Accidental hypothermia

Takotsubo Cardiomyopathy Complicating Diabetic Ketoacidosis, Hypothermia and Hypernatremia in a Comatose Patient

Takotsubo cardiomyopathy (TCM) is a transient wall motion abnormality of the left ventricular apex associated with emotional or physical stress. In the setting of diabetic ketoacidosis (DKA), it is thought to be caused by the compound effect of a catecholamine surge and the noxious effect of acidosis and ketones leading to myocardial stunning. In this report, the first of its kind in the Middle East, we describe the case of a 71-year-old comatose patient, who was being treated for DKA and hypernatremia and was incidentally diagnosed with TCM. We also review 15 case reports of DKA-induced TCM published to date in the literature, many of which had an atypical presentation and good outcomes. Furthermore, we discuss possible risk factors for TCM in our case and supporting literature. It is recommended to maintain increased vigilance and attempt early identification of such conditions in acutely ill patients to prevent life-threatening complications.

Hypothermic cardiac arrest patients admitted to hospital who were not rewarmed with extracorporeal life support: A retrospective study

Aims

Our goal was to study hypothermic cardiac arrest (CA) patients who were not rewarmed by Extracorporeal Life Support (ECLS) but were admitted to a hospital equipped for it. The focus was on whether the decisions of non-rewarming, meaning termination of resuscitation, were compliant with international guidelines based on serum potassium at hospital admission.

Methods

We retrospectively included all hypothermic CA who were not rewarmed, from three Swiss centers between 1st January 2000 and 2nd May 2021. Data were extracted from medical charts and assembled into two groups for analysis according to serum potassium. We identified the criteria used to terminate resuscitation. We also retrospectively calculated the HOPE score, a multivariable tool predicting the survival probability in hypothermic CA undergoing ECLS rewarming.

Results

Thirty-eight victims were included in the study. The decision of non-rewarming was compliant with international guidelines for 12 (33%) patients. Among the 36 patients for whom the serum potassium was measured at hospital admission, 24 (67%) had a value that - alone - would have indicated ECLS. For 13 of these 24 (54%) patients, the HOPE score was <10%, meaning that ECLS was not indicated. The HOPE estimation of the survival probabilities, when used with a 10% threshold, supported 23 (68%) of the non-rewarming decisions made by the clinicians.

Conclusions

This study showed a low adherence to international guidelines for hypothermic CA patients. In contrast, most of these non-rewarming decisions made by clinicians would have been compliant with current guidelines based on the HOPE score.

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.

Accidental Hypothermia Treated by Hemodialysis in the Acute Phase: Three Case Reports and a Review of the Literature

Accidental hypothermia is defined as a core body temperature <35°C. Even with the use of multiple active rewarming methods, it has a high mortality rate. No standard treatment strategy for moderate or severe hypothermia in the absence of cardiac arrest has yet been established. We herein report three patients with severe or moderate accidental hypothermia who were treated by hemodialysis in the acute phase. This case report with a literature review describes the usefulness of hemodialysis for the treatment of moderate and severe accidental hypothermia without cardiac arrest.

Accidental hypothermia

Accidental hypothermia causes profound changes to the body's physiology. After an initial burst of agitation (e.g., 36-37°C), vital functions will slow down with further cooling, until they vanish (e.g. <20-25°C). Thus, a deeply hypothermic person may appear dead, but may still be able to be resuscitated if treated correctly. The hospital use of minimally invasive rewarming for nonarrested, otherwise healthy patients with primary hypothermia and stable vital signs has the potential to substantially decrease morbidity and mortality for these patients. Extracorporeal life support (ECLS) has revolutionized the management of hypothermic cardiac arrest, with survival rates approaching 100%. Hypothermic patients with risk factors for imminent cardiac arrest (i.e., temperature <28°C, ventricular arrhythmia, systolic blood pressure <90 mmHg), and those who have already arrested, should be transferred directly to an ECLS center. Cardiac arrest patients should receive continuous cardiopulmonary resuscitation (CPR) during transfer. If prolonged transport is required or terrain is difficult, mechanic CPR can be helpful. Intermittent CPR may be appropriate in hypothermic arrest when continuous CPR is impossible. Modern postresuscitation care should be implemented following hypothermic arrest. Structured protocols should be in place to optimize prehospital triage, transport, and treatment as well as in-hospital management, including detailed criteria and protocols for the use of ECLS and postresuscitation care.

