Leo Buerger published Buerger’s exercises known as Buerger-Allen exercises (BAE) were first published in 1924. Arthur Allen later modified them to make a low-cost effective, and low-risk postural treatment option for individuals with chronic arterial dysfunction. No standard test exists for Buerger’s test because there are numerous changes to the test, including time limits and the position in which the limb is elevated. To evaluate potential ischemia, many practitioners employ a variation of Buerger’s test.
Active free exercises are used as a conservative therapy for peripheral arterial disease because they depend on how gravity affects the smooth muscles in the valves. To increase the circulation in the legs and feet, the exercises comprise elevating the leg from 35 to 90 degrees, then lowering it, and finally relaxing the leg horizontally. Buerger’s test is performed to determine the sufficiency of the leg’s vascular supply. It is accomplished in two stages.
Buerger’s Test Steps
The following steps are necessary for this test:
- Raise each leg to a 45-degree angle while the patient is supine and retain that position for 1-2 minutes.
- Look at the feet’s color.
- Ischemia is indicated by pallor. It occurs when the arterial pressure in the periphery is insufficient to overcome the forces of gravity.
- The lower the vascular flow, the greater the angle at which the legs are lifted to turn pale.
- The patient is then asked to sit up and hang their legs 90 degrees over the edge of the bed.
- Gravity improves blood circulation and restores color to the ischemic leg.
- The color of the skin changes from blue to red as a result of reactive hyperemia brought on by post-hypoxic vasodilatation. This occurs because the blood becomes deoxygenated as it travels through the ischemic tissue.
- Both legs are then evaluated at the same time since the alterations are most visible when one leg has normal circulation.
The change in gravitational position causes the blood vessels to alternately empty and fill as follows:
- Gravity’s effect on the veins during elevation improves the right atrium’s blood flow, which helps to boost cardiac output. Gravity also enhances the inputs to the arterioles when a leg is dependent on gravity, and the ankle movement compels the muscle contractions and strengthens the distal circulation.
Buerger’s Test Positive and Negative
Buerger’s test is simple to perform, easy to interpret, and only takes a few minutes out of a typical patient evaluation. A positive Buerger test increases the likelihood that a limb is significantly ischemic, whereas a negative test does not rule out major ischemia. A positive result shows distal arterial disease.
Buerger’s test is a useful addition to the usual clinical examination of claudicants when deciding on the necessity for further study, but it does not replace objective procedures like Doppler investigations and arteriography. A positive result shows a major artery obstruction and is evidenced by a pale complexion on elevation, best observed on the bottom, with a reactive hyperemic flush over the dorsal side of the foot.
Buerger’s Test Normal Findings
There is no such color shift in a leg with normal perfusion during this maneuver. Various variations to Buerger’s test, such as time limits, the angle of elevation of the limb, and exercise, have been advised; however, there is no consensus upon a standard test. The Buerger’s test is commonly used by doctors to detect probable ischemia, and it is frequently taught to medical students. Buerger’s test is not validated by contemporary investigative methods.
The following results of the Buerger’s test show a deviation from the standard:
- Discrepancies in volume.
- An arterial spasms or occlusion.
- Reduced, feeble, or thready pulsations.
- High cardiac output, hypertension, or circulatory overload.
- Dilated veins in the thigh, lower leg, or in the posterolateral region of the calf from the knee to the ankle.
- Palpable tenderness.
- Forceful foot dorsiflexion accompanied by calf pain (positive Homan’s test).
- A cyanotic (venous insufficiency).
- Arterial insufficiency.
Even when the feet are elevated by ninety degrees and pressure is given for a limited period to blanch the tissues of the toes, the capillaries in the toes of healthy people who are lying down show that there is capillary refill. The feet continue to be pink and perfused. When there is significant ischemia, however, a visible pallor is noticed after thirty seconds of elevation. In these situations, the vascular angle (also known as the “Buerger’s angle”) is found. The foot is in a catastrophic state of ischemia if the leg turns bluish at 20°.