IRCT20160102025811N4 IRCT 2020-04-17 Tabriz University of Medical Sciences Sildenafil on Improving Chronic Lung Disease of neonates Study of the Effect of Sildenafil on Improving Chronic Lung Disease of neonates 2018-07-23 anticipated 40 Complete https://irct.ir/trial/45589 interventional Randomization: Randomized, Blinding: Single blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Using Random allocation software: Random allocation software. So that all patients who were hospitalized in Al-Zahra Medical Center in Tabriz in 1398 and 1399 with the diagnosis of chronic lung disease and had entry criteria and no exit criteria, will enter the study. Using the software, they will be divided into two groups, Blinding description: All patients will undergo routine measures such as respiratory support and oxygen therapy, and after obtaining written consent from parents to participate in the study, sildenafil 50 mg overdose tablets at a dose of 2 mg per Kg of body weight will be started every 8 hours in the intervention and placebo tablets in the same color form as patients with the same characteristics in the control group. 3 Chronic lung disease of newborns. Intervention 1: Intervention group: Sildenafil 50 mg tablets from Obidi Company with a dose of 2 mg per kg body weight will be fed to infants every 8 hours. Intervention 2: Control group: The placebo will be given to babies in the same shape and color as Sildenafil. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no further information