ABSTRACT
To assess the acute effects of methylene blue infusion, an inhibitor of nitric oxyde synthesis, on hemodynamic parameters in patients with refractory septic shock. Fourteen patients admitted to intensive care units with septic shock of diverse etiologies and unable to maintain median arterial pressures over 60 mm Hg with the use of at least 2 vasoactive drugs, were studied. All received a 1 mg/kg bolus of methylene blue. Hemodinamic parameters were measured before and 30, 60, 120 and 180 min after the bolus. Systolic and diastolic blood pressure and systemic vascular resistance increased in all patients. There were no significant changes in cardiac output, oxygen consumption or extraction. Methylene blue has an acute pressor effect in patients with septic shock