Hypothermia is defined as a significant drop in core body temperature below 35°C (95°F). It is traditionally staged as mild, moderate, severe, and profound at temperatures of 35°C to 32°C (95°F to 89.6°F), 32°C to 28°C (89.6°F to 82.4°F), <28°C (<82.4°F), and <24°C (75.2°F), respectively. It can also be classified into the same stages by clinical presentations. We present a patient that fits into two different stages based on core body temperature and clinical presentation.  A 58-year-old homeless male with a history of seizures and alcohol use presented via emergency medical services after spending the night outside and uncovered with a core body temperature of 25.1°C (77.1°F) via a urinary bladder thermometer, meeting criteria for severe, near profound, hypothermia. However, he was alert and communicating, shivering, with tachycardia, tachypnea, normal oxygen saturation, and elevated blood pressure, suggestive of mild hypothermia clinically. Passive and active external and internal rewarming were utilized to treat, with the removal of wet clothing, forced air patient warming system, warm blankets, and warm lactated ringers given intravenously. He was soon transferred to the intensive care unit and first returned to normothermic levels after approximately 10 hours from presentation. An electrocardiogram was obtained after resolution of shivering and revealed atrial fibrillation without Osborn waves. He remained in the hospital for the following week to treat his atrial fibrillation, hypothermia-induced rhabdomyolysis, and alcohol withdrawal. He was discharged without neurologic deficits and medically stable with appropriate resources.  This case demonstrates a unique presentation of severe hypothermia. To our knowledge, there has not been a reported case of severe hypothermia that does not involve severe central nervous system depression, severe slowing of vitals, and/or comatose status. These clinical symptoms normally begin during moderate hypothermic levels near 32°C (89.6°F), yet our patient presented without any central nervous system depression and with accelerated vitals that are more consistent with mild hypothermia yet had a core temperature of 25.1°C (77.1°F). Treatment was dictated by his core body temperature rather than clinical presentation. Because of this incongruence between symptoms and true severity of disease in hypothermia, we recommend diagnosis and treatment of hypothermia always be confirmed and based on core body temperature via a low-reading thermometer instead of clinical presentation alone.

Cardiorespiratory arrest due to severe hypothermia may require prolonged cardiopulmonary resuscitation whilst the patient is rewarmed. There are reported cases of successful resuscitation with good neurological outcomes after prolonged arrests and resuscitation up to 9 h. However, in the majority of these cases, extracorporeal life support was used to maintain perfusion and rewarm the patient. Here, we report a case of successful cardiopulmonary resuscitation lasting 6.5 h, following cardiac arrest secondary to severe hypothermia, with rewarming using an Arctic Sun™ 5000. The Arctic Sun 5000 is a targeted temperature management device which is conventionally used to prevent hyperthermia post-cardiac arrest. In this report, we discuss the reasons why the device was used in this case and the effects of severe hypothermia on cardiac arrest management. We believe that this is the longest reported successful cardiopulmonary resuscitation in a severely hypothermic patient without the use of extracorporeal life support.

Supraphysiologic oxygen administration causes unfavorable clinical outcomes in various diseases, including traumatic brain injury, post-cardiac arrest syndrome, and acute lung injury. Accidental hypothermia is a critical illness that reduces oxygen demands, and excessive oxygen is likely to emerge. This study aimed to determine whether hyperoxia would be associated with increased mortality in patients with accidental hypothermia.
A post-hoc analysis of a nationwide multicenter prospective observational study (ICE-CRASH study) on patients with accidental hypothermia admitted in 2019-2022 was conducted. Adult patients without cardiac arrest whose core body temperature was < 32 °C and whose arterial partial pressure of oxygen (PaO2) was measured at the emergency department were included. Hyperoxia was defined as a PaO2 level of 300 mmHg or higher, and 28-day mortality was compared between patients with and without hyperoxia before rewarming. Inverse probability weighting (IPW) analyses with propensity scores were performed to adjust patient demographics, comorbidities, etiology and severity of hypothermia, hemodynamic status and laboratories on arrival, and institution characteristics. Subgroup analyses were conducted according to age, chronic cardiopulmonary diseases, hemodynamic instability, and severity of hypothermia.
Of the 338 patients who were eligible for the study, 65 had hyperoxia before rewarming. Patients with hyperoxia had a higher 28-day mortality rate than those without (25 (39.1%) vs. 51 (19.5%); odds ratio (OR) 2.65 (95% confidence interval 1.47-4.78); p < 0.001). IPW analyses with propensity scores revealed similar results (adjusted OR 1.65 (1.14-2.38); p = 0.008). Subgroup analyses showed that hyperoxia was harmful in the elderly and those with cardiopulmonary diseases and severe hypothermia below 28 °C, whereas hyperoxia exposure had no effect on mortality in patients with hemodynamic instability on hospital arrival.
Hyperoxia with PaO2 levels of 300 mmHg or higher before initiating rewarming was associated with increased 28-day mortality in patients with accidental hypothermia. The amount of oxygen to administer to patients with accidental hypothermia should be carefully determined.
The ICE-CRASH study was registered at the University Hospital Medical Information Network Clinical Trial Registry on April 1, 2019 (UMIN-CTR ID, UMIN000036132).

