<prompt> Maintenence level of Mixed venous oxygen saturation in shock must be7050-7040-5040  <response>: Mixed venous oxygen saturation The percentage saturation of oxygen returning to the hea from the body is a measure of the oxygen delivery and extraction by the tissues. Accurate measurements is analysis of blood drawn from a long central line placed in the right atrium Normal mixed venous oxygen saturation levels are 50-70. Levels below 50 indicate inadequate oxygen delivery and increased oxygen extraction by the cells. This is consistent with hypovolemic or cardiogenic shock. Ref: Bailey and love 27th edition Pgno: 17 