Manual versus automatic chest compression devices for cardiopulmonary resuscitation under zero gravity (The MACCC - 0G STUDY).

INTRODUCTION: Cardiopulmonary resuscitation (CPR) in microgravity requires specific methods to counteract weightlessness. Automatic chest compression devices (ACCDs) could improve CPR in microgravity. We aimed to compare ACCDs versus manual CPR in microgravity simulated through parabolic flights. METHODS: This prospective, open, controlled study compared 3 ACCDs (LUCAS 3©, AUTOPULSE©, EASYPULSE©) to manual CPR during the 66th CNES (Centre National d'Etudes Spatiales) parabolic flights campaign onboard the Novespace Air Zero-G A310 aircraft. Chest compression depths and rates were monitored by a Laerdal© Resusci-Ann-QCPR manikin. RESULTS: The LUCAS 3© device had a median compression depth of 53.0 [53.0-54.0] mm, significantly higher than the EASYPULSE©, AUTOPULSE©, and Manual CPR (Handstand method), measured at 29.0 [26.0-32.0] mm, 29.0 [27.5-30.7] mm and 34.5 [29.6-43.3] mm, respectively (p value < 0.001). Compression rates were 101 [101-101], 100 [100-100] and 80 [80-80] compressions per minute (cpm) for the LUCAS 3©, EASYPULSE©, and AUTOPULSE©, respectively. Manual CPR provided a significantly higher compression rate with 115 [109-123] cpm (p value < 0.001). CONCLUSION: Only LUCAS 3© provided effective CPR according to international guidelines. ACCDs should implement microgravity CPR algorithms.

Albumin Infusion Reduces Fluid Loading for Postresuscitation Syndrome in a Pig Model of Refractory Cardiac Arrest Resuscitated With Venoarterial Extra Corporeal Membrane Oxygenation.

Hemodynamic instability in postresuscitation syndrome worsens survival and neurological outcomes. Venoarterial extracorporeal membrane oxygenation (VA ECMO) for refractory cardiac arrest might improve outcomes. Hemodynamical support under VA ECMO relies on norepinephrine and crystalloids. The present work aims to assess the effects of albumin (ALB) infusion in a swine model of ischemic refractory cardiac arrest implanted by VA ECMO. Cardiac arrest was performed in 18 pigs and VA ECMO was initiated after 30 minutes cardiopulmonary resuscitation (CPR). Pigs were randomly assigned to standard care (norepinephrine + crystalloids) versus ALB group (ALB + standard care). Hemodynamical assessments were performed over 6 hours. Severe hypoalbuminemia was observed in the control group and could be reversed with ALB infusion. Total crystalloid load was significantly reduced with ALB infusion (1,000 [1,000-2,278] ml vs. 17,000 [10,000-19,000] ml, ALB versus control group, respectively, p < 0.001). There was no significant impact with regard to lactate clearance (29.16% [12.5-39.32] and 10.09% [6.78-29.36] for control versus ALB groups, respectively, p = 0.185), sublingual capillary microvascular parameters, or cerebral near-infrared spectrometer (NIRS) values. Compared to standard care, ALB infusion was highly effective in reducing fluid loading in a porcine model of postresuscitation syndrome after refractory cardiac arrest treated with VA ECMO.

Methylene Blue Reduces Fluid Loading and Norepinephrine Requirements for Post-Resuscitation Syndrome in a Pig Model of Refractory Cardiac Arrest Resuscitated with Veno-Arterial ECMO.

BACKGROUND: Refractory cardiac arrest management relies on extracorporeal cardiopulmonary resuscitation (ECPR), requiring the use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Circulatory flow recovery can be associated with an ischemia-reperfusion injury, leading to vasoplegia and vasopressor requirement. The aim of this work was to evaluate the impact on hemodynamics of a methylene blue bolus infusion in a porcine model of ischemic refractory cardiac arrest. METHODS: Ischemic refractory cardiac arrest was induced in 20 pigs. After a low flow period of 30 min, VA-ECMO was initiated and the pigs were randomly assigned to the standard care group (norepinephrine + crystalloids) or methylene blue group (IV 2 mg·kg-1 bolus of methylene blue over 30 min + norepinephrine and crystalloids). Macrocirculatory parameters and lactate clearance were measured. Sublingual microcirculation was evaluated with sidestream dark field (SDF) imaging. The severity of the ischemic digestive lesions was assessed according to the histologic Chiu/Park scale. RESULTS: Eighteen pigs were included. The total crystalloid load (5000 (6000-8000) mL vs. 17,000 (10,000-19,000) mL, p = 0.007, methylene blue vs. standard care group) and catecholamine requirements (0.31 (0.14-0.44) µg·kg-1·min-1 vs. 2.32 (1.17-5.55) µg·kg-1·min-1, methylene blue vs. standard care group, p = 0.004) were significantly reduced in the methylene blue group. There were no significant between-group differences in lactate clearance, sublingual capillary microvascular parameters assessed by SDF or histologic Chiu/Park scale. CONCLUSIONS: In our refractory cardiac arrest porcine model treated with ECPR, methylene blue markedly reduced fluid loading and norepinephrine requirements in comparison to standard care during the first 6 h of VA-ECMO.