Accidental Hypothermic Cardiac Arrest Research Articles

CASE SERIES OF SEVERE ACCIDENTAL HYPOTHERMIC CARDIAC ARREST TREATED SUCCESSFULLY WITH CARDIOPULMONARY BYPASS IN A UNIVERSITY HOSPITAL IN UNITED KINGDOM

Introduction Accidental hypothermia is unintentional decrease in body temperature below 35°C. Severe hypothermia is when temperature drops below 28°C and have a high mortality rate. Methods Case 1 A 48 year old man suspected CVA fall into freezing canal. He was clinging on the side of canal. He developed cardiac arrest when retrieved by crew. Three unsuccessful shocks administered. His temperature was 21° C in ED. A midline sternotomy performed and CPB achieved. He was slowly rewarmed and acidosis corrected. When temperature was 27.5° C,internal DC Cardioversion delivered, reverted him to sinus rhythm. He was successfully weaned of CPB. Total CPB time was 4 hours and 38 min. The patient was extubated next day. He had mild dysarthria and expressive dysphasia. He was discharged to stoke unit on day 3 and improved after stroke rehabilitation. Case 2 A 53 year old female, with previous history of mental illness, found unresponsive adjacent to reservoir, with weighted bag and ankles tied with chains and padlocks. She had cardiac arrest and temperature recorded as 14.1°C. She was airlifted to ED. Initial ABG pH 7.23, Lactate 2.5 and K of 4.0. No shockable rhythm achieved. She was profoundly coagulopathic with INR>10, APTT ratio>5 and Fibrinogen level A femoro-femoral bypass was done. She was slowly rewarmed, coagulopathy and acidosis corrected. She was severely vasoplegic and developed pulmonary oedema. At temperature of 28°C, developed sinus rhythm. She was successfully weaned off CPB after six hours with high doses of vasopressors. She developed TRALI and was ventilated for 12 days. She was confused, withdrawn and non-engaging with staff, with no focal neurological signs and a normal EEG. She received mental health support and rehabilitation and was discharged to a mental health unit on day 30. Results Severe accidental hypothermia is associated with high mortality rate ranging from 30-80% [1]. The neurological outcomes of the survivors are usually good, when the reason for cardiac arrest is not asphyxia. There are retrospective observational studies suggesting prognostic indicators which may predict survival on admission to hospital. Hyperkalemia, pH 400, increased ammonia levels and raised PaCO2 are bad prognostic indicators. A study by Eich et al showed that early initiation of basic life support, hypokalemia, female gender and slow rewarming to be indicators of superior outcomes. CPB is recommended for hypothermic patients in arrest and for patients with core temperatures lower than 25°C. CPB and ECMO has encouraging survival rate of unto 63%. CPB ensures controlled gradual increase in core body temperature and adequate tissue oxygenation. Discussion This case series demonstrates successful recovery with good neurological outcome from severe accidental hypothermic cardiac arrest with CPB in our institution over one year period. For severe hypothermia, CPB is extremely useful treatment device. The prognostic indicators are unclear and more evidence is required.

Clinician miscalibration of survival estimate in hypothermic cardiac arrest: HOPE-estimated survival probabilities in extreme cases

AimPatients with hypothermic cardiac arrest may survive with an excellent outcome after extracorporeal life support rewarming (ECLSR). The HOPE (Hypothermia Outcome Prediction after ECLS) score is recommended to guide the in-hospital decision on whether or not to initiate ECLSR in patients in cardiac arrest following accidental hypothermia. We aimed to assess the HOPE-estimated survival probabilities for a set of survivors of hypothermic cardiac arrest who had extreme values for the variables included in the HOPE score. MethodsSurvivors were identified and selected through a systematic literature review including case reports. We calculated the HOPE score for each patient who presented extraordinary clinical parameters. ResultsWe identified 12 such survivors. The HOPE-estimated survival probability was ≥10% for all (n=11) patients for whom we were able to calculate the HOPE score. ConclusionOur study confirms the robustness of the HOPE score for outliers and thus further confirms its external validity. These cases also confirm that hypothermic cardiac arrest is a fundamentally different entity than normothermic cardiac arrest. Using HOPE for extreme cases may support the proper calibration of a clinician’s prognosis and therapeutic decision based on the survival chances of patients with accidental hypothermic cardiac arrest.

