Central Venous/Right Atrial Pressure Monitoring
PREREQUISITE NURSING KNOWLEDGE
• Knowledge of the normal anatomy and physiology of the cardiovascular system is needed.
• Knowledge of the principles of aseptic technique and infection control is necessary.
• Knowledge is needed of the principles of hemodynamic monitoring.
• The central venous pressure (CVP)/right atrial pressure (RAP) represents right-sided heart preload or the volume of blood found in the right ventricle at the end of diastole.
• CVP/RAP influences and is influenced by venous return and cardiac function. Although the CVP/RAP is used as a measure of changes in the right ventricle, the relationship is not linear. Because the right ventricle has the ability to expand and alter its compliance, changes in volume can occur with little change in pressure.
• The CVP/RAP normally ranges from 2 to 8 mm Hg in the adult.
• The central venous catheter is inserted in a central vein with the tip of the catheter placed in the proximal superior vena cava.
• Knowledge is needed of the setup, leveling, and zeroing of the hemodynamic monitoring system (see Procedure 76).
• Understanding of a, c, and v waves is necessary. The a wave reflects right atrial contraction. The c wave reflects closure of the tricuspid valve. The v wave reflects the right atrial filling during ventricular systole. The CVP/RAP measurement is the mean of the a wave.
• CVP/RAP values are useful in evaluation of volume status, effect of medication therapy (especially medication that decreases preload), and cardiac function (Table 70-1).
Table 70-1
Conditions Causing Increased CVP
Elevated intravascular volume
Depressed right-sided cardiac function (RV infarct, RV failure)
Cardiac tamponade
Constrictive pericarditis
Pulmonary hypertension
Chronic left ventricular failure
Conditions Causing Decreased CVP
Reduced intravascular volume*
Decreased mean arterial pressure (MAP)
Venodilation
*Although the measured CVP is low, cardiac function may be depressed, normal, or hyperdynamic when there is reduced vascular volume.
• Monitoring parameters from the femoral catheter is not recommended. The catheter is too distant from the right atrium to produce reliable data.
EQUIPMENT
• Pressure transducer system, including flush solution recommended according to institution standard, a pressure bag or device, pressure tubing with transducer, and flush device (see Procedure 76)
• Pressure module and cable for interface with the monitor
Additional equipment to have available as needed includes the following:
PATIENT AND FAMILY EDUCATION
• Discuss the purpose of the central venous catheter and monitoring with both the patient and family. 
Rationale: This discussion reduces anxiety and includes the patient and family in the plan of care.
• Explain the patient’s expected participation during the procedure. 
Rationale: The explanation encourages patient assistance.
PATIENT ASSESSMENT AND PREPARATION
Patient Assessment
• Determine hemodynamic, cardiovascular, and peripheral vascular status. 
Rationale: This assessment provides baseline data.
• Determine the patient’s baseline pulmonary status. If the patient is mechanically ventilated, note the type of support, ventilator mode, and presence or absence of positive end-expiratory pressure (PEEP) or continuous positive airway pressure (CPAP). 
Rationale: The presence of mechanical ventilation alters hemodynamic waveforms and pressures.
• Assess for signs and symptoms of fluid volume deficit. Signs and symptoms may include thirst, oliguria, tachycardia, and dry mucous membranes. 
Rationale: Assessment data should correlate with a decreased CVP/RAP value.
• Assess for signs and symptoms of fluid volume excess. Signs and symptoms may include dyspnea, abnormal breath sounds (i.e., crackles), S3 heart sound, peripheral edema, tachycardia, and jugular vein distention. 
Rationale: Assessment data should correlate with an increased CVP/RAP value.
Patient Preparation
• Verify correct patient with two identifiers. 
Rationale: Prior to performing a procedure, the nurse should ensure the correct identification of the patient for the intended intervention.
• Ensure that the patient and family understand teaching. Answer questions as they arise, and reinforce information as needed. 
Rationale: Understanding of previously taught information is evaluated and reinforced.
• Place the patient in the supine position with the head of the bed flat or elevated up to 45 degrees. 
Rationale: This positioning prepares the patient for hemodynamic monitoring.
References
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