Passive leg raise

Source: Wikipedia, the free encyclopedia.
Not to be confused with Straight leg raise.
Passive leg raise
The five key points for a reliable passive leg raising test
passive leg raising test
SynonymsShock position

Passive leg raise, also known as shock position, is a treatment for

fluid resuscitation in a critically ill person.[1]

It is the position of a person who is lying flat on their back with the legs elevated approximately 8–12 inches (200–300 mm).[2][3][4][5] The purpose of the position is to elevate the legs above the heart in a manner that will help blood flow to the heart.

This test involves raising the legs of a person's (without their active participation), which causes

arterial catheter
).

The maneuver might be reinforced in a clinical setting by moving the patient's bed from a semi-recumbent (half sitting, half laying down) position to a recumbent (laying down) position with the legs raised. This is theorised to cause an additional mobilisation of blood from the

gastrointestinal circulation.[8][9] Direct measurement of cardiac output is the more reliable comparing to the measurement of blood pressure or pulse pressure because of pulse pressure amplification during this procedure. Cardiac output can be measured by arterial pulse contour analysis, echocardiography, esophageal Doppler, or contour analysis of the volume clamp-derived arterial pressure. Any bronchial secretions must be aspirated before performing this test. The legs should not be elevated manually because it may provoke pain, discomfort, or awakening that can cause adrenergic stimulation, giving false readings of cardiac output by increasing heart rate. After the maneuver, the bed should be placed back into semi-recumbent position with cardiac output measured again. The cardiac output should return to the values measured before the initiation of this maneuver. This test can be used to assess fluid responsiveness without any fluid challenge, where the latter can lead to fluid overload.[10] Compression stockings should be removed before the test so that adequate volume of blood will return to the heart during the maneuver.[11] The physiology of assessing fluid responsiveness via passive leg raise requires increasing systemic venous return without altering cardiac function - a form of functional hemodynamic monitoring.[12]

Several studies showed that this measure is a better predictor of response to rapid fluid loading than other tests such as respiratory variation in pulse pressure or echocardiographic markers.[12]

Placing the person in the

vasopressors.[2][3][4][5]

References

  1. ^
    PMID 18214429
    .
  2. ^
    ISBN 978-0-7817-3548-3. Archived from the original
    on 2005-11-07.
  3. ^
    ISBN 978-0-7817-4802-5. Archived from the original
    on 2009-11-29. Retrieved 2018-10-24.
  4. ^ a b "Fundamental Critical Care Support, A standardized curriculum of Critical Care". Society of Critical Care Medicine, Des Plaines, Illinois. Archived from the original on 2007-09-28. Retrieved 2018-10-24.
  5. ^ a b Harrison's Principles of Internal Medicine. Archived from the original on 2012-08-04.
  6. PMID 11948060
    .
  7. PMID 17508202
    .
  8. PMID 18795254
    .
  9. PMID 18467896
    .
  10. PMID 25658678
    .
  11. PMID 26028257
    .
  12. ^
    PMID 27858374
    .

See also
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