Influence of blood pressure variability on short-term outcome in patients with subarachnoid hemorrhage

Several recent investigations have demonstrated a significant influence of blood pressure variation during the immediate period after stroke. The present study was conducted to evaluate the effect of blood pressure, intracranial pressure and cerebral perfusion pressure variation on short-term outcome in patients after severe subarachnoid hemorrhage (SAH).

105 patients suffering from severe SAH were included in the study. The Glasgow Coma Scale (GCS) Score and World Federation of Neurological Surgeons (WFNS) grading were used to describe the patients on admission, and the short-term outcome was assessed using the GCS and the Glasgow Outcome Scale (GOS) Score. In all patients, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial blood pressure (MAP), intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were continuously recorded. For each recorded parameter (SBP, DBP, MAP, ICP and CPP) the first recorded value was defined as the baseline value (bas). The minimum (min), maximum (max) and average (mean) value was identified from all recorded values for each parameter and the range between minimum and maximum value was calculated (range). Based on the individual parameter range (absolute values) the variability of successive values was determined as the successive variation (sv). Finally, the values obtained were correlated to clinical outcome and analyzed statistically.

In 105 patients the database offered an average of 330.4 single readings (median 318). SBPmax, and SBPrange were significantly lower in the group with an improving short-term GCS than in the group with constant or deteriorating GCS ( P=0.0079 and P=0.0006, respectively). SBPmin was significantly higher in the improved GCS group (P=0.0235). With regard to successive variation (SBPsv) we could not demonstrate a significant difference between both groups (mean SBPsv 15.7 vs. 14.7; P=0.1223), and no correlation with either GCS at discharge (P=0.91) or GOS at discharge (P=0.841) was detectable. There was no statistically significant difference in CPP and ICP between both outcome groups.

Systolic blood pressure levels and range appear to be of importance for the management of patients suffering from SAH and may influence patient outcome.