Accidental hypothermia

The impact of therapeutic hypothermia on developmental outcomes in lower-middle income countries: A systematic review and meta-analysis with a health equity lens

Hypoxic-ischemic encephalopathy (HIE) from birth asphyxia is particularly burdensome on lower-middle income countries (LMICs). Our systematic review examined early and late developmental outcomes related to neonatal therapeutic hypothermia (TH) without disability thresholds or cut-offs pre-determined by high-income countries. A search of PubMed, Web of Science, and Embase databases yielded 364 articles; 11 studies met eligibility criteria. According to published standards for reporting of studies, 3 of the 11 studies were good quality and 8 studies were excellent. Within-group changes in early and late developmental outcomes showed large, significant effect sizes (d = -2.07; CI = -0.77, -3.36; d = 3.17; CI = 2.14, 4.21). Between-group differences showed significant effect sizes in late but not early developmental outcomes (d = 0.85; CI = 0.62, 1.07; d = -0.16; CI = -0.58, 0.25). The evidence indicates that TH improves developmental outcomes prior to hospital discharge and after 6 months, and surpasses standard of care for 6-month and later developmental outcomes.

The role of accidental hypothermia in drowning patients with out-of-hospital cardiac arrest: A nationwide registry-based cohort study

AIM

This study aimed to investigate the associations between hypothermia and mortality or poor neurological outcome in a nationwide cohort of drowning patients with out-of-hospital cardiac arrest (OHCA).

METHODS

This nationwide, registry-based cohort study reported in-hospital data on drowning patients with OHCA following the Utstein Style For Drowning. Drowning patients with OHCA were identified in the Danish Cardiac Arrest Registry from 2016 to 2021. The primary outcome was the rate of mortality or poor neurological outcome (corresponding to a modified Rankin Scale [mRS] score > 3) at 180 days after the drowning incident in patients with OHCA and accidental hypothermia (<35 °C) vs normothermia (≥35 °C).

RESULTS

This study identified 118 drowning patients with OHCA and found an increased rate of mRS > 3 at 180 days after the drowning incident in the hypothermic group compared to the normothermic group (74% vs 18%, p < 0.001). The 180-day mortality (mRS = 6) was 69% in the hypothermic group compared to 16% in the normothermic group (p < 0.001). The hypothermic group had higher rates of ongoing CPR at hospital admission (45% vs 7%, p < 0.001), intensive care unit admission (70% vs 41%, p = 0.003), and mechanical ventilation during hospitalisation (78% vs 32%, p < 0.001) compared to the normothermic group.

CONCLUSION

Hypothermic drowning patients with OHCA had a higher risk of mortality or poor neurological outcome at 180 days compared to normothermic drowning patients with OHCA. This association may likely be explained by confounding factors such as prolonged submersion and cardiac arrest. Further research is warranted.

Extracorporeal Life Support in Accidental Hypothermia with Cardiac Arrest-A Narrative Review

Severely hypothermic patients, especially suffering cardiac arrest, require highly specialized treatment. The most common problems affecting the recognition and treatment seem to be awareness, logistics, and proper planning. In severe hypothermia, pathophysiologic changes occur in the cardiovascular system leading to dysrhythmias, decreased cardiac output, decreased central nervous system electrical activity, cold diuresis, and noncardiogenic pulmonary edema. Cardiac arrest, multiple organ dysfunction, and refractory vasoplegia are indicative of profound hypothermia. The aim of these narrative reviews is to describe the peculiar pathophysiology of patients suffering cardiac arrest from accidental hypothermia. We describe the good chances of neurologic recovery in certain circumstances, even in patients presenting with unwitnessed cardiac arrest, asystole, and the absence of bystander cardiopulmonary resuscitation. Guidance on patient selection, prognostication, and treatment, including extracorporeal life support, is given.

Management of hypothermic submersion associated cardiac arrest in a 5-year-old child: A case report

We report a case of severe accidental hypothermia (core body temperature of 26.8 °C) in a five-year-old boy due to submersion in freezing lake water. The child was brought to the hospital intubated, in cardiac arrest rhythm of pulseless electrical activity and with dilated and nonreactive pupils. We continued with cardiopulmonary resuscitation and administrated adrenaline in boluses (10 μg/kg) and infusion (0.2 μg/kg/min). Spontaneous circulation returned after 50 minutes. Rewarming was performed with minimally invasive techniques. Post resuscitation he was admitted to the intensive care unit, where he required venovenous extracorporeal membrane oxygenation due to respiratory failure. He was discharged from the hospital neurologically intact and without organ damage on day 17 post arrest.

