title: Diaphragmatic dysfunction in patients with ICU-acquired weakness and its impact on extubation failure.
abstract: OBJECTIVE
  Diaphragm function is rarely studied in intensive care patients with unit-acquired weakness (ICUAW) in whom weaning from mechanical ventilation is challenging. The aim of the present study was to evaluate the diaphragm function and the outcome using a multimodal approach in ICUAW patients.
  
  
  METHODS
  Patients were eligible if they were diagnosed for ICUAW [Medical Research Council (MRC) Score <48], mechanically ventilated for at least 48 h and were undergoing a spontaneous breathing trial. Diaphragm function was assessed using magnetic stimulation of the phrenic nerves (change in endotracheal tube pressure), maximal inspiratory pressure and ultrasonographically (thickening fraction). Diaphragmatic dysfunction was defined by a change in endotracheal tube pressure below 11 cmH2O. The endpoints were to describe the correlation between diaphragm function and ICUAW and its impact on extubation.
  
  
  RESULTS
  Among 185 consecutive patients ventilated for more than 48 h, 40 (22 %) with a MRC score of 31 [20-36] were included. Diaphragm dysfunction was observed with ICUAW in 32 patients (80 %). Change in endotracheal tube pressure and MRC score were not correlated. Maximal inspiratory pressure was correlated with change in endotracheal tube pressure after magnetic stimulation of the phrenic nerves (r = 0.43; p = 0.005) and MRC score (r = 0.34; p = 0.02). Thickening fraction was less than 20 % in 70 % of the patients and was statistically correlated with change in endotracheal tube pressure (r = 0.4; p = 0.02) but not with MRC score. Half of the patients could be extubated without needing reintubation within 72 h.
  
  
  CONCLUSIONS
  Diaphragm dysfunction is frequent in patients with ICU-acquired weakness (80 %) but poorly correlated with the ICU-acquired weakness MRC score. Half of the patients with ICU-acquired weakness were successfully extubated. Half of the patients who failed the weaning process died during the ICU stay.
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.|Centre National de la Recherche Scientifique (CNRS 9214), Institut National de la Santé et de la Recherche Médicale (INSERM U-1046), Montpellier University, Montpellier, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Jung
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.
authors.forename: Pierre Henri
authors.initials: PH
authors.lastname: Moury
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.
authors.forename: Martin
authors.initials: M
authors.lastname: Mahul
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.
authors.forename: Audrey
authors.initials: A
authors.lastname: de Jong
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Galia
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.
authors.forename: Albert
authors.initials: A
authors.lastname: Prades
authors.affiliation: Pôle Anesthésie-Réanimation, UJF-Grenoble, Grenoble, France.|Université Grenoble Alpes/CNRS, ThEMAS TIMC UMR 5525, 38041, Grenoble, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Albaladejo
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France.|Centre National de la Recherche Scientifique (CNRS 9214), Institut National de la Santé et de la Recherche Médicale (INSERM U-1046), Montpellier University, Montpellier, France.
authors.forename: Gerald
authors.initials: G
authors.lastname: Chanques
authors.affiliation: Centre National de la Recherche Scientifique (CNRS 9214), Institut National de la Santé et de la Recherche Médicale (INSERM U-1046), Montpellier University, Montpellier, France.|Department of Statistics, University of Montpellier Lapeyronie Hospital, Montpellier, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Molinari
authors.affiliation: Intensive Care Unit, Anesthesia and Critical Care Department, Saint Eloi Teaching Hospital, 80 Av Fliche, 34295, Montpellier Cedex 5, France. s-jaber@chu-montpellier.fr.|Centre National de la Recherche Scientifique (CNRS 9214), Institut National de la Santé et de la Recherche Médicale (INSERM U-1046), Montpellier University, Montpellier, France. s-jaber@chu-montpellier.fr.
authors.forename: Samir
authors.initials: S
authors.lastname: Jaber
mesh_terms: D000328:Adult; D000368:Aged; D060666:Airway Extubation; D015897:Comorbidity; D003964:Diaphragm / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D018908:Muscle Weakness / Q000209:etiology*; D010791:Phrenic Nerve / Q000503:physiopathology; D011446:Prospective Studies; D012121:Respiration, Artificial / Q000009:adverse effects* / Q000401:mortality; D012307:Risk Factors; D017211:Treatment Failure
keywords: Diaphragmatic dysfunction; Intensive care unit-acquired weakness; Mechanical ventilation; Respiratory muscles; Weaning