Changes in brain biochemistry and oxygenation in the zone surrounding primary intracerebral hemorrhage

BACKGROUND: While the management of primary intracerebral hemorrhage (ICH) remains controversial, there remains a subset of patients that undergo clot evacuation. This study aims to characterize brain physiology and biochemistry after surgery for this condition. METHODS: Thirty-six consecutive patients requiring ventilation for primary ICH had intracranial pressure (ICP), tissue oxygenation (PbO2) and cerebral microdialysis (CMD) monitoring. 28 patients with a Glasgow Outcome Score (GOS) of 1-3 formed group 1 while 5 patients with a GOS of 4-5 formed group 2. The control group consisted of 3 patients managed conservatively without surgery. FINDINGS: The mean PbO2 (24.5 +/- 20.8 mmHg) was higher in the patients in group 1 (poor outcome) compared with those in the control group (13.6 +/- 9.0 mmHg) (p < 0.001). Compared to patients in group 2, the patients in group 1 also had a higher PbO2 (p = 0.02) together with worse levels of lactate/pyruvate (L/P) ratio and glycerol (p < 0.001). In all 3 groups, ICP reduction to < 20 mmHg was achieved together with a return to of pressure reactivity (PRx) to < 0.3. CONCLUSIONS: In spontaneous ICH, derangements in the perilesional tissue demonstrated by local techniques of PbO2 monitoring and CMD are not seen in global indices such as the PRx.