Resuscitative endovascular balloon occlusion of the aorta in zone I versus zone III in a porcine model of non-traumatic cardiac arrest and cardiopulmonary resuscitation: A randomized study.

INTRODUCTION: Resuscitative endovascular balloon occlusion of the aorta (REBOA) in zone I increases systemic blood pressure during cardiopulmonary resuscitation (CPR), while also obstructing the blood flow to distal organs. The aim of the study was to compare the effects on systemic blood pressure and visceral blood flow of REBOA-III (zone III, infrarenal) and REBOA-I (zone I, supraceliac) during non-traumatic cardiac arrest and CPR. METHODS: Cardiac arrest was induced in 61 anesthetized pigs. Thirty-two pigs were allocated to a hemodynamic study group where the primary outcomes were systemic arterial pressures and 29 pigs were allocated to a blood flow study group where the primary outcomes were superior mesenteric arterial (SMA) and internal carotid arterial (ICA) blood flow. After 7-8 min of CPR with a mechanical compression device, REBOA-I, REBOA-III or no aortic occlusion (control group) were initiated after randomization. RESULTS: Systemic mean and diastolic arterial pressures were statistically higher during CPR with REBOA-I compared to REBOA-III (50 mmHg and 16 mmHg in REBOA-I vs 38 mmHg and 1 mmHg in REBOA-III). Systemic systolic, mean and diastolic arterial pressures were statistically elevated during CPR in the REBOA-I group compared to the controls. The SMA blood flow increased by 49% in REBOA-III but dropped to the levels of the controls within minutes. The ICA blood flow increased the most in REBOA-I compared to REBOA-III and the control group (54%, 19% and 0%, respectively). CONCLUSION: In experimental non-traumatic cardiac arrest and CPR, REBOA-I increased systemic blood pressures more than REBOA-III, and the potential enhancement of visceral organ blood flow by REBOA-III was short-lived.

Resuscitative endovascular balloon occlusion of the inferior vena cava is made hemodynamically possible by concomitant endovascular balloon occlusion of the aorta-A porcine study.

BACKGROUND: Resuscitative endovascular balloon occlusion of the vena cava inferior (REBOVC) may provide a minimal invasive alternative for hepatic vascular and inferior vena cava isolation in severe retrohepatic bleeding. However, circulatory stability may be compromised by the obstruction of venous return. The aim was to explore which combinations of arterial and venous endovascular balloon occlusions, and the Pringle maneuver, are hemodynamically possible in a normovolemic pig model. The hypothesis was that lower-body venous blood pooling from REBOVC can be avoided by prior resuscitative endovascular aortic balloon occlusion (REBOA). METHODS: Nine anesthetized, ventilated, instrumented, and normovolemic pigs were used to explore the hemodynamic effects of 11 combinations of REBOA and REBOVC, with or without the Pringle maneuver, in randomized order. The occlusions were performed for 5 minutes but interrupted if systolic blood pressure dropped below 40 mm Hg. Hemodynamic variables were measured. RESULTS: Proximal REBOVC, isolated or in combination with other methods of occlusion, caused severely decreased systemic blood pressure and cardiac output, and had to be terminated before 5 minutes. The decreases in systemic blood pressure and cardiac output were avoided by REBOA at the same or a more proximal level. The Pringle maneuver had similar hemodynamic effects to proximal REBOVC. CONCLUSION: A combination of REBOA and REBOVC provides hemodynamic stability, in contrast to REBOVC alone or with the Pringle maneuver, and may be a possible adjunct in severe retrohepatic venous bleedings.

Classification of additives for organic photovoltaic devices.

The use of additives to improve the performance of organic photovoltaic cells has been intensely researched in recent years. However, so far, no system has been reported for the classification of additives and their functions. In this report, a system for classifying additives according to the fundamental mechanism by which they influence microstructure formation for P3HT:PCBM is suggested. The major parameters used for their classification are solubility and drying kinetics. Both are discussed in detail and their consequences on processing are analyzed. Furthermore, a general mechanism to classify the impact of additives on structure formation is suggested and discussed for different materials relevant to organic photovoltaic devices.