Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2012
Development of an experimental model to study the pathophysiology of cerebral salt wasting following subarachnoid hemorrhage.
Hyponatremia is frequent following cranial -neurosurgery or acute brain injury like subarachnoid hemorrhage (SAH), and increases mortality by 30%. The patho-physiology is not understood nor does a causal therapy exist. Since clinical trials are potentially dangerous in this very ill population, we examined whether an established rat model allows studying cerebral salt wasting (CSW) following SAH. ⋯ Neither SAH(mild) (100 μL), the injection of hemolyzed blood (100 μL) or hypertonic saline (200 μL) replicated the effect. The immediate release of ADH (32.23 ± 34.87 pg/mL) following SAH(severe) normalized over the next few days. We conclude that first, the rat model of SAH is suitable for studying CSW, second the increase in intracranial pressure generates the delayed hyponatremia, and third, the ADH release does not mediate natriuresis.
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From recent studies, it remains unclear whether CT angiography could be an alternative to other established ancillary tests for the diagnosis of brain death. We examined intracranial contrast enhancement in CT angiography after clinically established brain death and compared the results with EEG and TCD findings. ⋯ CT angiography is a promising method of evaluating intracranial circulatory arrest in brain death with a high spatial and temporal resolution, superior to all other established technical procedures. The examination is easily accessible in most hospitals, operator independent, minimally invasive and inexpensive. Therefore, CT angiography has the potential to enlarge the existing armamentarium of confirmatory brain death tests.
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Acta Neurochir. Suppl. · Jan 2012
How does moderate hypocapnia affect cerebral autoregulation in response to changes in perfusion pressure in TBI patients?
In traumatic brain injury, the hypocapnic effects on blood pressure autoregulation may vary from beneficial to detrimental. The consequences of moderate hypocapnia (HC) on the autoregulation of cerebral perfusion pressure (CPP) have not been monitored so far. Thirty head injured patients requiring sedation and mechanical ventilation were studied during normocapnia (5.1 ± 0.4 kPa) and moderate HC (4.4 ± 3.0 kPa). ⋯ Mx was adjusted to normal despite no significant change in CPP levels. Our study showed that short-term moderate HC may optimize the autoregulatory response to spontaneous CPP fluctuations with only a small CPP increase. Patients with impaired autoregulation seemed to benefit the most.
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Acta Neurochir. Suppl. · Jan 2012
Monitoring of the association between cerebral blood flow velocity and intracranial pressure.
Slow waves in intracranial pressure (ICP) are believed to originate from changes in cerebral blood volume secondary to adjustments in arteriolar diameter. Blood flow velocity (FV) signals recorded with transcranial Doppler ultrasound show similar oscillations. We investigated a continuous measure of FV/ICP association and its relationship to cerebral perfusion pressure (CPP), ICP, cerebral autoregulation (CA) and outcome after severe traumatic brain injury (TBI). ⋯ FIx correlated with ICP (Spearman's R = -0.40, p < 0.01), Mx (R = -0.54, p < 0.00005) and CPP (R = 0.34, p < 0.01), but not with PRx (p = 0.84). FIx was significantly associated with outcome after grouping into Glasgow Outcome Score (GOS) 1-3 or GOS 4-5 (Mann-Whitney p = 0.009). FIx may provide unique insights into the behaviour of the cerebral circulation during intracranial hypertension.
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Acta Neurochir. Suppl. · Jan 2012
Late decompressive craniectomy as rescue treatment for refractory high intracranial pressure in children and adults.
The purpose of this study was to determine the prognosis of children and adults in whom decompressive craniectomy (DC) was used as a rescue treatment to lower refractory high intracranial pressures if maximal conservative therapies failed. Data of DC patients were retrospectively reviewed. Three-month and 1-year outcomes were evaluated (modified Rankin Score). ⋯ Eleven suffered from traumatic brain swelling, in 10 the primary pathological condition was intracranial hemorrhage, arteriovenous malformation bleeding or subarachnoid hemorrhage. All 13 survivors (62%) had a favorable outcome after 1 year (mRS≤3), 8 (38%) lacked any disabilities at all. Therefore, decompressive craniectomy offers a chance for a favorable outcome in uncontrollable ICP.