Resolution of strain abnormalities during extracorporeal rewarming from accidental hypothermic cardiac arrest: a case report

Introduction Three-dimensional left (LV) and right-ventricular (RV) assessment by transesophageal echocardiography (TEE) overcomes problems of 2D TEE such as incomplete coverage and mathematical assumptions of chamber geometry. Myocardial deformation parameters (strain) are reported to allow earlier detection of subclinical abnormalities and to improve prognostic accuracy compared to global assessment. Strain data describing functional recovery of the myocardium from severe hypothermic arrest are scarce. Methods A 55 year-old male victim of an avalanche accident arrived at the emergency department in asystole at 28°C core temperature under ongoing CPR (hypothermia stage IV). Reperfusion and rewarming was performed by percutaneous cannulation and minimized extracorporeal circulation (MiECC). Ventricular fibrillation ensued at 32°C and converted to sinus rhythm after defibrillation. At 33°C a full-volume loop (6 beats) was acquired for each ventricle, and tissue doppler interrogation was performed for assessment of diastolic function. Exams were repeated at 36°C. Images were analyzed for ventricular function and strain for all AHA segments. Results In hypothermia, LV ejection fraction (LVEF, 54%) and global circumferential strain (-35.9%) appeared normal but longitudinal strain was impaired (-13.5%). Basal myocardial segments showed hypo- and dyskinesia, while peak strain in more apical segments was preserved. This resulted in marked heterogeneity of strain curves. Diastology revealed restrictive LV dysfunction (III°). RV ejection fraction (RVEF, 45%) and global longitudinal strain were impaired (-15.2%). After normothermia had been reestablished, LVEF (68%) and strain had improved further (circumferential: -37.7%, longitudinal: -14.5%). Contractile function of LV segments had regained homogeneity among all segments. Time to peak systolic strain was shortened. Diastolic dysfunction had improved to pseudonormal (II°). RVEF (74%) and strain (-44.1%) also showed marked recovery. The figure shows numerical function changes for both ventricles and LV strain curves at 33°C and 36°C core temperature. Discussion In post-arrest core hypothermia at 33°C, LVEF may appear normal and RVEF only mildly impaired, whereas segmental LV and global RV strain analysis may reveal a still severely ab-nor¬mal myocardial systolic function. Such a discordant pattern in a hypothermic post-ischemic heart may show marked improvement when core temperature normalizes. Three-dimensional TEE in combination with myocardial strain analysis may be a useful adjunct for evaluating post-arrest recovery of cardiac function in victims of accidental hypothermic cardiac arrest.

Accidental hypothermic cardiac arrest and rapid mediastinal warming with pleural lavage: a survivor after 3.5 hours of manual CPR

A 30-year-old man suffered post-traumatic hypothermic cardiac arrest. On arrival in the emergency department, rectal core temperature was 23°C. Manual cardiopulmonary resuscitation (CPR) was continued as no mechanical chest compression...

Recover of peripheral nerve function after prolong hypothermic cardiac arrest in a porcine model with extra corporeal life support

