My Son 2 Months Old 1 Month Back Had Open

My son 2 months old 1 month back had open heart (TAPVC) done, as his cardiologist said keep him away from public places to avoid infection, how ever due to heat he is kept in ac room, he some time has weezing and cough , has problem while feeding,so i use nebulisation , duolin repulse plus saline water, is it proper for me to use it or should i stop it, please suggest,plz also suggest a proper dosage,thank you.