Prehospital extracorporeal cardiopulmonary resuscitation for refractory out-of-hospital cardiac arrest in goat with severe primary blast lung Injury-a pilot study.

backgroundAlthough extracorporeal cardiopulmonary resuscitation (ECPR) has shown promise for refractory out-of-hospital cardiac arrest (CA), limited data exist regarding its application in cases involving severe primary blast lung injury (PBLI). This study evaluated the feasibility, indications, complications, and early management of ECPR for refractory out-of-hospital CA in goats with severe PBLI.

methodsTwenty adult goats (30.47 ± 4.74 kg) were randomly divided into five groups based on their distance from an 8 kg TNT-equivalent explosive: 2.5 m (n = 3), 3 m (n = 5), 4 m (n = 4), 5 m (n = 4), and 6 m (n = 4). Goats were positioned in concentric circles and fixed in special iron frames in the same direction (with the right chest facing the core of the explosion). Following detonation, all animals were transported 500 m to a field rescue unit. Cardiopulmonary resuscitation (CPR) was initiated 1 min after CA. Two of the twenty goats were used for gross lung pathology assessment. Four goats underwent neck vessel cannulation and venoarterial extracorporeal membrane oxygenation (VA-ECMO). Crystalloid and blood transfusions were administered, and animals were monitored for 4 h.

resultsAll goats within 3 m suffered severe lung damage and CA after the explosion. Despite effective chest compression support, six of the eight goats within 3 m of the explosion died due to progressive circulatory failure. Four goats received ECPR. Among them, two were successfully resuscitated using VA - ECMO, with perfusion pressures restored to 65 mmHg (range: 60-70 mmHg) at 25 and 30 min post-CA. In the remaining two, large thrombi in the carotid arteries prevented effective flow initiation. No complications such as hemorrhage or failed vascular access were observed during cannulation. The ECMO circuit was established via an open carotid artery and the jugular vein cannula started, leading to the return of spontaneous circulation in the two successfully treated animals. All goats in the 4-, 5-, and 6-meter groups survived.

conclusionsPrehospital ECPR improved the restoration of spontaneous circulation and hemodynamic stability in goats with severe PBLI-induced CA. These findings demonstrate the feasibility and early efficacy of ECPR in austere conditions. Further investigations in larger animal cohorts and human trials are warranted to validate its potential as a life-saving intervention for blast-induced CA.