Pressure-Controlled vs Volume-Controlled Ventilation During One Lung Ventilation

Compared with the information available in sepsis and trauma-associated ARDS, less is known about the cause and pattern of lung injury after thoracic surgery. Definition of lung injury in this context is difficult. Most now use the joint North American-European consensus conference definitions, but these are based only on gas exchange and radiology criteria. While gas exchange measures are reliable, thoracotomy inevitably causes radiological change and the interpretation of plain chest films becomes subjective. Definitions based on permeability and inflammatory changes would improve diagnosis, but are not routinely available in most units. Pressure-controlled volume (PCV) may be useful to improve gas exchange and alveolar recruitment with associated lower airway pressures and shunt fraction during one-lung ventilation (OLV). However, a recent prospective randomized study of the effects of PCV during OLV did not lead to improved oxygenation during OLV compared with VCV, but PCV did lead to lower peak airway pressures. To date, there are no reports of the effects of PCV versus VCV during OLV on the acute lung injury (ALI) after thoracotomy.