Predictors of cardiac arrest in severe accidental hypothermia.

STUDY OBJECTIVE: To indicate predictors of witnessed hypothermic cardiac arrest. METHODS: We conducted a retrospective analysis of 182 patients with severe accidental hypothermia (i.e., with core body temperature of ≤28 °C) who presented with preserved spontaneous circulation at first contact with medical services. We divided the study population into two groups: patients who suffered hypothermic cardiac arrest (HCA) at any time between encounter with medical service and restoration of normothermia, and those who did not sustain HCA. The analyzed outcome was the occurrence of cardiac arrest prior to achieving normothermia. Hemodynamic and biochemical parameters were analyzed with regard to their association with the outcome. RESULTS: Fifty-two (29%) patients suffered HCA. In a univariable analysis, four variables were significantly associated with the outcome, namely heart rate (p < 0.001), systolic blood pressure (p = 0.03), ventricular arrhythmia (p = 0.001), and arterial oxygen partial pressure (p = 0.002). In the multivariable logistic regression the best model predicting HCA included heart rate, PaO2, and Base Excess (AUROC = 0.78). In prehospital settings, when blood gas analysis is not available, other multivariable model including heart rate and occurrence of ventricular arrhythmia (AUROC = 0.74) can be used. In this study population, threshold values of heart rate of 43/min, temperature-corrected PaO2 of 72 mmHg, and uncorrected PaO2 of 109 mmHg, presented satisfactory sensitivity and specificity for HCA prediction. CONCLUSIONS: In patients with severe accidental hypothermia, the occurrence of HCA is associated with a lower heart rate, hypoxemia, ventricular arrhythmia, lower BE, and lower blood pressure. These parameters can be helpful in the early selection of high-risk patients and their allocation to extracorporeal rewarming facilities.

[Diagnostic criteria of death cause from low temperature in air and water established by traditional expert examination methods]. / Diagnosticheskie kriterii prichiny smerti ot deistviya nizkoi temperatury na vozdukhe i v vode, ustanavlivaemye s pomoshch'yu traditsionnykh metodov ekspertnogo issledovaniya.

Death from general hypothermia is one of the leading causes in the structure of violent death in the Russian Federation. OBJECTIVE: To clarify and supplement the complex of differential diagnostic macro- and microscopic signs of a fatal acute general cold trauma received when person is in the air and water. MATERIAL AND METHODS: The conclusions of forensic medical experts on the bodies of people who died from hypothermia in the air and in water (by 150 observations) were analyzed. Methods of descriptive statistics, calculation of the frequency ratio of signs' occurrence were used. RESULTS: The article provides quantitative assessment of occurrence (detection) rate of diagnostically significant signs established with the help of traditional methods of expert examination. A new classification of diagnostic death signs from hypothermia taking into account their differential diagnostic significance and reflecting the conditions of a person's stay in the air and water in the pre-mortem and post-mortem periods, as well as terminal period mechanisms is proposed. CONCLUSION: The established complexes of signs provide an objective basis for determining death cause in non-obvious conditions when cold exposure is expected to be one of the most damaging factors.

Unexplained hypothermia is associated with bacterial infection in the Emergency Department.

