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Object: Intracranial hypertension remains a common complication of traumatic brain injury (TBI). Ventriculostomy drainage is a recommended therapy to decrease intracranial pressure (ICP), but little empirical evidence exists to guide treatment. The authors conducted a study to examine systematically the effect of cerebral spinal fluid (CSF) drainage on ICP and indices of cerebral perfusion., Methods: Intracranial pressure, cerebral perfusion pressure (CPP), cerebral blood flow velocity (CBFV), and near-infrared spectroscopy-determined regional cerebral oxygenation (rSO2) were measured in 58 patients (with Glasgow Coma Scale scores < or = 8) before, during, and after ventriculostomy drainage. Three randomly ordered CSF drainage protocols varied in the volume of CSF removed (1 ml, 2 ml, and 3 ml). Physiological variables were time averaged in 1-minute blocks from baseline to 10 minutes after cessation of ventricular drainage. There was a significant dose-time interaction for ICP with the three-extraction volume protocol, with incremental decreases in ICP (F [20, 1055] = 6.10; p = 0.0001). There was a significant difference in the CPP depending on the amount of CSF removed (F [2, 1787] = 3.22; p = 0.040) and across time (F [10, 9.58] = 11.9; p = 0.0003) without a significant dose-time interaction. A 3-ml withdrawal of CSF resulted in a 10.1% decrease in ICP and a 2.2% increase in CPP, which were sustained for 10 minutes. There was no significant dose, time or dose-time interaction with CBFV or rSO2., Conclusions: Cerebrospinal fluid drainage (3 ml) significantly reduced ICP and increased CPP for at least 10 minutes. Analysis of these findings supports the use of ventriculostomy drainage as a means of at least temporarily reducing elevated ICP in patients with TBI.

Objective: In patients with severe head injuries, brain damage occurs not only from the primary trauma but also secondarily from a reduction in cerebral oxygenation as a result of brain swelling, ischemia, and elevated intracranial pressure (ICP). However, routine interventions designed to maintain oxygenation, such as endotracheal suctioning (ETS), also may negatively affect the cerebrovascular status by increasing the ICP. The purpose of this study was to determine whether ETS influences cerebral oxygenation in patients with traumatic brain injury., Design: Descriptive, prospective, with repeated assessments within each patient., Setting: Ten-bed trauma intensive care unit in a university Level I trauma center., Subjects: Nineteen patients who were 16 yrs or older, had acute head injury, a Glasgow Coma Scale score < or =8; external ventricular drain and arterial pressure devices in place, and were intubated and mechanically ventilated., Interventions: ETS protocol consisting of administration of four ventilator-delivered breaths at 135% of the patients' actual tidal volume, 100% F(IO)2, before and after suctioning with a standardized catheter at a 16-L flow rate., Measurements and Main Results: This study examined cerebrovascular responses as measured by the traditional measures of ICP and cerebral perfusion pressure, as well as middle cerebral artery velocity and jugular venous oxygen tension that occurred during ETS in head-injured adults. The results of this study show that both ICP and cerebral perfusion pressure are increased during ETS. In the majority of patients (84%), the ICP returned to baseline values within 2 mins., Conclusions: The increase in jugular venous oxygen tension associated with increases in middle cerebral artery velocity and mean arterial pressure suggests that cerebral oxygen delivery was maintained during ETS. Cerebral changes associated with ETS using the described protocol are consistent with the preservation of cerebral oxygenation.

A repeated measures randomized within-group design was used to determine the effectiveness of controlled short-duration hyperventilation (HV) in blunting the increase of intracranial pressure (ICP) during endotracheal suctioning (ETS). A multimodal continuous real-time computerized data acquisition procedure was used to compare the effects of two HV ETS protocols on ICP, arterial pressure, cerebral perfusion pressure (CPP), heart rate, and arterial oxygen saturation in severe head-injured adult patients. The results indicated that short-duration HV for 1 minute, which decreases the PaCO2, reduced ETS-induced elevations in ICP while maintaining CPP. However, it is not clear whether short-duration HV is neuroprotective, particularly in ischemic regions of the brain. Therefore, before a change in practice is implemented on the use of short-duration HV as a prophylactic treatment against ETS-induced elevations in ICP, additional questions on cerebral oxygen delivery and uptake need to be answered.

Objective: To describe the functional outcome of a select group of patients with severe head injuries who would a priori be assumed to have a dismal outcome and to determine prognostic factors that can be used for effective family counseling and rational utilization of scarce resources., Methods: Thirty-seven patients with severe head injuries (admission Glasgow Coma Scale (GCS) score < 8) with prolonged (> 96 hours) intracranial hypertension were studied. Parameters recorded included admission age, GCS, evidence of prehospital hypotension, initial computed tomography findings, intracranial pressure (ICP), cerebral perfusion pressure (CPP), and therapeutic intensity level., Results: Thirty-eight percent of patients in this study achieved a Glasgow Outcome Scale score (GOS) of 4 (moderate disability) or better when assessed 1 year after injury. Patients who achieved these good outcomes were significantly younger (mean 23.6 +/- 8.8 years) than patients who were severely disabled or worse (GOS 1-3) (34.3 +/- 15.0 years) (p = 0.0098). The mean admission GCS in the good-outcome group tended to be higher than that of the poor-outcome group (5.8 +/- 1.5 vs 4.8 +/- 1.6, p = 0.065). When patients with good outcomes (GOS 4 or 5) were compared with those with poor outcomes (GOS 1-3), no significant differences in mean or peak ICP, percentage of time intervals with elevated ICP, lowest recorded CPP, or length of ICP monitoring were detected., Conclusion: Younger patients, particularly those with GCS > 5, have the potential for excellent recovery despite prolonged (> 96 hours) intracranial hypertension. These patients will benefit from continued aggressive ICP and CPP management.

Recent studies have suggested that under certain conditions, inhalation of stable xenon can cause an increase in CBF or intracranial pressure (ICP). We reviewed the ICP changes that occurred during 48 stable xenon/CT CBF studies in 23 comatose head-injured patients to determine if the concentration (32%) and duration of inhalation (4.5 min) of stable xenon we used caused an increase in ICP. In the group as a whole, there was no significant difference between the mean ICP at the start of xenon inhalation and the mean ICP immediately after completion of the studies. An increase in ICP also was not found in subgroups with low, normal, or high global CBF, or groups with or without intracranial hypertension. Changes in ICP that occurred during individual studies usually were related to corresponding changes in the arterial pCO2 (p less than 0.0001, Pearson's correlation test). Our data suggest that 32% stable xenon administered for 4.5 min does not cause a significant increase in ICP during xenon/CT CBF studies.

Hyperventilation is used routinely to reduce intracranial pressure in victims of severe head injury. In the clinical setting, the effects of hyperventilation on regional cerebral blood flow usually are not known. We describe a case in which hyperventilation resulted in local, paradoxic increases in cerebral blood flow (i.e., "inverse steal") associated with a reduction in intracranial pressure. Although the reduced intracranial pressure was thought to be beneficial, serial computed tomographic scans suggested that the inverse steal response could have promoted cerebral edema, resulting in secondary brain injury.