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.

Death from Hypothermia during a Training Course under "Extreme Conditions": Related to Two Cases

Death from hypothermia following exhaustion or from various complicated pathologies is no longer a frequent cause of death among combat troops. During a training course under "extreme conditions" in the French Alps, two young African officers died. Confronted with these two clinically confirmed cases of hypothermia, the unknown anatomopathological and biological specificities associated with death from hypothermia were highlighted. In these typical and clinically confirmed cases of death from subacute exhaustion hypothermia, none of the signs revealed by the autopsy were specific. Although some recent publications have addressed the utility of postmortem biochemical markers when establishing a diagnosis, with no anamnesis, with no knowledge or analysis of the circumstances of death, and without an in situ examination of the body, it appears difficult, if not impossible, to confirm that death was caused by hypothermia.

A case of Takotsubo cardiomyopathy induced by accidental hypothermia and diabetic ketoacidosis

Takotsubo cardiomyopathy is known to be triggered by some stress. We report the first case of Takotsubo cardiomyopathy induced by hypothermia and diabetic ketoacidosis (DKA). A 59-year-old woman was brought to our emergency department. Upon examination, she was found to be lethargic and disoriented. The body temperature was 30.9°C, blood pressure was 86/68 mm Hg, blood glucose level was 1018 mg/dl. Urinalysis revealed the presence of ketones and arterial blood gas analysis revealed pH 6.87. She was diagnosed with DKA and accidental hypothermia. An ECG demonstrated a J wave (V(4-5)) and ST-segment elevation (V(3-5)), and an ultrasound cardiogram revealed contractile failure of the left ventricular wall at the apex with hypercontraction of the basal segment. Coronary artery disease was ruled out by coronary angiography, and the diagnosis of Takotsubo cardiomyopathy was confirmed. Physicians should keep in mind that Takotsubo cardiomyopathy can be induced by accidental hypothermia and DKA.

[A case of accidental hypothermia caused by cervical spinal cord injury]

Accidental hypothermia is the state in which body temperature falls due for exposure to a chilly environment. In accidental hypothermia, the mortality rate is higher the lower the body temperature. We report a case of a consciousness disorder and severe hypothermia, with a body temperature below 28 degrees C, in which it later became clear that a cervical spinal cord injury had been caused by a small external force. A 70-year-old woman was transported to our hospital in an ambulance for consciousness disturbance and severe hypothermia. At the time of arrival, her rectal temperature was 26.2 degrees C. We promptly performed rewarming. Her consciousness level became clear, but paralysis and diminished sensation were observed below the C5 domain. We suspected cervical spinal cord injury and performed cervical magnetic resonance imaging. She was diagnosed as having C5 cervical spinal cord injury. When there is a consciousness disorder due to accidental hypothermia, it might not be possible to evaluate the neurological value of the cervical spinal cord injury correctly. The presence of cervical spinal cord injury should be considered when patients have a decreased consciousness level due to hypothermia.