BACKGROUND: Early recognition and antibiotic therapy improve the prognosis of bacterial infections. Triage temperature in the Emergency department (ED) constitutes a diagnostic and prognostic marker of infection. The objective of this study was to assess the prevalence of community-acquired bacterial infections and the diagnostic ability of conventional biological markers in patients presenting to the ED with hypothermia. METHODS: We conducted a retrospective single-center study over a 1-year period before the COVID-19 pandemic. Consecutive adult patients admitted to the ED with hypothermia (body temperature < 36.0 °C) were eligible. Patients with evident cause of hypothermia and patients with viral infections were excluded. Diagnosis of infection was based on the presence of at least two among the three following pre-defined criteria: (i) the presence of a potential source of infection, (ii) microbiology data, and (iii) patient outcome under antibiotic therapy. The association between traditional biomarkers (white blood cells, lymphocytes, C-reactive protein [CRP], Neutrophil to Lymphocyte Count Ratio [NLCR]) and underlying bacterial infections was evaluated using a univariate and a multivariate (logistic regression) analysis. Receiver operating characteristic curves were built to determine threshold values yielding the best sensitivity and specificity for each biomarker. RESULTS: Of 490 patients admitted to the ED with hypothermia during the study period, 281 were excluded for circumstantial or viral origin, and 209 were finally studied (108 men; mean age: 73 ± 17 years). A bacterial infection was diagnosed in 59 patients (28%) and was mostly related to Gram-negative microorganisms (68%). The area under the curve (AUC) for the CRP level was 0.82 with a confidence interval (CI) ranging from 0.75 to 0.89. The AUC for the leukocyte, neutrophil and lymphocyte counts were 0.54 (CI: 0.45-0.64), 0.58 (CI: 0.48-0.68) and 0.74 (CI: 0.66-0.82), respectively. The AUC of NLCR and quick Sequential Organ Failure Assessment (qSOFA) reached 0.70 (CI: 0.61-0.79) and 0.61 (CI: 0.52-0.70), respectively. In the multivariate analysis, CRP ≥ 50 mg/L (OR: 9.39; 95% CI: 3.91-24.14; p < 0.01) and a NLCR ≥10 (OR: 2.73; 95% CI: 1.20-6.12; p = 0.02) were identified as independent variables associated with the diagnosis of underlying bacterial infection. CONCLUSION: Community-acquired bacterial infections represent one third of diagnoses in an unselected population presenting to the ED with unexplained hypothermia. CRP level and NLCR appear useful for the diagnosis of causative bacterial infection.

Accuracy of non-invasive sensors measuring core body temperature in cardiac surgery ICU patients - results from a monocentric prospective observational study.

PURPOSE: Temperature monitoring in the perioperative setting often represents a compromise between accuracy, invasiveness of probe placement, and patient comfort. Transcutaneous sensors using the Zero-Heat-Flux (ZHF) and Double-Sensor (DS) technology have been developed and evaluated in a variety of clinical settings. The present study is the first to compare the performance of both sensors simultaneously with temperature measured by a Swan-Ganz catheter (PAC) in patients admitted to the intensive care unit (ICU) after cardiac surgery. METHODS: In this monocentric prospective observational study patients were postoperatively transferred to the ICU and both sensors were placed on the patients' foreheads. Core body temperature measured by intraoperatively placed PAC served as gold standard. Measurements were recorded at 5-minute intervals and up to 40 data sets per patient were recorded. Bland and Altman's method for repeated measurements was used to analyse agreement. Subgroup analyses for gender, body-mass-index, core temperature, airway status and different time intervals were performed. Lin's concordance correlation coefficient (LCCC) was calculated, as well as sensitivity and specificity for detecting hyperthermia (≥ 38 °C) and hypothermia (< 36 °C). RESULTS: Over a period of six month, we collected 1600 sets of DS, ZHF, and PAC measurements, from a total of 40 patients. Bland-Altman analysis revealed a mean bias of -0.82 ± 1.27 °C (average ± 95% Limits-of-Agreement (LoA)) and - 0.54 ± 1.14 °C for DS and ZHF, respectively. The LCCC was 0.5 (DS) and 0.63 (ZHF). Mean bias was significantly higher in hyperthermic and hypothermic patients. Sensitivity and specificity were 0.12 / 0.99 (DS) and 0.35 / 1.0 (ZHF) for hyperthermia and 0.95 / 0.72 (DS) and 1.0 / 0.85 (ZHF) for hypothermia. CONCLUSION: Core temperature was generally underestimated by the non-invasive approaches. In our study, ZHF outperformed DS. In terms of agreement, results for both sensors were outside the range that is considered clinically acceptable. Nevertheless, both sensors might be adequate to detect postoperative hypothermia reliably when more invasive methods are not available or appropriate. TRIAL REGISTRATION: German Register of Clinical Trials (DRKS-ID: DRKS00027003), retrospectively registered 10/28/2021.

