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International Journal of Environmental... Aug 2021Hypothermia in trauma patients is a common condition. It is aggravated by traumatic hemorrhage, which leads to hypovolemic shock. This hypovolemic shock results in a... (Review)
Review
Hypothermia in trauma patients is a common condition. It is aggravated by traumatic hemorrhage, which leads to hypovolemic shock. This hypovolemic shock results in a lethal triad of hypothermia, coagulopathy, and acidosis, leading to ongoing bleeding. Additionally, hypothermia in trauma patients can deepen through environmental exposure on the scene or during transport and medical procedures such as infusions and airway management. This vicious circle has a detrimental effect on the outcome of major trauma patients. This narrative review describes the main factors to consider in the co-existing condition of trauma and hypothermia from a prehospital and emergency medical perspective. Early prehospital recognition and staging of hypothermia are crucial to triage to proper care to improve survival. Treatment of hypothermia should start in an early stage, especially the prevention of further cooling in the prehospital setting and during the primary assessment. On the one hand, active rewarming is the treatment of choice of hypothermia-induced coagulation disorder in trauma patients; on the other hand, accidental or clinically induced hypothermia might improve outcomes by protecting against the effects of hypoperfusion and hypoxic injury in selected cases such as patients suffering from traumatic brain injury (TBI) or traumatic cardiac arrest.
Topics: Blood Coagulation Disorders; Heart Arrest; Hemorrhage; Humans; Hypothermia; Rewarming; Wounds and Injuries
PubMed: 34444466
DOI: 10.3390/ijerph18168719 -
International Journal of Environmental... Jan 2022Accidental hypothermia is an unintentional drop of core temperature below 35 °C. Annually, thousands die of primary hypothermia and an unknown number die of secondary... (Review)
Review
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.
Topics: Aged; Cardiopulmonary Resuscitation; Extracorporeal Membrane Oxygenation; Heart Arrest; Humans; Hypothermia; Rewarming
PubMed: 35010760
DOI: 10.3390/ijerph19010501 -
Medicina (Kaunas, Lithuania) 2003Hypothermia is defined as a core body temperature less than 35 degrees C (95 degrees F) and results from prolonged exposure to cold environment, drugs, and underlying... (Review)
Review
Hypothermia is defined as a core body temperature less than 35 degrees C (95 degrees F) and results from prolonged exposure to cold environment, drugs, and underlying pathologic conditions. Hypothermia is associated with marked depression of cerebral blood flow and oxygen requirement, reduced cardiac output, and decreased arterial pressure. Victims can appear to be clinically dead because of marked depression of brain and cardiovascular function, bet full resuscitation with intact neurological recovery is possible. Alcohol or drug intoxication are the dominant precipitating factors. There are about 20,000 hypothermia--related deaths a year in Britain, about 25,000--in the USA, 8,000 deaths a year in Canada. There are suggestions that the unofficial number of hypothermia--related deaths is substantially higher, particularity in the elderly. This article reviews the cause, pathogenesis, pathophysiology, clinical features, electrocardiographic manifestations of hypothermia, diagnosis, pre-hospital stabilization, hospital passive, active external, active core rewarming methods, other questions of treatment, and mortality of hypothermia. It is very important to remember, thar if a hypothermic victim is alive when rescued but dies during recovery treatment, and there is no other significant trauma or disease, this suggests that death may have resulted from either inappropriate or ineffective treatment, or no treatment at all.