Prehospital resuscitation of the buried avalanche victim

In North America and Europe, approximately 150 people die of avalanches per year, and fatalities are presumed to be many times higher in developing countries. Four factors are decisive for survival: grade of burial, duration of burial, presence of an air pocket and a free airway, and severity of trauma. According to Swiss data, the overall mortality rate with avalanche burial is 23%, but it largely depends on the grade of burial. While the mortality rate is 52.4% in completely buried (head below the snow) victims in the Swiss population, it is only 4.2% in partially buried (head free) victims. Additionally, survival in completely buried victims drops to 30% within the first 35 min, initially due to death from lethal trauma, followed by asphyxia in 20-35 min. Thereafter, survival decreases more gradually and victims who are not fatally injured and are able to breath under the snow slowly succumb to hypoxia, hypercapnia, and hypothermia. In the absence of fatal injuries, rescue strategies depend on the duration of burial and the victim's core temperature. With a burial time<35 min, survival depends on preventing asphyxia by rapid extrication, adequate airway management, and cardiopulmonary resuscitation. With a burial time>35 min, tackling hypothermia is of utmost importance. Therefore, gentle extrication and continuous core temperature and electrocardiogram monitoring are recommended. Pulseless victims with a patent airway and a core temperature<32°C should receive uninterrupted cardiopulmonary resuscitation and be transported to a hospital with extracorporeal rewarming facilities.

Comparison of three different prehospital wrapping methods for preventing hypothermia--a crossover study in humans

BACKGROUND

Accidental hypothermia increases mortality and morbidity in trauma patients. Various methods for insulating and wrapping hypothermic patients are used worldwide. The aim of this study was to compare the thermal insulating effects and comfort of bubble wrap, ambulance blankets / quilts, and Hibler's method, a low-cost method combining a plastic outer layer with an insulating layer.

METHODS

Eight volunteers were dressed in moistened clothing, exposed to a cold and windy environment then wrapped using one of the three different insulation methods in random order on three different days. They were rested quietly on their back for 60 minutes in a cold climatic chamber. Skin temperature, rectal temperature, oxygen consumption were measured, and metabolic heat production was calculated. A questionnaire was used for a subjective evaluation of comfort, thermal sensation, and shivering.

RESULTS

Skin temperature was significantly higher 15 minutes after wrapping using Hibler's method compared with wrapping with ambulance blankets / quilts or bubble wrap. There were no differences in core temperature between the three insulating methods. The subjects reported more shivering, they felt colder, were more uncomfortable, and had an increased heat production when using bubble wrap compared with the other two methods. Hibler's method was the volunteers preferred method for preventing hypothermia. Bubble wrap was the least effective insulating method, and seemed to require significantly higher heat production to compensate for increased heat loss.

CONCLUSIONS

This study demonstrated that a combination of vapour tight layer and an additional dry insulating layer (Hibler's method) is the most efficient wrapping method to prevent heat loss, as shown by increased skin temperatures, lower metabolic rate and better thermal comfort. This should then be the method of choice when wrapping a wet patient at risk of developing hypothermia in prehospital environments.

Experience with helicopter rescue missions for crevasse accidents

We retrospectively studied incidence, patterns, and severity of injury and hypothermia in 95 victims of crevasse accidents. Fifteen (16%) victims were already dead when the rescue team arrived on the scene. Asphyxia (8 victims) was typically caused by snow burial owing to a collapse of snow bridges covering crevasses and was observed only during winter sports activities on glaciers. In 7 patients, death was caused by lethal trauma. Severe or critical multisystem trauma (ISS ≥ 16) was found in an additional 16 victims (17%). Severe or critical injuries were predominantly thoracic injuries and injuries of the extremities and/or pelvic region. Severe accidental hypothermia was observed in 9 of the 95 victims (10%). Three of these suffered from hypothermic sudden cardiac arrest during rescue and were immediately evacuated with ongoing CPR; all 3 made a full recovery after extracorporeal rewarming. More than two-thirds of all victims were still trapped in the crevasse when the rescue team arrived. However, the majority of them could be relatively easily extricated using standard mountaineering equipment and improvised rescue techniques. Prolonged and difficult extrication efforts were needed in less than 10% of victims. Summing up, trauma and asphyxia are the most important causes of mortality and acute life-threatening medical problems in this study, but asphyxia will be far less common in mountain regions offering fewer glacier sport activities in the winter months. Hypothermic sudden cardiac arrest could not be prevented during the difficult conditions of crevasse extrication in one-third of all hypothermic victims; however, prognosis was excellent with advanced life support at the scene and immediate helicopter evacuation to extracorporeal rewarming.