Intraoperative hypothermia in the neonate population: risk factors, outcomes, and typical patterns.

The risk factors, outcomes, and typical patterns of intraoperative hypothermia were studied in neonates to better guide the application of insulation measures in the operating room. This retrospective study enrolled 401 neonates undergoing surgery under general anaesthesia with tracheal intubation, including abdominal surgery, thoracic surgery, brain surgery, and others. The study collected basic characteristics, such as age, sex, weight, birth weight, gestational week, primary diagnosis and American Society of Anaesthesiologists (ASA) grade. Perioperative data included preoperative body temperature, length of hospital stay, length of intensive care unit (ICU) stay, intubation time, postoperative bleeding, postoperative pneumonia, postoperative death, and total cost of hospitalization. Intraoperative data included surgical procedures, anaesthesia duration, operation duration, blood transfusion, fluid or albumin infusion, and application of vasoactive drugs. The incidence of intraoperative hypothermia (< 36 °C) was 81.05%. Compared to normothermic patients, gestational week (OR 0.717; 95% CI 0.577-0.890; P = 0.003), preoperative temperature (OR 0.228; 95% CI 0.091-0.571; P = 0.002), duration of anaesthesia (OR 1.052; 95% CI 1.027-1.077; P < 0.001), and type of surgery (OR 2.725; 95% CI 1.292-5.747; P = 0.008) were associated with the risk of intraoperative hypothermia. Patients with hypothermia had longer length of ICU stay (P = 0.001), longer length of hospital stay (P < 0.001), and higher hospital costs (P < 0.001). But there were no association between clinical outcomes and intraoperative hypothermia in the multivariable regression adjusted analysis. The lowest point of intraoperative body temperature was approximately 1 h 30 min. Then, the body temperature of patients successively entered a short plateau phase and a period of slow ascent. The greatest decrease in body temperatures occurred in preterm babies and neonates with preoperative hypothermia. The lowest core temperatures that occurred in neonates with preoperative hypothermia was lower than 35 °C. This study shows that there is a high incidence of intraoperative hypothermia in the neonate population. The intraoperative body temperature of neonates dropped to the lowest point in 1-1.5 h. The greatest decrease in core temperatures occurred in preterm babies and neonates with lower preoperative temperature.

Blood culture utilization practices among febrile and/or hypothermic inpatients.

BACKGROUND: Predictors associated with the decision of blood culture ordering among hospitalized patients with abnormal body temperature are still underexplored, particularly non-clinical factors. In this study, we evaluated the factors affecting blood culture ordering in febrile and hypothermic inpatients. METHODS: We performed a retrospective study of 15,788 adult inpatients with fever (≥ 38.3℃) or hypothermia (< 36.0℃) from January 2016 to December 2017. We evaluated the proportion of febrile and hypothermic episodes with an associated blood culture performed within 24h. Generalized Estimating Equations were used to determine independent predictors associated with blood culture ordering among febrile and hypothermic inpatients. RESULTS: We identified 21,383 abnormal body temperature episodes among 15,788 inpatients (13,093 febrile and 8,290 hypothermic episodes). Blood cultures were performed in 36.7% (7,850/ 21,383) of these episodes. Predictors for blood culture ordering among inpatients with abnormal body temperature included fever ≥ 39℃ (adjusted odd ratio [aOR] 4.17, 95% confident interval [CI] 3.91-4.46), fever (aOR 3.48, 95% CI 3.27-3.69), presence of a central venous catheter (aOR 1.36, 95% CI 1.30-1.43), systemic inflammatory response (SIRS) plus hypotension (aOR 1.33, 95% CI 1.26-1.40), SIRS (aOR 1.26, 95% CI 1.20-1.31), admission to stem cell transplant / medical oncology services (aOR 1.09, 95% CI 1.04-1.14), and detection of abnormal body temperature during night shift (aOR 1.06, 95% CI 1.03-1.09) or on the weekend (aOR 1.05, 95% CI 1.01-1.08). CONCLUSION: Blood culture ordering for hospitalized patients with fever or hypothermia is multifactorial; both clinical and non-clinical factors. These wide variations and gaps in practices suggest opportunities to improve utilization patterns.

