BACKGROUND: The early posttraumatic period is critical in patients with traumatic brain injury (TBI) because of the increased risk of secondary ischemic injuries to the injured brain. For these patients, cerebral perfusion pressure (CPP) monitoring is recommended. This, however, requires an invasive device to measure intracranial pressure (ICP). Transcranial Doppler (TCD) ultrasonography is an effective, noninvasive method for the detection of cerebral hemodynamic changes. Use of the dimensionless TCD-pulsatility index (PI) has the advantage of eliminating errors in measurements due to insonation angle variations. MATERIAL/ METHODS: We investigated 37 patients with severe TBI (GCS < or = 8 on admission). The TCD parameters included the systolic, diastolic, and mean velocities of the middle cerebral artery (MCV) and the pulsatility index (PI). Mean arterial pressure (MAP), ICP, CPP, and simultaneous arterial and venous blood gases were also measured. RESULTS: We observed a strong correlation between ICP and PI (r = 0.82, p < 0.0001) for ICP values >20 mmHG. The correlation of CPP to PI were also statistically significant (P < 0.0001). The strongest inverse correlation between CPP and PI was obtained (r = 0.86, p < 0.0001) for CPP values below 70 mmHg. CONCLUSIONS: Pulsatility index measurements permit the early identification of patients with low CPP and high risk of cerebral ischemia. In emergency situations it can be used alone when ICP monitoring is contraindicated or not readily available.
BACKGROUND: The early posttraumatic period is critical in patients with traumatic brain injury (TBI) because of the increased risk of secondary ischemic injuries to the injured brain. For these patients, cerebral perfusion pressure (CPP) monitoring is recommended. This, however, requires an invasive device to measure intracranial pressure (ICP). Transcranial Doppler (TCD) ultrasonography is an effective, noninvasive method for the detection of cerebral hemodynamic changes. Use of the dimensionless TCD-pulsatility index (PI) has the advantage of eliminating errors in measurements due to insonation angle variations. MATERIAL/ METHODS: We investigated 37 patients with severe TBI (GCS < or = 8 on admission). The TCD parameters included the systolic, diastolic, and mean velocities of the middle cerebral artery (MCV) and the pulsatility index (PI). Mean arterial pressure (MAP), ICP, CPP, and simultaneous arterial and venous blood gases were also measured. RESULTS: We observed a strong correlation between ICP and PI (r = 0.82, p < 0.0001) for ICP values >20 mmHG. The correlation of CPP to PI were also statistically significant (P < 0.0001). The strongest inverse correlation between CPP and PI was obtained (r = 0.86, p < 0.0001) for CPP values below 70 mmHg. CONCLUSIONS: Pulsatility index measurements permit the early identification of patients with low CPP and high risk of cerebral ischemia. In emergency situations it can be used alone when ICP monitoring is contraindicated or not readily available.
Authors: Franck Amyot; David B Arciniegas; Michael P Brazaitis; Kenneth C Curley; Ramon Diaz-Arrastia; Amir Gandjbakhche; Peter Herscovitch; Sidney R Hinds; Geoffrey T Manley; Anthony Pacifico; Alexander Razumovsky; Jason Riley; Wanda Salzer; Robert Shih; James G Smirniotopoulos; Derek Stocker Journal: J Neurotrauma Date: 2015-09-30 Impact factor: 5.269
Authors: Henry W Querfurth; Philip Lieberman; Steve Arms; Steve Mundell; Michael Bennett; Craig van Horne Journal: BMC Neurol Date: 2010-11-01 Impact factor: 2.474