Tight Control of Systolic Blood Pressure in Spontaneous Intraparenchymal Brain Hemorrhage

Abstract

Background Tight blood pressure control is critical in neurosurgical patients. Systolic blood pressure (SBP) must be low enough to avoid injury and minimize intraparenchymal hemorrhage (IPH) but high enough to maintain cerebral perfusion. American Heart Association (AHA) guidelines recommend SBP <140 in intracerebral hemorrhage. This paper sought to elucidate the effect of early control of SBP on IPH expansion. Methods 134 patients with spontaneous IPH between 2011 and 2015 were analyzed utilizing chart review. Initial versus follow-up bleed size, presentation and discharge condition, discharge disposition, and blood pressure control adequacy were analyzed using the generalized linear model. Results Altered mental status was the most common presenting complaint (78%). Presenting GCS failed to demonstrate a significant main effect. Age, initial IPH volume, presenting SBP, and one-hour SBP significantly affected IPH percent expansion (p=0.002, =0.002, <0.0005, and =0.026). Several two-way interactions affected IPH percent change implying synergistic effects of the predictor variables. Conclusion Patients aged 60-70 years had the largest percent IPH expansion followed by patients aged 20-30 years. Initial IPH volume of 65.23-78.26 ml showed the largest expansion. Initial IPH volume of 52.18-65.22 ml demonstrated the least percentage of IPH expansion. One-hour control of SBP to binned groups of 111-121 mmHg or 121-132 mmHg portends relative minima in bleed expansion corresponding with AHA recommendations for IPH patients. This study suggests that this degree of early and aggressive control of SBP is achievable, safe, and may minimize IPH expansion. Future studies are needed to elucidate the role of co-morbidities and to confirm these findings in broader populations.

Keywords: blood pressure; intraparenchymal hemorrhage; systolic.

Figure 1. Average % change in IPH volume by initial GCS.

While patients who presented with GCS 10 had, in absolute value, that smallest change in IPH volume, the variance was again quite high and patients whose initial GCS was nine seemed to have an overall decrease in IPH size on follow-up imaging. Intraparenchymal hemorrhage: IPH Glasgow Coma Scale: GCS

Figure 2. Average % change in IPH volume by age group.

Patients in the 60-70 years age group tended to have the largest IPH expansion followed by the 20-30 years age group. Intraparenchymal hemorrhage: IPH

Figure 3. Average % change in IPH volume by initial volume of IPH.

Again, the data is roughly normally distributed with peak expansion occurring in the group of patients who presented with initial IPH volume of 65.23 to 78.26 ml. There is also a second maximum in patients who presented with initial IPH volume of 0.01 to 13.04 ml. Intraparenchymal hemorrhage: IPH

Figure 4. Average % change in IPH volume by initial SBP.

There is a bimodal distribution of % change in IPH size by initial SBP, with the largest expansion occurring in patients whose presenting SBP was 132-143 and those at 239-250. Intraparenchymal hemorrhage: IPH Systolic blood pressure: SBP

Figure 5. Average % change in IPH volume by SBP at one hour of presentation.

Patients whose SBP fell between 132 and 143 again had larger IPH expansions. Of note, the largest IPH expansion occurred with SBP 101-111 and there was another relative maximum at 196-207. Summary of Abbreviations in Figure 5: Intraparenchymal Hemorrhage: IPH Systolic Blood Pressure: SBP

Figure 6. Average % change in IPH volume by SBP control group.

Patients whose SBP was not controlled to < 160 and patients whose SBP was controlled to < 160 but not < 140 appeared to have smaller IPH expansion than patients whose SBP was controlled to < 140. There is, however, a large degree of variance in the data analyzed in this way. Summary of Abbreviations in Figure 6: Intraparenchymal Hemorrhage: IPH Systolic Blood Pressure: SBP Blood Pressure: BP