title: Diaphragm dysfunction on admission to the intensive care unit. Prevalence, risk factors, and prognostic impact-a prospective study.
abstract: BACKGROUND
  Diaphragmatic insults occurring during intensive care unit (ICU) stays have become the focus of intense research. However, diaphragmatic abnormalities at the initial phase of critical illness remain poorly documented in humans.
  
  
  OBJECTIVE
  To determine the incidence, risk factors, and prognostic impact of diaphragmatic impairment on ICU admission.
  
  
  METHODS
  Prospective, 6-month, observational cohort study in two ICUs. Mechanically ventilated patients were studied within 24 hours after intubation (Day 1) and 48 hours later (Day 3). Seventeen anesthetized intubated control anesthesia patients were also studied. The diaphragm was assessed by twitch tracheal pressure in response to bilateral anterior magnetic phrenic nerve stimulation (Ptr,stim).
  
  
  RESULTS
  Eighty-five consecutive patients aged 62 (54-75) (median [interquartile range]) were evaluated (medical admission, 79%; Simplified Acute Physiology Score II, 54 [44-68]). On Day 1, Ptr,stim was 8.2 (5.9-12.3) cm H2O and 64% of patients had Ptr,stim less than 11 cm H2O. Independent predictors of low Ptr,stim were sepsis (linear regression coefficient, -3.74; standard error, 1.16; P = 0.002) and Simplified Acute Physiology Score II (linear regression coefficient, -0.07; standard error, 1.69; P = 0.03). Compared with nonsurvivors, ICU survivors had higher Ptr,stim (9.7 [6.3-13.8] vs. 7.3 [5.5-9.7] cm H2O; P = 0.004). This was also true for hospital survivors versus nonsurvivors (9.7 [6.3-13.5] vs. 7.8 [5.5-10.1] cm H2O; P = 0.004). Day 1 and Day 3 Ptr,stim were similar.
  
  
  CONCLUSIONS
  A reduced capacity of the diaphragm to produce inspiratory pressure (diaphragm dysfunction) is frequent on ICU admission. It is associated with sepsis and disease severity, suggesting that it may represent another form of organ failure. It is associated with a poor prognosis. Clinical trial registered with www.clinicaltrials.gov (NCT 00786526).
authors: University Paris 6-Pierre et Marie Curie, ER10, Paris, France. alexandre.demoule@psl.aphp.fr
authors: Alexandre
authors: A
authors: Demoule
authors: Boris
authors: B
authors: Jung
authors: Hélène
authors: H
authors: Prodanovic
authors: Nicolas
authors: N
authors: Molinari
authors: Gerald
authors: G
authors: Chanques
authors: Catherine
authors: C
authors: Coirault
authors: Stefan
authors: S
authors: Matecki
authors: Alexandre
authors: A
authors: Duguet
authors: Thomas
authors: T
authors: Similowski
authors: Samir
authors: S
authors: Jaber
mesh_terms: D000368:Aged; D016638:Critical Illness; D003964:Diaphragm / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010791:Phrenic Nerve / Q000502:physiology; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D018805:Sepsis / Q000503:physiopathology*; D012720:Severity of Illness Index