Experimental model for cardiogenic shock with pericardial tamponade

Abstract

Pericardial tamponade (PT) is a life-threatening condition, with low cardiac output. The hemodynamic consequences of PT can severely affect the circulation of all tissues, including the microcirculation of the kidneys and the intestinal mucosa. Our aim was to develop a hemodynamically stable and controllable large animal model of PT to study the consequences of cardiogenic shock. Two groups of anesthetized vietnamese minipigs (n = 6, both groups) were used. Following laparotomy, a cannula was fixed into the pericardium through the diaphragm without thoracotomy. A sham-operated group served as control, in the second group 60-min PT was induced by intrapericardial injection of heparinised own blood. Throughout PT and 180-min reperfusion, macrohemodynamics, renal circulation and mesenteric macro- and microcirculation were monitored. Myeloperoxidase (MPO) activity was measured and in vivo histology was performed by confocal laser scanning endomicroscopy. The PT increased central venous pressure, heart rate and decreased mean arterial pressure, mesenteric flow (from 355.5 ± 112.4 vs 182.0 ± 59.1 ml/min) and renal arterial flow (from 159.63 ± 50.7 vs 35.902 ± 27.9 ml/min) and the microcirculation of the ileum. Elevated MPO activity (3.66 ± 1.6 vs 7.01 ± 1.44 mU/mg protein) and injury of the ileal mucosa were present also. The reproducible large animal model is suitable for clinically relevant investigations of the hemodynamic and biochemical consequences of PT.