The concept of ventilator induced lung injury (VILI) has been described more than 20 years ago (1,2). Lung injury can be the consequence of volotrauma when too high tidal volumes are delivered, to barotrauma when airway pressures are too high or to atelectrauma when some lungs area alternate between collapse and opening at every breath. Protective ventilation with low tidal volumes (VT) indexed to predicted body weight (PBW), moderately high plateau pressure and relatively high positive end-expiratory pressure (PEEP) has been recognized as effective in improving outcomes in patients suffering from acute respiratory distress syndrome (ARDS) (3).
The interest of delivering protective ventilation in other patients at risk for developing VILI has not been extensively described. Because transplanted lungs are exposed to cold ischemia after the retrieval process and then to ischemia-reperfusion injuries, they are probably particularly at risk for developing VILI. Protective ventilation strategies in the post-operative period should thus be of particular interest in lung transplanted patients. The effect of using such strategies after lung transplantation has however not been extensively described. In addition, there is some evidence that ventilation delivered in the post-operative period after lung transplantation is very heterogeneous and sometimes not very protective (4).
Primary graft dysfunction (PGD) is one of the most important cause of mortality and morbidity during the early post-transplantation period (0 to 30 days). In addition , PGD is correlated with an increased risk of developing a bronchiolitis obliterans syndrome, which is going to impact long term survival and quality of life (5).PGD usually occurs within the first 72 hours post-transplantation and affects nearly 30% of the transplanted patients (5). It is considered as the result of cold ischemia and reperfusion mechanisms resulting in pulmonary oedema, infiltrates and hypoxemia but could also be enhanced by non-protective ventilation (5, 6).
As according to the latest data of the International Society of Heart and Lung Transplantation (ISHLT), lung transplantation is widely performed around the world (7), the question of optimizing ventilatory support after lung transplantation is of major interest. In addition, it is important to be aware that even if the interest of applying lung protective ventilation strategies has been extensively described, recent studies have shown that the protective ventilation guidelines are often not optimally applied both in ARDS and in post-transplant patients (4, 8).
The main objective of this study was to analyse how mechanical ventilation was applied to the lung transplanted patients during their ICU stay in the Lausanne University Hospital ICU and to determine whether there were differences in the ventilation applied according to the lung disease that led to transplantation.
The second objective of this study was to assess whether the ventilation modalities applied in the post-operative period could be associated with lung transplant patients’ outcomes, in particular with the ventilation duration and the ICU length of stay.