Characteristics of antipsychotic drug-induced hypothermia in psychogeriatric inpatients.

OBJECTIVE: Hypothermia is a potentially lethal adverse reaction to typical and atypical antipsychotic drugs (APD). Among predisposing factors are advanced age and comorbid somatic diseases. The aim of this study was to assess the incidence of hypothermia and quantify risk factors. METHOD: Charts of N = 3002 psychogeriatric inpatients were screened for incidence of hypothermia (body core temperature <35.0°C). The frequency of hypothermia was compared between patients treated with versus without APD and, within the sample of APD-treated patients, for (1) specific APD, (2) sex, (3) main diagnosis, and (4) age. RESULTS: N = 54 cases (2.6%) of hypothermia occurred in APD-treated patients and 12 cases (1.3%) in non-APD-treated patients (p = 0.024). In APD-treated patients, only male sex (p = 0.038) and pipamperone were associated with a higher incidence of hypothermia (p = 0.0017). Whereas the main diagnosis delirium showed a trend to significance, age did not correlate with hypothermia. CONCLUSION: Medication with pipamperone was associated with an increased risk of hypothermia. The advanced age of our sample might as well explain the high incidence of hypothermia within our sample and the failure to detect high age as a risk factor due to a ceiling effect.

Prognostic role of TOPS in ambulance-transferred neonates in a low-resource setting: a retrospective observational study.

BACKGROUND: Assessing the severity of transferred neonates at admission can improve resource allocation. This study evaluated the role of TOPS (illness severity score including temperature, oxygen saturation, skin perfusion and blood sugar) in predicting mortality in neonates transferred by ambulance in a low-resource setting. METHODS: The study was conducted at Beira Central Hospital (Mozambique). Infants who were transferred by ambulance to the Neonatal Intensive Care Unit between 16th June and 16th October 2021 were included. The association between TOPS and mortality was investigated with a logistic regression model. Receiver-operating characteristics (ROC) curve was derived for TOPS; area under the ROC curve, sensitivity and specificity were calculated. RESULTS: In-transport mortality was 2/198 (1.0%) and in-hospital mortality was 75/196 (38.3%). Median gestational age and birthweight were 38 weeks and 2600 g. Main causes of admission were asphyxia (29.3%), prematurity (25.3%) and sepsis (22.7%). Hypothermia and oxygen desaturation at admission were 75.8% and 32.3%. TOPS ≥ 1 was associated with increased mortality risk (odds ratio 7.06. 95% confidence interval 1.90 to 45.82), with 0.97 sensitivity and 0.26 specificity. CONCLUSIONS: The high mortality rate calls for interventions and quality initiative studies to improve the transfer process and the conditions at admission. TOPS can be used to identify neonates at risk of mortality and concentrate efforts of health care providers. Interventions preventing hypothermia and oxygen desaturation should be implemented in pre-transport stabilization and care during transport.

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.

Brugada syndrome in the setting of hypothermia.

Hypothermia is a common diagnosis in the Emergency Department. It can cause a multitude of symptoms and complications if not treated promptly. The following case report discusses Brugada pattern on an electrocardiogram in a patient with hypothermia and diabetic ketoacidosis. There was resolution of the Brugada pattern on the electrocardiogram after the patient was warmed to 35.3 °C.

Validation of a Prediction Model for Intraoperative Hypothermia in Patients Receiving General Anesthesia.

