Spinal muscular atrophy (SMA) is associated with serious respiratory system complications,1 and pulmonary disease is the primary cause of morbidity and mortality in both SMA type 1 and SMA type 2 patients.2 Given the frequency and extent of oxygenation and breathing challenges in SMA patients, a number of assistive devices have been developed to help patients overcome these challenges. A few examples are provided below.
CoughAssist for Airway Clearance
CoughAssist is a device for mechanical insufflation/exsufflation that is often used at home to help those with SMA inhale and exhale. It has been shown to provide physical, social, and emotional benefits for patients with neuromuscular disorders. However, the device has also been associated with child resistance and is not always the preferred treatment by patients and their caregivers.3
VEPTR for Pulmonary Support
SMA patients with early onset scoliosis and thoracic insufficiency syndrome – which occurs when the thorax is unable to support normal lung growth or respiration – can benefit from a device known as the vertical expandable prosthetic titanium rib (VEPTR). Specifically, the VEPTR has been shown to successfully provide pulmonary support and prevent patients from experiencing respiratory deterioration and may be particularly useful in younger patients.4
RTX, Vest, and SmartVest for Removing Mucus from Airway and Lungs
High frequency chest wall oscillation (HFCWO) devices like the RTX gently shake the chest to loosen secretions located in the lungs.5 In some cases, like when the patient has severe chest-wall deformity, it can be difficult to achieve the seal that is needed for the RTX to work. To overcome that challenge, other HFCWO devices, such as the Vest or the SmartVest can be used.
BiPAP for Nighttime Breathing Support
The bilevel positive airway pressure (BiPAP) system has been shown to be valuable for pediatric patients with neuromuscular disorders like spinal muscular atrophy.6 It provides positive pressure and ventilation noninvasively through a nasal mask. BiPAP uses moderate gas pressure and is controlled electrically. Though similar to continuous positive airway pressure (CPAP), which is commonly used for sleep apnea, BiPAP can deliver different pressures during both inspiration and exhalation. Due to these details of its functioning, BiPAP can increase tidal volume during breathing and can improve ventilation and oxygenation without introducing enhanced infection risk or trauma to the airway.
Data show that BiPAP is safe and well tolerated among its pediatric population who suffer from chronic respiratory failure. One study showed that it was maintained in 87% of patients and improved vital signs and serum bicarbonate. Studies with BiPAP have also shown that using the device decreases the number of days of hospitalization that result from respiratory insufficiency. Additionally, better quality of sleep and the ability to return to school have also been associated with pediatric use of BiPAP.
BiPAP is associated with skin irritation on the bridge of the nose that is due to the mask’s pressure, but the skin irritation has been shown to be preventable with the utilization of a strip of moleskin placed between the skin and the mask. Other limitations include its lack of alarms, backup systems, and humidification.7
References
1. Iannaccone ST. Modern management of spinal muscular atrophy. J Child Neurol. 2007;22(8):974-978. doi:10.1177/0883073807305670
2. Baioni MTC, Ambiel CR. Spinal muscular atrophy: diagnosis, treatment and future prospects. J Pediatr (Rio J). 2010;86(4):261-270. doi:doi:10.2223/JPED.1988
3. Travlos V, Drew K, Patman S. The value of the CoughAssist(R) in the daily lives of children with neuromuscular disorders: Experiences of families, children and physiotherapists. Dev Neurorehabil. 2016;19(5):321-326. doi:10.3109/17518423.2014.993771
4. Nossov, SB, Curatolo, E, Campbell, RM, Mayer, OH, Garg S. VEPTR: Are we reducing respiratory assistance requirements? J Pediatr Orthop. 2017:1-5.
5. Keating JM, Collins N, Bush A, Chatwin M. High-frequency chest-wall oscillation in a noninvasive-ventilation-dependent patient with type 1 spinal muscular atrophy. Respir Care. 2011;56(11):1840-1843. doi:10.4187/respcare.01155
6. Padman R, Lawless S, Von Nessen S. Use of BiPAP by nasal mask in the treatment of respiratory insufficiency in pediatric patients: preliminary investigation. Pediatr Pulmonol. 1994;17(2):119-123.
7. Strumpf DA, Millman RP, Carlisle CC, et al. Nocturnal positive-pressure ventilation via nasal mask in patients with severe chronic obstructive pulmonary disease. Am Rev Respir Dis. 1991;144(6):1234-1239. doi:10.1164/ajrccm/144.6.1234
8. Zwillich CW, Pierson DJ, Creagh CE, Sutton FD, Schatz E, Petty TL. Complications of assisted ventilation. A prospective study of 354 consecutive episodes. Am J Med. 1974;57(2):161-170.