Dialysis blocks the passage of larger substances (for example, red blood cells, large proteins). This replicates the filtering process that takes place in the kidneys when the blood enters the kidneys and the larger substances are separated from the smaller ones in the glomerulus. The two main types of dialysis, hemodialysis and peritoneal dialysis, remove wastes and excess water from the blood in different ways. Hemodialysis removes wastes and water by circulating blood outside the body through an external filter, called a dialyzer, that contains a semipermeable membrane. The blood flows in one direction and the dialysate flows in the opposite.
Base excess data. The term and concept of base excess were first introduced by Poul Astrup and Ole Siggaard-Andersen in 1958. Base excess can be estimated from the bicarbonate concentration ([HCO]) and pH by the equation: formula_1 with units of mEq/L. The same can be alternatively expressed as formula_2 Calculations are based on the Henderson-Hasselbalch equation: Ultimately the end result is: Base excess beyond the reference range indicates Blood pH is determined by both a metabolic component, measured by base excess, and a respiratory component, measured by PaCO (partial pressure of carbon dioxide). Often a disturbance in one triggers a partial compensation