Changes in temperature in preheated crystalloids at ambient temperatures relevant to a prehospital setting: an experimental simulation study with the application of prehospital treatment of trauma patients suffering from accidental hypothermia.

BACKGROUND: Accidental hypothermia is common in all trauma patients and contributes to the lethal diamond, increasing both morbidity and mortality. In hypotensive shock, fluid resuscitation is recommended using fluids with a temperature of 37-42°, as fluid temperature can decrease the patient's body temperature. In Sweden, virtually all prehospital services use preheated fluids. The aim of the present study was to investigate how the temperature of preheated infusion fluids is affected by the ambient temperatures and flow rates relevant for prehospital emergency care. METHODS: In this experimental simulation study, temperature changes in crystalloids preheated to 39 °C were evaluated. The fluid temperature changes were measured both in the infusion bag and at the patient end of the infusion system. Measurements were conducted in conditions relevant to prehospital emergency care, with ambient temperatures varying between - 4 and 28 °C and flow rates of 1000 ml/h and 6000 ml/h, through an uninsulated infusion set at a length of 175 cm. RESULTS: The flow rate and ambient temperature affected the temperature in the infusion fluid both in the infusion bag and at the patient end of the system. A lower ambient temperature and lower flow rate were both associated with a greater temperature loss in the infusion fluid. CONCLUSION: This study shows that both a high infusion rate and a high ambient temperature are needed if an infusion fluid preheated to 39 °C is to remain above 37 °C when it reaches the patient using a 175-cm-long uninsulated infusion set. It is apparent that the lower the ambient temperature, the higher the flow rate needs to be to limit temperature loss of the fluid.

Delayed Rewarming Thrombocytopenia: A Suggested Preventable and Treatable Cause of Rewarming Deaths.

The lack of a consensus of accepted prognostic factors in hypothermia suggests an additional factor has been overlooked. Delayed rewarming thrombocytopenia (DRT) is a novel candidate for such a role. At body temperature, platelets undergoing a first stage of aggregation are capable of progression to a second irreversible stage of aggregation. However, we have shown that the second stage of aggregation does not occur below 32°C and that this causes the first stage to become augmented (first-stage platelet hyperaggregation). In aggregometer studies performed below 32°C, the use of quantities of ADP that cause a marked first-stage hyperaggregation can cause an augmented second-stage activation of the platelets during rewarming (second-stage platelet hyperaggregation). In vivo, after 24 hours of hypothermia, platelets on rewarming seem to undergo second-stage hyperaggregation, from ADP released from erythrocytes, leading to life-threatening thrombocytopenia. This hyperaggregation is avoidable if heparin is given before the hypothermia or if aspirin, alcohol or platelet transfusion is given during the hypothermia before reaching 32°C on rewarming. Many of the open questions existing in this field are explained by DRT. Prevention and treatment of DRT could be of significant value in preventing rewarming deaths and some cases of rescue collapse. Performing platelet counts during rewarming will demonstrate potentially fatal thrombocytopenia and enable treatment with platelet infusions aspirin or alcohol.

Therapeutic Hypothermia in Treating Glioblastoma: A Review.

Glioblastoma (GBM) is the most commonly occurring of all malignant central nervous system (CNS) tumors in adults. Considering the low median survival of only ∼15 months and poor prognosis in GBM patients, despite surgical resection with adjuvant radiation and chemotherapy, it is vital to seek brand new and innovative treatment in combination with already existing methods. Hypothermia participates in many metabolic pathways, inflammatory responses, and apoptotic processes, while also promoting the integrity of neurons. Following the successful application of therapeutic hypothermia across a spectrum of disorders such as traumatic CNS injury, cardiac arrest, and epilepsy, several clinical trials have set to evaluate the potency of hypothermia in treating a variety of cancers, including breast and ovaries cancer. In regard to primary neoplasms and more specifically, GBM, hypothermia has recently shown promising results as an auxiliary treatment, reinforcing chemotherapy's efficacy. In this review, we discuss the recent advances in utilizing hypothermia as treatment for GBM and other cancers.

[Neurointensive Care:Targeted Temperature Management].

