Question

what is central venous access with Venous pressure or right atrial pressure and what is their benefits in hemodynamic monitoring and respiratory function?

Answer 1

Ans. 1. Central venous pressure describes the pressure of blood in the thoracic vena cava, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood into the arterial system. It is a good approximation of right atrial pressure, which is a major determinant of right ventricular end diastolic volume. Normal CVP is 4- 8mmhg

The central venous pressure is the pressure measured in the central veins close to the heart. It indicates mean right atrial pressure and is frequently used as an estimate of right ventricular preload. The CVP does not measure blood volume directly, although it is often used to estimate this.In reality the CVP value is determined by the pressure of venous blood in the vena cava and by the function of the right heart, and it is therefore influenced not only by intravascular volume and venous return, but also by venous tone and intrathoracic pressure, along with right heart function and myocardial compliance.

In a normal patient the mean right atrial pressure measured by the CVP closely resembles the mean left atrial pressure . At end diastole left atrial pressure is assumed to equal left ventricular end diastolic pressure , which in turn is assumed to reflect left ventricular end diastolic volume . Thus, in normal patients, CVP is assumed to be a reflection of left ventricular preload. However, in patients with cardiac or pulmonary disease the right and left ventricles may function independently. In these cases left ventricular preload should be estimated by measuring the pulmonary capillary 'wedge' pressure, using a pulmonary artery catheter (PAC), as this is a better guide to the venous return to the left side of the heart than CVP. The PAC may also be connected to a computer to calculate the cardiac output using a thermodilution technique and further guide patient management.

Ans.2. Monitoring hemodynamic events provides information about the adequacy of a patient's circulation, perfusion, and oxygenation of the tissues and organ systems. The objective of hemodynamic monitoring is to ensure optimal tissue perfusion and oxygen delivery while maintaining adequate mean arterial blood pressure.

Hemodynamic monitoring measures the blood pressure inside the veins, heart, and arteries. It also measures blood flow and how much oxygen is in the blood. It is a way to see how well the heart is working.