title: Combined effects of hypocapnia and nicardipine on airway resistance: a pilot study.
abstract: OBJECTIVE
  The aim of this study was to investigate the modification of the resistive inspiratory properties of the respiratory system associated with hypocapnia in the presence of nicardipine.
  
  
  METHODS
  The resistance of the respiratory system, Rrsmin, 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 nicardipine (0.5 microgram.kg-1.min-1 i.v.) to prevent arterial vasospasm after subarachnoid haemorrhage.
  
  
  RESULTS
  There was no statistical difference between the groups concerning anthropometric and basal respiratory characteristics. In group 1, hypocapnia caused a 20.9% increase in Rrsmin, but no significant increase was observed in group 2.
  
  
  CONCLUSIONS
  Hypocapnic alkalosis had a significant bronchial constrictory effect, which was eliminated in the presence of nicardipine hydrochloride.
authors.affiliation: Département d'Anesthésie Réanimation 1, Centre Hospitalier Universitaire de Grenoble, France.
authors.forename: P
authors.initials: P
authors.lastname: Combes
authors.forename: B
authors.initials: B
authors.lastname: Fauvage
mesh_terms: D000403:Airway Resistance / Q000187:drug effects*; D000472:Alkalosis, Respiratory / Q000503:physiopathology*; D000704:Analysis of Variance; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D005260:Female; D006801:Humans; D016857:Hypocapnia / Q000188:drug therapy / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009529:Nicardipine / Q000494:pharmacology*; D010865:Pilot Projects
chemical_list: D002121:Calcium Channel Blockers; D009529:Nicardipine