Variable response to bronchodilator therapy in young children born prematurely.

The response to nebulized therapy was studied at a median postnatal age of 16 months (range 6-24 months) in 15 children born prematurely. Thoracic gas volume (TGV) and airways resistance (RAW) were measured by total body plethysmography and specific conductance (SGAW) calculated. The measurements were made prior to, and then 5 and 10 min after, nebulized saline (3 ml), and then 5, 10 and 15 min after administration of nebulized salbutamol (2.5 mg in 2.5 ml normal saline). There was no significant change in TGV throughout the study period. One child showed a significant improvement in airways resistance following nebulized saline, and no child had a significant deterioration. RAW and SGAW both significantly improved in the group overall at 15 min following salbutamol (P < 0.05, P < 0.03 respectively). Individual patients, however, showed a variable serial response in RAW and SGAW: four children had a paradoxical response (an increase in RAW and a decrease in SGAW) at 5 min and at 10 or 15 min, seven children had a significant improvement (decrease) in RAW and eight a significant improvement (decrease) in SGAW. The children who had an initial paradoxical effect did not differ significantly in either age or baseline lung function from the other infants. Patients in whom RAW and SGAW improved following bronchodilator did not differ in age from the rest of the study group, but had tended to have worse lung function prior to bronchodilator administration. We conclude that there is a variable response to nebulized salbutamol in children born preterm, this treatment should only be administered in association with careful monitoring.