The neuroprotective effects of hypothermia therapy have been sufficiently demonstrated; however, the conditions under which it is considered effective have become limited. Recently, the term "temperature management therapy" has been more frequently used than "hypothermia therapy." In neurointensive care, in the acute phase of neurological disorders, not only lowering body temperature but also targeted temperature management according to each case is an important technique. In our facility, targeted temperature management is primarily used to control intracranial pressure and fever. It is important to clarify the purpose of temperature management and emphasize neurointensive care that minimizes secondary brain damage instead of focusing only on temperature control.

ATP-induced hypothermia improves burn injury and relieves burn pain in mice.

Thermal burn injury is a severe and life-threatening form of trauma that presents a significant challenge to clinical therapy. Therapeutic hypothermia has been shown to be beneficial in various human pathologies. Adenosine triphosphate (ATP) induces a hypothermic state that resembles hibernation-like suspended animation in mammals. This study investigates the potential protective role of ATP-induced hypothermia in thermal burn injury. Male C57BL/6 mice underwent a sham procedure or third-degree burn, and ATP-induced hypothermia was applied immediately or 1 h after burn injury. Our results show that ATP-induced hypothermia significantly improved burn depth progression and reduced collagen degradation. Moreover, hypothermia induced by ATP alleviated burn-induced hyperinflammatory responses and oxidative stress. Metabolomic profiling revealed that ATP-induced hypothermia reversed the shifts of metabolic profiles of the skin in burn mice. In addition, ATP-induced hypothermia relieved nociceptive and inflammatory pain, as observed in the antinociceptive test. Our findings suggest that ATP-induced hypothermia attenuates burn injury and provides new insights into first-aid therapy after thermal burn injury.

Impact of hydrogen gas inhalation during therapeutic hypothermia on cerebral hemodynamics and oxygenation in the asphyxiated piglet.

We previously reported the neuroprotective potential of combined hydrogen (H2) gas ventilation therapy and therapeutic hypothermia (TH) by assessing the short-term neurological outcomes and histological findings of 5-day neonatal hypoxic-ischemic (HI) encephalopathy piglets. However, the effects of H2 gas on cerebral circulation and oxygen metabolism and on prognosis were unknown. Here, we used near-infrared time-resolved spectroscopy to compare combined H2 gas ventilation and TH with TH alone. Piglets were divided into three groups: HI insult with normothermia (NT, n = 10), HI insult with hypothermia (TH, 33.5 ± 0.5 °C, n = 8), and HI insult with hypothermia plus H2 ventilation (TH + H2, 2.1-2.7%, n = 8). H2 ventilation and TH were administered and the cerebral blood volume (CBV) and cerebral hemoglobin oxygen saturation (ScO2) were recorded for 24 h after the insult. CBV was significantly higher at 24 h after the insult in the TH + H2 group than in the other groups. ScO2 was significantly lower throughout the 24 h after the insult in the TH + H2 group than in the NT group. In conclusion, combined H2 gas ventilation and TH increased CBV and decreased ScO2, which may reflect elevated cerebral blood flow to meet greater oxygen demand for the surviving neurons, compared with TH alone.

Kidney outcomes in early adolescence following perinatal asphyxia and hypothermia-treated hypoxic-ischaemic encephalopathy.

BACKGROUND: Acute kidney injury (AKI) remains common among infants with hypothermia-treated hypoxic-ischaemic encephalopathy (HIE). Little is known about long-term kidney outcomes following hypothermia treatment. We recently reported that 21% of survivors of hypothermia-treated HIE had decreased estimated glomerular filtration rate (eGFR) based on plasma creatinine in early adolescence. Here, we assessed kidney functions more comprehensively in our population-based cohort of children born in Stockholm 2007-2009 with a history of hypothermia-treated HIE. METHODS: At 10-12 years of age, we measured cystatin C (cyst C) to estimate GFR. Children with decreased cyst C eGFR also underwent iohexol clearance examination. We measured urine-albumin/creatinine ratio, blood pressure (BP) and kidney volume on magnetic resonance imaging. Fibroblast growth factor 23 (FGF 23) levels in plasma were assessed by enzyme-linked immunosorbent assay (ELISA). Outcomes were compared between children with and without a history of neonatal AKI. RESULTS: Forty-seven children participated in the assessment. Two children (2/42) had decreased cyst C eGFR, for one of whom iohexol clearance confirmed mildly decreased GFR. One child (1/43) had Kidney Disease Improving Global Outcomes (KDIGO) category A2 albuminuria, and three (3/45) had elevated office BP. Subsequent ambulatory 24-h BP measurement confirmed high normal BP in one case only. No child had hypertension. Kidney volume and FGF 23 levels were normal in all children. There was no difference in any of the parameters between children with and without a history of neonatal AKI. CONCLUSION: Renal sequelae were rare in early adolescence following hypothermia-treated HIE regardless of presence or absence of neonatal AKI. A higher resolution version of the Graphical abstract is available as Supplementary information.

