Effects of scoliosis on respiratory muscle strength in patients with neuromuscular disorders
Received 21 November 2008; received in revised form 12 July 2009; accepted 26 August 2009. published online 12 October 2009.
Abstract
Background context
Neuromuscular disorders (NMD) are characterized by loss of lung volume and respiratory muscle weakness, but the effects of scoliosis on lung function are unclear.
Purpose
To compare pulmonary function and respiratory muscle strength in patients with NMD with and without scoliosis as well as in healthy controls.
Study design/setting
Prospective comparison of pulmonary function testing and respiratory muscle strength were made at the pediatric pulmonology and cardiopulmonary rehabilitation units of a university hospital.
Patient sample
Twenty-two patients with NMD and scoliosis, 17 patients with NMD without scoliosis, and 24 age- and sex-matched healthy controls. Outcome measures were compared in patients with NMD with and without scoliosis and healthy subjects using Student t test, Mann-Whitney U test, chi-square test, one-way analysis of variance (ANOVA), Kruskal-Wallis one-way ANOVA, Pearson correlation coefficients, and Spearman rank correlation, as appropriate.
Outcome measures
1) Pulmonary function: forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), peak expiratory flow rate (PEF), forced expiratory flow between 25% and 75% of FVC (FEF25–75%), and maximum expiratory flows at 75%, 50%, and 25% of FVC (MEF75, MEF50, and MEF25, respectively); 2) oxygen saturation: pulse oxymeter reading; and 3) respiratory muscle strength: maximal inspiratory mouth pressure (MIP) and maximal expiratory mouth pressure (MEP).
Methods
Pulmonary function, oxygen saturation, MIP, and MEP were measured and compared in patients with NMD, patients with and without scoliosis, and in healthy subjects.
Results
The patients with NMD, both with and without scoliosis, had significantly lower PEF, MIP, MEP, % predicted MIP (%MIP), and % predicted MEP (%MEP) than those of healthy subjects (p<.05). The patients with NMD and scoliosis had significantly lower values than those with NMD without scoliosis and controls (p<.05) for FVC, FEV1, and FEF25–75%.
Conclusion
Both inspiratory and expiratory muscle strength were diminished in patients with NMD compared with healthy controls. Significant differences were also noted in pulmonary function in patients with NMD with or without scoliosis. This suggests that NMD may impact respiratory function independently of the effects of scoliosis. Clinicians treating patients with NMD should be aware of the possibility of compromised respiratory function in these patients to address possible complications.
aDepartment of Physical Therapy and Rehabilitation, Faculty of Health Sciences, Hacettepe University, 06100 Samanpazari, Ankara, Turkey
bDepartment of Paediatrics, Paediatric Pulmonology Unit, Faculty of Medicine, Hacettepe University, 06100 Sihhiye, Samanpazari, Ankara, Turkey
Corresponding author. Department of Physical Therapy and Rehabilitation, Faculty of Health Sciences, Hacettepe University, 06100 Samanpazari, Ankara, Turkey. Tel.: +90-312-3051577 ext. 169; fax: +90-312-3052012.
FDA device/drug status: not applicable.
Author disclosures: DI-I (speaking arrangements, trips/travel, Congress Organization; research support, Hacettepe University); SS (speaking arrangements, trips/travel, Congress Organization; research support, Hacettepe University); HA (speaking arrangements, trips/travel, Congress Organization; research support, Hacettepe University); MS (trips/travel, Congress Organization); NV-Y (trips/travel, Congress Organization); MB-G (research support, Hacettepe University; trips/travel, Congress Organization); DD (speaking/arrangements, Congress Organization; research support, Hacettepe University).
ABSTRACT