Aim: We evaluated the association of physiological parameters measured by intracranial
multimodality neuromonitoring with neurologic outcome in a consecutive series of patients
with hypoxic-ischemic brain injury (HIBI).Methods: We retrospectively identified all
patients with HIBI who underwent combined invasive intracranial pressure (ICP) and
brain tissue oxygen (PbtO2) monitoring over a 3 year period. Cerebrovascular pressure
reactivity index (PRx) was calculated continuously as a surrogate of cerebral autoregulation.
Favorable outcome was defined as recovery of consciousness (Glasgow Coma Scale motor
score = 6). Differences in mean ICP, PRx and PbtO2 for the entire monitoring period
across outcomes were measured. Logistic regression and area under receiver operating
characteristic (AUROC) curve were used to assess the association of each monitoring
parameter with neurologic outcome.Results: We analyzed data from 36 patients. Most
(89%) had an antecedent sudden cardiac arrest. Favorable outcome occurred in 8 (22%)
patients. ICP and PRx were higher in patients with unfavorable outcome (ICP: 26 +/-
4.1 mmHg vs 7.5 +/- 2 mmHg, p = 0.0002; PRx: 0.51 +/- 0.05 vs 0.11 +/- 0.05, p < 0.0001).
There was no significant difference in PbtO2 between groups (unfavorable: 20 +/- 2.4
mmHg vs favorable: 25 +/- 1.5 mmHg, p = 0.12). Both ICP (AUROC 0.84, 95%CI 0.72-0.98,
p = 0.003) and PRx (AUROC 0.94, 95%CI 0.85-1, p = 0.0002) discriminated between favorable
and unfavorable outcome, in contrast to PbtO2, (AUROC 0.59, 95%CI 0.39-0.78, p = 0.52).
ICP > 15 mmHg, PRx > 0.2, and PbtO2 < 18 mmHg had sensitivity/specificity of 68%/100%,
89%/88%, and 40%/100% respectively for discriminating outcomes.Conclusion: Cerebrovascular
pressure reactivity and intracranial pressure appear to be associated with neurologic
outcome in patients with HIBI.