Variability in emergency department management of hypothermic infants ≤90 days of age.

OBJECTIVES: Hypothermic infants are at risk for serious bacterial and herpes simplex virus infections, but there are no evidence-based guidelines for managing these patients. We sought to characterize variations and trends in care for these infants in the emergency department (ED). METHODS: We conducted a retrospective cross-sectional study of infants under 90 days old presenting to 32 pediatric EDs from 2009 through 2019 with an International Classification of Diseases diagnosis code for hypothermia. We characterized variation in diagnostic testing, antimicrobial treatment, and disposition of children in three age groups (≤30 days, 31-60 days, and 61-90 days old) and analyzed care trends. RESULTS: Of 7828 ED encounters meeting inclusion criteria, most (81%) were ≤ 30 days of age. Infants in the 0-30 days old age group, compared to 61-90 days old age group, had a higher proportion of blood (75% vs. 68%), urine (72% vs. 64%), and cerebrospinal fluid (CSF; 35% vs. 22%) cultures obtained (p < 0.01) and greater antimicrobial use (81% vs. 68%; p < 0.01) in the ED. From 2009 to 2019, C-reactive protein (CRP), and procalcitonin usage steadily increased, from 25% to 40% and 0% to 30% respectively, while antibiotic use (83% to 77%), CSF testing (53% to 44%), and chest radiography (47% to 34%) decreased. Considerable interhospital variation was noted in testing and treatment, including CSF testing (14-70%), inflammatory markers (CRP and procalcitonin; 8-88%), and antibiotics (56-92%). CONCLUSION: Substantial hospital-level variation exists for managing hypothermic infants in the ED. Long-term trends are notable for changing practice over time, particularly with increased use of inflammatory markers. Prospective studies are needed to risk stratify and optimize care for this population.

Mild Hypothermia via External Cooling Improves Lung Function and Alleviates Pulmonary Inflammatory Response and Damage in Two-Hit Rabbit Model of Acute Lung Injury.

OBJECTIVES: Targeted temperature management (TTM) with therapeutic hypothermia (TH) has an organ-protective effect by mainly reducing inflammatory response. Here, our objective was to determine, for the first time, whether mild TH with external cooling, a simple and inexpensive method, could be safe or even beneficial in two-hit rabbit model of acute lung injury/acute respiratory distress syndrome (ALI/ARDS). METHODS: Twenty-two New Zealand rabbits (6-month-old) were randomly divided into healthy control (HC) with conventional ventilation, but without injury, model group (ALI), and hypothermia group with external cooling (ALI-HT). After induction of ALI/ARDS through mild lung-lavages followed by non-protective ventilation, mild hypothermia was started in ALI-HT group (body temperature of 33-34 °C). All rabbits were conventionally ventilated for an additional 6-h by recording respiratory parameters. Finally, lung histopathology and inflammatory response were evaluated. RESULTS: Hypothermia was associated with higher oxygen saturation, resulting in partial improvement in the P/F ratio (PaO2/FiO2), oxygenation index, mean airway pressure, and PaCO2, but did not affect lactate levels. The ALI-HT group had lower histopathological injury scores (hyperemia, edema, emphysema, atelectasis, and PMN infiltration). Further, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-6 and -8 levels in lung tissue and serum samples markedly reduced due to hypothermia. CONCLUSION: Mild TH with external cooling reduced lung inflammation and damage, whereas it resulted in partial improvement in gas exchanges. Our findings highlight that body temperature control may be a potentially supportive therapeutic option for regulating cytokine production and respiratory parameters in ALI/ARDS.

