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Falat C. Environmental Hypothermia. Emerg Med Clin North Am 2024; 42:493-511. [PMID: 38925770 DOI: 10.1016/j.emc.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/28/2024]
Abstract
Although a rare diagnosis in the Emergency Department, hypothermia affects patients in all environments, from urban to mountainous settings. Classic signs of death cannot be interpreted in the hypothermic patient, thus resulting in the mantra, "No one is dead until they're warm and dead." This comprehensive review of environmental hypothermia covers the clinical significance and pathophysiology of hypothermia, pearls and pitfalls in the prehospital management of hypothermia (including temperature measurement techniques and advanced cardiac life support deviations), necessary Emergency Department diagnostics, available rewarming modalities including extracorporeal life support, and criteria for termination of resuscitation.
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Affiliation(s)
- Cheyenne Falat
- Department of Emergency Medicine, University of Maryland School of Medicine, 110 South Paca Street, 6th Floor, Suite 200, Baltimore, MD 21201, USA.
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2
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Junaid M, Mahmud-Or-Rashid M. Computational insights into survival durations and prehospital interventions in accidental cold-water immersion: A comprehensive analysis of fresh and saltwater temperatures. Heliyon 2024; 10:e33022. [PMID: 38988563 PMCID: PMC11234009 DOI: 10.1016/j.heliyon.2024.e33022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 07/12/2024] Open
Abstract
This study examines the complex relationship between scenarios of cold-water immersion, survival durations, and prehospital interventions. It utilizes computational modeling methods to shed light on how different water temperatures affect individuals facing accidental cold-water immersion incidents. The analysis reveals significant variations in survival times based on water temperature. For example, subjects immersed in water at temperatures of 5 °C, 2 °C, and 0 °C had average survival times of 136, 113, and 100 min, respectively, under stable conditions. In flowing water at the same temperatures, survival times decreased to 119, 92, and 81 min, indicating the impact of water movement on cooling rates and survival durations. Likewise, individuals immersed in saltwater at temperatures of 5 °C, 2 °C, 0 °C, and -2 °C showed average survival times of 111, 88, 80, and 66 min, respectively, in static conditions. In flowing saltwater at the same temperatures, survival times decreased to 98, 74, 68, and 57 min, highlighting the influence of water flow on cooling rates and survival durations. A comparison between immersion in pure water and saltwater at 2 °C revealed survival times of 113 and 88 min under stable conditions and 92 and 74 min under dynamic conditions, emphasizing the role of water composition in survival outcomes. The study also challenges the notion that the demise of the Titanic's passengers and crew resulted from hypothermia, asserting instead that severe thermal shock was the primary cause. These numerical findings underscore the importance of considering water temperature, flow dynamics, and prompt medical responses in cold-water emergencies to enhance survival prospects. The study identifies water within the range of 41-43 °C as the most effective active external rewarming fluid for critical hypothermal conditions. By quantifying the impact of these variables on survival times, the study provides data-driven recommendations to improve emergency protocols and outcomes for individuals facing cold-water immersion incidents.
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Affiliation(s)
- Mohammad Junaid
- Department of Mechanical Engineering, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
| | - Md Mahmud-Or-Rashid
- Department of Mechanical Engineering, Shahjalal University of Science and Technology, Sylhet, 3114, Bangladesh
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3
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Kalisz S, Stoll T, Bouazza FZ, Claus M, Malinverni S. Extracorporeal Life Support for Recurrent Hypothermic Cardiac Arrest: A Case Report. Cureus 2023; 15:e49684. [PMID: 38161851 PMCID: PMC10756991 DOI: 10.7759/cureus.49684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/29/2023] [Indexed: 01/03/2024] Open
Abstract
Hypothermia-associated cardiac arrest (HACA) is a challenge for emergency physicians. Standard cardiopulmonary resuscitation (CPR) remains the primary intervention for the treatment of HACA, but extracorporeal life support (ECLS) may be needed as an adjunct to CPR. In this report, we present the case of an adult Asian patient who experienced two episodes of HACA at a two-year interval. In both episodes, the patient was treated with ECLS in addition to standard CPR. We discuss the fundamentals of HACA and how to safely and effectively incorporate ECLS into its management. No-flow time, age, comorbidities, and the cause of the cardiac arrest are criteria to consider when deciding on the duration of CPR and the intensity of the resources deployed. Hypothermia is a reversible cause of cardiac arrest, justifying prolonged CPR. According to the Hypothermia Outcome Prediction after ECLS (HOPE) score, active rewarming through ECLS is recommended. However, a history of cardiac arrest is rare and might be considered a severe comorbidity contraindicating ECLS use. Nevertheless, the indication is determined on a case-by-case basis.
