Cardiopulmonary resuscitation following profound immersion hypothermia

Rewarming From Hypothermic Cardiac Arrest Applying Extracorporeal Life Support: A Systematic Review and Meta-Analysis

Introduction: This systematic review and meta-analysis aims at comparing outcomes of rewarming after accidental hypothermic cardiac arrest (HCA) with cardiopulmonary bypass (CPB) or/and extracorporeal membrane oxygenation (ECMO). Material and Methods: Literature searches were limited to references with an abstract in English, French or German. Additionally, we searched reference lists of included papers. Primary outcome was survival to hospital discharge. We assessed neurological outcome, differences in relative risks (RR) of surviving, as related to the applied rewarming technique, sex, asphyxia, and witnessed or unwitnessed HCA. We calculated hypothermia outcome prediction probability score after extracorporeal life support (HOPE) in patients in whom we found individual data. P < 0.05 considered significant. Results: Twenty-three case observation studies comprising 464 patients were included in a meta-analysis comparing outcomes of rewarming with CPB or/and ECMO. One-hundred-and-seventy-two patients (37%) survived to hospital discharge, 76 of 245 (31%) after CPB and 96 of 219 (44 %) after ECMO; 87 and 75%, respectively, had good neurological outcomes. Overall chance of surviving was 41% higher (P = 0.005) with ECMO as compared with CPB. A man and a woman had 46% (P = 0.043) and 31% (P = 0.115) higher chance, respectively, of surviving with ECMO as compared with CPB. Avalanche victims had the lowest chance of surviving, followed by drowning and people losing consciousness in cold environments. Assessed by logistic regression, asphyxia, unwitnessed HCA, male sex, high initial body temperature, low pH and high serum potassium (s-K+) levels were associated with reduced chance of surviving. In patients displaying individual data, overall mean predictive surviving probability (HOPE score; n = 134) was 33.9 ± 33.6% with no significant difference between ECMO and CPB-treated patients. We also surveyed 80 case reports with 96 victims of HCA, who underwent resuscitation with CPB or ECMO, without including them in the meta-analysis. Conclusions: The chance of surviving was significantly higher after rewarming with ECMO, as compared to CPB, and in patients with witnessed compared to unwitnessed HCA. Avalanche victims had the lowest probability of surviving. Male sex, high initial body temperature, low pH, and high s-K+ were factors associated with low surviving chances.

Accidental hypothermic cardiac arrest and extracorporeal membrane oxygenation: a case report

BACKGROUND

Accidental hypothermic cardiac arrest, an involuntary drop in core body temperature resulting in cardiopulmonary arrest, is linked to 1500 deaths annually. We highlight the challenges with the treatment of accidental hypothermic cardiac arrest and describe improved preparations necessary for an integrated health system to care for similar patients.

CASE REPORT

Emergency medical services (EMS) were dispatched to a 34-year-old female who had been missing for several hours during a January snowfall. The patient was found unconscious over an embankment. The patient was found with a weak carotid pulse and two empty bottles of clozapine, an atypical antipsychotic. The EMS crew extricated the patient, performed a rapid trauma assessment, passive rewarming, and airway management. During transport, the patient suffered a ventricular fibrillation cardiac arrest, received defibrillation, and advanced life support measures. Resuscitative efforts continued in the emergency department while the treatment team addressed environmental exposure, assessed for traumatic injury and toxicologic exposure. On emergency department (ED) arrival, the patient's core temperature was 24°C, and despite aggressive resuscitation, the patient remained in cardiac arrest. The ED care team used extracorporeal membrane oxygenator (ECMO) and successfully resuscitated the patient with extracorporeal cardiopulmonary resuscitation. The patient achieved full neurologic recovery 15 days post-ED arrival.

CONCLUSION

This case highlights the importance of early recognition of accidental hypothermic cardiac arrest by EMS clinicians, rapid transport to a tertiary facility, and the timely application of active rewarming and in-hospital ECMO. Accidental hypothermic cardiac arrest is a reversible state; prompt and correct treatment allows for a high probability of a favorable neurologic outcome.

