An Exploration of Lung Volume Effects on Swallowing in Chronic Obstructive Pulmonary Disease.

Purpose Chronic obstructive pulmonary disease (COPD) limits respiration, which may negatively impact airway safety during swallowing. It is unknown how differences in lung volume in COPD may alter swallowing physiology. This exploratory study aimed to determine how changes in lung volume impact swallow duration and coordination in persons with stable state COPD compared with older healthy volunteers (OHVs). Method Volunteers ≥ 45 years with COPD (VwCOPDs; n = 9) and OHVs (n = 10) were prospectively recruited. Group and within-participant differences were examined when swallowing at different respiratory volumes: resting expiratory level (REL), tidal volume (TV), and total lung capacity (TLC). Participants swallowed self-administered 20-ml water boluses by medicine cup. Noncued (NC) water swallows were followed by randomly ordered block swallowing trials at three lung volumes. Estimated lung volume (ELV) and respiratory-swallow patterning were quantified using spirometry and respiratory inductive plethysmography. Manometry measured pharyngeal swallow duration from onset of base of tongue pressure increase to offset of negative pressure in the pharyngoesophageal segment. Results During NC swallows, the VwCOPDs swallowed at lower lung volumes than OHVs (p = .011) and VwCOPDs tended to inspire after swallows more often than OHVs. Pharyngeal swallow duration did not differ between groups; however, swallow duration significantly decreased as the ELV increased in VwCOPDs (p = .003). During ELV manipulation, the COPD group inspired after swallowing more frequently at REL than at TLC (p = .001) and at TV (p = .002). In conclusion, increasing respiratory lung volume in COPD should improve safety by reducing the frequency of inspiration after a swallow.

Relative Efficacy of Swallowing versus Non-swallowing Tasks in Dysphagia Rehabilitation: Current Evidence and Future Directions.

Clinical trials published in 2012 and the first six months of 2013 were reviewed. These involved either traditional dysphagia therapy, indirect methods not involving dysphagia therapy or a combination of direct and indirect methods. Of 27 studies, 7 were RCTs, 5 were controlled clinical trials and the remainder were uncontrolled case series. Sixteen studies combined an indirect treatment with traditional dysphagia therapy; only one study examined one technique for direct swallowing therapy. Effect sizes were computed and contrasted for each trial. Traditional dysphagia therapy had small to moderate effect sizes (between 0.3 and 0.6) while spontaneous recovery in acute stroke had effect sizes of 1.2. Placebo effects on patient ratings of degree of improvement on swallowing were estimated as small to moderate. To improve effect sizes, adaptive research designs are needed to develop the optimal methods and dosages of therapy before future clinical trials.