title: [Effect of hypophosphatemia on weaning success from mechanical ventilation].
abstract: BACKGROUND
  Hypophosphatemia may cause acute respiratory failure and tissue hypoxia. In this study we investigated the effect of hypophosphatemia on weaning success.
  
  
  METHODS
  A nested case-control study was conducted in a retrospective cohort of 76 patients who received invasive mechanical ventilation in 2005-2010 in the Medical Intensive Care Unit (MICU) of university hospital. Case patients (failure group) were those who could not be weaned in the first trial or who required post-extubation mechanical ventilation after first extubation. Control patients (success group) were successfully extubated in the first weaning attempt.
  
  
  RESULTS
  Frequency of hypophosphatemia (P level < 2.5 mg/dL) at admission was 23.7%. Weaning failure rate was 71.1%. Risk of weaning failure in the presence of hypophosphatemia was 88.9%, whereas risk in the absence of hypophosphatemia was 65.5%, resulting in risk ratio of 1.36 (1.06 - 1.74) (p= 0.096). Mean (± SD) P levels in the success and failure groups were 3.6 ± 1.0 and 3.2 ± 1.0 mg/dL, respectively (p= 0.113). Logistic regression analysis revealed four independent risk factors which were presence of underlying chronic pulmonary disease, high organ dysfunction score (SOFA) at admission, high blood urea nitrogen at the day of weaning trial and low P level at admission to predict weaning failure. Each 1 mg/dL increment in P level resulted in decreased probability of weaning failure with an OR of 0.43 (0.21-0.88).
  
  
  CONCLUSIONS
  In conclusion, a relation between hypophosphatemia and weaning failure was determined which has to be confirmed with prospective cohort and interventional studies with adequate power.
authors.forename: Atilla
authors.initials: A
authors.lastname: Kara
authors.forename: Muhammet Cemal
authors.initials: MC
authors.lastname: Kızılarslanoğlu
authors.forename: Başak
authors.initials: B
authors.lastname: Bolayır
authors.forename: Ebru
authors.initials: E
authors.lastname: Ortaç Ersoy
authors.forename: Serpil
authors.initials: S
authors.lastname: Öcal
authors.forename: Banu
authors.initials: B
authors.lastname: Çakır
authors.forename: Sabahat
authors.initials: S
authors.lastname: Tezcan
authors.affiliation: Medical Intensive Care Unit, Department of Internal Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey. atopeli@hacettepe.edu.tr.
authors.forename: Arzu
authors.initials: A
authors.lastname: Topeli
mesh_terms: D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002908:Chronic Disease; D005260:Female; D006801:Humans; D017674:Hypophosphatemia / Q000150:complications*; D007362:Intensive Care Units; D008171:Lung Diseases / Q000150:complications* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011446:Prospective Studies; D012189:Retrospective Studies; D012307:Risk Factors; D017211:Treatment Failure; D015300:Ventilator Weaning