Bronchitis is a lower respiratory tract infection, and most 11-month-old babies are young and prone to co-infection with bacteria. If the baby has a mono-cough, cephalosporin antibiotics, such as cefixime granules, can be given, supplemented with cough suppressant and phlegm-relieving drugs, such as orang-bai combination and tranylcypromine oral solution. If the sputum is sticky and not easy to cough up, it can be treated with terbutaline nebulizer inhalation twice a day for about a week. If your baby has a cough that is continuous or paroxysmal, especially at night, you should pay attention to the possibility of mycoplasma infection and give oral azithromycin for 3-5 days each time.