The acute broncholytic efficacy and the protective anticonstrictive effectiveness of a new β₂-receptor stimulator, Reproterol, was tested in 16 patients with the acetylcholine (ACH) provocation test. Plethysmographic airway resistance determinations (R_aw) and flow volume curves (VE_max50%/FVC) were used as assessment parameters. All patients proved susceptible to ACH provocation, in as much they demonstrated a significant rise in the R_aw from 2.46 to 11.53 cm H₂O / 1 sec and a significant decline of the VE_max50%/FVC from 884 to 565 (ml/sec/1) following ACH administration. With Reproterol inhalation (2 puffs at 500 µ each), almost complete elimination of ACH-induced bronchial constriction was achieved. The ACH provocation with the same patients the following day, however, was almost absent 60 min after oral ingestion of 20 mg of Reproterol tablets. Dose-efficacy studies in 7 volunteers from the same group revealed a subjectively better tolerance of the 10-mg tablets, but with a correspondingly lower antibronchia constrictive efficacy.

Clinical findings and respiratory function tests of a 47-year-old man with chronic respiratory failure based on bilateral diaphragmatic paralysis are reported. Severe restrictive ventilatory disorders due to immobile bilateral diaphragmatic rise have been evaluated. Obviously, severe obstructive ventilatory disturbances as analysed in pressure-flow diagrams were caused by intra-thoracic gas volume reduction and phasic alveolar gas compression. Disproportionately small «real» bronchial airway narrowing has been demonstrated. In conclusion, therefore, the only therapeutic means consist of enlarging the intra-thoracic gas volume probably by surgical intervention.