www.medicinaintensiva.com.br® - D.Ferrari Adapted

 GRADIENTE  A-a

Gradiente Alvéolo - arterial de O2 PAO2 = ( FiO2 * (760 - 47)) - (PaCO2 / 0.8) A-a gradient = PAO2 - PaO2

Input FiO2(em decimal) ( Ex : FiO2 40% = 0.4 )   
Input PaCO2 (torr) ( 1 torr - 1mmhg )
Input PaO 2 (torr) ( 1 torr - 1 mmhg )

Alveolar-arterial oxygen gradient =

A normal A-a gradient is less than 10 torr. High gradients result from impaired diffusion or by ventilation-perfusion inequality.