Therapeutic hypothermia after cardiac arrest caused by self-inflicted intoxication: a multicenter retrospective cohort study

Successful Use of Early Therapeutic Hypothermia in an MDMA and Amphetamine Intoxication-Induced Out-of-Hospital Cardiac Arrest: A Case Report

BACKGROUND

Deaths caused by recreational drug abuse have increased considerably in recent years. Therapeutic hypothermia offers the potential to improve neurological outcomes in post-resuscitation patients.

CASE REPORT

A 19-year-old man was brought to our emergency department after suffering out-of-hospital ventricular fibrillation (VF) cardiac arrest. He was resuscitated at our emergency department again due to VF. Urine analysis showed high levels of amphetamine and 3,4 methylenedioxymethamphetamine (MDMA) (ecstasy). The patient was intubated, sedated, and ventilated. Within 1 h after the return of spontaneous circulation and hemodynamic stabilization, therapeutic hypothermia was initiated for neurologic protection. An external-cooling device was used for cooling. He was maintained at 33^oC for 72 h. The patient was weaned from the ventilator and extubated on day 5. He was discharged from the hospital on the day 10 with good cerebral performance. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Initiation of early therapeutic hypothermia within 1 h after return of spontaneous circulation might contribute to better neurologic outcome in patients who suffer VF cardiac arrest. We suggest that early therapeutic hypothermia may be considered in patients who suffer out-of-hospital cardiac arrest due to MDMA and amphetamine intoxications.

Impact of Targeted Temperature Management on ED Patients with Drug Overdose-Related Cardiac Arrest

INTRODUCTION

Drug overdose is the leading cause of non-traumatic out-of-hospital cardiac arrest (OHCA) among young adults. This study investigates whether targeted temperature management (TTM) improves hospital survival from presumed overdose-related cardiac arrest.

METHODS

Retrospective chart review of consecutive cardiac arrests presenting to an urban tertiary care hospital ED from 2011 to 2015. ED patients with cardiac arrest were included if < 50 years old, and excluded if there was a non-overdose etiology (e.g., trauma, ST-elevation myocardial infarction, subarachnoid hemorrhage). The main intervention was TTM, carried out with a combination of the Arctic Sun device and refrigerated crystalloid/antipyretics (goal temperature 33-36 °C). The primary outcome was survival to hospital discharge; neurologically intact survival was the secondary outcome.

RESULTS

Of 923 patients with cardiac arrest, 802 (86.9%) met exclusion criteria, leaving 121 patients for final analysis. There were 29 patients in the TTM group (24.0%) vs 92 patients in the non-TTM group (76.0%). Eleven patients (9.1%) survived to hospital discharge. TTM was associated with increased odds of survival to hospital discharge (OR 11.3, 95% CI 2.8-46.3, p < 0.001), which increased substantially when palliative outcomes were excluded from the cohort (OR 117.3, 95% CI 17.0-808.4, p < 0.001). Despite achieving statistical significance (OR 1.1, 95% CI 1.0-1.3), TTM had no clinically significant effect on neurologically intact survival.

CONCLUSIONS

TTM was associated with improved survival in ED patients with presumed drug overdose-related cardiac arrest. The impact of TTM on neurologically intact survival among these patients requires further study.

Hypothermia Reduces Mortality, Prevents the Calcium Plateau, and Is Neuroprotective Following Status Epilepticus in Rats

Status Epilepticus (SE) is a major neurological emergency and is considered a leading cause of Acquired Epilepsy (AE). We have shown that SE produces neuronal injury and prolonged alterations in hippocampal calcium levels ([Ca²⁺]_i) that may underlie the development of AE. Interventions preventing the SE-induced Ca²⁺ plateau could therefore prove to be beneficial in lowering the development of AE after SE. Hypothermia is used clinically to prevent neurological complications associated with Traumatic Brain Injury, cardiac arrest, and stroke. Here, we investigated whether hypothermia prevented the development of Ca²⁺ plateau following SE. SE was induced in hippocampal neuronal cultures (HNC) by exposing them to no added MgCl₂ solution for 3 h. To terminate SE, low Mg²⁺ solution was washed off with 31°C (hypothermic) or 37°C (normothermic) physiological recording solution. [Ca²⁺]_i was estimated with ratiometric Fura-2 imaging. HNCs washed with hypothermic solution exhibited [Ca²⁺]_i ratios, which were significantly lower than ratios obtained from HNCs washed with normothermic solution. For in vivo SE, the rat pilocarpine (PILO) model was used. Moderate hypothermia (30–33°C) in rats was induced at 30-min post-SE using chilled ethanol spray in a cold room. Hypothermia following PILO-SE significantly reduced mortality. Hippocampal neurons isolated from hypothermia-treated PILO SE rats exhibited [Ca²⁺]_i ratios which were significantly lower than ratios obtained from PILO SE rats. Hypothermia also provided significant neuroprotection against SE-induced delayed hippocampal injury as characterized by decreased FluoroJade C labeling in hypothermia-treated PILO SE rats. We previously demonstrated that hypothermia reduced Ca²⁺ entry via N-methyl-D-aspartate and ryanodine receptors in HNC. Together, our studies indicate that by targeting these two receptor systems hypothermia could interfere with epileptogenesis and prove to be an effective therapeutic intervention for reducing SE-induced AE.