Topics: Adult; Aged; Algorithms; Body Temperature; Child; Diathermy; Extracorporeal Circulation; Humans; Hypothermia; Peritoneal Lavage; Risk Factors
PubMed: 12576771
DOI: No ID Found -
Postepy Higieny I Medycyny... Jan 2015This review focuses on the physiological responses and pathophysiological changes induced by hypothermia. Normal body function depends on its ability to maintain thermal... (Review)
Review
This review focuses on the physiological responses and pathophysiological changes induced by hypothermia. Normal body function depends on its ability to maintain thermal homeostasis. The human body can be divided arbitrarily into two thermal compartments: a core compartment (trunk and head), with precisely regulated temperature around 37°C, and a peripheral compartment (skin and extremities) with less strictly controlled temperature, and lower than the core temperature. Thermoregulatory processes occur in three phases: afferent thermal sensing, central regulation, mainly by the preoptic area of the anterior hypothalamus, and efferent response. Exposure to cold induces thermoregulatory responses including cutaneous vasoconstriction, shivering and non-shivering thermogenesis, and behavioral changes. Alterations of body temperature associated with impaired thermoregulation, decreased heat production or increased heat loss can lead to hypothermia. Hypothermia is defined as a core body temperature below 35ºC, and may be classified according to the origin as accidental (e.g. caused by exposure to a cold environment, drugs, or illness) or intentional (i.e. therapeutic), or by the degree of hypothermia as mild, moderate or severe. Classification by temperature is not universal. Lowering of body temperature disrupts the physiological processes at the molecular, cellular and system level, but hypothermia induced prior to cardiosurgical or neurosurgical procedures, by the decrease in tissue oxygen demand, can reduce the risk of cerebral or cardiac ischemic damage. Therapeutic hypothermia has been recommended as a clinical procedure in situations characterized by ischemia, such as cardiac arrest, stroke and brain injuries.
Topics: Cold Temperature; Humans; Hypothermia; Shivering
PubMed: 25614675
DOI: 10.5604/17322693.1136382 -
American Journal of Physiology. Heart... Dec 2015A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been... (Review)
Review
A growing number of extreme climate events are occurring in the setting of ongoing climate change, with an increase in both the intensity and frequency. It has been shown that ambient temperature challenges have a direct and highly varied impact on cardiovascular health. With a rapidly growing amount of literature on this issue, we aim to review the recent publications regarding the impact of cold and heat on human populations with regard to cardiovascular disease (CVD) mortality/morbidity while also examining lag effects, vulnerable subgroups, and relevant mechanisms. Although the relative risk of morbidity/mortality associated with extreme temperature varied greatly across different studies, both cold and hot temperatures were associated with a positive mean excess of cardiovascular deaths or hospital admissions. Cause-specific study of CVD morbidity/mortality indicated that the sensitivity to temperature was disease-specific, with different patterns for acute and chronic ischemic heart disease. Vulnerability to temperature-related mortality was associated with some characteristics of the populations, including sex, age, location, socioeconomic condition, and comorbidities such as cardiac diseases, kidney diseases, diabetes, and hypertension. Temperature-induced damage is thought to be related to enhanced sympathetic reactivity followed by activation of the sympathetic nervous system, renin-angiotensin system, as well as dehydration and a systemic inflammatory response. Future research should focus on multidisciplinary adaptation strategies that incorporate epidemiology, climatology, indoor/building environments, energy usage, labor legislative perfection, and human thermal comfort models. Studies on the underlying mechanism by which temperature challenge induces pathophysiological response and CVD await profound and lasting investigation.
Topics: Acclimatization; Animals; Body Temperature Regulation; Cardiovascular Diseases; Cardiovascular System; Climate Change; Cold Temperature; Fever; Hot Temperature; Humans; Hypothermia; Risk Assessment; Risk Factors; Seasons
PubMed: 26432837
DOI: 10.1152/ajpheart.00199.2015 -
The Cochrane Database of Systematic... Apr 2015Inadvertent perioperative hypothermia (a drop in core temperature to below 36°C) occurs because of interference with normal temperature regulation by anaesthetic drugs,... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Inadvertent perioperative hypothermia (a drop in core temperature to below 36°C) occurs because of interference with normal temperature regulation by anaesthetic drugs, exposure of skin for prolonged periods and receipt of large volumes of intravenous and irrigation fluids. If the temperature of these fluids is below core body temperature, they can cause significant heat loss. Warming intravenous and irrigation fluids to core body temperature or above might prevent some of this heat loss and subsequent hypothermia.
