Breath-holding test in subjects with near-fatal asthma. A new index for dyspnea perception

Respir Med. 2007 Feb;101(2):246-53. doi: 10.1016/j.rmed.2006.05.013. Epub 2006 Jul 7.


Rationale: Identification of asthmatic subjects with low perception of dyspnea (POD) that are at higher risk of hospitalization, near-fatal and fatal asthma could improve their management.

Objective: Create a simple procedure that facilitate the recognition of low POD.

Methods: We enrolled near fatal asthma (NFA) subjects and a wide spectrum of non-NFA subjects. Each subject was asked to stop breathing at end-expiration. Dyspnea was assesssed by a modified Borg scale. To design the new index, we combined the Borg score at the end of the voluntary breath-holding maneuver with the airway limitation. The equation was as follows: FEV(1)/FVC%/(breath-holding time in seconds/final Borg score minus basal Borg score).

Results: Eleven NFA subjects (4 females) aged 21-73yr and 55 non-NFA (14 severe, 18 moderate and 23 mild asthmatic subjects) completed the study. The threshold value of the index that could predict POD is <12. The mean (+/-sd) of the new index perception was significantly lower in NFA group (n=11; 5.21+/-3.59; vs. n=55; 13.67+/-11.08; P=0.006). This threshold value had 100% sensitivity and it best discriminated between mild and NFA groups. The negative likelihood ratio (when the index > or = 12) was zero. A result > or = 12 represented an almost null probability of poor POD.

Conclusion: The breath-holding test is simple and rapid. Its negative likelihood ratio was zero. Accordingly, a test result of 12 or greater might exclude the probability of poor perception of dyspnea in subjects with stable asthma.

MeSH terms

  • Adult
  • Aged
  • Asthma / complications
  • Asthma / physiopathology*
  • Asthma / psychology
  • Breath Tests / methods
  • Dyspnea / complications
  • Dyspnea / physiopathology*
  • Dyspnea / psychology
  • Female
  • Forced Expiratory Volume / physiology
  • Humans
  • Male
  • Middle Aged
  • Perception / physiology*
  • Severity of Illness Index
  • Vital Capacity / physiology