(1)Objectives;Effects of pre-bronchoscopy administration of intravenous hydrocortisone in patients with chronic obstructive pulmonary disease (2) Design: A double blind, single center, clinical trial design will conduct in 90 patients with COPD. Random assignment of subjects in both intervention and control groups will categorize(blocking). (3) Setting and conduct; 90 patients with COPD that need bronchoscopy, will divide randomly to two groups (intervention and control groups) and after signing permission form ,underwent bronchoscopy
(5) Intervention ;Neither physicians, nurses or patients know which patient is located either in intervention or control group. In each of the intervention and control groups,the Fhberoptic Bronchoscopy( FB) will performe and the measurement of PFT , Hemogolobin oxygen saturation, cough score and vital signs will record on a validated self made checklist before and after procedure. In intervention group intravenous hydrocortisone 200 mg in 5 ml, and for the subjects of the control group, the same volume of saline, will administer 2 hours befor FB . finally results will compare between two groups. (6) main outcome measures;primary outcome variables included, PFT, vital signs, Hemoglobin oxygen saturation and cough severity. we do not have secondary variable outcome.