Temporal dynamics of ICP, CPP, PRx, and CPPopt in relation to outcome in spontaneous intracerebral hemorrhage

Abstract

Objective: There is a paucity of studies on the optimal thresholds for neurointensive care (NIC) targets such as intracranial pressure (ICP) and cerebral perfusion pressure (CPP) in spontaneous intracerebral hemorrhage (sICH). There is also a need to clarify the role of cerebral pressure autoregulatory disturbances (pressure reactivity index [PRx]) and to determine if the autoregulatory CPP target (optimal CPP [CPPopt]) is superior to traditional fixed CPP targets in sICH. In this study, the authors aimed to explore the role of ICP, PRx, CPP, and CPPopt insults in sICH patients treated in the NIC unit.

Methods: In this observational study, 184 adults with sICH with intracerebral hemorrhage (ICH) volume above 10 ml who received > 12 hours of ICP monitoring during the first 7 days at the authors' NIC unit, Uppsala University Hospital, Sweden, between 2010 and 2019 (10 years) were included. Demographic characteristics, admission status, radiological examination, and clinical outcome were evaluated. Favorable outcome was defined as conscious at discharge, while unfavorable outcome as unconscious or deceased. ICP, CPP, PRx, and CPPopt during the first 7 days were analyzed in relation to outcome.

Results: In total, 138 (75%) patients recovered favorably at discharge. Lower percentage of good monitoring time with ICP above 25 mm Hg was independently associated with favorable outcome. CPP above 80 mm Hg was frequent and independently associated with favorable outcome. Median PRx did not differ between the outcome groups, but there was a trend toward worse outcome when PRx exceeded +0.5. Furthermore, when PRx was analyzed together with the concurrent ICP and CPP values, higher values increased the ICP and CPP interval associated with unfavorable outcome. Lastly, there was no independent correlation between CPP deviation from CPPopt and outcome.

Conclusions: Avoiding ICP elevations above 20 to 25 mm Hg and maintaining CPP above 80 mm Hg may be beneficial in sICH patients with large bleeding volume who require NIC. PRx was not independently associated with outcome, but higher values appeared to narrow the safe zones of ICP and CPP.

Keywords: cerebral autoregulation; cerebral perfusion pressure; intracerebral hemorrhage; intracranial pressure; neurointensive care; outcome; vascular disorders.