title: Atracurium versus vecuronium in asthmatic patients. A blinded, randomized comparison of adverse events.
abstract: BACKGROUND
  To determine which of atracurium or vecuronium is associated with fewer adverse cardiovascular and pulmonary events in high-risk patients, the authors administered these drugs to patients with known asthma.
  
  
  METHODS
  Sixty patients aged 18-75 yr taking bronchodilators chronically for asthma were anesthetized with midazolam, fentanyl, nitrous oxide, and isoflurane; the trachea was intubated without paralysis. When anesthetic conditions and mechanical ventilation were stable, patients were randomly given 0.5 mg/kg atracurium or 0.1 mg/kg vecuronium over 5-10 s, and a blinded observer recorded cardiovascular, pulmonary, and cutaneous signs of adverse reactions for 6 min.
  
  
  RESULTS
  Arterial pressures and heart rate decreased after atracurium, and systolic pressure and heart rate decreased with vecuronium; these changes were small in magnitude. Cardiovascular effects (decrease in blood pressure or change in heart rate) > 10% were common with both atracurium (60% of patients) and vecuronium (57%). Cardiovascular effects > 20% were more frequent with atracurium (37%) than with vecuronium (13%, P < 0.05). The incidence of noncardiovascular adverse events (increase in peak airway pressure > 5 cmH2O, tidal volume decrease > 10%, rashes, and wheezing) did not differ between atracurium (17%) and vecuronium (7%). The largest increase in peak airway pressure was 5.1 cmH2O in a patient whose tidal volume decreased 16% with vecuronium; in the remaining patients, tidal volume decreased < 10%. No patients experienced inspiratory wheezing, marked decreases in arterial oxygen saturation, or marked increases in end-tidal carbon dioxide tension.
  
  
  CONCLUSIONS
  The authors conclude that, in patients with asthma, adverse cardiovascular events are more common with atracurium than with vecuronium.
mesh_terms: D000328:Adult; D000368:Aged; D000768:Anesthesia, General; D001249:Asthma / Q000503:physiopathology*; D001279:Atracurium / Q000009:adverse effects*; D005260:Female; D005283:Fentanyl; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D008297:Male; D008874:Midazolam; D008875:Middle Aged; D003473:Neuromuscular Nondepolarizing Agents / Q000009:adverse effects*; D011446:Prospective Studies; D012119:Respiration / Q000187:drug effects; D016037:Single-Blind Method; D014673:Vecuronium Bromide / Q000009:adverse effects*
chemical_list: D003473:Neuromuscular Nondepolarizing Agents; D001279:Atracurium; D014673:Vecuronium Bromide; D008874:Midazolam; D005283:Fentanyl