Pulmonary & Respiratory Medicine

Background: Breath-holding test has been tested in some clinical scenarios and has proved to be of clinical utility.

Objectives: To determine the maximum voluntary breath-holding time in patients with obstructive ventilator defects and in normal subjects and to correlate the breath-holding times with pulmonary function tests.

Methods: We conducted a case-control study including patients with obstructive ventilator defects and a control group consisted of volunteers recruited in the same hospital, with normal spirometry. Spirometry was performed using a computerized spirometer. Breath-holding test was conducted using a pneumotachograph. All measured outputs were displayed in real time on a portable computer. The maximal voluntary apnea inspiratory and expiratory times (MVAIT and MVAET) were measured.

Results: A total of 35 patients with obstructive ventilatory defects (18 asthma and 17 COPD) and 16 controls met the inclusion criteria and were included in the analysis. The MVAIT was lower in COPD patients (21.6 ± 12.6 seconds) than in controls (31.5 ± 15.7 seconds) (p=0.049). MVAET was also lower in COPD cases than in controls (16.5 ± 6.0 vs 22.1 ± 7.9; p=0.030). We found positive and significant correlations between MVAIT and FVC (L) (r=0.656; p=0.004) and between MVAIT and FEV1 (L) (r=0.518; p=0.033) in COPD cases. MVAET was also correlated with FVC (L) (r=0.505; p=0.039) and FEV1 (L) (r=0.757; p<0.0001).

Conclusions: MVAIT and MVAET were significant lower in patients with obstructive ventilatory defects with COPD diagnosis than in controls, and they were correlated positively with FVC and FEV1 in COPD patients. Our results provide additional evidence of usefulness of MVAIT/MVAET as pulmonary function tests.