17. Severe hypoxemia without evidence of tissue hypoxia in adult respiratory distress syndrome. Lund T , Koller ME , Kofstad J . A patient with severe arterial hypoxemia in adult respiratory distress syndrome (ARDS) secondary to a fractured femur is reported. A marked discrepancy between the clinical condition and laboratory findings was observed. At one point, PaO2 was below 4 kPa (30 mm Hg) on F1O2 0.21 without signs of tissue hypoxia. This patient illustrates beneficial effects of a leftward shift of the oxyhemoglobin dissociation curve. Crit Care Med. 1984 Jan;12(1):75-6.
26. OXYGEN EXTRACTION VO 2 = Q x Hb X 13.4 X (SaO 2 - SvO 2 ) Arterial Inflow (Q) capillary O 2 O 2 O 2 O 2 O 2 O 2 O 2 Venous Outflow (Q) C ell O 2 (Adapted from the ICU Book by P. Marino)
27. OXYGEN DELIVERY DO 2 = Q X CaO 2 DO 2 = Q X (1.34 X Hb X SaO 2 ) X 10 Q = cardiac output CaO 2 = arterial oxygen content Normal DO 2 : 520-570 ml/min/m 2 Oxygen extraction ratio = (SaO 2 -SvO 2 /SaO 2 ) X 100 Normal O 2 ER = 20-30%
28. HEMODYNAMIC SUPPORT Max O 2 extraction Critical DO 2 Abnormal Flow Dependency DO 2 VO 2 Septic Shock/ARDS Max O 2 extraction Critical DO 2 VO 2 = DO 2 X O 2 ER DO 2 VO 2 Normal