Background and Purpose—Optimal monitoring of cardiac output and intravascular volume is of paramount importance for good fluid management of patients with subarachnoid hemorrhage (SAH). The aim of this study was to demonstrate the feasibility of advanced hemodynamic monitoring with transpulmonary thermodilution and to provide descriptive data early after SAH.

Methods—Forty-six patients with SAH treated within 24 hours of the ictus were investigated. Specific targets for cardiac index (3.0 L · min^-1 · m^-2), global end-diastolic volume index (700 to 900 mL/m²), and extravascular lung water index (14 mL/kg) were established by the single-indicator transpulmonary thermodilution technique, and a fluid management protocol emphasizing supplemental colloid administration was used to attain these targets. Plasma hormones related to stress and fluid regulation were also measured.

Results—A higher cardiac index (mean value of 5.3 L · min^-1 · m^-2) and a lower global end-diastolic volume index (555 mL/m²) were observed on initial measurement, for which elevations of plasma adrenaline, noradrenaline, and cortisol were also detected. Cardiac index was progressively decreased (3.5 L · min^-1 · m^-2) and global end-diastolic volume index was normalized by fluid administration aimed at normovolemia. The extent of the initial hemodynamic and hormonal profile was greater in patients with a poor clinical status (P<0.05). The extravascular lung water index was mildly elevated but within the target range throughout the study period. No patients developed pulmonary edema or congestive heart failure.

Conclusions—The impact of sympathetic hyperactivity after SAH predisposes patients to a hyperdynamic and hypovolemic state, especially in those whose clinical status is poor. Bedside monitoring with the transpulmonary thermodilution system may be a powerful tool for the systemic management of such patients.