Focal intra-colon cooling reduces organ injury and systemic inflammation after REBOA management of lethal hemorrhage in rats

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a lifesaving maneuver for the management of lethal torso hemorrhage. However, its prolonged use leads to distal organ ischemia-reperfusion injury (IRI) and systemic inflammatory response syndrome (SIRS). The objective of this study is to investigate the blood-based biomarkers of IRI and SIRS and the efficacy of direct intestinal cooling in the prevention of IRI and SIRS. A rat lethal hemorrhage model was produced by bleeding 50% of the total blood volume. A balloon catheter was inserted into the aorta for the implementation of REBOA. A novel TransRectal Intra-Colon (TRIC) device was placed in the descending colon and activated from 10 min after the bleeding to maintain the intra-colon temperature at 37 °C (TRIC37°C group) or 12 °C (TRIC12°C group) for 270 min. The upper body temperature was maintained at as close to 37 °C as possible in both groups. Blood samples were collected before hemorrhage and after REBOA. The organ injury biomarkers and inflammatory cytokines were evaluated by ELISA method. Blood based organ injury biomarkers (endotoxin, creatinine, AST, FABP1/L-FABP, cardiac troponin I, and FABP2/I-FABP) were all drastically increased in TRIC37°C group after REBOA. TRIC12°C significantly downregulated these increased organ injury biomarkers. Plasma levels of pro-inflammatory cytokines TNF-α, IL-1b, and IL-17F were also drastically increased in TRIC37°C group after REBOA. TRIC12°C significantly downregulated the pro-inflammatory cytokines. In contrast, TRIC12°C significantly upregulated the levels of anti-inflammatory cytokines IL-4 and IL-10 after REBOA. Amazingly, the mortality rate was 100% in TRIC37°C group whereas 0% in TRIC12°C group after REBOA. Directly cooling the intestine offered exceptional protection of the abdominal organs from IRI and SIRS, switched from a harmful pro-inflammatory to a reparative anti-inflammatory response, and mitigated mortality in the rat model of REBOA management of lethal hemorrhage.

Is prehospital use of active external warming dangerous for patients with accidental hypothermia: a systematic review

BACKGROUND

Optimal prehospital management and treatment of patients with accidental hypothermia is a matter of frequent debate, with controversies usually revolving around the subject of rewarming. The rule of thumb in primary emergency care and first aid for patients with accidental hypothermia has traditionally been to be refrain from prehospital active rewarming and to focus on preventing further heat loss. The potential danger of active external rewarming in a prehospital setting has previously been generally accepted among the emergency medicine community based on a fear of potential complications, such as "afterdrop", "rewarming syndrome", and "circum-rescue collapse". This has led to a reluctancy from health care providers to provide patients with active external rewarming outside the hospital. Different theories and hypotheses exist for these physiological phenomena, but the scientific evidence is limited. The research question is whether the prehospital use of active external rewarming is dangerous for patients with accidental hypothermia. This systematic review intends to describe the acute unfavourable adverse effects of active external rewarming on patients with accidental hypothermia.

METHODS

A literature search of the Cochrane Library, MEDLINE, EMBASE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL], and SveMed+ was carried out, and all articles were screened for eligibility. All article formats were included.

RESULTS

Two thousand three hundred two articles were screened, and eight articles met our search criteria. Three articles were case reports or case series, one was a prospective study, two were retrospective studies, one article was a literature review, and one article was a war report from the Napoleonic Wars.

CONCLUSIONS

One of the main findings in this article was the poor scientific quality and the low number of articles meeting our inclusion criteria. When conducting this review, we found no scientific evidence of acceptable quality to prove that the use of active external rewarming is dangerous for patients with accidental hypothermia in a prehospital setting. We found several articles claiming that active external rewarming is dangerous, but most of them do not cite references or provide evidence.

