UMEM Educational Pearls

Positioning for Ventilated, Critically Ill Obese Patients

  • Up to one-quarter of patients in the ICU are obese, as defined by a BMI > 35 kg/m2
  • Obesity can significantly alter pulmonary physiology causing
    • reduced lung volumes
    • decreased compliance
    • abnormal ventilation to perfusion relationships
    • respiratory muscle inefficiency
  • For intubated obese patients, body position can affect ventilatory management
  • In the supine position, obese patients can have collapse of lung segments along with increased impedance of the diaphragm
  • Elevating the head of the bed to 30-45 degrees in intubated obese patients has been shown to improve tidal volumes and lower respiratory rates.


Ashburn DD, DeAntonio A, Reed MJ. Pulmonary system and obesity. Crit Care Clin 2010; 26:597-602