Artikel
Intracranial hypertension in aneurysmal subarachnoid hemorrhage Relation to metabolism, decompressive surgery and outcome
Intrakranielle Hypertension und Hirnstoffwechselveränderungen bei Patienten mit aneurysmatischer Subarachnoidalblutung
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Veröffentlicht: | 30. Mai 2008 |
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Gliederung
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Objective: Intracranial hypertension occurs in up to 50-60% of patients with aneurysmal subarachnoid hemorrhage (SAH) and is associated with high levels of excitotoxic mediators, edema formation and poor outcome. We investigated the cerebral metabolic changes, such as glutamate-mediated excitotoxicity, in relation to high intracranial pressure (ICP>20 mmHg), decompressive surgery and outcome in patients with aneurysmal SAH.
Methods: In 182 SAH patients classified into low (n=164) and high (n=18) ICP-groups, a microdialysis catheter was inserted into the brain parenchyma of interest. Parameters of energy metabolism, glycerol and glutamate were analyzed hourly for seven days. ICP was monitored by a ventricular drainage. Seven patients with uncontrollable ICP underwent decompressive surgery. In all patients, the 12-month outcome was evaluated.
Results: In all patients with intracranial hypertension, cerebral metabolism was severely deranged. On days 1-7 after SAH, the glycerol concentrations and the lactate/pyruvate ratio (LP-ratio) were significantly higher in the high-ICP group (p=0.01). Secondarily, glutamate increased on days 5-7 (p=0.038). In 5 patients, who underwent decompressive surgery, cerebral metabolism was severely deranged already 39.5±12 before the start of refractory intracranial hypertension which occurred 21±15.5 hrs before decompressive surgery. Glycerol was the earliest marker of a metabolic crisis exceeding >80µM in all 6 patients compared to glutamate (4 patients, >10 µM) and LP-ratio (1 patient, >25). The outcome was significantly worse in the high-ICP group, independent of the WFNS grade (p<0.01).
Conclusions: Intracranial hypertension is associated with a severely deranged cerebral metabolism and an unfavourable outcome. A deterioration of markers of a cerebral crisis can be supporting factors to select patients and timing for decompressive surgery.