Machine learning-based prediction of acute severity in infants hospitalized for bronchiolitis: a multicenter prospective study

We aimed to develop machine learning models to accurately predict bronchiolitis severity, and to compare their predictive performance with a conventional scoring (reference) model. In a 17-center prospective study of infants (aged < 1 year) hospitalized for bronchiolitis, by using routinely-available pre-hospitalization data as predictors, we developed four machine learning models: Lasso regression, elastic net regression, random forest, and gradient boosted decision tree. We compared their predictive performance-e.g., area-under-the-curve (AUC), sensitivity, specificity, and net benefit (decision curves)-using a cross-validation method, with that of the reference model. The outcomes were positive pressure ventilation use and intensive treatment (admission to intensive care unit and/or positive pressure ventilation use). Of 1,016 infants, 5.4% underwent positive pressure ventilation and 16.0% had intensive treatment. For the positive pressure ventilation outcome, machine learning models outperformed reference model (e.g., AUC 0.88 [95% CI 0.84-0.93] in gradient boosted decision tree vs 0.62 [95% CI 0.53-0.70] in reference model), with higher sensitivity (0.89 [95% CI 0.80-0.96] vs. 0.62 [95% CI 0.49-0.75]) and specificity (0.77 [95% CI 0.75-0.80] vs. 0.57 [95% CI 0.54-0.60]). The machine learning models also achieved a greater net benefit over ranges of clinical thresholds. Machine learning models consistently demonstrated a superior ability to predict acute severity and achieved greater net benefit.

The Problematic 2014 American Academy of Pediatrics Bronchiolitis Guidelines

The 2014 American Academy of Pediatrics bronchiolitis guidelines do not adequately serve the needs and clinical realities of front-line clinicians caring for undifferentiated wheezing infants and children. This article describes the clinical challenges of evaluating and managing a heterogeneous disease syndrome presenting as undifferentiated patients to the emergency department. Although the 2014 American Academy of Pediatrics bronchiolitis guidelines and the multiple international guidelines that they closely mirror have made a good faith attempt to provide clinicians with the best evidence-based recommendations possible, they have all failed to address practical, front-line clinical challenges. The therapeutic nihilism of the guidelines and the dissonance between many of the recommendations and frontline realities have had wide-ranging consequences. Nevertheless, newer evidence of therapeutic options is emerging and forecasts hope for more therapeutically optimistic recommendations with the next revision of the guidelines.

Accidental hypothermia: factors related to long-term hospitalization. A retrospective study from northern Finland

Accidental hypothermia has a low incidence, but is associated with a high mortality rate. Knowledge about concomitant factors, complications, and length of hospital stay is limited. A retrospective cohort study on patients with accidental hypothermia admitted to Oulu University Hospital in Finland, over a 5-year period. Patients were categorized as short-stay patients (7 days or less) and long-stay patients (more than 7 days) according to their length of stay in hospital. From a total of 105 patients, 67 patients were included in the analyses. Alcohol abuse was the most common concomitant factor (54 %). Median length of hospital stay was 4 days, and 16 patients (24 %) stayed in hospital over 7 days (median 15 days). Thirty-day mortality was low (14/105, 13 %). Patients with long-term hospitalization had a lower initial temperature (28.4 versus 31.2 °C, p = 0.011), a lower level of consciousness (GCS score 8.4 versus 12.8, p = 0.003), more severe acidosis (pH 7.08 versus 7.28, p = 0.005, and lactate 7.2 versus 3.9, p = 0.043), and a lower level of platelets (183 versus 242, p = 0.041) on admission compared with short-stay patients. Thirty-six patients (54 %) had at least one complication, and this prolonged median hospital treatment for 2.5 days (p < 0.001). Alcohol is the most common concomitant factor and every fourth patient spends more than 7 days in hospital. Long-term hospitalization is related to a lower core temperature, lower consciousness, more severe lactic acidosis, lower platelet level and infections, rhabdomyolysis, and renal failure.

Etiology and clinical features of viral bronchiolitis in infancy

BACKGROUND

Bronchiolitis is a common lower respiratory tract infection in infancy. The aim of this review is to present the clinical profile of viral bronchiolitis, the different culprit viruses and the disease severity in relation to the viral etiology.

DATA SOURCES

Databases including PubMed and Google Scholar were searched for articles about the clinical features of bronchiolitis and its viral etiology. The most relevant articles to the scope of this review were analyzed.

