Cardiac performance indices during hypervolemic therapy for cerebral vasospasm.

Area of Science:

• Cardiology
• Critical Care Medicine
• Neurosurgery

Background:

• Aneurysmal subarachnoid hemorrhage (SAH) can lead to significant hemodynamic disturbances.
• Optimizing cardiac performance is crucial in managing SAH patients to prevent secondary brain ischemia.
• Hypervolemic therapy is a common strategy to enhance cardiac preload and output.

Purpose of the Study:

• To investigate the relationship between hypervolemic preload enhancement and cardiac performance in SAH patients.
• To determine the reliability of central venous pressure (CVP) as an index of cardiac performance during fluid resuscitation.
• To identify an optimal pulmonary artery wedge pressure (PAWP) target for maximizing cardiac output in this population.

Main Methods:

• Systematic analysis of cardiac performance in nine SAH patients undergoing hypervolemic therapy.
• Invasive monitoring of pulmonary artery wedge pressure (PAWP), central venous pressure (CVP), cardiac index (CI), stroke volume index (SVI), and left ventricular stroke work index (LVSWI).
• Intravenous infusion of hetastarch or plasmanate at 300 cc/hr with serial hemodynamic measurements every 15 minutes.

Main Results:

• A statistically significant correlation was found between increases in PAWP and improvements in CI, SVI, and LVSWI (p < 0.01).
• No significant correlation was observed between PAWP and CVP within the recorded ranges.
• No further improvement in cardiac performance was noted with PAWP increases above 14 mm Hg.

Conclusions:

• Central venous pressure (CVP) is an unreliable indicator of cardiac performance during hypervolemic therapy in SAH patients.
• A PAWP of 14 mm Hg is associated with maximal cardiac performance in previously healthy individuals with SAH.
• Targeting a PAWP of 14 mm Hg may be beneficial for optimizing cardiac output in this patient group.