Successful recovery of severe hypothermia with minimally invasive central catheter.

BACKGROUND: Severe hypothermia can result in malignant arrhythmias or cardiac arrest and require invasive central rewarming modalities due to a core body temperature < 28 °C. Difficult rescue missions can make continuous CPR challenging, but the decrease in oxygen consumption at these low temperatures allows for successful recovery despite the delay. Although other active warming techniques, such as peritoneal lavage, intravascular warming catheter, and renal replacement therapy can be beneficial, the consensus statements recommend extracorporeal life support as the preferred rewarming method. CASE PRESENTATION: A 42-year-old female was found in a pond after presumed exposure for 30-40 min with an outside temperature of 17 °F (-8 °C) and was found to be in ventricular fibrillation. ACLS protocol was then initiated. At the hospital, she was intubated and sedated with continuous CPR during multimodal rewarming, including active internal via the ZOLL Icy catheter. One hour after rewarming, with core temperature above 29 °C, she was defibrillated and achieved ROSC. As she continued to warm, she made purposeful movement and was warmed and maintained at euthermia. She was initiated on antibiotics due to aspiration concerns and titrated off vasopressors with extubation on day 2 of hospitalization. She had mild complaints of extremity numbness and chest pain from compressions prior to discharge on hospitalization day 4. CONCLUSIONS: This case has a successful resuscitation of severe hypothermia associated with cardiac arrest. The patient was warmed at greater than 4 °C/h with a less invasive, quicker and potentially more available approach to warming. With equipment improvements, the ability to provide prolonged CPR while rewarming may suggest that transferring to an extracorporeal life support center is not necessary.

Electrolyte profiles with induced hypothermia: A sub study of a clinical trial evaluating the duration of hypothermia after cardiac arrest.

BACKGROUND: Electrolyte disturbances can result from targeted temperature treatment (TTM) in out-of-hospital cardiac arrest (OHCA) patients. This study explores electrolyte changes in blood and urine in OHCA patients treated with TTM. METHODS: This is a sub-study of the TTH48 trial, with the inclusion of 310 unconscious OHCA patients treated with TTM at 33°C for 24 or 48 h. Over a three-day period, serum concentrations were obtained on sodium potassium, chloride, ionized calcium, magnesium and phosphate, as were results from a 24-h diuresis and urine electrolyte concentration and excretion. Changes over time were analysed with a mixed-model multivariate analysis of variance with repeated measurements. RESULTS: On admission, mean ± SD sodium concentration was 138 ± 3.5 mmol/l, which increased slightly but significantly (p < .05) during the first 24 h. Magnesium concentration stayed within the reference interval. Median ionized calcium concentration increased from 1.11 (IQR 1.1-1.2) mmol/l during the first 24 h (p < .05), whereas median phosphate concentration dropped to 1.02 (IQR 0.8-1.2) mmol/l (p < .05) and stayed low. During rewarming, potassium concentrations increased, and magnesium and ionizes calcium concentration decreased (p < .05). Median 24-h diuresis results on days one and two were 2198 and 2048 ml respectively, and the electrolyte excretion mostly stayed low in the reference interval. CONCLUSIONS: Electrolytes mostly remained within the reference interval. A temporal change occurred in potassium, magnesium and calcium concentrations with TTM's different phases. No hypothermia effect on diuresis was detected, and urine excretion of electrolytes mostly stayed low.

Induced Hypothermia as Cold as 3°C in Humans: Forgotten Cases Rediscovered.

Zafren, Ken, Raimund Lechner, Peter Paal, Hermann Brugger, Giles Peek, and Tomasz Darocha. Induced hypothermia as cold as 3°C in humans: Forgotten cases rediscovered. High Alt Med Biol. 23:105-113.-The lowest temperature from which humans can be successfully rewarmed from accidental hypothermia is unknown. The lowest published core temperature with survival from accidental hypothermia is 11.8°C. We recently reported a rediscovered case series of patients in whom profound hypothermia was induced for surgery. The patient in this case series with the lowest core temperature, 4.2°C, survived neurologically intact. We subsequently rediscovered several additional case series of induced hypothermia to core temperatures below 11.8°C. In one case series, at least one patient was cooled to 3°C. We do not know if any patient survived cooling to 3°C. As in the previous case series, the authors of the additional reports presented physiological data at various core temperatures, showing wide variations in individual responses to hypothermia. These data add to our understanding of the physiology of profound hypothermia. Although induced hypothermia for surgery differs from accidental hypothermia, survival from very low temperatures in induced hypothermia provides evidence that humans with accidental hypothermia can be resuscitated successfully from temperatures much lower than 11.8°C. We continue to advise against using core temperature alone to decide if a hypothermic patient in cardiac arrest has a chance of survival.

