ECG Monitoring in Anesthesia

Enormous progress has been made in the last 10 years toward an understanding of sodium homeostasis by the kidney. Much of the relevant literature is reviewed. Anesthesia and surgery are normally accompanied by severe sodium retention. 2 studies which investigated this area are summarized. Together they demonstrate the importance of the kidney in monitoring an individual's hemodynamic state and adjusting his sodium excretion accordingly. 1 study showed uniform fluid retention following surgery, even in patients receiving high levels of extra fluid. Water and sodium retention were shown to be responses to different, unrelated mechanisms. Plasma or extracellular fluid deficits were shown to be unrelated to the amount of retention. These 2 studies confirmed an earlier hypothesis by de Bono and Mills that changes in renal hemodynamics may be responsible for changes in sodium excretion. Actually, a number of substances, all with powerful vasoactive properties, have been isolated in the kidney.