title: [Increase in right-to-left intracardiac shunt with non-invasive ventilation].
abstract: BACKGROUND
  Hypoxia caused by an increase in right-to-left shunt has been reported in patients with patent foramen ovale treated with levels of positive end-expiratory pressures (PEEP) greater than 10 cmH2O. This phenomenon has not previously been described with non-invasive ventilation (NIV).
  
  
  METHODS
  A 23 year-old man with tetralogy of Fallot and a severe kyphoscoliosis was admitted at the hospital for chronic dyspnoea. Arterial blood gases on room air: pH 7.43, PaCO2 39 mmHg, PaO2 67 mmHg, HCO3- 25 mmol/l, SaO2 95%. Nocturnal oxymetry showed severe hypoxaemia resistant to oxygen. NIV with PEEP of 3 cm H2O was commenced. With ventilation, his oxygenation worsened. An echocardiogram performed during NIV showed an increase in the right-to-left interventricular gradient from 22 to 37 cmH2O, and of the right ventriculo-auricular gradient from 76 to 142 mmHg. Furthermore, his oxygen saturation decreased progressively from 95 to 85%. Following removal of NIV, the patient recovered in 15 minutes.
  
  
  CONCLUSIONS
  We report an increased right-to-left intracardiac shunt in a patient with tetralogy of Fallot. Compression of pulmonary vessels and cardiac cavities induced by NIV may have been enhanced by a reduction in thoracic compliance related to kyphoscoliosis. Right-to-left shunt in patients with kyphoscoliosis may be a contra-indication to NIV.
authors.affiliation: Service de Pneumologie, Hôpital Pasteur, CHU de Nice, France.
authors.forename: V
authors.initials: V
authors.lastname: Jullien
authors.forename: M
authors.initials: M
authors.lastname: Benhamou
authors.forename: P
authors.initials: P
authors.lastname: Lanfranchi
authors.forename: C
authors.initials: C
authors.lastname: Perrin
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D012039:Regional Blood Flow; D012121:Respiration, Artificial / Q000009:adverse effects*; D013771:Tetralogy of Fallot / Q000503:physiopathology*