Organ Donation After Cardiac Determination of Death (DCD): A Swine Model

Abstract

Donors after Cardiac Death (DCD) may reduce the organ scarcity; however, their use is limited because of warm ischemia time. Fortunately, this is less important in a subclass of DCD called expected (e-DCD), those with irreversible but incomplete brain injury. This study analyzed hemodynamic/pulmonary data to establish a clinically relevant model of cardiac death that would simulate an e-DCD setting. Hemodynamics, pulmonary artery flows, arterial blood gasses, and left atrial pressure were recorded q 5 minutes in anesthetized swine. After baseline data collection, the ventilator was discontinued and heparin was administered. Cardiac death was defined: as asystole, or mean arterial presusure < or = 25 mm Hg with a pulse pressure < or = 20 mm Hg. The time to death was approximately 14.8 minutes. Within 5 minutes of removal of the ventilator, there was a hyperdynamic period. Blood gases throughout the apneic time showed a rapid hypercapnia and acidosis. The hyperdynamic reflex response was followed by hypotension, bradycardia, and finally asystole or ventricular fibrillation. The protocol of withdrawal of ventilation, systemic anticoagulation, determination of death was developed to closely resemble the clinical e-DCD scenario. The physiologic changes that happen before death in DCD were described. An e-DCD model that can be used in studies related to organ transplantation was established.

Contribution of Large Pig for Renal Ischemia‐Reperfusion and Transplantation Studies: The Preclinical Model

“…There is room for experimental studies in these fields and particularly for large animal models. Several recent studies have shown that promising protocols could be used in the clinical situation [ 92 , 102 , 103 , 120 , 126 ]. More recently, new protocols have been evaluated and the use of normothermic venoarterial extracorporeal membrane oxygenation support seems an interesting alternative [ 80 ].…”

Donation After Circulatory Determination of Death

“…We have studied many of the details of E-DCDD in the laboratory, using a porcine model of apneic CA (21,22). We have learned that heparin given 5 min after CA is as effective as heparin given before; that the perfusion temperatures can be allowed to gradually drop from 37-C to room temperature, obviating the need for a heat exchanger and water bath in the circuit (23); that kidneys and livers can be successfully resuscitated by ECS after more than 30 min of warm ischemic time; and that lungs can be successfully resuscitated by ECS (relying on bronchial flow from the distal aorta) and lung function can be evaluated despite the fact that there is no pulmonary circulation (24).…”

A 10 min “no-touch” time - is it enough in DCD? A DCD Animal Study

“…In the previous literature, several animal models are described focusing on different DCD protocols. However, none of these studies has included brain death diagnosis [44–46].…”