title: Prevalence and outcomes of diaphragmatic dysfunction assessed by ultrasound technology during acute exacerbation of COPD: A pilot study.
abstract: The prevalence and clinical consequences of diaphragmatic dysfunction (DD) during acute exacerbations of COPD (AECOPD) remain unknown. The aim of this study was (i) to evaluate the prevalence of DD as assessed by ultrasonography (US) and (ii) to report the impact of DD on non-invasive mechanical ventilation (NIV) failure, length of hospital stay and mortality in severe AECOPD admitted to respiratory intensive care unit (RICU).
  
  
  
  Forty-one consecutive AECOPD patients with respiratory acidosis admitted over a 12-month period to the RICU of the University Hospital of Modena were studied. Diaphragmatic ultrasound (DU) was performed on admission before starting NIV. A change in diaphragmatic thickness (ΔTdi) less than 20% during spontaneous breathing was considered to confirm the presence of dysfunction (DD+). NIV failure and other clinical outcomes (duration of mechanical ventilation MV, tracheostomy, length of hospital stay and mortality) were recorded.
  
  
  
  A total of 10 out of 41 patients (24.3%) presented DD+, which was significantly associated with steroid use (P = 0.002, R-squared = 0.19). DD+ correlated with NIV failure (P < 0.001, R-squared = 0.27), longer intensive care unit (ICU) stay (P = 0.02, R-squared = 0.13), prolonged MV (P = 0.023, R-squared = 0.15) and need for tracheostomy (P = 0.006, R-squared = 0.20). Moreover, the Kaplan-Meyer survival estimates showed that NIV failure (log-rank test P value = 0.001, HR = 8.09 (95% CI: 2.7-24.2)) and mortality in RICU (log-rank test P value = 0.039, HR = 4.08 (95% CI: 1.0-16.4)) were significantly associated with DD+.
  
  
  
  In hospitalized AECOPD patients submitted to NIV, severe DD was seen in almost one-quarter of patients. DD may cause NIV failure, and impacts on the use of clinical resources and on the patient's short-term mortality.
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Antenora
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Fantini
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Iattoni
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Ivana
authors.initials: I
authors.lastname: Castaniere
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Antonia
authors.initials: A
authors.lastname: Sdanganelli
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Francesco
authors.initials: F
authors.lastname: Livrieri
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Tonelli
authors.affiliation: Infectious Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Zona
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Monelli
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.|Rehabilitation Hospital "Villa Pineta" Pavullo, Modena, Italy.
authors.forename: Enrico M
authors.initials: EM
authors.lastname: Clini
authors.affiliation: Respiratory Disease Unit, University Hospital of Modena, Modena, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Marchioni
mesh_terms: D000368:Aged; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology; D005260:Female; D006801:Humans; D007362:Intensive Care Units / Q000706:statistics & numerical data; D007558:Italy / Q000453:epidemiology; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000628:therapy; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods; D000067251:Symptom Flare Up; D014463:Ultrasonography / Q000379:methods*
keywords: chronic obstructive pulmonary disease exacerbation; diaphragmatic dysfunction; diaphragmatic ultrasound; non-invasive mechanical ventilation; respiratory failure