COMBINED EFFECTS OF HYPOCAPNIA AND NICARDIPINE ON AIRWAY-RESISTANCE -A PILOT-STUDY

Objective: The aim of this study was to investigate the modification o f the resistive inspiratory properties of the respiratory system assoc iated with hypocapnia in the presence of nicardipine. Methods: The res istance of the respiratory system, Rrs(min), was studied in two groups of patients who needed mechanical hyperventilation. Group 1 (n = 14; 47 years) was the control group (head injuries); group 2 (n = 12; 53.5 years) included patients treated over a 3 week period with nicardipin e (0.5 mu g . kg(-1). min(-1) i.v.) to prevent arterial vasospasm afte r subarachnoid haemorrhage. Results: There was no statistical differen ce between the groups concerning anthropometric and basal respiratory characteristics. In group 1, hypocapnia caused a 20.9% increase in Rrs (min), but no significant increase was observed in group 2. Conclusion : Hypocapnic alkalosis had a significant bronchial constrictory effect , which was eliminated in the presence of nicardipine hydrochloride.