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Affiliation(s)
- Simon Kalisz
- Emergency Department, CHU Saint-Pierre, Brussels, BEL
| | | | | | - Marc Claus
- Intensive Care Unit, CHU Saint-Pierre, Brussels, BEL
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Nedelea PL, Manolescu E, Ciumanghel AI, Constantin M, Hauta A, Sirbu O, Ionescu L, Blaj M, Corlade-Andrei M, Sorodoc V, Cimpoesu D. The Beginning of an ECLS Center: First Successful ECPR in an Emergency Department in Romania-Case-Based Review. J Clin Med 2023; 12:4922. [PMID: 37568324 PMCID: PMC10419366 DOI: 10.3390/jcm12154922] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 07/01/2023] [Accepted: 07/20/2023] [Indexed: 08/13/2023] Open
Abstract
According to the latest international resuscitation guidelines, extracorporeal cardiopulmonary resuscitation (ECPR) involves the utilization of extracorporeal membrane oxygenation (ECMO) in specific patients experiencing cardiac arrest, and it can be considered in situations where standard cardiopulmonary resuscitation efforts fail if they have a potentially reversible underlying cause, among which we can also find hypothermia. In cases of cardiac arrest, both witnessed and unwitnessed, hypothermic patients have higher chances of survival and favorable neurological outcomes compared to normothermic patients. ECPR is a multifaceted procedure that requires a proficient team, specialized equipment, and comprehensive multidisciplinary support within a healthcare system. However, it also carries the risk of severe, life-threatening complications. With the increasing use of ECPR in recent years and the growing number of centers implementing this technique outside the intensive care units, significant uncertainties persist in both prehospital and emergency department (ED) settings. Proper organization is crucial for an ECPR program in emergency settings, especially given the challenges and complexities of these treatments, which were previously not commonly used in ED. Therefore, within a narrative review, we have incorporated the initial case of ECPR in an ED in Romania, featuring a successful resuscitation in the context of severe hypothermia (20 °C) and a favorable neurological outcome (CPC score of 1).
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Affiliation(s)
- Paul Lucian Nedelea
- Department of Emergency Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Emergency Department, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
| | - Emilian Manolescu
- Department of Emergency Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Emergency Department, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
| | - Adi-Ionut Ciumanghel
- Department of Emergency Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Anesthesia Intensive Care Unit, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
| | - Mihai Constantin
- 2nd Internal Medicine Clinic, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Alexandra Hauta
- Department of Emergency Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Oana Sirbu
- 2nd Internal Medicine Clinic, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Lidia Ionescu
- 3rd Surgery Clinic, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
| | - Mihaela Blaj
- Anesthesia Intensive Care Unit, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
| | | | - Victorita Sorodoc
- 2nd Internal Medicine Clinic, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
- Internal Medicine Department, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
| | - Diana Cimpoesu
- Department of Emergency Medicine, “Grigore T. Popa” University of Medicine and Pharmacy, 700115 Iasi, Romania
- Emergency Department, “St. Spiridon” Emergency Clinical County Hospital, 700111 Iasi, Romania
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5
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Bjertnæs LJ, Næsheim TO, Reierth E, Suborov EV, Kirov MY, Lebedinskii KM, Tveita T. Physiological Changes in Subjects Exposed to Accidental Hypothermia: An Update. Front Med (Lausanne) 2022; 9:824395. [PMID: 35280892 PMCID: PMC8904885 DOI: 10.3389/fmed.2022.824395] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/28/2022] [Indexed: 12/01/2022] Open
Abstract
Background Accidental hypothermia (AH) is an unintended decrease in body core temperature (BCT) to below 35°C. We present an update on physiological/pathophysiological changes associated with AH and rewarming from hypothermic cardiac arrest (HCA). Temperature Regulation and Metabolism Triggered by falling skin temperature, Thyrotropin-Releasing Hormone (TRH) from hypothalamus induces release of Thyroid-Stimulating Hormone (TSH) and Prolactin from pituitary gland anterior lobe that stimulate thyroid generation of triiodothyronine and thyroxine (T4). The latter act together with noradrenaline to induce heat production by binding to adrenergic β3-receptors in fat cells. Exposed to cold, noradrenaline prompts degradation of triglycerides from brown adipose tissue (BAT) into free fatty acids that uncouple metabolism to heat production, rather than generating adenosine triphosphate. If BAT is lacking, AH occurs more readily. Cardiac Output Assuming a 