Quiz

Central Venous Pressure (CVP) Overview

• Central venous pressure (CVP) measures the pressure in the thoracic vena cava near the right atrium, reflecting right ventricular filling pressure.
• CVP indirectly reflects blood volume and venous return to the heart.

Right Ventricular End Diastolic Volume (RVEDV)

• Pressure in the right atrium is a major determinant of right ventricular end-diastolic volume (RVEDV).

Pressure Measurement Norms

• Mean pulmonary capillary wedge pressure (PCWP) normal range is typically between 6 to 15 mmHg.
• Mean arterial pressure (MAP) provides an average pressure in a patient's arteries during one cardiac cycle, generally around 70-100 mmHg.

CVP and Right Ventricular Filling

• CVP is a direct assessment of right ventricular filling pressure because it measures the pressure that directly influences the volume of blood filling the right ventricle.

O2 Saturation and Venous Return

• O2 saturation in the right atrium typically ranges from 60% to 70%.
• Venous return is influenced by several factors, including changes in venous pressure.

Effects of Gravity on Venous Return

• When standing, gravity can reduce venous return because blood pools in the lower extremities, creating a paradoxical effect.

Indications and Contraindications for Central Venous Cannulation

• Common indications for central venous cannulation include administration of medication or fluids and monitoring of CVP.
• Contraindications may include significant coagulopathy or infected insertion sites.

Factors Affecting Venous Return

• Factors decreasing CVP include diuresis, hypovolemia, and increased heart rate.
• Factors increasing venous return include muscle pump activity and cardiac output.

Central Venous Catheter Attributes

• Various central venous catheter types differ in length, gauge, and access site compatibility, though some features may not vary among types.
• Common central venous catheter lengths include 8, 12, and 16 cm.

Access Site Considerations

• Jugular access is associated with a lower risk for infection and easier access in both younger and elderly patients.
• Femoral access carries a higher risk for infection and thrombosis but allows for easier bleeding control, particularly in anticoagulated patients.
• Subclavian access has a lower rate of severe mechanical complications but presents a risk of pneumothorax.

Relationships and Equations

• The relationship between right ventricular end-diastolic pressure (RVEDP) and left ventricular end-diastolic pressure (LVEDP) can be expressed in specific hemodynamic equations.
• The relationship between venous pressure and venous return also follows certain physiological principles.

Summary of True Statements about CVP

• True statements regarding CVP highlight its role as an indicator of fluid status and its relationship with cardiac function in various clinical settings.