RESULTS

Currently there are two main definitions for bronchiolitis which are not identical, the European definition and the American one. The most common viral pathogen that causes bronchiolitis is respiratory syncytial virus which was identified in 1955; now many other viruses have been implicated in the etiology of bronchiolitis such as rhinovirus, adenovirus, metapneumovirus, and bocavirus. Several studies have attempted to investigate the correlation of bronchiolitis severity with the type of detected virus or viruses. However, the results were not consitent.

CONCLUSIONS

For the time being, the diagnosis of bronchiolitis remains clinical. The isolation of the responsible respiratory pathogens does not seem to confer to the prognosis of the disease severity.

Outcome after resuscitation beyond 30 minutes in drowned children with cardiac arrest and hypothermia: Dutch nationwide retrospective cohort study

OBJECTIVES

To evaluate the outcome of drowned children with cardiac arrest and hypothermia, and to determine distinct criteria for termination of cardiopulmonary resuscitation in drowned children with hypothermia and absence of spontaneous circulation.

DESIGN

Nationwide retrospective cohort study.

SETTING

Emergency departments and paediatric intensive care units of the eight university medical centres in the Netherlands.

PARTICIPANTS

Children aged up to 16 with cardiac arrest and hypothermia after drowning, who presented at emergency departments and/or were admitted to intensive care.

MAIN OUTCOME MEASURE

Survival and neurological outcome one year after the drowning incident. Poor outcome was defined as death or survival in a vegetative state or with severe neurological disability (paediatric cerebral performance category (PCPC) ≥ 4).

RESULTS

From 1993 to 2012, 160 children presented with cardiac arrest and hypothermia after drowning. In 98 (61%) of these children resuscitation was performed for more than 30 minutes (98/160, median duration 60 minutes), of whom 87 (89%) died (95% confidence interval 83% to 95%; 87/98). Eleven of the 98 children survived (11%, 5% to 17%), but all had a PCPC score ≥ 4. In the 62 (39%) children who did not require prolonged resuscitation, 17 (27%, 16% to 38%) survived with a PCPC score ≤ 3 after one year: 10 (6%) had a good neurological outcome (score 1), five (3%) had mild neurological disability (score 2), and two (1%) had moderate neurological disability (score 3). From the original 160 children, only 44 were alive at one year with any outcome.

CONCLUSIONS

Drowned children in whom return of spontaneous circulation is not achieved within 30 minutes of advanced life support have an extremely poor outcome. Good neurological outcome is more likely when spontaneous circulation returns within 30 minutes of advanced life support, especially when the drowning incident occurs in winter. These findings question the therapeutic value of resuscitation beyond 30 minutes in drowned children with cardiac arrest and hypothermia.

Temporal relationships of blood pressure, heart rate, baroreflex function, and body temperature change over a hibernation bout in Syrian hamsters

Hibernating mammals undergo torpor during which blood pressure (BP), heart rate (HR), metabolic rate, and core temperature (TC) dramatically decrease, conserving energy. While the cardiovascular system remains functional, temporal changes in BP, HR, and baroreceptor-HR reflex sensitivity (BRS) over complete hibernation bouts and their relation to TC are unknown. We implanted BP/temperature telemetry transmitters into Syrian hamsters to test three hypotheses: H-1) BP, HR, and BRS decrease concurrently during entry into hibernation and increase concurrently during arousal; H-2) these changes occur before changes in TC; and H-3) the pattern of changes is consistent over successive bouts. We found: 1) upon hibernation entry, BP and HR declined before TC and BRS, suggesting baroreflex control of HR continues to regulate BP as the BP set point decreases; 2) during the later phase of entry, BRS decreased rapidly whereas BP and TC fell gradually, suggesting the importance of TC in further BP declines; 3) during torpor, BP slowly increased (but remained relatively low) without changes in HR or BRS or increased TC, suggesting minimal baroreflex or temperature influence; 4) during arousal, increased TC and BRS significantly lagged increases in BP and HR, consistent with establishment of tissue perfusion before increased TC/metabolism; and 5) the temporal pattern of these changes was similar over successive bouts in all hamsters. These results negate H-1, support H-2 with respect to BP and HR, support H-3, and indicate that the baroreflex contributes to cardiovascular regulation over a hibernation bout, albeit operating in a fundamentally different manner during entry vs. arousal.