What Is Central Venous Pressure?
Central venous pressure (CVP) is the pressure at which the superior and inferior vena cava enters the right atrium. It is measured through the superior and inferior vena cava or the right atrial cannula. It reflects the right atrial pressure and is one of the main indicators for clinical observation of hemodynamics. It is affected by three factors: cardiac function, circulating blood volume, and vascular tone. The blood pressure of the right atrium and the large veins in the thorax is often referred to as central venous pressure. Determination of CVP is of great significance for understanding effective circulating blood volume and cardiac function. The normal value is 0.5 1.2Kpa or 0.49 1.18Kpa (50 120mmH 2 O).
- English name
- central venous pressure; CVP
- Visiting department
- Cardiology
Basic Information
Central venous pressure component
- CVP consists of four parts: filling pressure of right ventricle; pressure of venous wall; systolic pressure and tension of vein; venous capillary pressure.
Central venous pressure meaning
- Central venous pressure can be used clinically as an indicator of fluid replacement rate and volume.
- Volumetric load test-can be used as a reference for the treatment of patients with high CVP but still with insufficient cardiac output. If 500ml of fluid is quickly input within 20 minutes, the CVP does not increase significantly or even decreases; at the same time, blood pressure increases and heart rate decreases, indicating that the patient has absolute or relative insufficient capacity, and the heart has the potential to continue to receive large infusions On the contrary, the infusion must be cautious.
- Determination of CVP is of great significance for understanding effective circulating blood volume and cardiac function.
- Central venous pressure depends on the correlation between the ability of the heart to eject blood and the volume of venous return to the heart. If the heart has a strong ability to eject blood, the blood that returns to the heart can be injected into the artery in time, and the central venous pressure is low. Conversely, a decrease in ejection capacity due to heart failure and other reasons will cause the central venous pressure to increase. Central venous pressure indicates the return of venous blood to the central vein and right atrium, but does not directly reflect blood volume. If CVP cannot be obtained because of the cause, the inferior vena cava under the diaphragm can be measured instead of central venous pressure. Early change in arterial pressure.
- If the central venous pressure is less than 0.49kPa, the right atrium is insufficient or the blood volume is insufficient. When the central venous pressure is greater than 1.47kPa (150mmH 2 O), it may indicate cardiac insufficiency, excessive vascular bed contraction, or increased pulmonary circulation resistance; kPa (200mmH 2 O), it indicates the presence of congestive heart failure.
Central venous pressure indication
- Indications for CVP testing:
- 1. Critical patients such as severe trauma, various shocks and acute circulatory failure.
- 2. Various major and medium surgeries, especially major surgeries for cardiovascular, craniocerebral and abdominal operations.
- 3. Patients who need long-term infusion or receive complete parenteral nutrition.
- 4. Patients who need to receive a large amount of rapid blood transfusion.
Central venous pressure pathway
- CVP common pressure measurement methods:
- 1. Right internal jugular vein.
- 2. Subclavian vein.
- 3. External jugular vein.
- 4. Femoral vein.