Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2012
Is P(br)O (2) pressure reactivity index (ORx) dependent on the type of oxygen probe? An in vivo study.
To evaluate if ORx is dependent on the type of brain tissue O(2) (P(br)O(2)) probe in an in vivo setting. ⋯ Despite this significant difference in absolute values of P(br)O(2) the derived mean ORx values were not different. Similar to the established Licox system, the Raumedic system seems to enable a valid ORx recording.
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Acta Neurochir. Suppl. · Jan 2012
Association between ICP pulse waveform morphology and ICP B waves.
The study aimed to investigate changes in the shape of ICP pulses associated with different patterns of the ICP slow waves (0.5-2.0 cycles/min) during ICP overnight monitoring in hydrocephalus. Four patterns of ICP slow waves were characterized in 44 overnight ICP recordings (no waves - NW, slow symmetrical waves - SW, slow asymmetrical waves - AS, slow waves with plateau phase - PW). The morphological clustering and analysis of ICP pulse (MOCAIP) algorithm was utilized to calculate a set of metrics describing ICP pulse morphology based on the location of three sub-peaks in an ICP pulse: systolic peak (P(1)), tidal peak (P(2)) and dicrotic peak (P(3)). ⋯ Based on relative changes in variability of amplitudes of P(2) and P(3) we were able to distinguish between the combined groups NW + SW and AS + PW (p < 0.000001). The AS pattern can be differentiated from PW based on respective changes in the mean curvature of P(2) and P(3) (p < 0.000001); however, none of the MOCAIP feature separates between NW and SW. The investigation of ICP pulse morphology associated with different ICP B waves may provide additional information for analysing recordings of overnight ICP.
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Acta Neurochir. Suppl. · Jan 2012
Pressure reactivity index correlates with metabolic dysfunction in a porcine model of intracerebral hemorrhage.
We correlated oxygen, flow, and pressure indices of cerebrovascular reactivity (CR) with extracellular cerebral metabolite concentrations in a porcine model of intracerebral hemorrhage (ICH). ⋯ We found evidence for impaired CR in a porcine model of ICH. The findings suggest that, among other parameters of CR, positive PRx coefficients have the highest significance and could be associated with microdialysis alterations during hypoxic events.
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Acta Neurochir. Suppl. · Jan 2012
Spontaneous cortical spreading depression and intracranial pressure following acute subdural hematoma in a rat.
Acute subdural hemorrhage (ASDH) is a frequent and devastating consequence of traumatic brain injury. Tissue damage develops rapidly and makes treatment even more difficult. Management of increased intracranial pressure (ICP) due to extravasated blood volume and brain swelling is often insufficient to control all adverse effects of ASDH. ⋯ Tissue impedance increased by around 203% of baseline during subdural infusion of 300 μl of autologous, venous blood and dropped back to baseline within 22 min. Fifty-six minutes after the start of ASDH a cluster of four short-lasting (3-3.5 min; 140-160% of baseline) IMP increases started that reflected spontaneous CSDs. This pattern presumes that CSD occurs early after ASDH and therefore may contribute to the rapid lesion development in this disease.