Objectives: There have been no fully validated tools for the rapid identification of surgical patients at risk of intraoperative hypothermia. The objective of this study was to validate the performance of a previously established prediction model in estimating the risk of intraoperative hypothermia in a prospective cohort. Methods: In this observational study, consecutive adults scheduled for elective surgery under general anesthesia were enrolled prospectively at a tertiary hospital between September 4, 2020, and December 28, 2020. An intraoperative hypothermia risk score was calculated by a mobile application of the prediction model. A wireless axillary thermometer was used to continuously measure perioperative core temperature as the reference standard. The discrimination and calibration of the model were assessed, using the area under the receiver operating characteristic curve (AUC), Hosmer-Lemeshow goodness-of-fit test, and Brier score. Results: Among 227 participants, 99 (43.6%) developed intraoperative hypothermia, and 10 (4.6%) received intraoperative active warming with forced-air warming. The model had an AUC of 0.700 (95% confidence interval [CI], 0.632-0.768) in the overall cohort with adequate calibration (Hosmer-Lemeshow χ 2 = 13.8, P=0.087; Brier score = 0.33 [95% CI, 0.29-0.37]). We categorized the risk scores into low-risk, moderate-risk, and high-risk groups, in which the incidence of intraoperative hypothermia was 23.0% (95% CI, 12.4-33.5), 43.4% (95% CI, 33.7-53.2), and 62.7% (95% CI, 51.5-74.3), respectively (P for trend <0.001). Conclusions: The intraoperative hypothermia prediction model demonstrated possibly helpful discrimination and adequate calibration in our prospective validation. These findings suggest that the risk screening model could facilitate future perioperative temperature management.

Cold Weather Injuries: Initial Evaluation and Management.

ABSTRACT: As more people take to extreme sporting activities and hobbies, the sports medicine physician should be proficient in early identification and initial sideline or field management of cold weather injuries. There is significant mortality and morbidity associated with these conditions. The most severe of these are hypothermia and frostbite, which have limited evidence for their field management. Nonfreezing cold injuries and chilblains are much rarer, although appropriate prevention and treatment strategies can be used to minimize harm to athletes. This article will provide the most updated recommendations for field or sideline evaluation and initial management of hypothermia, frostbite, nonfreezing cold injury, and chilblains.

Early Skin-to-Skin Care with a Polyethylene Bag for Neonatal Hypothermia: A Randomized Clinical Trial.

OBJECTIVE: To determine whether early polyethylene bag use with skin-to-skin care compared with skin-to skin care alone reduce hypothermia among infants born at term in resource-limited settings. STUDY DESIGN: Infants born at term in the tertiary referral center in Lusaka, Zambia, were randomized using sequentially numbered sealed opaque envelopes in 2 phases: after birth (phase 1) and at 1 hour after birth (phase 2) to either skin-to-skin care with polyethylene bags or skin-to-skin care alone. Infant and maternal temperatures were recorded at birth, 1 hour, and every 4 hours until discharge or 24 hours. RESULTS: We enrolled 423 infants from May 2017 to August 2017. The rate of moderate-severe hypothermia (temperature <36.0°C) at 1 hour was 72 of 208 (34.6%) in the skin-to-skin care with a polyethylene bag group compared with 101 of 213 (47.4%) in the skin-to-skin care alone group (relative risk, 0.71; 95% CI 0.56-0.90; P < .01; number needed to treat = 8). phase 1 treatment assignment significantly modified the effect of phase 2 treatment (P = .02 for interaction effect). Among infants randomized to skin-to-skin care with a polyethylene bag in phase 1, the risk of moderate-severe hypothermia was decreased in infants randomized to continue this intervention until discharge compared with infants randomized to skin-to-skin care alone. The rates of severe hypothermia, hyperthermia, and other adverse events did not differ significantly between groups. CONCLUSIONS: Low-cost polyethylene bags started after birth in combination with skin-to-skin care reduced moderate or severe hypothermia at 1 hour and at discharge among infants born at term in a resource-limited setting compared with skin-to-skin care alone. TRIAL REGISTRATION: ClinicalTrials.gov: NCT03141723.

Effect of amino acid infusion during cesarean delivery on newborn temperature: a randomized controlled trial.

