Effect of dexamethasone therapy on pulmonary function in chronic lung disease: a comparison of disease types.

Background: In the present study, we investigated the effect of dexamethasone (DEX) therapy on extubation and pulmonary function in patients with chronic lung disease (CLD) who required long-term mechanical ventilation. In addition, we compared the effects of DEX therapy among CLD types.

Methods: Twenty-two CLD patients who were ventilator dependent for 28 days or longer received DEX therapy for the purposes of extubation. A tapering dose of DEX, starting from 0.5 mg/kg per day, was administered for 7 days. Pulmonary function was measured at initiation of administration and 4 days after initiation. We evaluated static respiratory system compliance (Crs) and static respiratory system resistance (Rrs) adjusted by bodyweight. Chronic lung disease types were categorized according to the classification of the Ministry of Health and Welfare Research Project. We compared the effect of DEX therapy among CLD types.

Results: Dexamethasone therapy was started at a mean (+/-SD) 45 =/- 11 days after birth and 32.1 +/- 1.3 weeks of postconceptional age in infants with a mean bodyweight of 939 +/- 153 g. After DEX therapy, extubation was successful in all 22 patients. Following DEX administration, Crs was significantly increased from 0.69 +/- 0.13 to 1.17 +/- 0.21 mL/cm H2O per kg. In contrast, Rrs did not show any clear changes. Comparing CLD types, no difference was observed for Crs and Rrs in each disease type.

Conclusions: Dexamethasone was administered to CLD patients requiring long-term mechanical ventilation for the purposes of extubation and extubation was successful in all patients. It was found that Crs was increased in all patients following DEX, regardless of CLD type. The increase in Crs following DEX administration may have been related to successful extubation.