mild hypothermic patients.ConclusionMild hypothermia significantly impaired coagulation function in patients receiving thoracic surgeries, which could be detected by TEGs other than the standard coagulation tests. Temperature-adjusted TEGs may provide a preferable method of hemostatic monitoring and transfusion guidance in thoracic surgeries, which warrants further clinical investigations.

Low-flow time and outcomes in hypothermic cardiac arrest patients treated with extracorporeal cardiopulmonary resuscitation: a secondary analysis of a multi-center retrospective cohort study

BackgroundIn out-of-hospital cardiac arrest (OHCA) patients with extracorporeal cardiopulmonary resuscitation (ECPR), the association between low-flow time and outcomes in accidental hypothermia (AH) patients compared to those of patients without AH has not been fully investigated.MethodsThis was a secondary analysis of the retrospective multicenter registry in Japan. We enrolled patients aged ≥ 18 years who had been admitted to the emergency department for OHCA and had undergone ECPR between January, 2013 and December, 2018. AH was defined as an arrival body temperature below 32 °C. The primary outcome was survival to discharge. Cubic spline analyses were performed to assess the non-linear associations between low-flow time and outcomes stratified by the presence of AH. We also analyzed the interaction between low-flow time and the presence of AH.ResultsOf 1252 eligible patients, 105 (8.4%) and 1147 (91.6%) were in the AH and non-AH groups, respectively. Median low-flow time was 60 (47–79) min in the AH group and 51 (42–62) min in the non-AH group. The survival discharge rates in the AH and non-AH groups were 44.8% and 25.4%, respectively. The cubic spline analyses showed that survival discharge rate remained constant regardless of low-flow time in the AH group. Conversely, a decreasing trend was identified in the survival discharge rate with longer low-flow time in the non-AH group. The interaction analysis revealed a significant interaction between low-flow time and AH in survival discharge rate (p for interaction = 0.048).ConclusionsOHCA patients with arrival body temperature < 32 °C who had received ECPR had relatively good survival outcomes regardless of low-flow time, in contrast to those of patients without AH.

Effect of a vapor barrier in combination with active external rewarming for cold-stressed patients in a prehospital setting: a randomized, crossover field study

BackgroundUse of a vapor barrier in the prehospital care of cold-stressed or hypothermic patients aims to reduce evaporative heat loss and accelerate rewarming. The application of a vapor barrier is recommended in various guidelines, along with both insulating and wind/waterproof layers and an active external rewarming device; however, evidence of its effect is limited. This study aimed to investigate the effect of using a vapor barrier as the inner layer in the recommended “burrito” model for wrapping hypothermic patients in the field.MethodsIn this, randomized, crossover field study, 16 healthy volunteers wearing wet clothing were subjected to a 30-minute cooling period in a snow chamber before being wrapped in a model including an active heating source either with (intervention) or without (control) a vapor barrier. The mean skin temperature, core temperature, and humidity in the model were measured, and the shivering intensity and thermal comfort were assessed using a subjective questionnaire. The mean skin temperature was the primary outcome, whereas humidity and thermal comfort were the secondary outcomes. Primary outcome data were analyzed using analysis of covariance (ANCOVA).ResultsWe found a higher mean skin temperature in the intervention group than in the control group after approximately 25 min (p < 0.05), and this difference persisted for the rest of the 60-minute study period. The largest difference in mean skin temperature was 0.93 °C after 60 min. Humidity levels outside the vapor barrier were significantly higher in the control group than in the intervention group after 5 min. There were no significant differences in subjective comfort. However, there was a consistent trend toward increased comfort in the intervention group compared with the control group.ConclusionsThe use of a vapor barrier as the innermost layer in combination with an active external heat source leads to higher mean skin rewarming rates in patients wearing wet clothing who are at risk of accidental hypothermia.Trial registrationClinicalTrials.gov identifier: NCT05779722.

Prolonged critical avalanche burial for nearly 23 h with severe hypothermia and severe frostbite with good recovery: a case report

BackgroundAccidental hypothermia with severe frostbite is a rare combination of injuries with a high risk for long-term sequelae. There are widely accepted recommendations for the management of avalanche victims and for frostbite treatment, but no recommendation exists for the treatment of frostbite in severe hypothermic patients, specifically for the management of hypothermic avalanche victims presenting with frostbite.Case presentationWe present a case of a previously healthy, 53-year-old male skier who was critically buried by an avalanche at 2300 m of altitude at an ambient temperature of − 8 °C for nearly 23 h. The victim was found with the right hand out of the snow and an air connection to outside. He was somnolent with Glasgow Coma Scale 11 (Eye 4, Verbal 2, Motor 5) and spontaneously breathing, in a severely hypothermic state with an initial core temperature of 23.1 °C and signs of cold injuries in all four extremities. After rescue and active external forced air rewarming in the intensive care unit, the clinical signs of first-degree frostbite on both feet and the left hand vanished, while third- to fourth-degree frostbite injuries became apparent on all fingers of the right hand. After reaching a core body temperature of approximately 36 °C, aggressive frostbite treatment was started with peripheral arterial catheter-directed thrombolysis with alteplase, intravenous iloprost, ibuprofen, dexamethasone and regional sympathicolysis with a right-sided continuous axillary block. After ten months, the patient had no tissue loss but needed neuropathic pain treatment with pregabalin.ConclusionThe combination of severe accidental hypothermia and severe frostbite is rare and challenging, as drug metabolism is unpredictable in a hypothermic patient and no recommendations for combined treatment exist. There is general agreement to give hypothermia treatment the priority and to begin frostbite treatment as early as possible after full rewarming of the patient. More evidence is needed to identify the optimal dosage and time point to initiate treatment of frostbite in severely hypothermic patients. This should be taken into consideration by future treatment recommendations.

