Week 12 Handout CVP Flashcards
What does Central Venous Pressure (CVP) measure?
CVP directly measures the pressure in the venous system near the right atrium (RA).
What is required for accurate measurement of CVP?
A central venous catheter (CVC) is required for accurate measurement of CVP.
Where should the tip of the CVC be placed?
The tip of the catheter should be placed just outside the junction of the vena cavae and RA.
What does CVP reflect?
CVP reflects right heart preload and volume status.
How do CVP values assist in patient care?
CVP values help guide fluid therapy and diagnose right-sided heart problems.
What are the three major factors affecting CVP?
- Intravascular volume – More volume increases CVP.
- Venous backup – Right heart failure or valve issues can raise CVP.
- Intrathoracic pressure – Conditions like high PEEP or tension pneumothorax can artificially elevate CVP.
What should be considered when interpreting CVP?
Always consider both cardiac and pulmonary causes when interpreting CVP.
What are common CVC placement sites?
- Internal Jugular (IJ) – Most commonly used.
- Subclavian Vein – Convenient, but increased risk of pneumothorax.
- Femoral Vein – Used in emergencies; higher septic infection risk.
- External Jugular and Basilic Veins – Alternatives if primary sites are not usable.
What is the most common CVC insertion technique?
The Seldinger technique is the most common.
What are the steps in the Seldinger technique?
1- Place the patient in the Trendelenburg position and numb the apex of the triangle formed by the SCM muscle.
2- Using ultrasound guidance, place an 18-gauge needle into the patient’s Internal Jugular vein.
3- Place a guidewire through the needle and into the internal jugular vein.
4- Slide the central venous catheter over the guidewire and confirm placement.
What are the benefits of CVP monitoring?
CVP monitoring provides real-time assessment of right atrial pressure and fluid status.
What are the risks and complications of CVC?
Potential complications include pneumothorax, hemothorax, chylothorax, infection, thrombus or air embolism, hematoma, arrhythmias, cardiac perforation, tamponade, and vascular trauma.
What are contraindications for CVC insertion?
Avoid insertion at sites with infection, tumors, thrombosis, or tricuspid valve vegetations.
What do Cannon A waves indicate?
Cannon A waves appear much larger and can be caused by complete AV block, junctional rhythms, V-Pacing, PVCs, tricuspid stenosis, MI, diastolic dysfunction, and ventricular hypertrophy.
What does an absent A wave indicate?
Absent A waves are caused by atrial fibrillation or V-pacing.
What do large V waves indicate?
Large V waves often indicate tricuspid regurgitation or fluid overload.
What is the normal range for CVP values?
Normal CVP is typically 1–10 mmHg.
What does low CVP suggest?
Low CVP suggests hypovolemia.
What does high CVP indicate?
High CVP may indicate fluid overload, right heart failure, pulmonary hypertension, tricuspid disease, tamponade, or increased thoracic pressure.
When is CVP monitoring useful?
CVP monitoring is beneficial in cardiac surgeries, shock, heart failure, and severe hemodynamic instability.
What is the distance from the right internal jugular vein to the junction of the Venae Cavae and
Right Atrium?
A. 10 cm
B. 15 cm
C. 20 cm
D. 40 cm
Answer: B. 15 cm
Rationale: The distance between the right Internal Jugular vein and the junction of the Venae
Cavae and Right Atrium is 15 cm. 10 cm is the distance from subclavian vein, 20 cm is the
distance from the left internal jugular vein, and 40 cm is the distance from the femoral vein.
What causes the A wave in the CVP waveform?
A. Tricuspid Valve closure
B. Tricuspid Valve opening
C. RA contraction
D. RA passive filling
Answer: C. RA contraction
Rationale: The contraction of the right atrium (RA) causes the central venous pressure to
increase, leading to the A wave in the CVP waveform
What causes the x decline (x and x1) in the CVP waveform? Select 2 of the following answers:
A. Tricuspid Valve opening
B. RA diastole
C. The right atrioventricular septum being pulled toward RV during ventricular systole
D. Bicuspid Valve opening
Answers: B & C. RA diastole and the right atrioventricular septum being pulled toward
RV during ventricular systole.
Rationale: The x decline (x and x1) indicates a decrease in pressure in the CVP waveform caused
by RA diastole (x) and the right atrioventricular septum being pulled toward the RV during
ventricular systole (x1). The tricuspid valve opening does cause a decrease in pressure, but this is
the y decline in the CVP waveform.
Which of the following would cause cannon A waves in the CVP waveform? Select 2 of the
following:
A. V-Pacing (asynchronous)
B. V-Pacing (underlying asystole)
C. Atrial Fibrillation
D. Complete AV Block
Answers: A & D. V-Pacing (asynchronous) and Complete AV Block
Rationale: Cannon A waves appear much larger and are caused by complete AV block, junctional
rhythms, V-Pacing that is asynchronous, PVCs, Tricuspid stenosis, MI, diastolic dysfunction, and
ventricular hypertrophy. Atrial Fibrillation and V-Pacing with underlying asystole would cause
no a waves to be present.
