Noninvasive Ventilation and Mechanical Insufflator-Exsufflator for Acute Respiratory Failure in Children With Neuromuscular Disorders

Abstract

Children with neuromuscular disorder (NMD) usually have pulmonary involvement characterized by weakened respiratory muscles, insufficient coughing, and inability to clear airway secretions. When suffering from community-acquired pneumonia, these patients are more likely to develop acute respiratory failure (ARF). Therefore, recurrent pneumonias leading to acute on chronic respiratory failure accounts for a common cause of mortality in children with NMD. For many years, noninvasive ventilation (NIV) has been regarded as a life-prolonging tool and has been used as the preferred intervention for treating chronic hypoventilation in patients with advanced NMD. However, an increasing number of studies have proposed the utility of NIV as first-line management for acute on chronic respiratory failure in NMD patients. The benefits of NIV support in acute settings include avoiding invasive mechanical ventilation, shorter intensive care unit or hospital stays, facilitation of extubation, and improved overall survival. As the difficulty in clearing respiratory secretions is considered a significant risk factor attributing to NIV failure, combined coughing assistance of mechanical insufflator-exsufflator (MI-E) with NIV has been recommended the treatment of acute neuromuscular respiratory failure. Several recent studies have demonstrated the feasibility and effectiveness of combined NIV and MI-E in treating ARF of children with NMD in acute care settings. However, to date, only one randomized controlled study has investigated the efficacy of NIV in childhood ARF, but subjects with underlying NMD were excluded. It reflects the need for more studies to elaborate evidence-based practice, especially the combined NIV and MI-E use in children with acute neuromuscular respiratory failure. In this article, we will review the feasibility, effectiveness, predictors of outcome, and perspectives of novel applications of combined NIV and MI-E in the treatment of ARF in NMD children.

Keywords: acute respiratory failure; mechanically assisted coughing; neuromuscular disorder; noninvasive ventilation; risk factors.

Figure 1

Pathophysiological mechanisms underlying ARF in children with NMD.

Figure 2

Resolution of right upper lobe opacification in an infant with severe type 1 spinal muscular atrophy (SMA) after combining NIV and MI-E. (A) Chest X-ray on admission showing right lung pneumonia with significant atelectasis complicated by copious secretions. (B) A significant improvement was found after 2-days treatment, with a resolution of atelectasis. (C) A progressive improvement of the pneumonic patch was observed on day 7 when discharged from PICU.

Figure 3

Demonstration of chest X-ray in a toddler with congenital myopathy who immediately received NIV and MI-E for post-extubation respiratory support. (A) Previously failed extubation in another hospital was related to frequent right lung atelectasis and mucus plugging developing soon after extubation. (B) In our hospital, appropriate expansion of both lungs were noted before extubation. (C) Day 2 post-extubation showed mild right lung infiltration without atelectasis. (D) Discharge from PICU on day 7 post-extubation showed re-expansion of both lungs.