Background: Severe accidental hypothermia (AH) accounts for over 1300 deaths/year in the United States. Early extracorporeal life support (ECLS) is recommended for hypothermic cardiac arrest. We describe the use of a rapid-deployment extracorporeal cardiopulmonary resuscitation (E-CPR) team using intensivist physicians (IPs) as cannulators and report the outcomes of consecutive patients cannulated for ECLS to manage cardiac arrest due to AH. Methods: We reviewed all patients managed with veno-arterial (V-A) ECLS for hypothermic cardiac arrest between January 1, 2017 and November 1, 2021. For each patient- age, sex, cause of hypothermia, initial core temperature, initial rhythm, time from arrest to cannulation, cannula configuration, pH, lactate, potassium, cannulation complications, duration of ECLS, hospital length of stay, mortality, and cerebral performance category (CPC) at discharge were reviewed. Results: Nine consecutive patients were identified that underwent V-A ECLS for cardiac arrest due to AH. Seven (78%) were witnessed arrests. Initial rhythm was ventricular fibrillation (VF) in eight patients and pulseless electrical activity (PEA) in one. The mean initial core temperature was 23.8 degrees Celsius. The mean time from arrest to cannulation was 58 min (range 17 to 251 min). There were no complications related to cannulation. The mean duration of ECLS was 39.1 h. All nine patients were discharged alive with a Cerebral Performance score of one or two. Conclusion: In this case series of consecutive patients reporting intensivist-deployed E-CPR for cardiac arrest due to AH, all patients survived to discharge with a favorable neurologic outcome. A rapidly available E-CPR team utilizing intensivist cannulators may improve outcomes in patients with cardiac arrest due to AH.

Data on management of severe accidental hypothermia published from an established high-volume extracorporeal membrane oxygenation centre are scarce.
A total of 28 patients with intravesical temperature lower than 28°C on admission were either treated with veno-arterial extracorporeal membrane oxygenation or rewarmed conservatively.
A total of 10 patients rewarmed on veno-arterial extracorporeal membrane oxygenation (age: 37 ± 12.6 years) and 18 conservatively (age: 55.2 ± 11.2 years) were collected over a course of 5 years. The dominant cause was alcohol intoxication with exposure to cold (39%), 12 patients were resuscitated prior to admission. The admission temperature in the extracorporeal membrane oxygenation group (23.8 ± 2.6°C) was lower than in the non-extracorporeal membrane oxygenation group (26.0 ± 1.5°C, p = 0.01). The peripheral percutaneous veno-arterial extracorporeal membrane oxygenation was always cannulated in malignant arrhythmias causing refractory cardiac arrest. The typical extracorporeal membrane oxygenation blood flow was 3-4 L/minute and sweep gas flow 2 L/minute, the median extracorporeal membrane oxygenation duration was 48.3 (28.1-86.7) hours. The median rates of rewarming did not differ (0.41 (0.35-0.7)°C/hour in extracorporeal membrane oxygenation and 0.77 (0.54-0.98)°C/hour in non-extracorporeal membrane oxygenation, p = 0.46) as well as the admission arterial lactate, pH and potassium. Their development was not different between the groups except for higher pH between the third and ninth hour of rewarming in the extracorporeal membrane oxygenation group. The hospital mortality was 10% in the extracorporeal membrane oxygenation group and 11.1% in the non-extracorporeal membrane oxygenation group with the median last Glasgow Coma Scale 15 and Cerebral Performance Score 1.
Veno-arterial extracorporeal membrane oxygenation for severe hypothermia shows promising outcome data collected in an extracorporeal membrane oxygenation/extracorporeal cardiopulmonary resuscitation centre located in a European urban area. Except for presence of refractory cardiac arrest, the established hypothermia-related prognostic indicators did not differ between patients in need for extracorporeal membrane oxygenation and those rewarmed without extracorporeal membrane oxygenation.