ObjectivesSurviving long lasting cardiac arrest following accidental hypothermia has been reported after treatment with extra corporeal life support (ECLS), but there is a risk of neurologic injury. Most surviving hypothermia patients have a prolonged stay in the intensive care unit, where most patients experience polyneuropathy. Theoretically, accidental hypothermic cardiac arrest may in itself contribute to polyneuropathy. This study was designed to examine the impact of three hours of cardiac arrest at a core temperature of 20°C followed by reanimation of peripheral nerve function. MethodsSeven pigs were cannulated for ECLS and cooled to a core temperature of 20°C followed by three hours of circulatory arrest where the extremities were packed with ice. After three hours, ECLS was started and rewarming was performed. During the process, neural testing of the ulnar nerve (a somatic nerve) and of the vagus nerve (an autonomic nerve) were performed and blood was drawn for analysis of p-potassium, serum-neuron-specific enolase, and S100b protein. ResultsThe ulnar nerve was cooled from 34.9±1.6°C to 12.8±3.8°C and the vagus nerve from 36.2±1.2°C to 15.4±1.4°C. Physiologic function of both somatic and autonomic nerves were strongly affected by cooling, but recovered to almost normal levels during rewarming, even after three hours of hypothermic cardiac arrest. P-potassium rose from 3.9 (3.6–4.6)mmol/l to 8.1 (7.2–9.1)mmol/l after three hours of cardiac arrest, but normalized after recirculation. There was no rise in serum-neuron-specific enolase, but a slight rise in S100b protein during three hours of hypothermic cardiac arrest was observed. All pigs obtained return of spontaneous circulation (ROSC). ConclusionsReanimation after three hours of hypothermic cardiac arrest using ECLS was possible with no or, if present, minor damage to the two nerves tested.

Cardiac arrest due to accidental hypothermia—A 20 year review of a rare condition in an urban area

BackgroundAccidental hypothermic cardiac arrest is associated with unfortunate prognosis and large studies are rare. We therefore have performed an outcome analysis in patients that were admitted to Vienna University Hospital with the diagnosis of accidental hypothermic cardiac arrest. MethodsThis study employed a retrospective outcome analysis of prospectively collected data in a selected cohort of hypothermic cardiac arrest patients. We screened 3800 cardiac arrest patients, treated at our department between 1991 and 2010, for eligibility. Inclusion criteria were cardiac arrest with a body core temperature ≤28°C and return of spontaneous circulation. ResultsA total of 18 patients who achieved return of spontaneous circulation were analysed. Nine patients (50%) achieved survival in good neurologic condition (defined as cerebral performance category CPC 1 or 2). Accidental hypothermia with consecutive cardiac arrest was caused by intoxication in most cases (67%). These patients had a better outcome than patients with other causes of accidental hypothermic cardiac arrest (OR=28; 95%KI 2–37.9; p<0.01). Hypothermia associated typical ECG changes after return of spontaneous circulation (Osborne waves) were more frequent in the surviving population (OR 16; 95%KI 1.3–19.5; p=0.05). ConclusionsAccidental hypothermic cardiac arrest in a central European urban area is rare. Prognosis was excellent in patients where hypothermic cardiac arrest was caused by intoxication.

Outcome from severe accidental hypothermia with cardiac arrest resuscitated with extracorporeal cardiopulmonary resuscitation

PurposeThis study aimed to identify factors of neurologic prognosis in severe accidental hypothermic patients with cardiac arrest. Basic proceduresThis retrospective observational study was performed in a tertiary care university hospital in Sapporo, Japan (January 1994 to December 2012). We investigated 26 patients with accidental hypothermic cardiac arrest resuscitated with extracorporeal cardiopulmonary resuscitation (ECPR). We evaluated the neurologic outcome in patients who were resuscitated with ECPR at discharge from hospital. Main findingsIn those 26 patients, their median age was 50.5 years; and 69.2% were male. The cause of hypothermia was exposure to cold air in 46.1%, submersion in 46.1%, and avalanche in 7.8%. Ten (38.5%) of these patients survived to favorable neurological outcome at discharge. Factors associated with favorable neurological outcome were a cardiac rhythm other than asystole (P = .009), nonasphyxial hypothermia (P = .006), higher pH (P = .01), and lower serum lactate (P = .01). In subgroup analyses, the patients with hypothermic cardiac arrest due to submersion or avalanche (asphyxia group) showed no factors associated with good neurological outcome, whereas the nonasphyxia group showed a significantly lower core temperature (P = .02) and a trend towards a lower serum lactate (P = .09). Principal conclusionsPatients with hypothermic cardiac arrest due to nonasphyxial hypothermia have improved neurologic outcomes when treated with ECPR compared to patients with asphyxial hypothermic cardiac arrest. Further investigation is needed to develop a prediction rule for patients with nonasphyxial hypothermic cardiac arrest to determine which patients would benefit from treatment with ECPR.