BACKGROUND: The effect of maternal amino acid (AA) infusion before and during cesarean delivery on neonatal temperature remains unknown. We hypothesized that thermogenic effects of AA metabolism would help maintain body temperature of newborn babies and their mothers. METHODS: Seventy-six parturients scheduled for elective singleton term cesarean delivery were equally randomized to receive intravenous 200 ml of AA or placebo approximately 1 h before subarachnoid block (infusion rate:100 ml/h). The primary outcome was the newborn rectal temperature at 0, 5 and 10 min after birth. The secondary outcomes included the maternal rectal temperature at six time-points: T0 = before starting study solution infusion, T1 = 30 min after starting infusion, T2 = one hour after starting infusion, T3 = during spinal block, T4 = half an hour after spinal block, T5 = at the time of birth and T6 = at the end of infusion, as well as maternal thermal discomfort and shivering episodes. RESULTS: There were no differences in newborn temperature between the two groups at any of the time-points (intervention-time-interaction effect, P = 0.206). The newborn temperature (mean [95%CI] °C) at birth was 37.5 [37.43-37.66] in the AA and 37.4 [37.34-37.55] in the placebo group. It showed a significant (P < 0.001) downward trend at 5 and 10 min after birth (time effect) in both groups. One neonate in the AA and five in the placebo group were hypothermic (temperature < 36.5 °C) (P = 0.20). There was a significant difference in the maternal temperature at all time points between the two groups (Intervention-time interaction effect, P < 0.001). However, after adjustment for multiplicity, the difference was significant only at T6 (P = 0.001). The mean difference [95%CI] in temperature decline from baseline (T0) till the end of infusion (T6) between the two groups was - 0.39 [- 0.55;- 0.22] °C (P < 0.0001). Six mothers receiving placebo and none receiving AA developed hypothermia (temperature < 36 °C) (P = 0.025). Maternal thermal discomfort and shivering episodes were unaffected by AA therapy. CONCLUSIONS: Under the conditions of this study, maternal AA infusion before and during spinal anesthesia for cesarean delivery did not influence the neonatal temperature within 10 min after birth. In addition, the maternal temperature was only maintained at two hours of AA infusion. TRIAL REGISTRATION: ClinicalTrials.government, Identifier NCT02575170 . Registered on 10th April, 2015 - Retrospectively registered.

Outcomes of patients suffering unwitnessed hypothermic cardiac arrest rewarmed with extracorporeal life support: A systematic review.

Prolonged cardiac arrest (CA) may lead to neurologic deficit in survivors. Good outcome is especially rare when CA was unwitnessed. However, accidental hypothermia is a very specific cause of CA. Our goal was to describe the outcomes of patients who suffered from unwitnessed hypothermic cardiac arrest (UHCA) supported with Extracorporeal Life Support (ECLS). We included consecutive patients' cohorts identified by systematic literature review concerning patients suffering from UHCA and rewarmed with ECLS. Patients were divided into four subgroups regarding the mechanism of cooling, namely: air exposure; immersion; submersion; and avalanche. A statistical analysis was performed in order to identify the clinical parameters associated with good outcome (survival and absence of neurologic impairment). A total of 221 patients were included into the study. The overall survival rate was 27%. Most of the survivors (83%), had no neurologic deficit. Asystole was the presenting CA rhythm in 48% survivors, of which 79% survived with good neurologic outcome. Variables associated with survival included the following: female gender (P < .001); low core temperature (P = .005); non-asphyxia-related mechanism of cooling (P < .001); pulseless electrical activity as an initial rhythm (P < .001); high blood pH (P < .001); low lactate levels (P = .003); low serum potassium concentration (P < .001); and short resuscitation duration (P = .004). Severely hypothermic patients with unwitnessed CA may survive with good neurologic outcome, including those presenting as asystole. The initial blood pH, potassium, and lactate concentration may help predict outcome in hypothermic CA.

Association between frailty and mortality among patients with accidental hypothermia: a nationwide observational study in Japan.