A 64-year-old female was found lying by a river. She was unconscious and her lower body was under water. The patient was transported to the emergency room of our hospital. On arrival, her rectal temperature was 24.6°C. We immediately started rewarming and artificial respiration. Five days after admission, rewarming was completed and she became conscious and could communicate. Initially, she had been injured and examination showed paraplegia. Magnetic resonance imaging of her cervical spine showed no findings indicating bony or ligament injury, but there was a T2 high intensity area at C5/6 and C6/7 levels. The patient was diagnosed with spinal cord injury without radiological abnormality.
At 5 months post-injury, the patient was able to walk without crutches.
Spinal cord injury might be missed if there are no radiographic abnormalities. Spinal cord injury without radiological abnormality should be considered as a differential diagnosis of accidental hypothermia.

Sixty pullets, aged 17 weeks, were presented when presumed to be \'dead\' after being exposed to wet-cold weather transportation. The birds appeared unconscious and their feathers were soaking wet, and with a body rigid and cold to touch. The aim of the study was to resuscitate the hypothermic pullets. Blood samples were obtained and core body temperature recorded before and after rewarming. The birds were resuscitated using active external rewarming technique. Blood samples revealed significant (P < 0.05) decreases in the concentrations of serum electrolytes of Na, Cl, K, Ca and P; and renal function and activities of the serum enzymes of AST, ALT, ALP and CRT decreased compared to baseline reference normal values. Colonic temperature, recorded through the cloacae, revealed a temperature of 29 ± 0.4°C. The presumptive diagnosis was severe hypothermia. Treatment of the pullets using active external rewarming technique for 7 to 10 h resulted in successful restoration of all the behavioural, biochemical and colonic temperature responses to normal values. The treatment resulted in a complete recovery of all the birds with no signs of illness at 4-week follow-up. To the best of our knowledge, this study is one of the first reports to evaluate the behavioural and biochemical responses of pullets accidentally exposed to severe hypothermia, and successful treatment of the birds using active external rewarming technique.

BACKGROUND: Severe accidental hypothermia is defined as a core temperature below 28 Celsius degrees. Within the last years, the issue of accidental hypothermia and accompanying cardiac arrest has been broadly discussed and European Resuscitation Council (ERC) Guidelines underline the importance of Extracorporeal Rewarming (ECR) in treatment of severely hypothermic victims. The study aimed to evaluate the actual costs of ECR with VA-ECMO and of further management in the Intensive Care Unit of patients admitted to the Severe Accidental Hypothermia Centre in Cracow, Poland.
METHODS: We carried out the economic analysis of 31 hypothermic adults in stage III-IV (Swiss Staging) treated with VA ECMO. Twenty-nine individuals were further managed in the Intensive Care Unit. The actual treatment costs were evaluated based on current medication, equipment, and dressing pricing. The costs incurred by the John Paul II Hospital were then collated with the National Health Service (NHS) funding, assessed based on current financial contract.
RESULTS: In most of the cases, the actual treatment cost was greater than the funding received by around 10000 PLN per patient. The positive financial balance was achieved in only 4 (14%) individuals; other 25 cases (86%) showed a financial loss.
CONCLUSIONS: Performed analysis clearly shows that hospitals undertaking ECR may experience financial loss due to implementation of effective treatment recommended by international guidelines. Thanks to new NHS funding policy since January 2017 such loss can be avoided, what shall encourage hospitals to perform this expensive, yet effective method of treatment.

We report a case of a 64-year-old caucasian male who was transported to the emergency department (ED) after being found unconscious on the side of the road. On arrival to the ED the patient went into ventricular fibrillation and advanced cardiac life support was started at that time. Thirty minutes into the resuscitation, after multiple rounds of code drugs and defibrillation attempts, the patient was found to be severely hypothermic with a rectal temperature of 24.9°C (76.9°F). Through the use of passive and active re-warming measures the patient\'s temperature increased enough to allow successful cardioversion and stabilization. Within minutes of cardiac stabilization the patient regained consciousness and was able to follow commands, but was found to be paralyzed from the neck down. Subsequent CT scans revealed no acute fractures, subluxations or acute spinal cord injury. This case represents the rare finding of severe hypothermia secondary to occult spinal cord injury. Case report was taken from case at Bayfront Hospital, St. Petersburg, Florida.