Blood pH is the negative logarithm of the concentration of hydrogen ions in the blood. All biochemical changes in the cells are affected by blood pH. When the blood pH is below 6.9 or above 7.7, life is at risk. Arterial blood is usually taken without exposure to air. The pH is normal, there are three cases without acid-base imbalance, compensatory acid-base imbalance or complex acid-base imbalance. To distinguish whether it is respiratory, metabolic, or a combination of the two, it must be combined with other relevant indicators for comprehensive judgment.

Basic Information

Specialist classification: cardiovascular examination classification: blood examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:
A decrease in pH suggests decompensated acidosis.

Normal value:
Arterial blood: 7.35-7.45
Venous blood: 7.33-7.41

Above normal:
Increased pH indicates decompensated alkalosis.

negative:

Positive:

Tips: Some drugs can affect the pH of the blood. The doctor should inform the doctor about the recent medication before the test. Normal value

Arterial blood is 7.35 to 7.45 (or H+ concentration is 36 to 44 nmol/L). Venous blood is 7.33 to 7.41. (37 °C must be corrected according to body temperature)

Clinical significance

1. Increased pH indicates decompensated alkalosis.

1. Respiratory alkalosis is caused by excessive ventilation, such as central nervous system diseases with increased excitability in the respiratory center.

2, metabolic alkalosis often caused by too much alkali or excessive acid loss, such as long-term large amount of vomiting.

2. pH reduction suggests decompensated acidosis.

1, respiratory acidosis is mainly due to lung dysfunction of carbon dioxide, such as respiratory muscle paralysis, lung diseases such as pulmonary edema, obstructive pulmonary disease, asthma persistent state.

2, metabolic acidosis 1 excessive acid production in the body, such as diabetic ketoacidosis, hunger acidosis. 2 kidney excretion, such as uremia. 3 Loss of too much alkali, such as chronic diarrhea. 4 Acidic drugs are taken too much.

3. The pH is normal, there may be no acid-base imbalance, compensatory acid-base imbalance or complex acid-base imbalance in three cases. To distinguish whether it is respiratory, metabolic, or a combination of the two, it must be combined with other relevant indicators for comprehensive judgment.

Low results may be diseases: metabolic alkalosis, renal tubular acidosis results may be high disease: complex acid-base imbalance considerations

1. Conventional arterial blood should be taken for examination. If venous blood is to be taken, the forearm should be immersed in warm water at 45 °C for 20 minutes to make the venous blood arterial. It is not advisable to use a tourniquet when drawing blood.

2. Flush with heparin beforehand in the syringe.

3. Ensure that the needle and needle of the syringe are tightly combined, and there must be no air leakage to ensure that the blood sample does not come into contact with the outside air.

4. Send the specimen in time.

5. Some drugs may affect the pH of the blood, and the doctor should be informed of the recent medication before the test.

Inspection process

Same as pH electrode potential measurement.

Not suitable for the crowd

Inappropriate people: Generally there are no people who are not suitable.

Adverse reactions and risks

Discomfort: There may be pain, swelling, tenderness, and visible subcutaneous ecchymosis at the puncture site.