Monitoring of hypervolemic-hemodilution and hypertensive therapy in subarachnoid hemorrhage

Introduction: Prophylactic hypervolemic-hemodilution-hypertensive (HHH) therapy in subarachnoid hemorrhage (SAH) may be beneficial in reducing delayed ischemia after early aneurysm clipping. The aim of this study was to assess the correlation among pulmonary artery catheter (PAC) measurements, effectiveness of HHH-therapy and mean flow velocity (MFV) in the middle cerebral artery (MCA) by transcranial Doppler. Methods: We recorded Hunt-Hess classification, hematocrit, hemodynamic and PAC values, bilateral MFV in the MCA and Rankin scale in 37 ICU patients with SAH and no vasospasm receiving prophylactic HHH therapy according to an Institutional protocol following early surgery. HHH therapy efficacy was defined as high when systolic blood pressure (SBP) ≥ 160 and wedge pressure (PCWP) ≥ 12, moderate when only SBP ≥ 160 or PCWP ≥ 12, and ineffective when SBP ≤ 160 and PCWP ≤ 12. Fisher's t test and multiple regression analysis were used for data analysis, p <0.05 was significant. Results: An effective prophylactic HHH therapy did not reduce occurrence of vasospasm. Outcome did not correlate with clinical state on admission or effectiveness of HHH therapy. A constantly elevated SVRI was associated with a good outcome while the combination of high MFV in MCA and low SVRI with poor outcome (p<0.05). Multiple regression analysis showed that SVRI and hematocrit explained 46% of variance of MFV in patients without vasospasm (MFV 140 cm/s, n=16) (Fig. 1). (Figure Presented) Conclusion: Our data demonstrate a correlation among SVRI, hematocrit and MFV. The differences in the outcome between the high and low SVRI with high MFV may be due to a falsely elevated MFV in the high SVRI group.