OBJECTIVES
To estimate the effectiveness of preoperative or intraoperative warming, or both, of intravenous and irrigation fluids in preventing perioperative hypothermia and its complications during surgery in adults.
SEARCH METHODS
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 2), MEDLINE Ovid SP (1956 to 4 February 2014), EMBASE Ovid SP (1982 to 4 February 2014), the Institute for Scientific Information (ISI) Web of Science (1950 to 4 February 2014), Cumulative Index to Nursing and Allied Health Literature (CINAHL) EBSCOhost (1980 to 4 February 2014) and reference lists of identified articles. We also searched the Current Controlled Trials website and ClinicalTrials.gov.
SELECTION CRITERIA
We included randomized controlled trials or quasi-randomized controlled trials comparing fluid warming methods versus standard care or versus other warming methods used to maintain normothermia.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data from eligible trials and settled disputes with a third review author. We contacted study authors to ask for additional details when needed. We collected data on adverse events only if they were reported in the trials.
MAIN RESULTS
We included in this review 24 studies with a total of 1250 participants. The trials included various numbers and types of participants. Investigators used a range of methods to warm fluids to temperatures between 37°C and 41°C. We found that evidence was of moderate quality because descriptions of trial design were often unclear, resulting in high or unclear risk of bias due to inappropriate or unclear randomization and blinding procedures. These factors may have influenced results in some way. Our protocol specified the risk of hypothermia as the primary outcome; as no trials reported this, we decided to include data related to mean core temperature. The only secondary outcome reported in the trials that provided useable data was shivering. Evidence was unclear regarding the effects of fluid warming on bleeding. No data were reported on our other specified outcomes of cardiovascular complications, infection, pressure ulcers, bleeding, mortality, length of stay, unplanned intensive care admission and adverse events.Researchers found that warmed intravenous fluids kept the core temperature of study participants about half a degree warmer than that of participants given room temperature intravenous fluids at 30, 60, 90 and 120 minutes, and at the end of surgery. Warmed intravenous fluids also further reduced the risk of shivering compared with room temperature intravenous fluidsInvestigators reported no statistically significant differences in core body temperature or shivering between individuals given warmed and room temperature irrigation fluids.
AUTHORS' CONCLUSIONS
Warm intravenous fluids appear to keep patients warmer during surgery than room temperature fluids. It is unclear whether the actual differences in temperature are clinically meaningful, or if other benefits or harms are associated with the use of warmed fluids. It is also unclear if using fluid warming in addition to other warming methods confers any benefit, as a ceiling effect is likely when multiple methods of warming are used.
Topics: Administration, Intravenous; Anesthesia; Body Temperature; Hot Temperature; Humans; Hypothermia; Infusions, Intravenous; Randomized Controlled Trials as Topic; Shivering; Therapeutic Irrigation
PubMed: 25866139
DOI: 10.1002/14651858.CD009891.pub2 -
Deutsches Arzteblatt International Mar 201525-90% of all patients undergoing elective surgery suffer from inadvertent postoperative hypothermia, i.e., a core body temperature below 36°C. Compared to normothermic...
BACKGROUND
25-90% of all patients undergoing elective surgery suffer from inadvertent postoperative hypothermia, i.e., a core body temperature below 36°C. Compared to normothermic patients, these patients have more frequent wound infections (relative risk [RR] 3.25, 95% confidence interval [CI] 1.35-7.84), cardiac complications (RR 4.49, 95% CI 1.00-20.16), and blood transfusions (RR 1.33, 95% CI 1.06-1.66). Hypothermic patients feel uncomfortable, and shivering raises oxygen consumption by about 40%.
METHODS
This guideline is based on a systematic review of the literature up to and including October 2012 and a further one from November 2012 to August 2014. The recommendations were developed and agreed upon by representatives of five medical specialty societies in a structured consensus process.