Heated Humidified Breathing Circuit Rewarming in Hypothermic Patients Post-Cardiopulmonary Bypass-Pilot Study.

OBJECTIVES: Hypothermia on intensive care unit (ICU) admission after cardiac surgery and cardiopulmonary bypass is common. It contributes to postoperative complications including shivering, coagulopathy, increased blood loss and transfusion requirements, morbid cardiac events, metabolic acidosis, increased wound infections, and prolonged hospital length of stay. The current standard of care for rewarming ICU patients is forced air warming blankets. However, high-quality evidence on additional benefit rendered by other warming methods, such as heated humidified breathing circuits (HHBC), is lacking. Therefore, the authors conducted a pilot study to examine whether the addition of HHBC to standard forced air warming blankets in hypothermic patients (≤35°C) admitted to the ICU after cardiac surgery using cardiopulmonary bypass reduced time to normothermia. DESIGN: Prospective study conducted at a single large academic medical center. PARTICIPANTS: The study group was composed of 14 patients who were enrolled prospectively between April 1 and June 14, 2019. The study group was compared with a 2:1 matched retrospective control group. The matched group consisted of 28 patients from a 12-month period from July 1, 2018 June 30, 2019. INTERVENTIONS: Study patients received warming via forced air warming blankets and HHBC and were compared with patients in a control group who received only warming blankets. Time to normothermia, time to extubation, time to normal pH, blood loss, blood transfusions, and coagulation profile laboratory values were compared between the study and control groups. MEASUREMENTS AND MAIN RESULTS: The present study found no statistical difference in time to normothermia, for which the standard-of-care retrospective group achieved normothermia after a median (Q1-Q3) 4.8 (4.0-6.0) hours compared with 4.4 (3.5-5.5) hours in the prospective group receiving HHBC. All secondary outcomes, including time to extubation, time to normal pH, ICU blood product transfusion, chest tube output, and coagulation profile, were similar. CONCLUSIONS: The present pilot study detected a similar time to normothermia, extubation, and normal pH when HHBC were added to standard forced air warming blankets in hypothermic patients (≤35°C) admitted to the ICU after cardiac surgery using cardiopulmonary bypass. A future larger prospective study designed to detect smaller, but clinically meaningful, reductions in the time to key clinical events for patients treated with HHBC is feasible and warranted.

Impacto de uma intervenção educativa no manejo da hipotermia terapêutica neonatal: estudo quase experimental / Impact of an educational intervention in the management of neonatal therapeutic hypothermia: a quasi-experimental study