Hemodialysis as a treatment of severe accidental hypothermia

We describe a case of severe accidental hypothermia (core body temperature 23.2 degrees C) successfully treated with hemodialysis in a diabetic patient with preexisting renal insufficiency. Consensus exists about cardiopulmonary bypass as the treatment of choice in cases of severe accidental hypothermia with cardiac arrest. Prospective randomized controlled trials comparing the different rewarming modalities for hemodynamically stable patients with hypothermia, however, are lacking. In our opinion, the choice of a rewarming technique should be patient tailored, knowing that hemodialysis is an efficient, minimally invasive, and readily available technique with the advantage of providing electrolyte support.

Submersion, accidental hypothermia and cardiac arrest, mechanical chest compressions as a bridge to final treatment: a case report

Three young men were trapped in a car at the bottom of a canal at two meters depth, after losing control of their vehicle. They were brought up by rescue divers and found in cardiac arrest. One of three patients had return of spontaneous circulation (ROSC), at 47 min after the accident. This sole survivor had the longest submersion time of the three and he received continued mechanical chest compressions during transportation to the hospital. His temperature at admission was 26.9 degrees C, he was rewarmed to 33 degrees C and kept there for 24 h, followed by continued rewarming to normothermia. On day three, he woke up from coma and was discharged from the intensive care unit after one week. At follow-up six months later, he had a complete cerebral recovery but still had myoclonic twitches in the lower extremities. A mechanical device facilitates chest compressions during transportation and may be beneficial as a bridge to final treatment in the hospital. We recommend that comatose patients after submersion, accidental hypothermia and cardiac arrest are treated with mild hypothermia for 12-24 h.

The use of extrication devices in crevasse accidents: official statement of the International Commission for Mountain Emergency Medicine and the Terrestrial Rescue Commission of the International Commission for Alpine Rescue intended for physicians, paramedics, and mountain rescuers

Injured patients in crevasses who are suspected of having sustained spinal injuries should ideally be extricated after being immobilized in a horizontal position on a stretcher and having a cervical collar applied. Sometimes, however, horizontal stabilization is not possible, because the crevasse is too narrow, and the patient needs to be stabilized in a vertical position. In such cases an extrication device can be a useful adjunct. The Kendrick Extrication Device stabilizes the position of the body and maintains firm support of the head, neck, and torso. Therefore, the International Commission for Mountain Emergency Medicine supports the use of this device in narrow crevasses, if horizontal evacuation is not possible.

A novel intravascular rewarming method to treat severe hypothermia

We report here a patient with severe hypothermia (27 degrees C), who was successfully rewarmed by using a novel intravascular rewarming method (in combination with an airways rewarming method) through endotracheal tube.

[Management of accidental hypothermia]

Patients with hypothermia are frequently encountered in emergency medicine. Particularly trauma patients, but also other predisposed persons, can be expected to suffer from hypothermia at any time of the year. Therapy focuses not only on symptom-oriented intensive care to stabilize and secure vital functions, but also on rewarming. Even in cases of severe hypothermia with circulatory arrest, therapy can produce excellent results. This paper first gives a brief overview of the typical clinical symptoms of hypothermia, before giving a detailed description of the preclinical and in-hospital management of the hypothermia patient. The various rewarming strategies are the subject of special attention and critical evaluation.

[Severe accidental hypothermia with cardiac arrest and extracorporeal rewarming. A case report of a 2-year-old child]

In patients with severe hypothermia and cardiac arrest, active rewarming is recommended by extracorporeal circulation with cardiopulmonary bypass. The current guidelines for resuscitation of the European Resuscitation Council now include the recommendation regarding patients with hypothermia remaining comatose after initial resuscitation to accomplish an active rewarming only up to a temperature of 32-34 degrees C and to maintain a mild hypothermia for 12-24 h. We report the case of a 2-year-old boy who suffered from severe hypothermia after falling into ice-cold water. On discovery cardiac arrest with asystole was present and the first measured temperature was 23.8 degrees C. Resuscitation led to restoration of spontaneous circulation. The patient was rewarmed by extracorporeal circulation with cardiopulmonary bypass to 33 degrees C then mild hypothermia was maintained for a further 12 h. On the third day after the accident the patient was extubated and after a further 9 days was discharged without any sequelae.

