How should the darling of 7 months cough have phlegm to do

Seven months old baby cough sputum should be fed more hot water, dilute sputum, but also can take the baby to the right lateral position, and then use empty palm slap back, sputum can be accumulated together, and then cough out. If sputum is more viscous, then to hospital according to the doctor to take cough expectorant drugs for treatment, but also according to the doctor for aerosol inhalation treatment.