This study was conducted in 120 patients aged from 54-65 years scheduled for elective valve replacement surgeries. Patients were randomly allocated to nitro glycerine or PGI2 groups. Patients of nitro glycerine group received nebulized nitro glycerine at a rate of 2.5-5 mcg/kg/min (5 mg, 1 mg/ml) over 10 minutes by ultrasonic nebuliser. Patients of PGI2 group received nebulized PGI2 (epoprostenol), 20000 ng/ml (20000 ng/ml in 60 ml syringe was attached to an intravenous pump which delivers a titrating rate of 8 ml/h . The primary outcome was mean pulmonary artery pressure. The secondary outcomes included mean arterial blood pressure (MAP) (mmHg), PaO2/FiO2 ratio, cardiac index (CI) (l/min/m2) right ventricular ejection fraction (RVEF), central venous pressure(CVP) , 30-day mortality rate and the incidence of complications such as facial flushing, hypotension and re-exploration for bleeding.

Postoperative pulmonary hypertension (PHT) is the most challenging complication of valvular heart disease about 73% of the patients particularly in those posted for mitral valve replacement surgery Methods This prospective study was conducted in 120 patients aged from 54-65 years scheduled for elective valve replacement surgeries. Patients were randomly allocated to either nitro glycerine or PGI2 groups. Patients of nitro glycerine group received nebulized nitro glycerine (its starting concentration was 200 mcg/ml); nitro glycerine was delivered at a rate of 2.5-5 mcg/kg/min (5 mg, 1 mg/ml) over 10 minutes by ultrasonic nebuliser connected to the inspiratory limb of the breathing circuit. Patients of PGI2 group received nebulized PGI2 (epoprostenol), 20000 ng/ml (20000 ng/ml in 60 ml syringe was attached to an intravenous pump which delivers a titrating rate of 8 ml/h to the nebulizer compartment. The primary outcome was mean pulmonary artery pressure. The secondary outcomes included mean arterial blood pressure (MAP) (mmHg), PaO2/FiO2 ratio, cardiac index (CI) (l/min/m2) right ventricular ejection fraction (RVEF), central venous pressure(CVP) measured at the end of cardiopulmonary bypass then 30 minutes after start of treatment then 4 hours after start of treatment, 30-day mortality rate and the incidence of complications such as facial flushing, hypotension and re-exploration for bleeding.

Inclusion Criteria:

• 35 to 66 years old
• elective valve replacement surgery
• pulmonary arterial hypertension

Exclusion Criteria:

• Emergency surgery
• severe renal and hepatic dysfunction
• uncontrolled supraventricular arrhythmia
• those requiring preoperative inotropes

study protocol

5-6 months

The collected data are coded, tabulated, and statistically analyzed using statistical package for social sciences software, version 17.0 (SPSS Inc., Chicago, Illinois, USA). Descriptive statistics are carried out for numerical parametric data and presented as mean±SD, whereas categorical data are presented as number and percentage. Variables such as demographic data and comorbidities are compared using the χ2-test. A P value less than 0.05 was considered significant.