Characteristics and outcomes of accidental hypothermia in Japan: the J-Point registry.

BACKGROUND: Accidental hypothermia (AH) has higher incidence and mortality in geriatric populations. Japan has a rapidly ageing population, and little is known about the epidemiology of hypothermia in this country. METHODS: We created an AH registry based on retrospective review of patients visiting the ED of 12 institutions with temperature ≤35°C between April 2011 and March 2016. The severity of AH was classified as mild (≤35, ≥32°C), moderate (<32, ≥28°C) or severe (<28°C). The relationship between in-hospital mortality and severity of AH was assessed using a multivariable logistic regression analysis. RESULTS: A total of 572 patients were registered in this registry and 537 patients were eligible for our analysis. The median age was 79 (IQR 66-87) years and the proportion of men was 51.2% (273/537). AH was more likely to occur in elderly patients aged ≥65 years (424/537, 80.0%) and in indoor settings (418/537, 77.8%). The condition most frequently associated with AH, irrespective of severity, was acute medical illness. A lower mean outside temperature was associated with a higher prevalence of AH, and particularly severe AH (p for trend <0.001). The overall proportion of cases resulting in in-hospital death was 24.4% (131/537), with no significant difference between severity levels observed in a multivariable logistic regression analysis (severe group (37/118, 31.4%) vs mild group (42/192, 21.9%), adjusted OR (AOR) 1.01, 95% CI 0.61 to 1.68; and moderate group (52/227, 22.9%) vs mild group, AOR 1.11, 95% CI 0.58 to 2.14). CONCLUSION: Active prevention and intervention should occur for this important public health issue.

Validity and reliability of the Cold Discomfort Scale: a subjective judgement scale for the assessment of patient thermal state in a cold environment.

Complementary measures for the assessment of patient thermoregulatory state, such as subjective judgement scales, might be of considerable importance in field rescue scenarios where objective measures such as body core temperature, skin temperature, and oxygen consumption are difficult to obtain. The objective of this study was to evaluate, in healthy subjects, the reliability of the Cold Discomfort Scale (CDS), a subjective judgement scale for the assessment of patient thermal state in cold environments, defined as test-retest stability, and criterion validity, defined as the ability to detect a difference in cumulative cold stress over time. Twenty-two healthy subjects performed two consecutive trials (test-retest). Dressed in light clothing, the subjects remained in a climatic chamber set to -20 °C for 60 min. CDS ratings were obtained every 5 min. Reliability was analysed by test-retest stability using weighted kappa coefficient that was 0.84 including all the 5-min interval measurements. When analysed separately at each 5-min interval the weighted kappa coefficients were was 0.48-0.86. Criterion validity was analysed by comparing median CDS ratings of a moving time interval. The comparison revealed that CDS ratings were significantly increased for every interval of 10, 15, and 30 min (p < 0.001) but not for every interval of 5 min. In conclusion, in a prehospital scenario, subjective judgement scales might be a valuable measure for the assessment of patient thermal state. The results of this study indicated that, in concious patients, the CDS may be both reliable and valid for such purpose.

[Management of severe accidental hypothermia]. / Manejo de la hipotermia accidental severa.

Accidental hypothermia is an environmental condition with basic principles of classification and resuscitation that apply to mountain, sea or urban scenarios. Along with coagulopathy and acidosis, hypothermia belongs to the lethal triad of trauma victims requiring critical care. A customized healthcare chain is involved in its management, extending from on site assistance to intensive care, cardiac surgery and/or the extracorporeal circulation protocols. A good classification of the degree of hypothermia preceding admission contributes to improve management and avoids inappropriate referrals between hospitals. The most important issue is to admit hypothermia victims in asystolia or ventricular fibrillation to those hospitals equipped with the medical technology which these special clinical scenarios require. This study attempts to establish the foundations for optimum management of accidental hypothermia from first emergency care on site to treatment in hospital including, resuscitation and rewarming with extracorporeal circulation.

Accidental Hypothermia: 'You're Not Dead Until You're Warm and Dead'.

[Full article available at http://rimed.org/rimedicaljournal-2019-02.asp].

Management of pediatric hypothermia and peripheral cold injuries in the emergency department.

Hypothermia occurs when the core body temperature falls below 35ºC (95ºF) due to primary exposure (eg, environmental exposure) or secondary to other pathologies. Infants, children, and adolescents are at higher risk for primary cold injuries due to a combination of physiologic and cognitive factors, but quick rewarming and appropriate disposition can result in survival and improved neurological outcomes. Treatment for cold injuries is guided by severity and can include passive or active measures. This issue reviews the stages of hypothermia and offers recommendations for emergent management of pediatric patients with hypothermia; guidance is also provided for the identification and management of frostnip and frostbite.

