What Is a Blood Gas Analysis?
Blood gas analysis (BG) is a means of understanding the human respiratory function and acid-base balance by measuring the H + concentration of human blood and the gas dissolved in the blood (mainly CO2 and O2) using a blood gas analyzer. It directly reflects the function of lung ventilation and its acid-base balance. The specimens used are often arterial blood. Applicable to: diagnosis of hypoxemia and respiratory failure; differential diagnosis of dyspnea; differential diagnosis of coma; selection of surgical indications; application, adjustment and withdrawal of ventilator; observation of respiratory therapy; diagnosis of acid-base imbalance Wait. The blood gas analyzer can directly measure the arterial oxygen partial pressure (PO2), arterial carbon dioxide partial pressure (PCO2), and arterial hydrogen ion concentration (pH), and calculate a series of parameters. It has been developed to measure more than 50 indicators today:
- Chinese name
- Blood gas analysis
- Foreign name
- blood gas analysis
- Category
- testing method
- Scope of application
- Clinical medicine
Basic Information
Clinical significance of blood gas analysis
- Used to determine whether the body has an acid-base balance disorder and the degree of hypoxia and hypoxia.
- 1. The pH value indicates the actual state of blood acid and alkali, and reflects the index of H concentration. pH> 7.45 is alkalemia.
- 2. PO 2 refers to the partial pressure produced by physically dissolved O 2 in arterial plasma. The level of PO 2 is related to respiratory function, and directly affects the release of O 2 in tissues. During respiratory dysfunction, PO 2 decreases, and when PO 2 is lower than 60 mmHg, it enters the stage of respiratory failure; when PO 2 is lower than 55 mmHg, there is respiratory failure. For example, when PO 2 is lower than 20mmHg, the tissue cells lose the ability to take oxygen from the blood. Therefore, clinically, PO 2 is often used as one of the indicators for oxygen inhalation to patients.
- 3. PCO 2 refers to the partial pressure of physically dissolved CO 2 in plasma. PCO 2 > 45mmHg primary exhaled acid or secondary compensatory alkali. PCO 2 <35mmhg is primary nephrine or secondary compensatory acid replacement. CO 2 has a strong ability to disperse, so arterial blood PCO 2 basically reflects the average value of alveolar PCO 2 and is an objective indicator of pulmonary respiratory function.
Reference range for normal blood gas analysis
- pH: 7.35 to 7.45, PO 2 : 60 to 90 mmHg, PCO 2 : 35 to 45 mmHg.