BACKGROUND: Frailty has been associated with a risk of adverse outcomes, and mortality in patients with various conditions. However, there have been few studies on whether or not frailty is associated with mortality in patients with accidental hypothermia (AH). In this study, we aim to determine this association in patients with AH using Japan's nationwide registry data. METHODS: The data from the Hypothermia STUDY 2018&19, which included patients of ≥18 years of age with a body temperature of ≤35 °C, were obtained from a multicenter registry for AH conducted at 120 institutions throughout Japan, collected from December 2018 to February 2019 and December 2019 to February 2020. The clinical frailty scale (CFS) score was used to determine the presence and degree of frailty. The primary outcome was the comparison of mortality between the frail and non-frail patient groups. RESULTS: In total, 1363 patients were included in the study, of which 920 were eligible for the analysis. The 920 patients were divided into the frail patient group (N = 221) and non-frail patient group (N = 699). After 30-days of hospitalization, 32.6% of frail patients and 20.6% of non-frail patients had died (p < 0.001). Frail patients had a significantly higher risk of 90-day mortality (Hazard ratio [HR], 1.64; 95% confidence interval [CI], 1.25-2.17; p < 0.001). Based on the Cox proportional hazards analysis using multiple imputation, after adjustment for age, potassium level, lactate level, pH value, sex, CPK level, heart rate, platelet count, location of hypothermia incidence, and rate of tracheal intubation, the HR was 1.69 (95% CI, 1.25-2.29; p < 0.001). CONCLUSIONS: This study showed that frailty was associated with mortality in patients with AH. Preventive interventions for frailty may help to avoid death caused by AH.

New-onset intra-operative hyperthermia in a large surgical patient population: A retrospective observational study.

BACKGROUND: Intra-operative hypothermia has been extensively investigated. However, the incidence of intra-operative hyperthermia has not been investigated in detail. OBJECTIVE: The main objective of this study was to assess the incidence and risk factors of new-onset intra-operative hyperthermia in a large surgical patient population. DESIGN: Retrospective database review. SETTING: Tertiary-care teaching hospital. PATIENTS: Patients undergoing surgery with general anaesthesia between 1 January 2002 and 31 December 2017 were included. MAIN OUTCOME MEASURES: The primary outcome measurement was new-onset intra-operative hyperthermia (>37.5 °C). A logistic regression model was fitted to identify risk factors for intra-operative hyperthermia. RESULTS: A total of 103 648 patients were included in the final analyses. The incidence of new-onset hyperthermia in the overall patient cohort was 6.45%, reaching 20 to 30% after prolonged (>8 h) surgery, and was up to 26.5% in paediatric patients. The use of forced air active patient warming, larger amounts of fluid administration, longer surgery, younger age and smaller body size were all independently associated with intra-operative hyperthermia. The adoption of the Surgical Care Improvement Project (SCIP) temperature measures was associated with an increased incidence of intra-operative hyperthermia. CONCLUSION: Mild intra-operative hyperthermia is not uncommon particularly in longer procedures and small children.

Hypothermia in Young Infants: Frequency and Yield of Sepsis Workup.

OBJECTIVES: Serious bacterial infections (SBIs) in young infants can present with fever or hypothermia. There are substantial data on fever as a presentation for SBI that help to inform the clinical approach. In contrast, data on hypothermia are lacking, thus leaving clinicians without guidance. We aimed to describe the workup and findings, specifically the occurrence, of SBIs in infants younger than 60 days of life with hypothermia. METHODS: We reviewed the medical records of infants younger than 60 days of life with rectal temperature of less than 36.5°C upon arrival to a children's hospital emergency department between January 2013 and December 2014. Comparisons were made between those who were found to have an SBI and those without. Serious bacterial infection was defined as bacteremia, bacterial meningitis, pneumonia, or urinary tract infection (UTI). RESULTS: From the 414 patients identified, 104 (25%) underwent a sepsis evaluation of blood, urine, and/or cerebrospinal fluid culture. Serious bacterial infections were identified in 9 patients: 4 with UTI, 1 with pneumonia, 2 with bacteremia, 1 with pneumonia and UTI, and 1 with meningitis and bacteremia. Compared with patients with negative cultures, patients with SBI were older and had elevated absolute band counts and elevated immature-to-total neutrophil ratio. CONCLUSIONS: Approximately a quarter of infants younger than 60 days with hypothermia were evaluated for SBI. Serious bacterial infection was identified in 9% of evaluated infants (2% of all hypothermic infants). Hypothermia can be a presenting sign of SBI.

