Acute hemodynamic effects of inhaled nitroglycerine, intravenous nitroglycerine, and their combination with intravenous dobutamine in patients with secondary pulmonary hypertension

OBJECTIVES: The presence of pulmonary artery hypertension (PAH) affects the prognosis of patients; therefore, it is important to treat it. The aim of this study is to compare the acute hemodynamic effects of inhaled nitroglycerine (iNTG), intravenous nitroglycerine (IV NTG) alone and their combination with intravenous dobutamine (IV DOB) during the early postoperative period, in patients with PAH undergoing mitral valve or double valve replacement surgery. MATERIALS AND METHODS: In the study, 40 patients with secondary PAH were administered iNTG 2.5 microg/kg/min, IV NTG 2.5 microg/kg/min, a combination of iNTG 2.5 microg/kg/min + IV DOB 10 microg/kg/min, and IV NTG 2.5 microg/kg/min + IV DOB 10 microg/kg/min for 10 minutes each following valve replacement surgery, in random order. The hemodynamic parameters were recorded before (T0) and immediately after the intervention. (T1). RESULTS: iNTG effectively decreased mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance index (PVRI), and the PVR / SVR ratio, without affecting arterial pressures, systemic vascular resistance or mixed venous oxygen saturation (SvO2). IV NTG produced both systemic and pulmonary vasodilation along with a significant fall in SvO2. The combination of iNTG and IV DOB caused a significant decrease in mPAP and PVRI, with no significant change in SVRI, PVR / SVR ratio, and SvO2. A combination of IV NTG + IV DOB caused both pulmonary and systemic vasodilatation with a significant decrease in SvO2. None of the drugs caused any significant change in the cardiac index. CONCLUSION: All drugs were of similar efficacy in reducing the pulmonary vascular resistance index. Only iNTG produced selective pulmonary vasodilatation, while IV NTG and its combination with IV dobutamine had a significant concomitant systemic vasodilatory effect.