7% drop in metabolism per °C, a BCT decrease of 10°C can reduce metabolism by 70% paralleled by a corresponding decline in CO. Consequently, it is possible to maintain adequate oxygen delivery provided correctly performed cardiopulmonary resuscitation (CPR), which might result in approximately 30% of CO generated at normal BCT. Liver and Coagulation AH promotes coagulation disturbances following trauma and acidosis by reducing coagulation and platelet functions. Mean prothrombin and partial thromboplastin times might increase by 40–60% in moderate hypothermia. Rewarming might release tissue factor from damaged tissues, that triggers disseminated intravascular coagulation. Hypothermia might inhibit platelet aggregation and coagulation. Kidneys Renal blood flow decreases due to vasoconstriction of afferent arterioles, electrolyte and fluid disturbances and increasing blood viscosity. Severely deranged renal function occurs particularly in the presence of rhabdomyolysis induced by severe AH combined with trauma. Conclusion Metabolism drops 7% per °C fall in BCT, reducing CO correspondingly. Therefore, it is possible to maintain adequate oxygen delivery after 10°C drop in BCT provided correctly performed CPR. Hypothermia may facilitate rhabdomyolysis in traumatized patients. Victims suspected of HCA should be rewarmed before being pronounced dead. Rewarming avalanche victims of HCA with serum potassium > 12 mmol/L and a burial time >30 min with no air pocket, most probably be futile.
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Affiliation(s)
- Lars J Bjertnæs
- Department of Clinical Medicine, Faculty of Health Sciences, Anesthesia and Critical Care Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Torvind O Næsheim
- Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway.,Department of Clinical Medicine, Faculty of Health Sciences, Cardiovascular Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway
| | - Eirik Reierth
- Science and Health Library, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway
| | - Evgeny V Suborov
- The Nikiforov Russian Center of Emergency and Radiation Medicine, St. Petersburg, Russia
| | - Mikhail Y Kirov
- Department of Anesthesiology and Intensive Care, Northern State Medical University, Arkhangelsk, Russia
| | - Konstantin M Lebedinskii
- Department of Anesthesiology and Intensive Care, North-Western State Medical University named after I.I. Mechnikov, St. Petersburg, Russia.,Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology, Moscow, Russia
| | - Torkjel Tveita
- Department of Clinical Medicine, Faculty of Health Sciences, Anesthesia and Critical Care Research Group, University of Tromsø, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
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6
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ECMO Predictors of Mortality: A 10-Year Referral Centre Experience. J Clin Med 2022; 11:jcm11051224. [PMID: 35268314 PMCID: PMC8911127 DOI: 10.3390/jcm11051224] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 02/20/2022] [Accepted: 02/23/2022] [Indexed: 02/06/2023] Open
Abstract
Background: Extracorporeal membrane oxygenation (ECMO) is a specialised life support modality for patients with refractory cardiac or respiratory failure. Multiple studies strived to evaluate the benefits of ECMO support, but its efficacy remains controversial with still inconsistent and sparse information. Methods: This retrospective analysis included patients with ECMO support, admitted between January 2010 and December 2019 at a tertiary university ECMO referral centre in Austria. The primary endpoint of the study was overall all-cause three-month mortality with risk factors and predictors of mortality. Secondary endpoints covered the analysis of demographic and clinical characteristics of patients needing ECMO, including incidence and type of adverse events during support. Results: In total, 358 patients fulfilled inclusion criteria and received ECMO support due to cardiogenic shock (258, 72%), respiratory failure (88, 25%) or hypothermia (12, 3%). In total, 41% (145) of patients died within the first three months, with the median time to death of 9 (1−87) days. The multivariate analysis identified hypothermia (HR 3.8, p < 0.001), the Simplified Acute Physiology Score III (HR 1.0, p < 0.001), ECMO initiation on weekends (HR 1.6, p = 0.016) and haemorrhage during ECMO support (HR 1.7, p = 0.001) as factors with higher risk for mortality. Finally, the most frequent adverse event was haemorrhage (160, 45%) followed by thrombosis. Conclusions: ECMO is an invasive advanced support system with a high risk of complications. Nevertheless, well-selected patients can be successfully rescued from life-threatening conditions by prolonging the therapeutic window to either solve the underlying problem or install a long-term assist device. Hypothermia, disease severity, initiation on weekends and haemorrhage during ECMO support increase the risk for mortality. In the case of decision making in a setting of limited (ICU) resources, the reported risk factors for mortality may be contemplable, especially when judging a possible ECMO support termination.
