Spontaneous Elevation of Blood Pressure After SAH: An Epiphenomenon of Disease Severity and Demand, But Not a Surrogate for Outcome?

Background Spontaneous blood pressure increase is frequently observed after aneurysmal subarachnoid hemorrhage (aSAH). These episodes of spontaneous blood pressure alterations are usually tolerated under the assumption of an endogenous response to maintain cerebral perfusion. The relevance of blood pressure variability and its relationship to disease severity and outcome, however, remain obscure. Methods A total of 115 consecutive patients with aSAH were included for this retrospective analysis of a continuously collected data pool. Demographics, initial clinical severity of aSAH (HH°, mFS), treatment modality, clinical course, and outcome (development of DCI, cerebral infarction, and GOS after 3 months) were recorded. Hemodynamic information—recorded automatically with a frequency of 1/15 min—was analyzed for spontaneous blood pressure increase (SBI) and endogenous persistent hypertension (EPH) after exclusion of iatrogenic factors and relevant co-medication. Subgroup analysis included stratification for day 0–3, 4–14, and 14–21. Results SBI and EPH incidence varied from 17 to 84% depending on detection threshold (15–35 mmHg) and time period under scrutiny. Incidence of blood pressure increase correlated with disease severity upon admission ( p