Severe hypoxaemia with a left ventricular assist device in a minipig model with an undiagnosed congenital cardiac disease

Abstract

We describe the placement of a left ventricular assist device (LVAD) in a pig with spontaneously occurring atrial septal defect (ASD) (incidental finding) that created a right -left cardiac shunt, with subsequent severe hypoxaemia. Early diagnosis was critical in order to prevent end-organ damage due to hypoxaemia. Adequate monitoring alerted us to the deterioration in oxygenation, haemodynamics and cerebral oxygen metabolism. This forced us to change the level of assistance provided by the pump, and thus dramatically correct this impairment. Necropsy revealed an ostium secundum ASD. In conclusion, if hypoxaemia presents after implementation of an LVAD, the presence of a right -left shunt must be ruled out. The first step must be a judicious reduction in assist device flow to minimize intracardiac shunting. Subsequently, atrial septal closure of the defect should be considered. We report an experimental model of severe hypoxaemia after placement of an LVAD as part of a larger research project.

Effects of Sevoflurane and Propofol on Organ Blood Flow in Left Ventricular Assist Devices in Pigs

“…The pigs were provided with oxygen 100% via a face mask, a 20 G cannula was inserted into an ear vein, and anesthesia was induced with intravenous fentanyl 2.5 μ g/kg (Fentanest, Kern Pharma, Barcelona, Spain) and propofol 4 mg/kg (Diprivan 1%, AstraZeneca, Madrid, Spain). After intubation, the animal was connected to a volume-controlled ventilator (Dräger SA1, Dräger Medical AG, Lübeck, Germany) with FIO 2 of 1, an inspiratory : expiratory ratio of 1 : 2, a tidal volume of 12–15 mL/kg, and the respiratory rate adjusted to maintain normocapnia as previously described [ 18 ]. Anesthesia was maintained with intravenous fentanyl (2.5 μ g/kg/30 min) in all animals and propofol in continuous infusion (11-12 mg/kg/h) (propofol group) or 2% sevoflurane (sevoflurane group).…”

New Advances in Monitoring Cardiac Output in Circulatory Mechanical Assistance Devices. A Validation Study in a Porcine Model

“…Cardiac output measurement using the CAP in the LVAD can be influenced by atrial or ventricular septal defect, tricuspid regurgitation, or aortic insufficiency (Boerboom et al, 1993;Goldstein et al, 1998). Mini-pigs have a higher incidence of congenital abnormalities (Ho et al, 1991;Quintana-Villamandos et al, 2012), however, in the present study, epicardial echocardiography was performed, and two animals with atrial septal defect were excluded from the study. Epicardial echocardiography showed the absence of tricuspid regurgitation in pigs.…”

Nahinfrarotspektroskopie unter kardiopulmonaler Reanimation und mechanischer Kreislaufunterstützung

“…So kann ein Abfall der zerebralen rSO2 unmittelbar nach Start des VAD-Systems ein Hinweis auf einen atrialen Septumdefekt sein. Durch Änderung des interatrialen Druckgradienten kann es zu einer Zunahme eines Rechts-LinksShunts kommen [48]. Die zerebrale rSO2 korreliert auch gut mit dem Herzzeitvolumen und scheint schneller und sensitiver auf VAD-Veränderungen zu reagieren als kontinuierliche Messungen mit dem Pulmonaliskatheter [3].…”