Introdução: A hipotermia terapêutica é o tratamento indicado para encefalopatia moderada a grave em recém-nascidos. A terapia requer uma equipe de enfermagem capacitada e integrada, visando um cuidado qualificado, efetivo e seguro. Modelos teóricos têm sido desenvolvidos para auxiliar a incorporação de evidências científicas à prática dos enfermeiros, representando um desafio na área da saúde. A implementação de uma intervenção educativa, guiada pela estrutura i-PARIHS (Estrutura Integrada de Promoção da Ação na Implementação de Pesquisa em Serviços de Saúde), poderá preencher a lacuna entre a teoria e a prática, beneficiando a assistência e tornando os sujeitos ativos no manejo do recém-nascido em hipotermia terapêutica. Objetivo geral: avaliar o impacto de uma intervenção educativa, guiada pelo referencial teórico i-PARIHS, sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal no conhecimento, atitudes e práticas de enfermeiros. Objetivos específicos: analisar o conhecimento, atitude e prática dos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica pré e pós-intervenção educativa; identificar as barreiras e facilitadores percebidos pelos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal; implementar uma intervenção educativa, guiada pelo referencial i-PARIHS, para melhorar o conhecimento, a atitude e a prática dos enfermeiros sobre o manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal; comparar o conhecimento, atitude e prática dos enfermeiros após a intervenção educativa e os indicadores quanto ao manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica. Método: trata-se de um estudo de intervenção, do tipo quase-experimental, realizado com 29 enfermeiros de uma unidade intensiva neonatal, referência no Rio de Janeiro. O desfecho principal: conhecimento, atitudes e práticas dos enfermeiros no manejo do recém-nascido com asfixia perinatal em hipotermia terapêutica na unidade intensiva neonatal A intervenção compreendeu três fases: pré-intervenção - intervenção educativa- pós-intervenção. A intervenção educativa contou com cinco encontros: "Asfixia Perinatal x Hipotermia Terapêutica", "Controle da temperatura", "Cuidados de enfermagem na HT: avaliação de dor", "Monitoramento neurológico" e "Cuidado Centrado na Família". Para a análise estatística utilizou-se de análise descritiva e aplicação dos testes Wilcoxon-Mann-Whitney e Mc Nemar, sendo o nível de significância adotado de 0,05. Resultados: a análise dos resultados do pré e pós-teste demonstrou um incremento no escore de acertos das questões sobre conhecimento, atitude e prática dos enfermeiros no manejo do recém-nascido submetido à hipotermia terapêutica na unidade intensiva neonatal, apresentando significância estatística para a maioria dos itens. Para a inovação foram construídos lembretes, fluxo de admissão para recém-nascido da instituição e uma cartilha para os pais como produto da intervenção com os enfermeiros. Conclusão: O resultado das auditorias realizadas, após a implementação das evidências, constatou uma transformação positiva da prática dos enfermeiros. A utilização da estrutura i-PARIHS evidenciou a necessidade e o valor de investir no engajamento das partes interessadas, na avaliação colaborativa do contexto e na cocriação de inovação usando facilitação qualificada. A intervenção educativa, guiada pela estrutura i-PARIHS, mostrou ter impacto no manejo do recém-nascido submetido à hipotermia terapêutica por enfermeiros.

Introduction: Therapeutic hypothermia is the currently indicated treatment for moderate to severe encephalopathy in newborns. Therapy requires a trained and integrated nursing team, aiming at qualified, effective and safe care. Theoretical models have been developed to help the incorporation of scientific evidence into nurses' practice, representing a challenge in the health area. The implementation of an educational intervention, guided by the i-PARIHS (Integrated Promoting Action on Research Implementation in Health Services Framework) framework, can fill the gap between theory and professional practice, benefiting care and making subjects active in the management of newborns with therapeutic hypothermia. General objective: to evaluate the impact of an educational intervention guided by the theoretical framework i-PARIHS, on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit on the knowledge, attitudes and practices of nurses. Specific objectives: to analyze the knowledge, attitude and practice of nurses on the management of newborns with perinatal asphyxia in pre- and post-educational therapeutic hypothermia; to identify barriers and facilitators perceived by nurses on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit; implement an educational intervention, guided by the i-PARIHS framework, to improve nurses' knowledge, attitude and practice on the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive care unit and compare the knowledge, attitude and practice of nurses after the participatory educational intervention program and indicators regarding the management of newborns with perinatal asphyxia in therapeutic hypothermia. Method: this is a quasi-experimental intervention study carried out with 29 nurses from a neonatal intensive care unit, a reference in Rio de Janeiro. The main outcome: knowledge, attitudes and practices of nurses in the management of newborns with perinatal asphyxia in therapeutic hypothermia in the neonatal intensive unit The intervention comprised three phases: pre-intervention - educational intervention - post-intervention. The educational intervention had five meetings: "Perinatal Asphyxia x Therapeutic Hypothermia", "Temperature control", "Nursing care in HT: pain assessment", "Neurological monitoring" and "Family-Centered Care". For the statistical analysis, descriptive analysis and application of the Wilcoxon-Mann-Whitney and Mc Nemar tests were used, with the adopted significance level of 0.05. Results: the analysis of pre- and post-test results showed an increase in the correct score of questions about nurses' knowledge and practices in the management of newborns submitted to therapeutic hypothermia in the neonatal intensive care unit, showing statistical significance for most items. For innovation, reminders, admission flow for newborns at the institution and a booklet for parents were created as a product of the intervention with nurses. Conclusion: The result of the audits carried out, after the implementation of the evidence, found a positive transformation of the nurses' practice. Using the i-PARIHS framework highlighted the need and value of investing in stakeholder engagement, collaborative context assessment, and co-creation of innovation using qualified facilitation. The educational intervention guided by the i-PARIHS framework was shown to have an impact on the management of newborns with perinatal asphyxia in therapeutic hypothermia by nurses.

