Aerosol kinetics and bronchodilator efficacy during continuous positive airway pressure delivered by face mask

Scott N. Parkes, Andrew D. Bersten

Research output: Contribution to journalArticlepeer-review

59 Citations (Scopus)


Background - Rates of fresh gas flow (FGF) commonly used when continuous positive airway pressure (CPAP) is delivered by face mask theoretically reduce the delivery and availability of therapeutic aerosols. As it may be hazardous for patients with acute respiratory failure to interrupt mask CPAP, the effects of CPAP on aerosol kinetics and bronchodilator efficacy were investigated. Method - The effect of CPAP at 10 cm H2O at a FGF rate of 50 l/min on the delivery of technetium labelled aerosol generated from a readily available jet nebuliser was measured using a bench model of spontaneous respiration. In a separate clinical study the bronchodilator responses to incremental doses of nebulised salbutamol were measured in nine stable asthmatic subjects in a random sequence of conventional nebulisation (control) or nebulisation whilst receiving CPAP via a tight fitting face mask. Each patient acted as his or her own control. Results - CPAP significantly reduced total aerosol delivery to the face mask from 6.85 (1.52)% to 1.3 (0.37)% of the initial nebuliser charge. In the clinical study a significant bronchodilator response to nebulised salbutamol was seen during both conventional nebulisation and nebulisation whilst receiving CPAP by face mask. The shape of the dose-response curves and the magnitude of the total increase in the forced expiratory volume in one second (FEV1) was identical for CPAP and control conditions. Conclusions - Despite a reduction in aerosol presented to the proximal airway, the bronchodilator response to inhaled β2 agonists in stable asthmatic subjects was not affected when CPAP was delivered by face mask. Despite a high rate of FGF, nebulised β2 agonists are effective when administered in conjunction with CPAP delivered by face mask.

Original languageEnglish
Pages (from-to)171-175
Number of pages5
Issue number2
Publication statusPublished - 1 Jan 1997
Externally publishedYes


  • aerosols
  • bronchodilator
  • positive pressure respiration


Dive into the research topics of 'Aerosol kinetics and bronchodilator efficacy during continuous positive airway pressure delivered by face mask'. Together they form a unique fingerprint.

Cite this