Effect of wet clothing removal on skin temperature in subjects exposed to cold and wrapped in a vapor barrier: a human, randomized, crossover field study

BackgroundPrehospital care for cold-stressed and hypothermic patients focuses on effective insulation and rewarming. When encountering patients wearing wet clothing, rescuers can either remove the wet clothing before isolating the patient or isolate the patient using a vapor barrier. Wet clothing removal increases skin exposure but avoids the need to heat the wet clothing during rewarming. Leaving wet clothing on will avoid skin exposure but is likely to increase heat loss during rewarming. This study aimed to evaluate the effect of wet clothing removal compared to containing the moisture using a vapor barrier on skin temperature in a prehospital setting.MethodsThis randomized crossover experimental field study was conducted in a snow cave in Hemsedal, Norway. After an initial cooling phase of 30 min while wearing wet clothes, the participants were subjected to one of two rewarming scenarios: (1) wet clothing removal and wrapping in a vapor barrier, insulating blankets, and windproof outer shell (dry group) or (2) wrapping in a vapor barrier, insulating blankets, and windproof outer shell (wet group). The mean skin temperature was the primary outcome whereas subjective scores for both thermal comfort and degree of shivering were secondary outcomes. Primary outcome data were analyzed using the analysis of covariance (ANCOVA).ResultsAfter an initial decrease in temperature during the exposure phase, the dry group had a higher mean skin temperature compared to the wet group after only 2 min. The skin-rewarming rate was highest in the initial rewarming stages for both groups, but increased in the dry group as compared to the wet group in the first 10 min. Return to baseline temperature occurred significantly faster in the dry group (mean 12.5 min [dry] vs. 28.1 min [wet]). No intergroup differences in the subjective thermal comfort or shivering were observed.ConclusionRemoval of wet clothing in combination with a vapor barrier increases skin rewarming rate compared to encasing the wet clothing in a vapor barrier, in mild cold and environments without wind.Trial registrationClinicalTrials.gov ID NCT05996757, retrospectively registered 18/08/2023.

Hypothermia: Beyond the Narrative Review-The Point of View of Emergency Physicians and Medico-Legal Considerations.

Hypothermia is a widespread condition all over the world, with a high risk of mortality in pre-hospital and in-hospital settings when it is not promptly and adequately treated. In this review, we aim to describe the main specificities of the diagnosis and treatment of hypothermia through consideration of the physiological changes that occur in hypothermic patients. Hypothermia can occur due to unfavorable environmental conditions as well as internal causes, such as pathological states that result in reduced heat production, increased heat loss or ineffectiveness of the thermal regulation system. The consequences of hypothermia affect several systems in the body-the cardiovascular system, the central and peripheral nervous systems, the respiratory system, the endocrine system and the gastrointestinal system-but also kidney function, electrolyte balance and coagulation. Once hypothermia is recognized, prompt treatment, focused on restoring body temperature and supporting vital functions, is fundamental in order to avert preventable death. It is important to also denote the fact that CPR has specificities related to the unique profile of hypothermic patients.

The Role of Extracorporeal Membrane Oxygenation ECMO in Accidental Hypothermia and Rewarming in Out-of-Hospital Cardiac Arrest Patients-A Literature Review.

Accidental hypothermia, defined as an unintentional drop of the body core temperature below 35 °C, is one of the causes of cardiocirculatory instability and reversible cardiac arrest. Currently, extracorporeal life support (ECLS) rewarming is recommended as a first-line treatment for hypothermic cardiac arrest patients. The aim of the ECLS rewarming is not only rapid normalization of core temperature but also maintenance of adequate organ perfusion. Veno-arterial extracorporeal membrane oxygenation (ECMO) is a preferred technique due to its lower anticoagulation requirements and potential to prolong circulatory support. Although highly efficient, ECMO is acknowledged as an invasive treatment option, requiring experienced medical personnel and is associated with the risk of serious complications. In this review, we aimed to discuss the clinical aspects of ECMO management in severely hypothermic cardiac arrest patients.