Review and Outcome of Prolonged Cardiopulmonary Resuscitation

The maximal duration of cardiopulmonary resuscitation (CPR) is unknown. We report a case of prolonged CPR. We have then reviewed all published cases with CPR duration equal to or more than 20 minutes. The objective was to determine the survival rate, the neurological outcome, and the characteristics of the survivors. Measurements and Main Results. The CPR data for 82 patients was reviewed. The median duration of CPR was 75 minutes. Patients mean age was 43 ± 21 years with no significant comorbidities. The main causes of the cardiac arrests were myocardial infarction (29%), hypothermia (21%), and pulmonary emboli (12%). 74% of the arrests were witnessed, with a mean latency to CPR of 2 ± 6 minutes and good quality chest compression provided in 96% of the cases. Adjunct therapy included extracorporeal membrane oxygenation (18%), thrombolysis (15.8%), and rewarming for hypothermia (19.5%). 83% were alive at 1 year, with full neurological recovery reported in 63 patients. Conclusion. Patients undergoing prolonged CPR can survive with good outcome. Young age, myocardial infarction, and potentially reversible causes of cardiac arrest such as hypothermia and pulmonary emboli predict a favorable result, especially when the arrest is witnessed and followed by prompt and good resuscitative efforts.

Retrospective evaluation of prehospital triage, presentation, interventions and outcome in paediatric drowning managed by a physician staffed helicopter emergency medical service

Background

Drowning patients may benefit from the advanced airway management capabilities that can be provided by physician staffed helicopter emergency medical services. The aim of this study is to describe paediatric drowning patients treated by such a service examining tasking systems, initial physiology at the incident scene, survival and neurological outcome.

Methods

Retrospective analysis of paediatric drowning victims over a 5- year period. Case identification system, patient age, site of drowning, presence or absence of cardiac output, first Glasgow Coma Scale (GCS) score and interventions were collected from prehospital notes, and survival and neurological outcomes from hospital and rehabilitation notes.

Results

The P-HEMS direct case identification system operating in parallel with a central control system identified all severe drowning cases but 3 of 7 cases (43 %) were missed when the central control system operated in isolation. All severe drowning cases (22) identified for P-HEMS response were intubated and transported directly to a paediatric specialist centre. Intubation required adjuvant anaesthesia in 10 (45 %) cases. All children with GCS greater than eight on arrival of the P-HEMS survived neurologically intact. Seven of eight children with a GCS between four and seven survived without neurological impairment and all children with a GCS greater than three survived. Four of twelve asystolic children survived including one child who at 18 months post drowning is neurologically normal. All children who survived had return of spontaneous circulation prior to arrival in the emergency department.

Conclusions

P-HEMS played a significant role in the management of severe paediatric drowning in this case series. Requirement for P-HEMS only interventions were high and all identified cases were transferred directly to a paediatric specialist centre. Discontinuation of the P-HEMS direct case identication system that operated during the majority of the study period resulted in deterioration in system performance with some paediatric drowning cases subsequently not identified for P-HEMS response being transported to adult hospitals.

Resuscitation of drowning victims in south-east Scotland

INTRODUCTION

Immersion in cold water is compatible with long-term survival, even when the period of immersion is relatively long. Guidelines for resuscitation after immersion stress the importance of prolonged resuscitation using advanced life support techniques.

METHODS

Deaths due to drowning in south-east Scotland between 1991 and 1997 were reviewed, using a variety of data sources.

RESULTS

95 deaths (69 males, 26 females) from drowning occurred in the following sites: sea, 35; bath, 15; flowing freshwater, 26; still freshwater, 19; 22 (23%) of the drowning incidents were witnessed, 73 (77%) were unwitnessed. 28 individuals were recovered within 1 h of being seen alive, 13 having had witnessed accidents, 15 having had unwitnessed accidents. Six individuals were not resuscitated at the scene by the emergency services, despite being last seen alive within the previous hour. A further five individuals were initially resuscitated, but declared dead at the scene within 1 h of being known to be alive.

CONCLUSIONS

Members of the emergency services, are failing to both initiate prehospital resuscitation and to continue this to hospital for victims of near drowning. There appears to be potential to reduce the drowning death rate by improving resuscitation. The emergency services and the public should be educated about the need to resuscitate those found in water.