Osborn Wave Is Related to Ventricular Fibrillation and Tachycardia in Hypothermic Patients.

BACKGROUND: The Osborn wave (OW) is often observed in hypothermic patients; however, whether OW in hypothermic patients is related to the development of fatal ventricular arrhythmia, including ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT), remains undetermined. This study aimed to estimate the association between OW and the incidence of fatal ventricular arrhythmias.Methods and Results: This retrospective study used the Japanese Accidental Hypothermia Network registry database and included 572 hypothermic patients. Patients were divided into the OW group (those with OW) and non-OW group (those without OW). The relationship between the development of fatal arrhythmias and presence of OW was assessed using the chi-squared test. All patients who developed VF/VT (n=10) had OW on electrocardiogram upon hospital arrival. The presence of OW had a sensitivity of 100%, specificity of 47.8%, positive predictive value of 4.0%, and negative predictive value of 100% for VF/VT development. The in-hospital mortality rate was 22.3% in the OW group and 21.2% in the non-OW group (P=0.781). CONCLUSIONS: OW was observed in all hypothermic patients with VF/VT. The occurrence of ventricular arrhythmias is highly unlikely in the absence of OW on the electrocardiogram. Although the presence of OW might be used to predict these fatal arrhythmias in hypothermic patients, there was no association between the presence of OW and in-hospital mortality.

Secondary hypothermia in patients with super-refractory status epilepticus managed with propofol and ketamine.

BACKGROUND: Therapeutic hypothermia as a potent nonpharmacologic antiseizure therapy has been investigated experimentally in animal models and humans. Although induced hypothermia has been shown to be neuroprotective in acute convulsive status epilepticus, whether its use will translate into improved outcomes for patients with super-refractory nonconvulsive status epilepticus (SRNCSE) has been debated. No clinical data are available on the occurrence and prognostic impact of secondary hypothermia (s-HT) in patients with SRNCSE. With the possibility of core to periphery redistribution of heat with propofol and a centrally mediated dose-dependent fall in body temperature with ketamine, we aimed to investigate the incidence of s-HT events in patients with SRNCSE managed with propofol and ketamine and their impact on clinical outcomes. METHODS: We performed a retrospective observational analysis of consecutive patients with SRNCSE managed with propofol and/or ketamine in a single-center neurological intensive care unit between December 1, 2012 and December 31, 2015. Patients were divided according to the occurrence of hypothermia (temperature < 35.0 °C) into an s-HT group and a nonhypothermia (n-HT) group. Patients who received targeted temperature management therapy were excluded. We compared the demographics, comorbidities, treatment characteristics, and outcomes between groups. RESULTS: Ninety-nine consecutive patients with SRNCSE managed with propofol and/or ketamine were identified during the study period. Twenty patients who received targeted temperature management were excluded, leaving a total of 79 patients for analysis. Hypothermia was observed in 52% (41/79) of the study population. Ketamine was used in 63/79 patients (80%). Ketamine infusion rates were higher and of longer duration among patients who developed s-HT compared with those who did not (mean dosage: 57.35 ±â€¯26.6 mcg/kg/min vs 37.17 ±â€¯15 mcg/kg/min, P = 0.001; duration: 116.36 ±â€¯81.9 h vs 88 ±â€¯89.7 h, P = 0.048). Propofol was used in 78/79 patients (99%), with no significant differences in characteristics between groups (mean dosage: 46.44 ±â€¯20.2 mcg/kg/min vs 36.9 ±â€¯12.9 mcg/kg/min, P = 0.058; duration: 125.43 ±â€¯96.4 h vs 102.3 ±â€¯87.1 h, P = 0.215). No significant differences in demographics, comorbidities, status epilepticus duration and resolution rates, and outcomes were observed between groups. CONCLUSION: In this single-center retrospective analysis of patients whose SRNCSE is being treated, higher doses and longer durations of ketamine were associated with the occurrence of s-HT. Further investigation is warranted to clarify the thermogenic effects of ketamine and its effect on status epilepticus outcomes.