title: Parasternal electromyography to determine the relationship between patient-ventilator asynchrony and nocturnal gas exchange during home mechanical ventilation set-up.
abstract: BACKGROUND
  Patient-ventilator asynchrony (PVA) can adversely affect the successful initiation of non-invasive home mechanical ventilation (HMV). The aim of this observational study was to quantify the prevalence of PVA during initiation of HMV and to determine the relationship between PVA and nocturnal gas exchange.
  
  
  METHODS
  Type and frequency of PVA were measured by surface parasternal intercostal muscle electromyography, thoracoabdominal plethysmography and mask pressure during initiation of HMV. Severe PVA was defined, as previously, as asynchrony affecting ≥10% of breaths.
  
  
  RESULTS
  28 patients (18 male) were enrolled aged 61±15 years and with a body mass index of 35±9 kg/m(2). Underlying diagnoses were neuromuscular disease with or without chest wall disease (n=6), obesity related chronic respiratory failure (n=12) and COPD (n=10). PVA was observed in all patients with 79% of patients demonstrating severe PVA. Triggering asynchrony was most frequent, observed in 24% (IQR: 11-36%) of breaths, with ineffective efforts accounting for 16% (IQR: 4-24%). PVA types were similar between disease groups, with the exception of auto-triggering, which was higher in patients with COPD (12% (IQR: 6-26%)). There was no correlation observed between PVA and time spent with oxygen saturations ≤90%, mean oxygen saturations or transcutaneous carbon dioxide levels during overnight ventilation.
  
  
  CONCLUSIONS
  Severe PVA was identified in the majority of patients, irrespective of pathophysiological disease state. This was not associated with ineffective ventilation as evidenced by gas exchange.
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Ramsay
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.
authors.forename: Swapna
authors.initials: S
authors.lastname: Mandal
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.
authors.forename: Eui-Sik
authors.initials: ES
authors.lastname: Suh
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK Division of Asthma, Allergy and Lung Biology, King's College London, London, UK.
authors.forename: Joerg
authors.initials: J
authors.lastname: Steier
authors.affiliation: Department of Public Health Sciences, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust and King's College London, National Institute Health Research Biomedical Research Centre, London, UK.
authors.forename: Abdel
authors.initials: A
authors.lastname: Douiri
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK.
authors.forename: Patrick Brian
authors.initials: PB
authors.lastname: Murphy
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Polkey
authors.affiliation: NIHR Respiratory Biomedical Research Unit, Royal Brompton & Harefield NHS Foundation Trust and Imperial College, London, UK.
authors.forename: Anita
authors.initials: A
authors.lastname: Simonds
authors.affiliation: Lane Fox Respiratory Unit, Guy's, St Thomas' NHS Foundation Trust, London, UK Division of Asthma, Allergy and Lung Biology, King's College London, London, UK Guy's and St Thomas' NHS Foundation Trust and King's College London, National Institute Health Research Biomedical Research Centre, London, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Hart
mesh_terms: D000368:Aged; D002908:Chronic Disease; D004576:Electromyography; D005260:Female; D006699:Home Care Services; D006801:Humans; D007366:Intercostal Muscles / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D011659:Pulmonary Gas Exchange / Q000502:physiology; D012121:Respiration, Artificial; D012131:Respiratory Insufficiency / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D015656:Respiratory Mechanics / Q000502:physiology; D012122:Ventilators, Mechanical
keywords: Lung Physiology; Non invasive ventilation; Respiratory Muscles