buffer

Buffer base refers to the sum of all buffering bases in the blood. It reflects the total buffer capacity of the body's acid-base imbalance. Since the buffer base is affected by plasma proteins and hemoglobin, it does not accurately reflect the internal stability of metabolic acids and bases. Arterial blood was drawn and measured with a blood gas analyzer. Basic Information Specialist classification: Digestive examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Before taking blood, please indicate whether you are taking oxygen. The blood specimen should be isolated from the outside air and sent to the test in time. Normal value In normal plasma, [HCO3-]: [CO2] = 20:1. pH = 6.1 + lg 20/1 = 7.4. Clinical significance Abnormal results: reduced in metabolic acidosis and compensatory respiratory alkalosis. Elevation is seen in metabolic alkalosis and compensatory respiratory acidosis. Precautions Before the test: Before the blood is drawn, it is necessary to indicate whether or not to take oxygen. The blood sample should be isolated from the outside air and sent to the test in time. Arterial blood gas analysis of blood collection sites, generally the radial artery, radial artery, femoral artery and so on. If venous blood is required, the forearm should be placed in warm water at 45 ° C for 20 min to make the venous blood arterial. It is not advisable to use a tourniquet when drawing blood. After the examination: the use of certain drugs can increase or decrease the pH of the blood, such as the use of sodium bicarbonate, etalic acid, sodium glutamate, phenylbutazone, aspirin, etc. to increase blood pH; use tetracycline, isoniazid Bismuth, phenformin, ammonium chloride can reduce blood pH. Inspection process In order to prepare a buffer solution of a certain pH, first select a weak acid whose pKaφ is as close as possible to the pH of the buffer solution to be prepared, and then calculate the acid to alkali concentration ratio, according to which the desired buffer solution can be prepared. . Accurately weigh 3.533 g of anhydrous sodium hydrogen phosphate and 3.387 g of potassium dihydrogen phosphate which were dried at 115 ± 5 ° C for 2 to 3 hours, dissolved in water and diluted to 1000 ml. Accurately weigh 4.330 g of anhydrous sodium hydrogen phosphate and 1.179 g of potassium dihydrogen phosphate which were dried at 115 ± 5 ° C for 2 to 3 hours, dissolved in water and diluted to 1000 ml. Not suitable for the crowd There are no special taboos. Adverse reactions and risks No related complications or hazards.