Human touch vs. axillary digital thermometry for detection of neonatal hypothermia at community level.

We examined the diagnostic accuracy of human touch (HT) method in assessing hypothermia against axillary digital thermometry (ADT) by a trained non-medical field investigator (who supervised activities of community health volunteers) in seven villages of Agra district, Uttar Pradesh, India. Body temperature of 148 newborns born between March and August 2005 was measured at four points in time for each enrolled newborn (within 48 h and on days 7, 30 and 60) by the field investigator under the axilla using a digital thermometer and by HT method using standard methodology. Total observations were 533. Hypothermia assessed by HT was in agreement with that assessed by ADT (<36.5 degrees C) in 498 observations. Hypothermia assessed by HT showed a high diagnostic accuracy when compared against ADT (kappa 0.65-0.81; sensitivity 74%; specificity 96.7%; positive predictive value 22; negative predictive value 0.26). HT is a simple, quick, inexpensive and programmatically important method. However, being a subjective assessment, its reliability depends on the investigator being adequately trained and competent in making consistently accurate assessments. There is also a need to assess whether with training and supervision even the less literate mothers, traditional birth attendants and community health volunteers can accurately assess mild and moderate hypothermia before promoting HT for early identification of neonatal risk in community-based programs.

Prediction and risk stratification of survival in accidental hypothermia requiring extracorporeal life support: An individual patient data meta-analysis.

BACKGROUND: Extra-corporeal life support (ECLS) is a life-saving intervention for patients with hypothermia induced cardiac arrest or severe cardiovascular instability. However, its application is highly variable due to a paucity of data in the literature to guide practice. Current guidelines and recommendations are based on expert opinion, single case reports, and small case series. Combining all of the published data in a patient-level analysis can provide a robust assessment of the influence of patient characteristics on survival with ECLS. OBJECTIVE: To develop a prediction model of survival with good neurologic outcome for accidental hypothermia treated with ECLS. METHODS: Electronic searches of PubMed, EMBASE, CINAHL were conducted with a hand search of reference lists and major surgical and critical care conference abstracts. Studies had to report the use of ECLS configured with a circuit, blood pump and oxygenator with an integrated heat exchanger. Randomized and observational studies were eligible for inclusion. Non-human, non-English and review manuscripts were deemed ineligible. Study authors were requested to submit patient level data when aggregate or incomplete individual patient data was provided in a study. Survival with good neurologic outcome was categorized for patients to last follow-up based on the reported scores on the Cerebral Performance Category (1 or 2), Glasgow Outcome Scale (4 or 5) and Pediatric Overall Performance Category (1 or 2). A one-stage, individual patient data meta-analysis was performed with a mixed-effects multi-level logistic regression model reporting odds ratio (OR) with a 95% confidence interval (CI). RESULTS: Data from 44 observational studies and 40 case reports (n = 658) were combined and analyzed to identify independent predictors of survival with good neurologic outcome. The survival rate with good neurologic outcome of the entire cohort was 40.3% (265 of 658). ECLS rewarming rate (OR: 0.93; 95% CI: 0.88, 0.98; p = .007), female gender (OR: 2.78; 95% CI: 1.69, 4.58; p < 0.001), asphyxiation (OR: 0.19; 95% CI: 0.11, 0.35; p < 0.001) and serum potassium (OR: 0.62; 95% CI: 0.53, 0.73; p < 0.001) were associated with survival with a good neurologic outcome. The logistic regression model demonstrated excellent discrimination (c-statistic: 0.849; 95% CI: 0.823, 0.875). CONCLUSIONS: The use of extracorporeal life support in the treatment of hypothermic cardiac arrest provides a favourable chance of survival with good neurologic outcome. When used in a weighted scoring system, asphyxiation, serum potassium and gender can help clinicians prognosticate the benefit of resuscitating hypothermic patients with ECLS.

The impact of therapeutic hypothermia on peripheral blood cell in newborns with hypoxic ischemic encephalopathy

Abstract The effect of hypothermia treatment on white blood cell (WBC), neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR) and platelet-to-lymphocyte ratio (PLR) values as an indicator of inflammation was evaluated in newborns with hypoxic ischemic encephalopathy (HIE). The study was performed that the before-therapeutic hypothermia (TH) and after-TH WBC, lymphocytes, neutrophils, monocytes and NLR, LMR and PLR values of the complete blood cell count were retrospectively evaluated. The results of the patient group were compared with the results of healthy newborns. A total of 78 patients who underwent TH were evaluated in our study. Mean values before and after TH were NLR3.8/2.7, LMR 5.6/8.6, and PLR 60.3/67.1 respectively. A statistical significance was present for NLR values before and after TH in those with seizure in our study (4.15±2.95/3.01±2.54) but no statistical significance was found for LMR or PLR. In neonates with HIE, effect of TH on complete blood cell count and inflammatory mechanisms (mediated neutrophil and lymphocyte) may be minimal.