Prolonged extracorporeal membrane oxygenation-assisted support provides improved survival in hypothermic patients with cardiocirculatory arrest

OBJECTIVE

Extracorporeal circulation is considered the gold standard in the treatment of hypothermic cardiocirculatory arrest; however, few centers use extracorporeal membrane oxygenation instead of standard extracorporeal circulation for this indication. The aim of this study was to evaluate whether extracorporeal membrane oxygenation-assisted resuscitation improves survival in patients with hypothermic cardiac arrest.

METHODS

A consecutive series of 59 patients with accidental hypothermia in cardiocirculatory arrest between 1987 and 2006 were included. Thirty-four patients (57.6%) were resuscitated by standard extracorporeal circulation, and 25 patients (42.4%) were resuscitated by extracorporeal membrane oxygenation. Accidental hypothermia was caused by avalanche in 22 patients (37.3%), drowning in 22 patients (37.3%), exposure to cold in 8 patients (13.5%), and falling into a crevasse in 7 patients (11.9%). Multivariate logistic regression analysis was used to compare extracorporeal membrane oxygenation with extracorporeal circulation resuscitation, with adjustment for relevant parameters.

RESULTS

Restoration of spontaneous circulation was achieved in 32 patients (54.2%). A total of 12 patients (20.3%) survived hypothermia. In the extracorporeal circulation group, 64% of the nonsurviving patients who underwent restoration of spontaneous circulation died of severe pulmonary edema, but none died in the extracorporeal membrane oxygenation group. In multivariate analysis, extracorporeal membrane oxygenation-assisted resuscitation showed a 6.6-fold higher chance for survival (relative risk: 6.6, 95% confidence interval: 1.2-49.3, P = .042). Asphyxia-related hypothermia (avalanche or drowning) was the most predictive adverse factor for survival (relative risk: 0.09, 95% confidence interval: 0.01-0.60, P = .013). Potassium and pH failed to show statistical significance in the multivariate analysis.

CONCLUSIONS

Extracorporeal rewarming with an extracorporeal membrane oxygenation system allows prolonged cardiorespiratory support after initial resuscitation. Our data indicate that prolonged extracorporeal membrane oxygenation support reduces the risk of intractable cardiorespiratory failure commonly observed after rewarming.

The Osborn wave in accidental hypothermia

Hypothermia is generally defined as a core body temperature less than 35 degrees C (95 degrees F), and is one of the most common environmental emergencies encountered by emergency physicians. A 32-year-old male hunter was admitted to the hospital with altered mental status. He remained unconscious, Glasgow Coma Scale (GCS) score was recorded as 5/15, and pupils were dilated and unreactive. His vital signs showed a heart rate of 48 beats/min, respiratory rate of 10 breaths/min, blood pressure of 95/50 mm Hg, and rectal temperature of 31 degrees C. An electrocardiogram (ECG) was obtained and showed marked sinus bradycardia and J waves. His finger-stick glucose was 85. He was intubated. After 3 h of active rewarming, his temperature was 34 degrees C, and the repeat ECG showed near-complete resolution of the J waves and acceleration of the sinus rate to 68 beats/min. At the same time, emergency head computed tomography (CT) scan showed subarachnoid hemorrhage (SAH) and subdural hemorrhage. The patient died on the third day of admission. In this case we want to indicate that J waves and obtunded state could be due to either SAH or hypothermia, and SAH could have been missed if initial obvious hypothermia had been believed to cause all symptoms.

