Perioperative management of patients undergoing lung transplantation

Ventilation strategy and its influence on the functional performance of lung grafts in an experimental model of single lung transplantation using non-heart-beating donors

OBJECTIVE

To compare the influence of two different ventilation strategies-volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV)-on the functional performance of lung grafts in a canine model of unilateral left lung transplantation using donor lungs harvested after three hours of normothermic cardiocirculatory arrest under mechanical ventilation.

METHODS

The study comprised 40 mongrel dogs, randomized into two groups: VCV and PCV. Of the 20 recipients, 5 did not survive the transplant, and 5 died before the end of the post-transplant assessment period. The remaining 10 survivors (5 in each group) were evaluated for 360 min after lung transplantation. The functional performance of the grafts was evaluated regarding respiratory mechanics, gas exchange, and lung graft histology.

RESULTS

There were no significant differences between the groups regarding respiratory mechanics (peak inspiratory pressure, plateau pressure, mean airway pressure, dynamic compliance, and static compliance) or gas exchange variables (PaO2, venous oxygen tension, PaCO2, venous carbon dioxide tension, and the arterial-venous oxygen content difference). The histopathological findings were consistent with nonspecific acute lung injury and did not differ between the groups.

CONCLUSIONS

This model of lung transplantation showed that the functional performance of lung grafts was not influenced by the ventilation strategy employed during the first six hours after reperfusion.

Pulmonary transplantation

Anesthetic technique for pulmonary transplantation varies with recipient's underlying lung disease, procedure performed and regional practice. The pulmonary allograft is vulnerable to mechanical and biochemical injury throughout the harvesting, preservation and engraftment procedures. Mechanisms of allograft injury are reviewed, with suggestions for incorporation of strategies to minimize injury into clinical practice. Particular emphasis is placed on the use of nitric oxide for treatment of reperfusion injury.