Evaluation of fitness to utilize Self-Contained Breathing Apparatus (SCBA)

J Asthma. 2010 Mar;47(2):178-84. doi: 10.3109/02770900903483782.


Background: Breathing dry, cold air may cause bronchoconstriction in asthmatics working with self-contained breathing apparatus (SCBA). Air delivered by SCBA is cooler than ambient air. It is unclear whether a bronchial challenge test using mannitol (BCTM) can predict a fall in forced expiratory volume in one second (FEV(1)) during exercise with SCBA.

Methods: A prospective study of army recruits assigned to work with SCBA was carried out. Participants completed self-administered questionnaires on respiratory symptoms, BCTM, and measurement of exhaled nitric oxide. A subgroup of participants with a positive BCTM (BTCM+) and with negative BCTM underwent exercise test on bicycle ergometer (ET) while using SCBA.

Results: One hundred and six recruits participated in this study. One hundred and two underwent BCTM and 28 ET. Nineteen out of 97 participants had a positive BCTM and 6 out of 27 had a positive ET. Seventeen out of 19 participants with a positive BCTM had current respiratory symptoms such as wheeze, cough, chest tightness, or dyspnea. Sensitivity, specificity, positive predictive value, and negative predictive value for a positive ET under SCBA were 100%, 64%, 43%, and 100% for the BCTM, respectively. BCTM-positive participants with respiratory symptoms had more physician consultations during MBT compared to BCTM-negative participants.

Conclusion: Despite medical evaluation and exclusion of asthmatics by a physician during conscription, a high proportion of recruits assigned to work with SCBA smoke, have respiratory symptoms, and have a positive BCTM suggesting current asthma. BCTM has a high sensitivity to predict a significant fall in FEV(1) after exercise with SCBA and participants with a positive BCTM tend to use more health care resources during basic military training. Recruits should be counseled about smoking cessation prior and during basic military training.

Publication types

  • Evaluation Study

MeSH terms

  • Adult
  • Ambulatory Care / statistics & numerical data
  • Asthma, Exercise-Induced / complications
  • Asthma, Exercise-Induced / diagnosis*
  • Asthma, Exercise-Induced / physiopathology
  • Breath Tests
  • Bronchial Hyperreactivity / complications
  • Bronchial Hyperreactivity / diagnosis*
  • Bronchial Hyperreactivity / physiopathology
  • Bronchial Provocation Tests
  • Cough / complications
  • Dyspnea / complications
  • Exercise Test*
  • Forced Expiratory Volume / physiology
  • Hospitalization / statistics & numerical data
  • Humans
  • Male
  • Mannitol
  • Military Personnel
  • Nitric Oxide / analysis
  • Nitric Oxide / metabolism
  • Predictive Value of Tests
  • Respiratory Protective Devices*
  • Respiratory Sounds / diagnosis
  • Rhinitis, Allergic, Perennial / complications
  • Rhinitis, Allergic, Seasonal / complications
  • Sensitivity and Specificity
  • Smoking / adverse effects
  • Smoking / physiopathology
  • Surveys and Questionnaires
  • Switzerland
  • Vital Capacity / physiology
  • Young Adult


  • Nitric Oxide
  • Mannitol