Early noncardiogenic pulmonary edema and the use of PEEP and prone ventilation after emergency liver transplantation

Abstract

Noncardiogenic pulmonary edema in liver transplant recipients is usually secondary to TRALI (transfusion related acute lung injury) or liver ischemic-reperfusion injury. If persistent, the resultant hypoxemia is associated with increased ventilator days, prolonged length of stay (intensive care and hospital) and increased 28-day mortality. Ventilation strategies for the management of hypoxemia in acute lung injury include moderate to high levels of PEEP (positive and expiratory pressure) and prone ventilation (PV). Such strategies have theoretical adverse effects on graft perfusion. Evidence does however exist to demonstrate that maintenance of cardiac output and correct positioning of the prone patient to allow abdominal excursion can negate the deleterious effects of PEEP and PV. A liver transplant recipient became profoundly hypoxemic on our intensive care unit following the onset of noncardiogenic pulmonary edema. A risk-benefit assessment performed at the time deemed that the potential adverse effects of PEEP and PV were outweighed by the life-threatening nature of hypoxemia. The patient's condition improved following prone positioning and application of PEEP (10-15 cm H 2 O). We conclude that such ventilation strategies are appropriate in hypoxemic liver transplant recipients if an appropriate risk-benefit assessment is performed. Liver Transpl 13: 459-462, 2007.

Intensive Care of Pulmonary Complications Following Liver Transplantation

“…Permeability-type pulmonary edema is driven by inflammation in the setting of liver ischemia-reperfusion injury via multiple pathways: (1) triggering of inflammatory cytokines that activate nuclear factor kb and subsequent downstream transcription of proinflammatory molecules, (2) translocation of endotoxin to the systemic circulation, and (3) oxidative stress. 74,76 Other mechanisms of permeability-type pulmonary edema occurring post-liver transplantation include transfusion-related acute lung injury [77][78][79][80][81] and was seen more frequently after calcineurin inhibitors came into use 81,82 as well as fast tapering of steroids 79 and less commonly, reexpansion. 81,83 There is no significant difference between whether the edema resolved or persisted between hydrostatic-type and permeability-type pulmonary edema.…”

How far can we go with positive end-expiratory pressure (PEEP) in liver transplant patients?

“…Prolonged periods of ventilation above 15 cm H 2 O may be necessary to improve oxygenation during the reperfusion phase of a liver transplantation [4], in patients with primary non-function of the liver graft [3], and in patients with accompanying severe lung injury. Although reports have described prolonged ventilation with PEEP levels of 15 cm H 2 O in liver transplant patients without detrimental effects on the liver [30,31], the effect of mechanical ventilation with a higher PEEP over a prolonged period of time has yet to be analyzed in a prospective clinical trial.…”

Perioperative Care of the Liver Transplant Patient

“…There is minimal published experience with the use of permissive hypercapnia and high-frequency oscillation in patients after LT. Reports of the use of prone positioning provide conflicting messages. 47,48 Perioperative hepatopulmonary syndrome Hepatopulmonary syndrome (HPS) is discussed in detail in Respiratory Complication in Liver Disease by Ramalingam VS, Ansari S and Fisher M, in this issue. In the perioperative period, a failure of the PaO 2 to adequately increase with administration of 100% O 2 may result in critical hypoxemia.…”