Ankle–brachial pressure index: Difference between revisions

From Wikipedia, the free encyclopedia
Browse history interactively
← Previous editNext edit →
Content deleted Content added
VisualWikitext
No edit summary
corrected with ref
Line 1: Line 1:
The '''Ankle Brachial Pressure Index''' ('''ABPI'''), known more commonly as an ABI, is the ratio of the [[blood pressure]] in the lower legs to the blood pressure in the arms. Compared to the arm, lower blood pressure in the leg is an [[indication]] of blocked arteries ([[peripheral vascular disease]]). The ABI is calculated by dividing the higher [[Systole (medicine)|systolic]] [[blood pressure]] in either the [[dorsalis pedis]] or [[posterior tibial artery|posterior tibial]] arteries by the higher of the two systolic blood pressures in the arms.
The '''Ankle Brachial Pressure Index''' ('''ABPI'''), known more commonly as an ABI, is the ratio of the [[blood pressure]] in the lower legs to the blood pressure in the arms. Compared to the arm, lower blood pressure in the leg is an [[indication]] of blocked arteries ([[peripheral vascular disease]]). The ABI is calculated by dividing the [[Systole (medicine)|systolic]] [[blood pressure]] at the ankle by the higher of the systolic blood pressures in the arm. <ref name=Review09>{{cite journal|last=Al-Qaisi|first=M|coauthors=Nott, DM, King, DH, Kaddoura, S|title=Ankle brachial pressure index (ABPI): An update for practitioners.|journal=Vascular health and risk management|date=2009|volume=5|pages=833-41|pmid=19851521}}</ref>


==Method==
==Method==

Revision as of 06:07, 20 January 2011

The Ankle Brachial Pressure Index (ABPI), known more commonly as an ABI, is the ratio of the blood pressure in the lower legs to the blood pressure in the arms. Compared to the arm, lower blood pressure in the leg is an indication of blocked arteries (peripheral vascular disease). The ABI is calculated by dividing the systolic blood pressure at the ankle by the higher of the systolic blood pressures in the arm. [1]

Method

A Doppler ultrasound blood flow detector, commonly called Doppler Wand or Doppler probe, and a sphygmomanometer (blood pressure cuff) are usually needed. The blood pressure cuff is inflated proximal to the artery in question. Measured by the doppler wand, the inflation continues until the pulse in the artery ceases. The blood pressure cuff is then slowly deflated. When the artery's pulse is re-detected through the doppler probe the pressure in the cuff at that moment indicates the systolic pressure of that artery.

The higher systolic reading of the left and right arm brachial artery is generally used in the assessment. The pressures in each foot's posterior tibial artery and dorsalis pedis artery are measured with the higher of the two values used as the ABI for that leg.[2]

Where PLeg is the systolic blood pressure of dorsalis pedis or posterior tibial arteries
and PArm is the highest of the left and right arm brachial systolic blood pressure

The ABPI test is a popular tool for the non-invasive assessment of PVD. Studies have shown the sensitivity of ABPI is 90% with a corresponding 98% specificity for detecting hemodynamically significant (Serious) stenosis >50% in major leg arteries, defined by angiogram.[3]

However, ABPI has known issues:

  • ABPI is known to be unreliable on patients with arterial calcification (hardening of the arteries) which results in less or incompressible arteries,[4] as the stiff arteries produce falsely elevated ankle pressure, giving false negatives[5]). This is often found in patients with diabetes melitus[6] (41% of PAD patients have diabetes[7]), renal failure or heavy smokers. ABPI values < 0.9 & >1.3 should be investigated further regardless.
  • Performing ABPI is time consuming.[8]
  • Resting ABPI is insensitive to mild PAD.[9] Treadmill tests (6 minute) are sometimes used to increase ABPI sensitivity,[10] but this is unsuitable for patients who are obese or have co-morbidities such as Aortic aneurysm, and increases assessment duration.
  • Lack of protocol standardisation,[11] which reduces intra-observer reliability.[12]
  • Skilled Operators are required for consistent, accurate results.[13]

However, technology is emerging that allows for the oscillometric calculation of ABI. This is achieved by doing simultaneous readings of blood pressure at the levels of the ankle and upper arm using specially calibrated oscillometric modules. This idea has been pioneered by Uwe DIEGEL and Roland ASMAR in France. The main interest in the introduction of an oscillometric system to measure ABI is that it standardizes the method and makes the measurement of ABI accessible to all doctors.

Interpretation of results

In a normal subject the pressure at the ankle is slightly higher than at the elbow (there is reflection of the pulse pressure from the vascular bed of the feet, whereas at the elbow the artery continues on some distance to the wrist). The ABPI is the ratio of the highest ankle to brachial artery pressure and an ABPI of greater than 0.9 is considered normal (Free from significant PAD).

However, an ABPI value greater than 1.3 is considered abnormal, and suggests calcification of the walls of the arteries and incompressible vessels, reflecting severe peripheral vascular disease.

