Cardiopulmonary haemodynamic changes after severe head injury.

Haemodynamic studies were performed by pulmonary artery catheter in 15 patients with severe head injury. To our knowledge, few data are available about the detailed haemodynamic changes after head injury using pulmonary artery catheter. All patients were assessed by the Glasgow Coma Scale, computed tomography and intracranial pressure monitoring. We divided the patients into hypotensive and normotensive groups. All patients showed a high pulmonary vascular resistance and a high pulmonary capillary wedge pressure, probably due to pulmonary vasoconstriction. In the hypotensive group, the two major changes were a marked decrease of the cardiac index and a slight increase of systemic vascular resistance. The low cardiac index was the result of heart failure secondary to myocardial dysfunction. In contrast, the normotensive group was characterized by a high systemic vascular resistance that was induced by generalized vasoconstriction. Increased intracranial pressure is initially associated with an increase of the cardiac index and systemic vascular resistance, so patients with severe head injury also suffer from profound circulatory disturbance.