Malignant Hyperthermia During Cardiac Surgery Successfully Treated by Deep Hypothermia Using Cardiopulmonary Bypass: A Case Report.

Malignant hyperthermia (MH) is a life-threatening hypermetabolic disorder triggered by volatile anesthetics and/or succinylcholine. We report a case of a 58-year-old patient with a type-A aortic dissection. After induction of general anesthesia, a hypermetabolic reaction was successfully treated by deep hypothermia using cardiopulmonary bypass. Dantrolene became available in theater after the hypermetabolism was already treated successfully by hypothermia. Because of a low suspicion of MH, dantrolene was not administered when it became available. The patient fully recovered, and MH susceptibility was confirmed. Cardiopulmonary bypass should be considered to treat MH in case dantrolene and conservative therapy are unavailable or insufficient.

The efficiency of continuous renal replacement therapy for rewarming of patients in accidental hypothermia--An experimental study.

Severe accidental hypothermia carries high mortality and morbidity and is often treated with invasive extracorporeal methods. Continuous veno-venous hemodiafiltration (CVVHDF) is widely available in intensive care units. We sought to provide theoretical basis for CVVHDF use in rewarming of hypothermic patients. CVVHDF system was used in the laboratory setting. Heat balance and transferred heat units were evaluated for the system without using blood. We used 5L of crystalloid solution at the temperature of approximately 25°C, placed in a thermally insulated tank (representing the "central compartment" of a hypothermic patient). Time of warming the central compartment from 24.9 to 30.0°C was assessed with different flow combinations: "blood" (central compartment fluid) 50 or 100 or 150 mL/min, dialysate solution 100 or 1500 mL/h, and substitution fluid 0 or 500 mL/h. The total circulation time was 1535 minutes. There were no differences between heat gain values on the filter depending on blood flow (P = .53) or dialysate flow (P = .2). The mean heating time for "blood" flow rates 50, 100, and 150 mL/min was 113.7 minutes (95% CI, 104.9-122.6 minutes), 83.3 minutes (95% CI, 76.2-90.3 minutes), and 74.7 minutes (95% CI, 62.6-86.9 minutes), respectively (P < .01). The respective median rewarming rate for different "blood" flows was 3.6°C/h (IQR, 3.0-4.2°C/h), 4.8 (IQR, 4.2-5.4°C/h), and 5.4 (IQR, 4.8-6.0°C/h), respectively (P < .01). The dialysate flow did not affect the warming rate. Based on our experimental model, CVVHDF may be used for extracorporeal rewarming, with the rewarming rates increasing achieved with higher blood flow rates.

Fetal heart rate mirrors maternal temperature during posterior fossa craniotomy: a case report.

While it is well known that maternal temperature affects fetal heart rate, the exact relationship is not well described. The circumstances accompanying most cases of maternal hypothermia and rewarming (e.g. a drowning event) have precluded a precise quantitative description of this relationship. We describe hypothermia and controlled rewarming during resection of a maternal brain stem tumor in the early third trimester. Continuous electronic fetal heart rate and core temperature monitoring demonstrated a near linear relationship during the development of hypothermia and rewarming. Recognition of the close relationship between maternal temperature and fetal heart rate can help safeguard maternal and fetal health, and prevent unnecessary delivery during non-obstetric surgery in pregnancy.

Impact of rescue collapse on mortality rate in severe accidental hypothermia: A matched-pair analysis.