Proposed guidelines for skin-to-skin treatment of neonatal hypothermia.

Hypothermia is not uncommon in full-term, low-risk newborns during the first days of life. Standard care for treating hypothermia often involves the separation of the mother and the newborn while the infant is placed under a warmer and observed in the nursery. Because one important role of the postpartum nurse is to promote mother-infant attachment by encouraging the mother to spend time "getting to know" her infant, this separation can be problematic. This article proposes that skin-to-skin (STS) care, also called kangaroo care, an intervention in which the unclothed, diapered infant is placed on the mother's bare chest, be used to promote thermoregulation instead of using separation and a warmer. STS care has been recognized as a way to facilitate maternal-infant attachment and promote thermoregulation. The literature review here provides an analysis of the available evidence and the author's conclusion that the research supports the use of STS care as an alternative to traditional rewarming. The evidence was graded and organized into an evidence-based practice guideline for the use of STS care in the treatment of mild hypothermia in the low-risk infant. Suggestions for further research and outcomes measurement are included.

Influence of Peri-Operative Hypothermia on Surgical Site Infection in Prolonged Gastroenterological Surgery.

BACKGROUND: There have been several recent studies on the correlation between intra-operative hypothermia and the occurrence of surgical site infection (SSI). Differences in the depth and timing of hypothermia and the surgical procedure may have led to conflicting results. METHODS: Patients undergoing gastroenterologic surgery with a duration of >3 h were analyzed. Hypothermia was defined as a core temperature <36°C and was classified as mild (35.5-35.9°C), moderate (35.0-35.4°C), or severe (<35.0°C). Hypothermia also was classified as early-nadir (<36°C within two h of anesthesia induction) and late-nadir (after that time). Risk factors for SSIs were analyzed according to these classifications. RESULTS: Among 1,409 patients, 528 (37.5%) had hypothermia, which was classified as mild in 358, moderate in 137, and severe in 33. Early-nadir and late-nadir hypothermia was found in 23.7% and 13.8%, respectively. There was no significant difference in the incidence of SSIs between patients with and without hypothermia (relative risk 1.00; 95% confidence interval [CI] 0.80-1.25; p = 0.997). However, there was a significantly greater incidence of SSIs in patients with severe hypothermia (33.3%) than in those with normothermia (19.2%; p = 0.045) or mild hypothermia (17.0%; p = 0.021). The incidence of SSIs also was significantly greater in patients with late-nadir than in those with early-nadir hypothermia (23.7% vs. 16.5%; p = 0.041). The incidence of organ/space SSIs was significantly greater in patients with late-nadir hypothermia (19.6%) than in patients with normothermia (12.7%; p = 0.012). In multivariable analysis, neither severe hypothermia (odds ratio 1.24; 95% CI 0.56-2.77] nor late-nadir hypothermia (OR 0.71; 95% CI 0.46-1.01) was an independent risk factor for SSIs. CONCLUSIONS: Severe and late-nadir hypothermia were associated with a greater incidence of SSIs and organ/space SSIs. However, neither of these patterns was identified as an independent risk factor for SSIs, possibly because of the small number of patients.

Cold stress, near drowning and accidental hypothermia: a review.

This paper reviews literature on the topic of cold stress, near-drowning and hypothermia, written mainly since the last review of this type in this journal. The main effects of cold stress, especially in cold water immersion, include the "cold shock" response, local cooling causing decrements in physical and mental performance, and ultimately core cooling as hypothermia occurs. The section on cold-water submersion (near-drowning) includes discussion regarding the various mechanisms for brain and body cooling during submersion. The mechanisms for cold-induced protection of the anoxic brain are discussed with attention given to decreased brain temperature and the Q10 principle, the mammalian dive reflex and a newly considered mechanism; cold-induced changes in neurotransmitter release (i.e., glutamate and dopamine). The section on the post-cooling period includes the post-rescue collapse and subsequent rewarming strategies used in the field, during emergency transport or in medical facilities. Recent research on topics such as inhalation warming, body-to-body warming, radio wave therapy, warm water immersion, exercise, body cavity lavage, and cardiopulmonary bypass is reviewed. Information on new methods of warming, including arteriovenous anastomoses (AVA) warming (by application of heat- with or without negative pressure application-to distal extremities in an effort to increase AVA blood flow), forced-air warming, and peripheral vascular extracorporeal warming, are discussed.

[Cold-induced pathology at high altitude]. / Kältepathologie in der Höhe.

