Lung function measurements in young children with spinal muscle atrophy; a cross sectional survey on the effect of position and bracing.
BACKGROUND
Spinal muscular atrophy (SMA) affects respiratory muscles, which in addition to progressive scoliosis leads to respiratory impairment. Children with developing scoliosis are usually treated with spinal bracing to delay the progress.


OBJECTIVE
To assess the impact of body position and application of spinal bracing on lung function during tidal breathing in children with SMA.


METHODS
Lung function was determined by tidal flow volume loops and passive respiratory mechanics (single breath occlusion technique) in all eight children in southern Norway with SMA type I and II, in both the sitting and supine position. Additional measurements were performed with and without bracing in five children. Muscle strength was assessed by the Brooks scale.


RESULTS
Tidal expiratory volume (V(E)) and compliance of the respiratory system (CRS) tended to be higher in the sitting compared to the supine position, but this was not statistically significant. However, applying bracing in the sitting position significantly reduced V(E). The highest values of CRS and V(E) were found in the sitting position without bracing.


CONCLUSIONS
Impairment of tidal respiration must be considered when applying spinal bracing in very young children developing scoliosis with SMA.
Tangsrud
S E
SE
Department of Paediatrics, Woman and Child Clinic, Ullevål Hospital, N-0407 Oslo, Norway. svein-erik.tangsrud@ulleval.no
Carlsen
K C
KC
Lund-Petersen
I
I
Carlsen
K H
KH
D001915:Braces / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009134:Muscular Atrophy, Spinal / Q000503:physiopathology*; D011187:Posture / Q000502:physiology*; D012129:Respiratory Function Tests; D012600:Scoliosis / Q000503:physiopathology / Q000628:therapy; D018709:Statistics, Nonparametric; D016683:Supine Position / Q000502:physiology