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Paal P, Pasquier M, Darocha T, Lechner R, Kosinski S, Wallner B, Zafren K, Brugger H. Accidental Hypothermia: 2021 Update. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:501. [PMID: 35010760 PMCID: PMC8744717 DOI: 10.3390/ijerph19010501] [Citation(s) in RCA: 57] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 12/08/2021] [Accepted: 12/09/2021] [Indexed: 12/13/2022]
Abstract
Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousands die of primary hypothermia and an unknown number die of secondary hypothermia worldwide. Hypothermia can be expected in emergency patients in the prehospital phase. Injured and intoxicated patients cool quickly even in subtropical regions. Preventive measures are important to avoid hypothermia or cooling in ill or injured patients. Diagnosis and assessment of the risk of cardiac arrest are based on clinical signs and core temperature measurement when available. Hypothermic patients with risk factors for imminent cardiac arrest (temperature < 30 °C in young and healthy patients and <32 °C in elderly persons, or patients with multiple comorbidities), ventricular dysrhythmias, or systolic blood pressure < 90 mmHg) and hypothermic patients who are already in cardiac arrest, should be transferred directly to an extracorporeal life support (ECLS) centre. If a hypothermic patient arrests, continuous cardiopulmonary resuscitation (CPR) should be performed. In hypothermic patients, the chances of survival and good neurological outcome are higher than for normothermic patients for witnessed, unwitnessed and asystolic cardiac arrest. Mechanical CPR devices should be used for prolonged rescue, if available. In severely hypothermic patients in cardiac arrest, if continuous or mechanical CPR is not possible, intermittent CPR should be used. Rewarming can be accomplished by passive and active techniques. Most often, passive and active external techniques are used. Only in patients with refractory hypothermia or cardiac arrest are internal rewarming techniques required. ECLS rewarming should be performed with extracorporeal membrane oxygenation (ECMO). A post-resuscitation care bundle should complement treatment.
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Affiliation(s)
- Peter Paal
- Department of Anesthesiology and Intensive Care Medicine, St. John of God Hospital, Paracelsus Medical University, 5020 Salzburg, Austria
- International Commission for Mountain Emergency Medicine (ICAR MedCom), 8302 Kloten, Switzerland; (M.P.); (K.Z.); (H.B.)
| | - Mathieu Pasquier
- International Commission for Mountain Emergency Medicine (ICAR MedCom), 8302 Kloten, Switzerland; (M.P.); (K.Z.); (H.B.)
- Department of Emergency Medicine, Lausanne University Hospital, 1011 Lausanne, Switzerland
| | - Tomasz Darocha
- Department of Anesthesiology and Intensive Care, Medical University of Silesia, 40-001 Katowice, Poland;
| | - Raimund Lechner
- Department of Anesthesiology, Intensive Care Medicine, Emergency Medicine and Pain Therapy, Military Hospital, 89081 Ulm, Germany;
| | - Sylweriusz Kosinski
- Faculty of Health Sciences, Jagiellonian University Medical College, 34-500 Krakow, Poland;
| | - Bernd Wallner
- Department of Anesthesiology and Critical Care Medicine, Medical University of Innsbruck, 6020 Innsbruck, Austria;
| | - Ken Zafren
- International Commission for Mountain Emergency Medicine (ICAR MedCom), 8302 Kloten, Switzerland; (M.P.); (K.Z.); (H.B.)
- Department of Emergency Medicine, Alaska Native Medical Center, Anchorage, AK 99508, USA
- Department of Emergency Medicine, Stanford University Medical Center, Stanford University, Palo Alto, CA 94304, USA
| | - Hermann Brugger
- International Commission for Mountain Emergency Medicine (ICAR MedCom), 8302 Kloten, Switzerland; (M.P.); (K.Z.); (H.B.)