RESULTS
The patient's core temperature should be measured 1-2 hours before the start of anesthesia, and either continuously or every 15 minutes during surgery. Depending on the nature of the operation, the site of temperature measurement should be oral, naso-/oropharyngeal, esophageal, vesical, or tympanic (direct). The patient should be actively prewarmed 20-30 minutes before surgery to counteract the decline in temperature. Prewarmed patients must be actively warmed intraoperatively as well if the planned duration of anesthesia is longer than 60 minutes (without prewarming, 30 minutes). The ambient temperature in the operating room should be at least 21°C for adult patients and at least 24°C for children. Infusions and blood transfusions that are given at rates of >500 mL/h should be warmed first. Perioperatively, the largest possible area of the body surface should be thermally insulated. Emergence from general anesthesia should take place at normal body temperature. Postoperative hypothermia, if present, should be treated by the administration of convective or conductive heat until normothermia is achieved. Shivering can be treated with medications.
CONCLUSION
Inadvertent perioperative hypothermia can adversely affect the outcome of surgery and the patient's postoperative course. It should be actively prevented.
Topics: Germany; Humans; Hypothermia; Monitoring, Intraoperative; Perioperative Care; Practice Guidelines as Topic; Rewarming
PubMed: 25837741
DOI: 10.3238/arztebl.2015.0166 -
JAMA Pediatrics Sep 2021Prevention of hypothermia in the delivery room is a cost-effective, high-impact intervention to reduce neonatal mortality, especially in preterm neonates. Several... (Meta-Analysis)
Meta-Analysis
IMPORTANCE
Prevention of hypothermia in the delivery room is a cost-effective, high-impact intervention to reduce neonatal mortality, especially in preterm neonates. Several interventions for preventing hypothermia in the delivery room exist, of which the most beneficial is currently unknown.
OBJECTIVE
To identify the delivery room thermal care intervention that can best reduce neonatal hypothermia and improve clinical outcomes for preterm neonates born at 36 weeks' gestation or less.
DATA SOURCES
MEDLINE, the Cochrane Central Register of Controlled Trials, Embase, and CINAHL databases were searched from inception to November 5, 2020.
STUDY SELECTION
Randomized and quasi-randomized clinical trials of thermal care interventions in the delivery room for preterm neonates were included. Peer-reviewed abstracts and studies published in non-English language were also included.
DATA EXTRACTION AND SYNTHESIS
Data from the included trials were extracted in duplicate using a structured proforma. A network meta-analysis with bayesian random-effects model was used for data synthesis.
MAIN OUTCOMES AND MEASURES
Primary outcomes were core body temperature and incidence of moderate to severe hypothermia on admission or within the first 2 hours of life. Secondary outcomes were incidence of hyperthermia, major brain injury, and mortality before discharge. The 9 thermal interventions evaluated were (1) plastic bag or plastic wrap covering the torso and limbs with the head uncovered or covered with a cloth cap; (2) plastic cap covering the head; (3) skin-to-skin contact; (4) thermal mattress; (5) plastic bag or plastic wrap with a plastic cap; (6) plastic bag or plastic wrap along with use of a thermal mattress; (7) plastic bag or plastic wrap along with heated humidified gas for resuscitation or for initiating respiratory support in the delivery room; (8) plastic bag or plastic wrap along with an incubator for transporting from the delivery room; and (9) routine care, including drying and covering the body with warm blankets, with or without a cloth cap.
RESULTS
Of the 6154 titles and abstracts screened, 34 studies that enrolled 3688 neonates were analyzed. Compared with routine care alone, plastic bag or wrap with a thermal mattress (mean difference [MD], 0.98 °C; 95% credible interval [CrI], 0.60-1.36 °C), plastic cap (MD, 0.83 °C; 95% CrI, 0.28-1.38 °C), plastic bag or wrap with heated humidified respiratory gas (MD, 0.76 °C; 95% CrI, 0.38-1.15 °C), plastic bag or wrap with a plastic cap (MD, 0.62 °C; 95% CrI, 0.37-0.88 °C), thermal mattress (MD, 0.62 °C; 95% CrI, 0.33-0.93 °C), and plastic bag or wrap (MD, 0.56 °C; 95% CrI, 0.44-0.69 °C) were associated with greater core body temperature. Certainty of evidence was moderate for 5 interventions and low for plastic bag or wrap with a thermal mattress. When compared with routine care alone, a plastic bag or wrap with heated humidified respiratory gas was associated with less risk of major brain injury (risk ratio, 0.23; 95% CrI, 0.03-0.67; moderate certainty of evidence) and a plastic bag or wrap with a plastic cap was associated with decreased risk of mortality (risk ratio, 0.19; 95% CrI, 0.02-0.66; low certainty of evidence).
