In any patient with acute respiratory failure, it is extremely important to consider patient positioning after initiating mechanical ventilation. Both ventilation (V) and perfusion (Q) of the lungs can be significantly altered by manipulating the way you position your patient.
Routine Care: A good rule of thumb is to alays keep the patient's head of bed > 30 degrees whenever possible to maximize diaphragmatic excursion, increase lung expansion, and prevent downstream incidence of ventilator associated pneumonias.
Lateral Decubitus Positioning: Severe unilateral lung disease may warrant alternative patient positiong.
Good lung DOWN: In general, the good lung should be placed in the dependent position to improve V/Q matching.
Good lung UP: Exceptions where the patient should be placed so the bad lung is in the dependent position include massive hemoptysis (prevent blood from filling the good lung), large pulmonary abscesses (prevent pus from filling the good lung), & unilateral emphysema (prevent hyperinflation)
Reverse Trendelenburg: In the morbidly obese patient, or those who must remain flat in bed, a trick of the trade to achieve a pseudo-semirecumbent position is to utilize reverse trendelenburg to > 30 degrees.
