Effects of nebulised iloprost on pulmonary function and gas exchange in severe pulmonary hypertension

SummaryNebulised iloprost is established therapy of severe pulmonary hypertension; however, the effects on the bronchoalveolar compartment have not been investigated so far. We studied the short- and long-term effects of nebulised iloprost on pulmonary function tests and gas exchange in 63 patients with severe pulmonary hypertension (idiopathic n=17, chronic thromboembolism n=15, connective tissue disease n=12, congenital heart disease n=11, respiratory diseases n=8). Patients received iloprost in increasing dose up to 140μg iloprost/24h via an ultrasonic nebuliser.Short-term effects were assessed before and after every nebulisation: peak expiration flow decreased in mean by 1.9% (423±98 to 415±98) and percutaneous oxygen saturation increased in mean by 0.7% (90±6 to 91±5) post-nebulisation. There were no significant differences concerning underlying diagnosis or dose of nebulised iloprost. Within 3 months, 9 patients stopped treatment due to non-compliance with frequent nebulisations (n=3), or severe side effects (n=4); 2 patients with additional obstructive lung disease developed bronchoconstriction.Long-term effects were assessed by pulmonary function tests and gas exchange parameters at baseline and after 3 months treatment. There were no significant differences after 3 months therapy neither in FEV1, FVC, TLC, residual volume nor in diffusions capacity, SO2 at rest and during 6min walking test, also in respect of the underlying diseases. However, there was a significant increase in 6min walking distance (6 MWD) after 3 months (246±113 to 294±115m, P