Cold injury is an objective danger in mountain climbing as well as in many outdoor and recreational sports such as skiing, fishing, etc. Symptoms are easily recognizable by the experienced, and prevention is mostly possible. Cold injury should be divided by pathological means in general hypothermia and local frostbite injuries. Life-threatening deep hypothermia with coma and insufficient circulation or cardiac arrest is reversible under the condition of sufficient core rewarming, for instance by CEC. Because of the big tolerance of hypothermic patients to hypoxia, clinical death is not like biological death and therefore reversible. Local frostbite is not life-threatening, but has often deleterious effects. Rapid rewarming in warm water of 37 to 42 degrees C is mandatory. After rewarming, the difference between superficial and deep frostbite can be established. Scintigraphy seems to be of great help in setting early prognosis. Daily sterile treatment of the injury, whirlpool bath and prevention of infections belong to standard treatment. There are little objective informations about the role of vasodilators, anticoagulants, antibiotics, sympathectomy and others. Early experience with Prostavasine seems to bee encouraging.

Hypothermia: risk factors and guidelines for nursing care.

Hypothermia occurs when heat loss from the body exceeds heat gain and the core temperature of the body falls below 35 degrees C. Although death from hypotheRmia is rare, 80 per cent of associated mortalities are in older people. There are many underlying conditions that increase a person's susceptibility to cold and this includes not having the ability to make appropriate environmental adjustments to maintain body temperature. The nursing management of a patient with hypothermia depends upon the severity of the condition. The nurse's primary concern is to treat the symptoms and re-warm the patient appropriately.

Risk of mortality associated with neonatal hypothermia in southern Nepal.

OBJECTIVE: To quantify the neonatal mortality/hypothermia relationship and develop evidence-based cutoffs for global definitions of neonatal hypothermia. DESIGN: Cohort study. Field workers recorded neonatal axillary temperature at home and recorded vital status at 28 days. SETTING: Rural Nepal. PARTICIPANTS: Twenty-three thousand two hundred forty infants in Sarlahi, Nepal. MAIN EXPOSURE: Hypothermia. OUTCOME MEASURES: Mortality risk was estimated using binomial regression models. Infants were classified using (1) World Health Organization (WHO) cutoffs for mild, moderate, and severe hypothermia; (2) quarter-degree intervals from 32.0 degrees C to 36.5 degrees C; and (3) continuous temperatures. Estimates were adjusted for age, ambient temperature, and other potential confounders. RESULTS: Mortality increased among mild (relative risk [RR], 1.70; 95% confidence interval [CI], 1.23-2.35]), moderate (RR, 4.66; 95% CI, 3.47-6.24]), and severe (RR, 23.36; 95% CI, 4.31-126.70]) hypothermia cases. Within the WHO's moderate classification, risk relative to normothermic infants ranged from 2 to 30 times. Adjusted mortality risk increased 80% (95% CI, 63%-100%) for each degree decrease, was strongly associated with temperatures below 35.0 degrees C (RR, 6.11; 95% CI, 3.98-9.38), and was substantially higher among preterm infants (RR, 12.02; 95% CI, 6.23-23.18]) compared with full-term infants (RR, 3.12; 95% CI, 1.75-5.57). Relative risk was highest in the first 7 days, but remained elevated through 28 days. CONCLUSIONS: A new hypothermia classification system should be considered by the WHO for global guidelines. We recommend that grade 1 be equivalent to the current mild category (36.0 degrees C), restricting and splitting the moderate category into grades 2 (35.0 degrees C-36.0 degrees C) and 3 (34.0 degrees C-35.0 degrees C), and expanding severe hypothermia to less than 34.0 degrees C (grade 4). Reducing hypothermia may dramatically decrease the global neonatal mortality burden.

Cold injury in the United States military population: current trends and comparison with past conflicts.

OBJECTIVE: The war in Afghanistan represents the first large-scale conflict involving military troops in a cold, mountainous climate since the Korean War. An analysis was conducted to identify the extent of cold weather injuries, especially frostbite, in the deployed military population. DESIGN: A retrospective analysis of military databases was conducted with tabulation of all cases of cold-weather injuries in Operations Enduring Freedom and Iraqi Freedom. Casualties reviewed occurred between 2001 and 2009. SETTING: The 81st Medical Group at Keesler AFB. PARTICIPANTS: A total of 18,214 patients reported in the Joint Theater Trauma Registry (JTTR). RESULTS: Overall, 19 cases of cold-weather injury were identified in the Afghanistan Conflict. Two cases of frostbite were identified with only 1 likely requiring surgical intervention. No cases were identified in Iraq. CONCLUSION: The 19 cold-weather injuries represent a dramatic decrease from the 6300 cases of cold-weather injury reported in the last major cold-weather conflict, the Korean War. This decrease results from the shorter and weather-dependent engagements, cold-weather education, and improved equipment of United States and allied personnel.