- Institute of Mountain Emergency Medicine, Eurac Research, 39100 Bolzano, Italy
- Department of Anesthesiology and Intensive Care Medicine, Medical University of Innsbruck, 6020 Innsbruck, Austria
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Nivfors JO, Mohyuddin R, Schanche T, Nilsen JH, Valkov S, Kondratiev TV, Sieck GC, Tveita T. Rewarming With Closed Thoracic Lavage Following 3-h CPR at 27°C Failed to Reestablish a Perfusing Rhythm. Front Physiol 2021; 12:741241. [PMID: 34658927 PMCID: PMC8511428 DOI: 10.3389/fphys.2021.741241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/30/2021] [Indexed: 11/20/2022] Open
Abstract
Introduction: Previously, we showed that the cardiopulmonary resuscitation (CPR) for hypothermic cardiac arrest (HCA) maintained cardiac output (CO) and mean arterial pressure (MAP) to the same reduced level during normothermia (38°C) vs. hypothermia (27°C). In addition, at 27°C, the CPR for 3-h provided global O2 delivery (DO2) to support aerobic metabolism. The present study investigated if rewarming with closed thoracic lavage induces a perfusing rhythm after 3-h continuous CPR at 27°C. Materials and Methods: Eight male pigs were anesthetized, and immersion-cooled. At 27°C, HCA was electrically induced, CPR was started and continued for a 3-h period. Thereafter, the animals were rewarmed by combining closed thoracic lavage and continued CPR. Organ blood flow was measured using microspheres. Results: After cooling with spontaneous circulation to 27°C, MAP and CO were initially reduced by 37 and 58% from baseline, respectively. By 15 min after the onset of CPR, MAP, and CO were further reduced by 58 and 77% from baseline, respectively, which remained unchanged throughout the rest of the 3-h period of CPR. During CPR at 27°C, DO2 and O2 extraction rate (VO2) fell to critically low levels, but the simultaneous small increase in lactate and a modest reduction in pH, indicated the presence of maintained aerobic metabolism. During rewarming with closed thoracic lavage, all animals displayed ventricular fibrillation, but only one animal could be electro-converted to restore a short-lived perfusing rhythm. Rewarming ended in circulatory collapse in all the animals at 38°C. Conclusion: The CPR for 3-h at 27°C managed to sustain lower levels of CO and MAP sufficient to support global DO2. Rewarming accidental hypothermia patients following prolonged CPR for HCA with closed thoracic lavage is not an alternative to rewarming by extra-corporeal life support as these patients are often in need of massive cardio-pulmonary support during as well as after rewarming.
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Affiliation(s)
- Joar O Nivfors
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Rizwan Mohyuddin
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Torstein Schanche
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| | - Jan Harald Nilsen
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway.,Department of Research and Education, Norwegian Air Ambulance Foundation, Drøbak, Norway
| | - Sergei Valkov
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Timofei V Kondratiev
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States
| | - Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT-The Arctic University of Norway, Tromsø, Norway.,Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, United States.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
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9
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Tveita T, Sieck GC. Physiological Impact of Hypothermia: The Good, the Bad and the Ugly. Physiology (Bethesda) 2021; 37:69-87. [PMID: 34632808 DOI: 10.1152/physiol.00025.2021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Hypothermia is defined as a core body temperature of < 35°C, and as body temperature is reduced the impact on physiological processes can be beneficial or detrimental. The beneficial effect of hypothermia enables circulation of cooled experimental animals to be interrupted for 1-2 h without creating harmful effects, while tolerance of circulation arrest in normothermia is between 4 and 5 min. This striking difference has attracted so many investigators, experimental as well as clinical, to this field, and this discovery was fundamental for introducing therapeutic hypothermia in modern clinical medicine in the 1950's. Together with the introduction of cardiopulmonary bypass, therapeutic hypothermia has been the cornerstone in the development of modern cardiac surgery. Therapeutic hypothermia also has an undisputed role as a protective agent in organ transplantation and as a therapeutic adjuvant for cerebral protection in neonatal encephalopathy. However, the introduction of therapeutic hypothermia for organ protection during neurosurgical procedures or as a scavenger after brain and spinal trauma has been less successful. In general, the best neuroprotection seems to be obtained by avoiding hyperthermia in injured patients. Accidental hypothermia occurs when endogenous temperature control mechanisms are incapable of maintaining core body temperature within physiologic limits and core temperature becomes dependent on ambient temperature. During hypothermia spontaneous circulation is considerably reduced and with deep and/or prolonged cooling, circulatory failure may occur, which may limit safe survival of the cooled patient. Challenges that limit safe rewarming of accidental hypothermia patients include cardiac arrhythmias, uncontrolled bleeding, and "rewarming shock".
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Affiliation(s)
- Torkjel Tveita
- Anesthesia and Critical Care Research Group, Department of Clinical Medicine, UiT The Arctic University of Norway, Tromsø, Norway.,Division of Surgical Medicine and Intensive Care, University Hospital of North Norway, Tromsø, Norway
| | - Gary C Sieck
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, Minnesota, United States
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