Provided that there are no other significant conditions affecting the arteries of the leg, the following ABPI ratios can be used to predict the severity of PAD as well as assess the nature and best management of various types of leg ulcers:[2]

ABPI value Interpretation Action Nature of ulcers, if present
above 1.2 Abnormal
Vessel hardening from PVD		 Refer routinely Venous ulcer
use full compression bandaging
1.0 - 1.2 Normal range None
0.9 - 1.0 Acceptable
0.8 - 0.9 Some arterial disease Manage risk factors
0.5 - 0.8 Moderate arterial disease Routine specialist referral Mixed ulcers
use reduced compression bandaging. Claudication may be present at values less than 0.6.[14]
under 0.5 Severe arterial disease Urgent specialist referral Arterial ulcers
no compression bandaging used. Pain at rest may be present at values less than 0.25.[14]

Predictor of atherosclerosis mortality

Studies in 2006 suggests that an abnormal ABPI may be an independent predictor of mortality, as it reflects the burden of atherosclerosis.[15][16]

See also

References

  1. ^ Al-Qaisi, M (2009). "Ankle brachial pressure index (ABPI): An update for practitioners". Vascular health and risk management. 5: 833–41. PMID 19851521. {{cite journal}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ a b Vowden P, Vowden K (2001). "Doppler assessment and ABPI: Interpretation in the management of leg ulceration". Worldwide Wounds. {{cite journal}}: Unknown parameter |month= ignored (help) - describes ABPI procedure, interpretation of results, and notes the somewhat arbitrary selection of "ABPI of 0.8 has become the accepted endpoint for high compression therapy, the trigger for referral for a vascular surgical opinion and the defining upper marker for an ulcer of mixed aetiology"
  3. ^ McDermott MM, Criqui MH, Liu K, Guralnik JM, Greenland P, Martin GJ, Pearce W (2000). "Lower ankle/brachial index, as calculated by averaging the dorsalis pedis and posterior tibial arterial pressures, and association with leg functioning in peripheral arterial disease". JJ Vasc Surg. 32 (6): 1164–71. doi:10.1067/mva.2000.108640. PMID 11107089. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  4. ^ Allison MA, Hiatt WR, Hirsch AT, Coll JR, Criqui MH (2008). "A high ankle-brachial index is associated with increased cardiovascular disease morbidity and lower quality of life". J Am Coll Cardiol. 51 (13): 1292–8. doi:10.1016/j.jacc.2007.11.064. PMID 18371562. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  5. ^ American Diabetes Association (2003). "Peripheral Arterial Disease in People with Diabetes". Diabetes Care. 26 (12): 3333–3341. doi:10.2337/diacare.26.12.3333. PMID 14633825. {{cite journal}}: Unknown parameter |month= ignored (help)
  6. ^ Aboyans V, Ho E, Denenberg JO, Ho LA, Natarajan L, Criqui MH (2008). "The association between elevated ankle systolic pressures and peripheral occlusive arterial disease in diabetic and nondiabetic subjects". J Vasc Surg. 48 (5): 1197–203. doi:10.1016/j.jvs.2008.06.005. PMID 18692981. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  7. ^ Novo S (2002). "Classification, epidemiology, risk factors, and natural history of peripheral arterial disease". Diabetes Obes Metab. 4: S1–6. doi:10.1046/j.1463-1326.2002.0040s20s1.x. PMID 12180352. {{cite journal}}: Unknown parameter |month= ignored (help); Unknown parameter |supplement= ignored (help)
  8. ^ Doubeni CA, Yood RA, Emani S, Gurwitz JH (2006). "Identifying unrecognized peripheral arterial disease among asymptomatic patients in the primary care setting". Angiology. 57 (2): 171–80. doi:10.1177/000331970605700206. PMID 16518524. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  9. ^ Stein R, Hriljac I, Halperin JL, Gustavson SM, Teodorescu V, Olin JW (2006). "Limitation of the resting ankle-brachial index in symptomatic patients with peripheral arterial disease". J Vasc Med. 11 (1): 29–33. doi:10.1191/1358863x06vm663oa. PMID 16669410. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  10. ^ Montgomery PS, Gardner AW, (1998). "The clinical utility of a six-minute walk test in peripheral arterial occlusive disease patients". J Am Geriatr Soc. 46 (6): 706–11. PMID 9625185. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: extra punctuation (link) CS1 maint: multiple names: authors list (link)
  11. ^ Jeelani NU, Braithwaite BD, Tomlin C, MacSweeney ST (2000). "Variation of method for measurement of brachial artery pressure significantly affects ankle-brachial pressure index values". Eur J Vasc Endovasc Surg. 20 (1): 25–8. doi:10.1053/ejvs.2000.1141. PMID 10906293. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  12. ^ Caruana MF, Bradbury AW, Adam DJ (2005). "The validity, reliability, reproducibility and extended utility of ankle to brachial pressure index in current vascular surgical practice". Eur J Vasc Endovasc Surg. 29 (5): 443–51. doi:10.1016/j.ejvs.2005.01.015. PMID 15966081. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  13. ^ Kaiser V, Kester AD, Stoffers HE, Kitslaar PJ, Knottnerus JA (1999). "The influence of experience on the reproducibility of the ankle-brachial systolic pressure ratio in peripheral arterial occlusive disease". Eur J Vasc Endovasc Surg. 18 (1): 25–9. doi:10.1053/ejvs.1999.0843. PMID 10388635. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  14. ^ a b Sawyer, