Surgical ICU in a university hospital.
PATIENTS: All patients underwent invasive hemodynamic monitoring followed by volume
resuscitation and inotropic support to reverse flow-dependent oxygen consumption and
lactic acidosis. Patients with persistent
hypotension (mean arterial pressure [MAP] less than 65 mm Hg) and vasodilation (systemic vascular resistance index [SVRI] less than 1500 dyne.sec/cm5.m2 received
phenylephrine at iv infusion rates of 0.5 to 9 micrograms/kg.min to maintain MAP greater than 70 mm Hg. MAP, SVRI, left ventricular
stroke work index, and stroke volume index were significantly (p less than .05) increased after
phenylephrine administration and at the time of highest oxygen consumption (VO2). Cardiac index was unchanged initially but increased at the time of highest VO2 (p less than .05). Pulmonary artery occlusion pressure and heart rate were unchanged. Average baseline VO2 increased from 145 to 200 mL/min.m2 and
oxygen delivery (DO2) increased from 447 to 597 mL/min.m2 during
phenylephrine treatment (p less than .05). Blood
lactate concentrations decreased and urine output increased significantly (p less than .05), while serum
creatinine concentrations remained unchanged during
phenylephrine therapy.
CONCLUSIONS: