IPPB-assisted coughing in neuromuscular disorders

In neuromuscular disorders, reduced peak cough flows (PCFs) are considered to increase the risk of respiratory complications such as pneumonia or chronic atelectasis. Different methods were described to improve PCF. However, these studies were primarily carried out in adults, and there is limited information regarding the use and efficacy of these methods in children with respiratory muscle weakness. The aim of this study was to investigate whether hyperinsufflation with an intermittent positive-pressure breathing (IPPB) device is effective in cough augmentation in pediatric patients. Spirometry (forced inspiratory vital capacity; FIVC; forced expiratory volume in 1 sec, FEV1), respiratory muscle pressures (peak inspiratory pressure, PIP; peak expiratory pressure, PEP), and PCF were measured in 29 schoolchildren with various neuromuscular disorders. IPPB-assisted hyperinsufflation was taught individually to increase lung volumes (maximum insufflation capacity, MIC) above FIVC. The impact of hyperinsufflation on peak cough flow was documented. In 28/29 patients, IPPB-assisted hyperinsufflation enhanced FIVC from 0.68 +/- 0.40 I to an MIC of 1.05 +/- 0.47 I (P < 0.001). Unassisted PCF was 119.0 +/- 57.7 I/min, and increased to 194.5 +/- 74.9 I/min (P < 0.001) in 27/29 patients. This effect was similar in young patients (ages 6-10 years) and older patients (aged > 10 years). Augmentation of lung volumes from FIVC to MIC correlated with an increase of PCF(R = 0.42, P < 0.05). IPPB-assisted hyperinsufflation improves PCF in pediatric neuromuscular disorders. The results suggest that this technique can be used to improve clearance of airway secretions and therefore reduce respiratory morbidity in children with NMD.