Cough Characteristics and FVC Maneuver in Cystic Fibrosis

Abstract

BACKGROUND: Cough is part of life in patients with cystic fibrosis (CF). Weak coughing may add to increased respiratory disease that affects the mechanical properties of cough in these patients. In this study, we investigated cough characteristics in relation to forced expiratory flow/volume indices in CF. METHODS: This prospective study included 54 subjects (26 ؎ 10 y old) with CF. Similar indices of the maneuvers were compared. Additionally, other cough characteristics revealed by the maneuvers were investigated. Cough was considered efficient with 6 or more secondary spikes at a flow of > 2.67 L/s. RESULTS: Cough peak flows similar to peak expiratory flows (regardless of FEV 1 severity level) were found in 98% of subjects. The secondary spike flows deteriorated alongside the percent-of-predicted FEV 1 (r 2 ‫؍‬ 0.17, P ‫؍‬ .002), yet inefficient secondary spike flows could also be found when FEV 1 was within normal range. Mean efficient spike number was low (2.5 ؎ 1.2 spikes/maneuver). Most cough spike flows were very small (< 0.9 L/s), resembling vibration that may contribute to the propulsion of mucus toward the central airways. Cough maneuver duration ended faster than forced expiration duration (3.7 ؎ 1.7 s vs 6.8 ؎ 2.5 s, P < .001), resulting in a smaller cough vital capacity compared with expiratory vital capacity (2.1 ؎ 0.9 l vs 3.1 ؎ 0.7 l, P < .001). Inspiratory volume below 2.23 ؎ 0.07 L reduced efficient secondary spike number. CONCLUSIONS: The cough flow/volume maneuver reveals abnormalities in cough velocities and volume. A low secondary spike correlates with FEV 1 severity level. The method may lead to earlier intervention to assist cough in CF.

Association between lung function, thoracoabdominal mobility and posture in cystic fibrosis: pilot study

“…Reduction in PEF may indicate that PCF is also reduced, as in obstructive pulmonary diseases such as CF, reduced expiratory flow and increased viscosity of bronchial secretion are probably the leading causes of ineffective cough [30]. In addition, PEF and PCF values were similar in an earlier study in CF patients [31], and PCF reduction has been reported in children and adolescents with CF [9]. This variable deserves attention because it is known that cough is an important physiological mechanism for bronchial hygiene, which is essential for the prevention of recurrent infections and bacterial colonization, which accelerate the decline of pulmonary function in CF [1,32,33], with an impact on quality of life [2,3] and mortality due to the disease [1,32,33].…”

Effect of expiratory muscle training on peak cough flow in children and adolescents with cystic fibrosis: A randomized controlled trial

“…As a result of ineffective cough, infections may increase. Cough characteristics can be impaired in CF and, abnormalities in cough maneuvers can show correlation with pulmonary functions 3 . Cough consists of three phases physiologically: the inspiratory, compressive, and expiratory phase.…”

The benefits of mechanical insufflator‐exsufflator compared to autogenic drainage in adults with cystic fibrosis

“…Peak cough flow (PCF) maneuver test participants were asked to inhale maximally then cough once into the flow meter 19 …”

“…Peak cough flow (PCF) maneuver test participants were asked to inhale maximally then cough once into the flow meter. 19 Lung volume measurements performed as part of the whole-body plethysmography and included: total lung capacity (TLC), residual volume (RV), functional residual capacity (FRC), and RV/TLC ratio. 20 64 CF patients treated in the Sheba Medical Center were eligible for the study and were invited to participate, 40 declined.…”