title: Non-invasive assessment of respiratory muscle strength in patients with previous poliomyelitis.
abstract: In patients with poliomyelitis, respiratory failure requiring ventilatory support may occur during the acute illness. Some patients continue to require long-term nocturnal ventilatory support; others are weaned but subsequently require support because of a late deterioration in ventilatory function.
  
  
  OBJECTIVE
  To assess the sensitivity of sniff nasal inspiratory pressure (SNIP) to post-poliomyelitis respiratory muscle weakness and to assess the relationship between the respiratory muscle strength and the need for ventilatory support in patients with previous poliomyelitis (post-polio patients).
  
  
  METHODS
  Respiratory muscle strength was measured in 50 post-polio patients. Tests included forced vital capacity (FVC), maximum inspiratory and expiratory pressures (MIP and MEP), and SNIP.
  
  
  RESULTS
  Twenty-one patients used non-invasive nocturnal ventilatory support (NIV group) compared to 29 on no support (non-NIV group). The percentage predicted FVC was significantly lower in the NIV group compared to the non-NIV group (P=0.01). Similarly, the percentage predicted MIP was significantly lower in NIV group (P=0.007). Low SNIP values (both absolute value and percentage predicted) were associated with the need for ventilatory support (P<0.001). Of the patients requiring no support, those who had been ventilated during the acute episode of poliomyelitis had a significantly lower SNIP than those who had never been ventilated (P=0.04).
  
  
  CONCLUSIONS
  Post-polio patients who are currently on nocturnal ventilation have significantly lower FVC, MIP and SNIP compared to currently non-ventilated patients. Non-ventilated patients who were ventilated during the acute episode of poliomyelitis have significantly weaker respiratory muscle strength than patients who were never ventilated. This study indicates that SNIP is more sensitive to post-polio respiratory muscle weakness than other non-invasive tests. Thus measurement of SNIP is a valuable tool for monitoring the progression of respiratory muscle weakness due to previous poliomyelitis and this can be applied to other neuromuscular disorders.
authors.affiliation: Guy's, King's and St. Thomas' School of Medicine, St. Thomas Hospital, Lane-Fox Unit, Lambeth Palace Road, London SE1 7EH, UK. mohamed.gouda@doctors.net.uk
authors.forename: Mohamed Gouda
authors.initials: MG
authors.lastname: Soliman
authors.forename: Sean E
authors.initials: SE
authors.lastname: Higgins
authors.forename: Desirie R
authors.initials: DR
authors.lastname: El-Kabir
authors.forename: Arthur C
authors.initials: AC
authors.lastname: Davidson
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Williams
authors.forename: Robin S
authors.initials: RS
authors.lastname: Howard
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D001239:Inhalation / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009666:Nose / Q000503:physiopathology*; D016262:Postpoliomyelitis Syndrome / Q000150:complications / Q000503:physiopathology*; D012132:Respiratory Muscles / Q000502:physiology*; D014797:Vital Capacity