血气分析（blood gas analysis）.docVIP

血气分析（blood gas analysis） acid-base balance Extracellular hydrogen ion concentration of the body remained in the normal range (PH7.35 - 7.45), is a necessary condition for human survival. The buffer system in the blood is composed of heavy carbonic acid, hemoglobin, plasma protein and phosphoric acid, neutralizing acids and bases in excess body fluid. The lower pH of the blood promotes breathing; elevated PH in the blood inhibits breathing. When the body fixed acid excessive hydrogen ion secretion by renal tubular function, so that the fixed acid excreted in urine. Acidosis: The HCO3/H2CO3 ratio tends to be less than 20/1, PH is lower than the lower limit of normal (7.35) tendency or 7.35, called acidosis. Metabolic acidosis: The metabolism of H + produced in the lactic acidosis due to hypoxia, enhanced glycolysis, lactate production more than liver treatment utilization ability and lactic acidosis. Common in shock and hypoxia caused by various causes. Sudden cardiac arrest, the body immediately hypoxia, within 3 minutes pH can be reduced to less than 7. Ketoacidosis: a large number of body fat decomposition, ketone bodies are generated too much, more than the peripheral tissue compensatory oxidation ability, ketoacidosis can occur, mainly in diabetes and hunger. Excessive intake of acidic drugs: in the use of salicylic acid, dilute hydrochloric acid or ammonium chloride and so on. The metabolism of H + row at the main obstacles in acute renal failure and chronic renal failure. Metabolic acidosis occurs when the glomerular filtration rate is reduced to 20% of the normal level. The metabolic acidosis caused by excess metabolic H + or excessive discharge is acidic acidosis. The HCO3 lost too much under the physiological condition of plasma HCO3 continuously with acid buffering and consumption, at the same time by intestinal alkaline intestinal absorption and renal tubular reabsorption of urine from the original to supplement, so as to maintain the normal concentration