Hemodynamic and Cardiometabolic Effects of Prenalterol in Patients with Gram Negative Septic Shock

The hernodynamic eflects of prenalterol, a new inotropic agent, were investigated in 10 patients with gram negative septic shock. In four of the patients, coronary sinus blood flow (CSF) and myocardial oxygen and lactate extraction were also determined. After baseline hemodynamic measurements, prenalterol was infused intravenously over a 10-min period to a total dose of 150 pg/kg. All patients responded within 15 min after completion of prenalterol infusion by increasing mean arterial pressure from 57±11 to 75 ± 20 mmHg (7.58f 1.46 to 9.97±2.66 kPa), (+32%), ( P<0.01 ) and cardiac index from 2.65±0.40 to 3.80±0.47 l min^-l m^-2 (+44%) ( P < 0.001). There was no change in heart rate or systemic vascular resistance, nor were any arrhythmias recorded. The urinary output increased significantly. After prenalterol, CSF increased from 185kl 4 to 246±14 ml.min-¹, (+33%), (P<0.001) and myocardial oxygen and lactate extraction rose from 19.8±2.1to26.6±2.1 ml O₂.min^-1, (+ 34%) (P<0.00l) andfrom33.2±2.3 to44.7k2.1 μmol.min^-1, (+35%), (P<0.001), respectively. The total body oxygen consumption increased from 287f 13 to 348±23 ml O₂.min^-1, (+21 %), ( P<0.01 ) and the arterial lactate concentration decreased from 5.61±0.55 to 3.94±0. 16 mmol.l^-1, (- 30%), (P<0.01), suggesting improved tissue perfusion. The results demonstrate that prenalterol is a potent, highly selective inotropic agent inducing the same magnitude of increase in blood pressure and cardiac output as reported for dopamine in septic shock.