Physiologic monitoring of circulatory dysfunction in patients with severe head injuries

Secondary brain insults influence outcome significantly in patients with severe head injuries. Inadequate tissue perfusion should be identified and treated early to avoid such insults. Conventional hemodynamic monitoring (blood pressure, heart rate, urine output) is not a reliable method for evaluating circulatory function in such patients. Invasive monitoring by means of pulmonary artery catheters may offer more precise information on early circulatory abnormalities. The objective of this study was to study the hemodynamic patterns of patients with severe closed head trauma by invasive methods and to correlate the derived information with survival. Fifty-nine consecutive patients with blunt trauma, closed head injuries, and Glascow Coma Scale < 8 were studied. Pulmonary artery catheters were placed in all patients shortly after admission, and flow and flow-derived variables were monitored for 96 hours or patient demise. Survivors had higher cardiac index, oxygen delivery, and oxygen consumption values compared to nonsurvivors during the first 24 hours after injury. Following this period increased values were recorded in both groups. These temporal hemodynamic patterns were similar for patients with isolated head trauma and patients with other associated injuries. Thus initial hemodynamic patterns are associated with final outcome in patients with severe head injuries. Aggressive early hemodynamic monitoring may reveal subtle but significant changes. Further studies are warranted to investigate whether treatment guided by such information can improve survival.