CONCLUSIONS AND RELEVANCE
Results of this study indicate that most thermal care interventions in the delivery room for preterm neonates were associated with improved core body temperature (with moderate certainty of evidence). Specifically, use of a plastic bag or wrap with a plastic cap or with heated humidified gas was associated with lower risk of major brain injury and mortality (with low to moderate certainty of evidence).
Topics: Body Temperature Regulation; Delivery Rooms; Gestational Age; Humans; Hypothermia; Infant, Newborn; Network Meta-Analysis
PubMed: 34028513
DOI: 10.1001/jamapediatrics.2021.0775 -
Sports Health 2016Hypothermia and frostbite injuries occur in cold weather activities and sporting events. (Review)
Review
CONTEXT
Hypothermia and frostbite injuries occur in cold weather activities and sporting events.
EVIDENCE ACQUISITION
A PubMed search was used to identify original research and review articles related to cold, frostbite, and hypothermia. Inclusion was based on their relevance to prevention and treatment of cold-related injuries in sports and outdoor activities. Dates of review articles were limited to those published after 2010. No date limit was set for the most recent consensus statements or original research.
STUDY DESIGN
Clinical review.
LEVEL OF EVIDENCE
Level 5.
RESULTS
Frostbite and hypothermia are well-documented entities with good prevention strategies and prehospital treatment recommendations that have changed very little with time. A layered approach to clothing is the best way to prevent injury and respond to weather changes. Each athlete, defined as a participant in a cold weather sport or activity, will respond to cold differently depending on anthropometric measurements and underlying medical risk factors. An understanding of wind-chill temperatures, wetness, and the weather forecast allows athletes and event coordinators to properly respond to changing weather conditions. At the first sign of a freezing cold injury, ensure warm, dry clothes and move to a protected environment.
CONCLUSION
Cold injuries can be prevented, and cold weather activities are safe with proper education, preparation, and response to changing weather conditions or injury.
Topics: Cold Temperature; Frostbite; Humans; Hypothermia; Risk Factors; Wind
PubMed: 26857732
DOI: 10.1177/1941738116630542 -
The Journal of International Medical... Aug 2019It must be remembered that clinically important haemostasis occurs in vivo and not in a tube, and that variables such as the number of bleeding events and bleeding... (Review)
Review
It must be remembered that clinically important haemostasis occurs in vivo and not in a tube, and that variables such as the number of bleeding events and bleeding volume are more robust measures of bleeding risk than the results of analyses. In this narrative review, we highlight trauma, surgery, and mild induced hypothermia as three clinically important situations in which the effects of hypothermia on haemostasis are important. In observational studies of trauma, hypothermia (body temperature <35°C) has demonstrated an association with mortality and morbidity, perhaps owing to its effect on haemostatic functions. Randomised trials have shown that hypothermia causes increased bleeding during surgery. Although causality between hypothermia and bleeding risk has not been well established, there is a clear association between hypothermia and negative outcomes in connection with trauma, surgery, and accidental hypothermia; thus, it is crucial to rewarm patients in these clinical situations without delay. Mild induced hypothermia to ≥33°C for 24 hours does not seem to be associated with either decreased total haemostasis or increased bleeding risk.
Topics: Hemorrhage; Hemostasis; Humans; Hypothermia; Prognosis; Risk Factors
PubMed: 31475619
DOI: 10.1177/0300060519861469