Ventolin Inhalers

- Role of Oxygen Debt in the Development of Organ Failure Sepsis, and Death in High-Risk Surgical Patients (1)

Figure-1In 1922, Blalock defined shock as a failure of tissue perfusion and in experimental shock demonstrated reduced renal and splanchnic oxygen consumption as a measure of perfusion. Subsequent studies on lethal hemorrhagic shock in dogs confirmed the early reduced rate of oxygen consumption (Vo2).’ When the survivors of experimental hemorrhagic shock were followed over an appropriate time period, there were later increases in Vo2.
Cuthbertson measured Vo2 by external spirometry after orthopedic injuries or operations in six patients. He found initial decreases in Vo2, followed by increased Vo2; he termed this pattern the “ebb and flow” of oxygen. Guyton and Crowell measured Vo2 in dogs under normal control conditions and during hemorrhage; these investigators then calculated the net cumulative Vo2 debt (or excess) as the time integral of the difference between the Vo2 measured during and after hemorrhagic shock minus the Vo2 need measured under control conditions. They found no mortality when the Vo2 deficit was less than 100 ml/kg and a uniformly lethal outcome when the Vo2 deficit wras greater than 140 mlAg.
Initial reductions of cardiac output and Vo2 were reported during the initial hemodynamic crisis of trauma and in postoperative patients.

July 29, 2013 Oxygen
Tags: anesthesia cardiac output organ failure oxygen