Temporal Dynamics of ICP, CPP, PRx, and CPPopt in High-Grade Aneurysmal Subarachnoid Hemorrhage and the Relation to Clinical Outcome

Abstract

Background High intracranial pressure (ICP) and low cerebral perfusion pressure (CPP) may induce secondary brain injury following aneurysmal subarachnoid hemorrhage (aSAH). In the current study, we aimed to determine the temporal incidence of insults above/below certain ICP/CPP thresholds, the role of pressure autoregulation in CPP management (PRx and CPPopt), and the relation to clinical outcome. Methods In this retrospective study, 242 patients were included with aSAH, who were treated in the neurointensive care unit, Uppsala University Hospital, Sweden, 2008–2018, with ICP monitoring the first 10 days post-ictus. Data from ICP, pressure autoregulation (PRx), CPP, and CPPopt (the CPP with the lowest/optimal PRx) were analyzed the first 10 days. The percentage of good monitoring time (GMT) above/below various ICP and CPP thresholds was calculated, e.g., ICP > 20 mm Hg (%), CPP < 60 mm Hg (%), and ∆CPPopt (CPP–CPPopt) < − 10 mm Hg (%). Results Of the 242 patients, 63 (26%) had favorable (GOS-E 5–8) and 179 (74%) had unfavorable (GOS-E 1–4) outcome at 12 months. Higher proportion (GMT) of ICP insults above 20 mm Hg was most common the first 3 days post-ictus and was then independently associated with unfavorable outcome. CPP gradually increased throughout the 10 days post-ictus, and higher proportion of GMT with CPP < 90 mm Hg was independently associated with unfavorable outcome in the late vasospasm phase (days 6.5–10). PRx was above 0 throughout the 10 days and deteriorated in the late vasospasm phase. Higher values were then independently associated with unfavorable outcome. There was no difference in GMT of CPP deviations from CPPopt between the outcome groups. Conclusions Avoiding intracranial hypertension early and maintaining a high CPP in the vasospasm phase when the pressure autoregulation is most disturbed may improve clinical outcome after aSAH.

Intracranial pressure- and cerebral perfusion pressure threshold-insults in relation to cerebral energy metabolism in aneurysmal subarachnoid hemorrhage

“…The current guidelines for TBI suggest keeping ICP below 22 mmHg and maintaining CPP between 60 and 70 mmHg [3]. aSAH patients commonly exhibit intracranial hypertension and cerebral ischemia [26], but there are currently no established aSAH guideline recommendations for ICP and CPP [5,8]. There is some support for extrapolating the targeted thresholds from TBI to aSAH, as ICP above 20 mmHg seems similarly dangerous and associated with unfavorable clinical outcome in both brain injury conditions [10,18,22,26,32].…”

“…aSAH patients commonly exhibit intracranial hypertension and cerebral ischemia [26], but there are currently no established aSAH guideline recommendations for ICP and CPP [5,8]. There is some support for extrapolating the targeted thresholds from TBI to aSAH, as ICP above 20 mmHg seems similarly dangerous and associated with unfavorable clinical outcome in both brain injury conditions [10,18,22,26,32]. However, whereas a CPP-target within 60-70 mmHg is associated with favorable outcome in TBI [3,27], CPP above 70 mmHg and higher is associated with a reduced risk of clinical deterioration and higher chance of favorable outcome in aSAH [22,26].…”

Critical care management of patients with spontaneous subarachnoid haemorrhage – a review

“…14 Tíðni sjálfsprottinna innanskúmsblaeðinga er mjög breytileg eftir löndum en í flestum rannsóknum er hún um 510 tilfelli á hverja 100.000 íbúa á ári. 15 Um 10% þeirra sem fá sjálfsprottna innanskúmsblaeðingu deyja áður en þeir komast á sjúkrahús. 13 Slagaeðagúlar í heila myndast oftast á svaeðum þar sem aeðar greinast.…”

“…13,14 Miðað er við að halda innankúpuþrýstingi ≤20 mmHg. 13,15 Sé um að raeða haekkaðan innankúpuþrýsting er mik ilvaegt að haekka höfuðendann á rúmi sjúklingsins (miðað við 3045° halla), viðhalda eðlilegu gildi koltvísýrings í blóði (3548 mmHg) og nota slaevingar og verkjalyf. 13,14 Slaevingar og verkjalyf laekka innankúpuþrýsting með því að draga úr óróleika, vanlíðan og verkjum auk þess sem þau haegja á efnaskiptum í heilanum og draga úr blóðrúmmáli hans.…”

Advanced Bio-signal Analytics for Continuous Bedside Monitoring of Aneurysmal Subarachnoid Hemorrhage: The Future

“…The recent publication by Svedung Wettervik et al in Neurocrit Care [42] is a major step forward in our understanding of integrated MMM and bio-signal analytic approaches in aSAH patients, and should be considered a seminal work in the field. To date, this is the largest population of aSAH patients with high-frequency digital physiologic recordings described.…”