לחץ ורידי ג'וגולרי

What is jugular venous pressure?

Jugular venous pressure (JVP) provides an indirect measure of central venous pressure. The internal jugular vein connects to the right atrium without any intervening valves - thus acting as a column for the blood in the right atrium. The JVP consists of certain waveforms and abnormalities of these can help to diagnose certain conditions¹ . Unfortunately, detection of these abnormalities and even the JVP itself, can be difficult and has also been superseded by other diagnostic methods.

How to examine jugular venous pressure¹

• Use the right internal jugular vein (IJV).

• The patient should be at a 45° angle.

• The patient's head should be turned slightly to the left.

• If possible, have a tangential light source that shines obliquely from the left.

• Locate the surface markings of the IJV - this runs from the medial end of the clavicle to the ear lobe, under the medial aspect of the sternocleidomastoid.

• Locate the JVP - look for the double waveform pulsation (palpating the contralateral carotid pulse will help).

• Measure the level of the JVP by measuring the vertical distance between the sternal angle and the top of the JVP. Measure the height - usually less than 3 cm.

Waveforms of jugular venous pressure

Jugular venous pulse

© By Ecgtocardiology, via Wikimedia Commons

The a and v waves can be identified by timing the double waveform with the opposite carotid pulse. The a wave will occur just before the pulse and the v wave occurs towards the end of the pulse. Distinguishing the c wave, x and y descents is an almost impossible task.

How to differentiate a jugular venous pulse from the carotid pulse

Hepatojugular reflux (abdominojugular reflux sign)²

• This can help to confirm that the pulsation is caused by the JVP.

• In the classic test for hepatojugular reflux, firm pressure is applied to the right upper quadrant using the palm of the hand. It has been realised that pressure anywhere over the abdomen will produce the same result (abdominojugular reflux sign). Pressure over the peri-umbilical region is the usual method and may be more appropriate in patients with a tender liver.

• A transient increase in the JVP will be seen in normal patients.

• There may be a delayed recovery back to baseline which is more marked in right ventricular failure.

Raised jugular venous pressure causes

• Heart failure.

• Constrictive pericarditis (JVP increases on inspiration - called Kussmaul's sign).

• Cardiac tamponade.

• Fluid overload - eg, renal disease.

• Superior vena cava obstruction (no pulsation).

Jugular venous pressure abnormalities^{1 3}

Prognostic use of jugular venous pressure

Elevated JVP in patients with heart failure is associated with an increased risk of hospital admission, death and subsequent hospitalisation for heart failure⁴ . Therefore, appreciation of this sign can be clinically helpful.