Kardiopulmonale Reanimation nach Heroinintoxikation und Hypothermie

We present the case of a 21-year-old female drug addict with severe accidental hypothermia (core body temperature 27.5 degrees C) and cardiorespiratory arrest. After successful cardiopulmonary resuscitation the patient was actively internally rewarmed without the use of extracorporal circulation. Although at the first clinical presentation the patient appeared to be dead, an excellent neurological outcome was achieved. This case report reviews the epidemiology, pathophysiology, prognostic markers and the therapeutic approaches of severe hypothermia.

Rewarming rates in urban patients with hypothermia: prediction of underlying infection

BACKGROUND

In the urban setting, hypothermia is commonly associated with illness or intoxication, with death often secondary to infection.

OBJECTIVES

To evaluate factors that affect the rewarming rate (RWR) and the ability of the RWR and other clinical markers to predict the presence or absence of underlying infection in an adult urban population.

METHODS

This was a prospective observational study of hypothermic patient visits to a large emergency department. Serial temperatures were obtained during rewarming to construct rewarming curves. Rewarming modalities selected by emergency physicians were correlated with admission temperatures. Univariate associates of RWR and infection were assessed.

RESULTS

The authors identified 96 patient visits. The median temperature was 89.5 degrees F (31.9 degrees C; range, 73.0 degrees F to 95.0 degrees F [22.8 degrees C to 35.0 degrees C]). Thirteen patients had temperatures of < 80.0 degrees F (26.0 degrees C). Seven died within 14 hours of presentation; six, of infection. No patient experienced ventricular fibrillation. Potential candidate predictors of infection from a multivariate analysis were a RWR of < 1.80 degrees F (1.0 degrees C) per hour and a serum albumin of < 2.7 g/dL. Rapid rewarming was associated with the absence of infection and a temperature below 86.0 degrees F (30.0 degrees C). In patients without significant underlying illness, rewarming rates appeared to be independent of the modality of rewarming.

CONCLUSIONS

Rewarming rates reflect intrinsic capacity for thermogenesis. Increased RWRs were associated with the absence of infection. The achievement of normothermia did not prevent death in infected patients. Initiation of invasive rewarming in urban patients with hypothermia who have not had hypothermic cardiac arrest may be unwarranted. Management of this population should emphasize support, detection, and treatment of underlying illness.

Accidental hypothermia

Hypothermia is a life threatening condition, and management can be challenging, with little robust evidence to support the various treatments. This article should help doctors to understand the condition better

[Resuscitation from accidental hypothermia of 22 degrees C with circulatory arrest: importance of prehospital management]

In winter, French Medicalised Ambulance Service rescued a 50-year-old patient after suicide attempts by jump from a bridge in the Seine. The body was discovered after more than 10 minutes of immersion. She was unconscious and in deep hypothermia with circulatory arrest. Basic CPR was started immediately and oral intubation and 100% oxygen ventilation was performed. Ventricular fibrillation appeared but repeated defibrillation failed due to profound hypothermia (rectal temperature: 28 degrees C). The patient was immediately transported to hospital. CPR and mechanical ventilation was continued during transport. The patient was taken in emergency room. The oesophageal temperature was 22 degrees C. Rewarming using extracorporeal circulation was immediately initiated after insertion of femoral access. At 27 degrees C, ventricular fibrillation started and was converted by external defibrillation to a pulse-generating cardiac rhythm. At 360 minutes, the patient's rectal temperature had reached 36 degrees C and she was disconnected from cardiopulmonary bypass with inotropic support. She was transferred to the intensive care unit after 9 hours of resuscitation, rewarming and stabilisation. Mechanical ventilation was needed for 15 days because of adult respiratory distress syndrome. Renal failure, pneumonia also occurred. She was successfully extubated on day 15 and was discharged from intensive care unit on day 21, suffering no neurological side effects.

Der Lawinennotfall

In North America and Europe around 140 persons die every year due to avalanches, approximately 35 in North America, 100 in the European Alps, and 5 in other parts of Europe. Most of the victims are skiers and snowboarders. This article outlines the specific pathophysiology of avalanche burials, such as hypoxia, hypercapnia, and hypothermia and also other factors which influence survival. Strategies to minimize the mortality due to avalanches and the on-site treatment of buried persons are discussed. Finally, possibilities to reduce the number of avalanche deaths are pointed out.

