Fig. 1

Potential pathophysiological interactions between severe brain injury and severe lung injury, and their conflicting therapeutical needs. Severe brain injury and severe lung damage may ensue as consequence of the same noxious agent (for example in severe multiple trauma or severe liver failure), but also one be the cause of the other (e.g., neurogenic pulmonary edema in subarachnoid hemorrhage, or lung aspiration and infection in a comatous patient). Indeed, once coexisting, disease of one organ can negatively affect the other, in a harmful organ cross-talk (e.g., hypoxemia can worsen brain damage). Finally, some therapeutical interventions directed at protecting one organ may have detrimental effects on the other (e.g., mechanical ventilation strategies can either reduce systemic mean arterial pressure, decrease cerebral venous return, or cause cerebral vasodilation, thus inducing a worsening of intracranial hypertension and reducing the cerebral perfusion pressure)