L-NMMA (a nitric oxide synthase inhibitor) is effective in the treatment of cardiogenic shock

Background - The objective was to assess the safety and efficacy of L- NMMA in the treatment of cardiogenic shock. Methods - We enrolled 11 consecutive patients with cardiogenic shock that persisted after >24 hours from admission, despite coronary catheterization and primary percutaneous transluminal coronary revascularization, when feasible, and treatment with mechanical ventilation, intraaortic balloon pump (IABP), and high doses of catecholamines. L-NMMA was administered as an IV bolus of 1 mg/kg and continuous drip of 1 mg · kg^-1 · h^-1 for 5 hours. Treatment with catecholamines, mechanical ventilation, and IABP was kept constant throughout the study. Results - Within 10 minutes of L-NMMA administration, mean arterial blood pressure (MAP) increased from 76±9 to 109±22 mm Hg (+43%). Urine output increased within 5 hours from 63±25 to 156±63 cc/h (+ 148%). Cardiac index decreased during the steep increase in MAP from 2.0±0.5 to 1.7±0.4 L/(min · m²) (-15%); however, it gradually increased to 1.85±0.4 L/(min · m²) after 5 hours. The heart rate and the wedge pressure remained stable. Twenty-four hours after L-NMMA discontinuation, MAP (+36%) and urine output (+189%) remained increased; however, cardiac index returned to pretreatment level. No adverse events were detected. Ten out of eleven patients could be weaned off mechanical ventilation and IABP. Eight patients were discharged from the coronary intensive care unit, and seven (64%) were alive at 1-month follow-up. Conclusions - L-NMMA administration in patients with cardiogenic shock is safe and has favorable clinical and hemodynamic effects.