Accidental Hypothermia

Hypothermia is a multi-system disorder that significantly increases morbidity and mortality in the injured patient. It is an environmental hazard that can kill in its own right. The most difficult differentiation and management decisions are likely to be with victims in Stage II or Stage III hypothermia. Following successful rescue in these cases, arresting any further cooling of the core temperature, instituting rewarming strategies and careful patient handling will be the key factors in reducing morbidity and mortality.

Akzidentelle urbane Unterkühlung

In emergency medicine accidental hypothermia (<35 degrees C) is a common epiphenomenon of many medical conditions. In contrast, severe hypothermia (<28 degrees C) occurs very seldom and presents a difficult medical situation. Here we present a female patient with severe urban hypothermia (core temperature of 20.7 degrees C) and circulatory arrest. An overview of the emergency treatment, rewarming strategy with extracorporeal circulation and the clinical course will be given. The survival of the patient and the favorable neurological outcome will be discussed considering the current literature. Due to the paucity of treatment guidelines or clear prognostic criteria of withholding or withdrawing treatment in severe hypothermia, the decision of prolonged resuscitation and rewarming strategy is solely dependent on the individual judgement and medical experience of the physician. The positive clinical outcome which can be gleaned from case reports or single retrospective studies should encourage the emergency physician to selectively rewarm a severe hypothermic patient with extracorporeal circulation under prolonged CPR.

Thoracic lavage in accidental hypothermia with cardiac arrest — report of a case and review of the literature

BACKGROUND

Accidental hypothermia resulting in cardiac arrest poses numerous therapeutic challenges. Cardiopulmonary bypass (CPB) should be used if feasible since it optimally provides both central rewarming and circulatory support. However, this modality may not be available or is contraindicated in certain cases. Thoracic lavage (TL) provides satisfactory heat transfer and may be performed by a variety of physicians. This paper presents the physiological rationale, technique, and role for TL in accidental hypothermia with cardiac arrest.

METHODS

A patient with hypothermic cardiac arrest, treated by the author using TL, serves as the basis for this report. A search of the English language literature using PubMed (National Library of Medicine, Bethesda, Maryland) was conducted from 1966 to 2003 and 13 additional patients were identified. Demographic information, lavage method, rewarming rate, complications, and neurological outcome were analysed.

RESULTS

There were numerous causes for hypothermia, with drug and alcohol intoxication being the most common (n = 4; 28.6%). Patient age ranged from 8 to 72 years (median = 36 years). Mean core temperature was 24.5+/-0.60 degrees C. Most patients were without blood pressure or pulse upon presentation to the Emergency Department and the predominant cardiac rhythm was ventricular fibrillation (VF) (n = 9; 64.3%). Thoracic lavage was accomplished by thoracotomy in seven patients and tube thoracotomy in the remaining seven. Median rewarming rate was 2.95 degrees C/h. Median time until sinus rhythm was restored was 120 min. Median length of hospital stay was 2 weeks. Four (28.6%) patients died. Complications were seen in 12 (85.7%) patients. Among survivors, neurological outcome was normal in 8 (80%) while two were left with residual impairments.

CONCLUSIONS

Patients presenting in cardiac arrest from accidental hypothermia may be rewarmed effectively using TL. Among survivors, normal neurological recovery is seen. Thoracic lavage should be strongly considered for these patients if CPB is not available or contraindicated.

Differential expression of neuronal fos protein after cold water drowning and controlled rewarming

BACKGROUND

Cardiopulmonary bypass has often been applied to revive victims of cold water drowning. The success of resuscitative efforts in patients who have sustained severe hypothermia is largely determined by neurologic outcomes. Measurement of Fos, the protein product of the immediate-early gene c-fos, is a marker of cerebral injury.