AIM: To assess the impact of the occurrence of cardiac arrest associated with initial management on the outcome of severely hypothermic patients who were rewarmed with Extracorporeal Life Support (ECLS). METHODS: We collected the individual data of patients in a state of severe accidental hypothermia who were found with spontaneous circulation and rewarmed with ECLS, from cardiac surgery departments. Patients were divided into two groups: those with a subsequent cardiac arrest (RC group); and those with the retained circulation (HT3 group), and compared by using a matched-pair analysis. The mortality rates and the neurological status in survivors were compared as the main outcomes. The difference in the risk of death between the HT3 and RC groups was calculated. RESULTS: A total of 124 patients were included into the study: 45 in the HT3 group and 79 in the RC group. The matched cohorts consisted of 45 HT3 patients and 45 RC patients. The mortality rate in both groups was 24% and 49% (p = 0.02) respectively; the relative risk of death was 2.0 (p = 0.02). ICU length of stay was significantly longer in the RC group (p < 0.001). Factors associated with survival in the HT3 group included patient age, rewarming rate, and blood BE; while in the RC group, patient age and lactate concentration. CONCLUSIONS: The occurrence of rescue collapse is linked to a doubling of the risk of death in severely hypothermic patients. Procedures which are known as potential triggers of rescue collapse should be performed with special attention, including in conscious patients.

Unrecognized platelet physiology is the cause of rewarming deaths in accidental hypothermia and neonatal cold injury.

BACKGROUND: The lack of improvement in prognosis of accidental hypothermia and neonatal cold injury suggests that a major cause of mortality has not been appreciated. AIM OF THE ARTICLE: To show that thrombocytopenia that deepens on rewarming under certain conditions is that missing factor. SCIENTIFIC BASIS: Below 34 °C the first stage of aggregation is accentuated, the platelets are more sensitive to ADP and aggregation studies show an increased response "first stage hyper aggregation". We have confirmed that the irreversible second stage of platelet aggregation does not occur below 34 °C. On rewarming, the first stage of aggregation is followed by disaggregation. When platelets are warmed to 34 °C the potential exists for the platelets to undergo an irreversible second stage of aggregation "second stage platelet hyper aggregation" that can cause a further drop in platelet count and a bleeding diathesis. This only occurs if the platelets have been sufficiently primed when cold and may not be appreciated if platelet counts are not followed. SIGNIFICANCE OF THIS DATA AND CORRELATION WITH THE LITERATURE: This thesis explains many other open questions. Why has the overall prognosis remained without improvement over the last half century? Why hypothermic cardiac surgery is free of this problem? Why the depth of hypothermia is alone not prognostic? Has following platelet counts been associated with improved prognosis? Why cardiac arrest does not affect prognosis? Why some patients die suddenly after recovering from hypothermia? Why are so many different rewarming techniques used? Why is the prognosis better in hypothermic suicide attempts? What is the pathophysiological explanation for reversible sequestration of platelets to the liver and spleen in hypothermia? Is DIC (diffuse intravascular coagulation) a problem in hypothermia? And how this new approach could improve prognosis? CONCLUSION: Prognosis can be improved by following platelet counts during rewarming. In patients with prolonged hypothermia, this will show a life-threatening drop in such counts easily treated by platelet infusion.

Cardiac arrest caused by accidental severe hypothermia and myocardial infarction during general anesthesia.

Therapeutic hypothermia is often used for traumatic brain injury because of its neuroprotective effect and decreased secondary brain injury. However, this procedure lacks clinical evidence supporting its efficacy, and adverse outcomes have been reported during general anesthesia. A 61-year-old man with a history of percutaneous coronary intervention (PCI) was admitted with traumatic brain injury. Immediately after admission, he underwent mild therapeutic hypothermia with a target temperature of 33.0°C for neuroprotection. During general anesthesia for emergency surgery because he developed a mass effect, hypothermic cardiac arrest occurred following an additional decrease in the core body temperature. Moreover, myocardial infarction caused by restenosis of the previous PCI lesion also contributed to the cardiac arrest. Although the patient recovered spontaneous circulation after an hour-long cardiopulmonary resuscitation with rewarming, he eventually died of subsequent repetitive cardiac arrests. When anesthetizing patients undergoing therapeutic hypothermia, caution is required to prevent adverse outcomes that can be caused by unintentional severe hypothermia and exacerbation of underlying heart disease.