Heparin does not improve graft function in uncontrolled non-heart-beating lung donation: an experimental study in pigs

Abstract

Objectives: Non-heart-beating donation (NHBD) has the potential to increase the number of patients treated with lung transplantation. Our study investigated, in a simulated clinical situation in the uncontrolled NHBD setting, whether or not heparin administration after death affects the donor lung function.

Methods: Twelve Swedish domestic pigs underwent ventricular fibrillation and were left untouched for 7 min followed by cardiopulmonary resuscitation with mechanical compressions for 20 min. The animals were declared dead after a 'hands-off' period of 10 min and randomized to heparin (300 IU/kg) or placebo given into a central venous catheter. In the animals receiving heparin, 2 more minutes of chest compression followed. Intrapleural cooling was initiated 1 h after death, and prevailed for 2 h. Ex vivo lung perfusion (EVLP) was performed with the Vivoline(®) system. Lung function was evaluated with blood gases at different oxygen levels, pulmonary vascular resistance (PVR), wet/dry weight ratio, macroscopic appearance and histology.

Results: During EVLP, there were no significant differences between groups in PaO(2) or PVR at any investigated FiO(2) level (1.0, 0.5 or 0.21). At FiO(2) 1.0 the PaO(2) in the heparin group was 64 ± 2 (range 57-73) kPa and in the non-heparin group 63 ± 4 (range 51-71) kPa. The values for PVR were 592 ± 90 (range 402-1007) and 647 ± 97 (range 426-1044), respectively. There was no significant difference between groups in wet/dry ratio or histology.

Conclusions: The use of heparin is of no obvious benefit to the donor lungs in the uncontrolled NHBD situation. The exclusion of heparin will simplify lung donation from NHBDs.