STUDY DESIGN

Twenty-eight infant lambs were sedated and ventilated. Group 1 lambs were immersed in a cold water bath for 2 hours (17.3 +/- 2.7 degrees C). Group 2 lambs were placed on normothermic cardiopulmonary bypass for 2 hours (37.7 degrees +/- 0.7 degrees C). Group 3 lambs were immersed in a cold water bath for 2 hours (17.6 degrees +/- 2.4 degrees C), and then rewarmed for a period of 2 hours on cardiopulmonary bypass (37.0 degrees +/- 0.6 degrees C). The lambs were euthanized and immunohistochemical analysis for neuronal Fos was performed.

RESULTS

There was significant induction of Fos-labeled nuclear profiles (cells/1130 microm(2)) in group 3 in the hippocampal regions and dentate gyrus compared with groups 1 and 2 (p < 0.001).

CONCLUSION

Isolated exposure to either hypothermia or cardiopulmonary bypass results in minimal expression of neuronal Fos; the significant induction of Fos in the group 3 animals may represent an ischemic-reperfusion phenomenon. Modifications of rewarming techniques that minimize Fos expression may improve neurologic outcomes in victims of cold water drowning.

Outcome from severe accidental hypothermia in Southern Finland—a 10-year review

The charts of all adult patients with accidental hypothermia who were admitted to a single academic hospital during a 10 year period were retrospectively retrieved. The aim was to identify factors associated with survival of those with hypothermic cardiac arrest. Of 75 admitted patients, 44 were found to be haemodynamically stable and not to require invasive rewarming measures. Of the remaining 31 patients, 23 were in refractory cardiac arrest due to primary hypothermia and rewarmed using cardiopulmonary bypass (CPB). The aetiology of hypothermia was immersion in cold water in 48%, exposure to cold environment in 39% and submersion in 13% of these patients. Their median age was 50 years, and 83% were males. The patients received a total of 70 min of conventional CPR before institution of CPB. Fourteen of these patients (61%) survived to discharge from hospital. Factors associated with survival were age (P=0.015), arterial pH (P=0.011), PaCO2 (P=0.003), and serum potassium (P=0.007). Logistic regression analysis showed that of the 23 patients, 22 could be correctly classified as survivor or nonsurvivor based on the level of serum potassium and arterial pCO2. It is concluded that patients with cardiac arrest due to primary hypothermia tolerate long periods of conventional CPR before institution of CPB. The possible predictive role of serum potassium and arterial pCO2 needs further evaluation.

Neither vasopressin nor amiodarone improve CPR outcome in an animal model of hypothermic cardiac arrest

BACKGROUND

Aim of this experimental animal study was to investigate the influence of vasopressin and amiodarone on cardiopulmonary resuscitation (CPR) outcome in a pig model of hypothermic cardiac arrest.

METHODS

After surface cooling to a core temperature of 26 degrees C, ventricular fibrillation was induced in 14 12-16-week-old domestic pigs. After 15 min of untreated cardiac arrest, a manual closed chest CPR was started and pigs were randomly assigned to two treatment groups: Group 1 pigs (n = 7) received vasopressin 0.4 U kg-1 as initial drug therapy, followed by a combination vasopressin (0.4 U kg-1) and amiodarone (4 mg kg-1) as subsequent drug therapy. Subsequent drug therapy was administered in animals without permanent restoration of spontaneous circulation after a first series of electrical countershocks 10 min after drug administration. Group 2 pigs (n = 7) received saline placebo as initial drug therapy and saline placebo and amiodarone (4 mg kg-1) as subsequent drug therapy.

RESULTS

Vasopressin significantly increased coronary perfusion pressure and defibrillation success (successful defibrillation in five of seven Group 1 vs. none of seven Group 2 pigs, P = 0.02). Due to refibrillation within 30-150 s, the 60-min survival rate was not improved by vasopressin. Subsequent drug therapy with amiodarone had no further effect on defibrillation success or the refibrillation rate.

CONCLUSIONS

Data from this experimental animal model suggest that vasopressin and amiodarone may not be beneficial for treatment of ventricular fibrillation associated with severe hypothermia when concomitant measures at core rewarming are not applied.