Intracranial Hypertension and Cerebral Perfusion Pressure
Object. Recently, a renewed emphasis has been placed on managing severe head injury by elevating cerebral perfusion pressure (CPP), which is defined as the mean arterial pressure minus the intracranial pressure (ICP). Some authors have suggested that CPP is more important in influencing outcome than is intracranial hypertension, a hypothesis that this study was designed to investigate.
Methods. The authors examined the relative contribution of these two parameters to outcome in a series of 427 patients prospectively studied in an international, multicenter, randomized, double-blind trial of the N-methyl-D-aspartate antagonist Selfotel. Mortality rates rose from 9.6% in 292 patients who had no clinically defined episodes of neurological deterioration to 56.4% in 117 patients who suffered one or more of these episodes; 18 patients were lost to follow up. Correspondingly, favorable outcome, defined as good or moderate on the Glasgow Outcome Scale at 6 months, fell from 67.8% in patients without neurological deterioration to 29.1% in those with neurological deterioration. In patients who had clinical evidence of neurological deterioration, the relative influence of ICP and CPP on outcome was assessed. The most powerful predictor of neurological worsening was the presence of intracranial hypertension (ICP
20 mm Hg) either initially or during neurological deterioration. There was no correlation with the CPP as long as the CPP was greater than 60 mm Hg.
Conclusions. Treatment protocols for the management of severe head injury should emphasize the immediate reduction of raised ICP to less than 20 mm Hg if possible. A CPP greater than 60 mm Hg appears to have little influence on the outcome of patients with severe head injury.
EAD injury is one of the leading causes of death in the industrialized world and is responsible for more than 50% of the 100,000 deaths from trauma in the United States each year. Furthermore, hundreds of thousands of people live with long-term disabilities from head injury. The impact of secondary insults, particularly hypertension and hypoxia, on outcome after head injury has been described previously, but there has been little attention focused on deterioration following hospitalization. Stein, et al., have shown that the patients who deteriorate neurologically have a far worse outcome compared with those who do not. In our study this subgroup of patients was selected for detailed analysis of the influence of different levels of ICP and CPP. In an attempt to improve outcome in patients with traumatic head injury, a renewed emphasis has been placed on CPP. Some authors have even suggested that therapy directed at improving CPP is more important than that aimed at elevated ICP. In the present manuscript we examine the relationship and relative importance of ICP and CPP in severely head injured patients by examining the higher risk group who manifest neurological deterioration following initial resuscitation after admission to the hospital.
Object. Recently, a renewed emphasis has been placed on managing severe head injury by elevating cerebral perfusion pressure (CPP), which is defined as the mean arterial pressure minus the intracranial pressure (ICP). Some authors have suggested that CPP is more important in influencing outcome than is intracranial hypertension, a hypothesis that this study was designed to investigate.
Methods. The authors examined the relative contribution of these two parameters to outcome in a series of 427 patients prospectively studied in an international, multicenter, randomized, double-blind trial of the N-methyl-D-aspartate antagonist Selfotel. Mortality rates rose from 9.6% in 292 patients who had no clinically defined episodes of neurological deterioration to 56.4% in 117 patients who suffered one or more of these episodes; 18 patients were lost to follow up. Correspondingly, favorable outcome, defined as good or moderate on the Glasgow Outcome Scale at 6 months, fell from 67.8% in patients without neurological deterioration to 29.1% in those with neurological deterioration. In patients who had clinical evidence of neurological deterioration, the relative influence of ICP and CPP on outcome was assessed. The most powerful predictor of neurological worsening was the presence of intracranial hypertension (ICP
20 mm Hg) either initially or during neurological deterioration. There was no correlation with the CPP as long as the CPP was greater than 60 mm Hg.
Conclusions. Treatment protocols for the management of severe head injury should emphasize the immediate reduction of raised ICP to less than 20 mm Hg if possible. A CPP greater than 60 mm Hg appears to have little influence on the outcome of patients with severe head injury.
EAD injury is one of the leading causes of death in the industrialized world and is responsible for more than 50% of the 100,000 deaths from trauma in the United States each year. Furthermore, hundreds of thousands of people live with long-term disabilities from head injury. The impact of secondary insults, particularly hypertension and hypoxia, on outcome after head injury has been described previously, but there has been little attention focused on deterioration following hospitalization. Stein, et al., have shown that the patients who deteriorate neurologically have a far worse outcome compared with those who do not. In our study this subgroup of patients was selected for detailed analysis of the influence of different levels of ICP and CPP. In an attempt to improve outcome in patients with traumatic head injury, a renewed emphasis has been placed on CPP. Some authors have even suggested that therapy directed at improving CPP is more important than that aimed at elevated ICP. In the present manuscript we examine the relationship and relative importance of ICP and CPP in severely head injured patients by examining the higher risk group who manifest neurological deterioration following initial resuscitation after admission to the hospital.
Source...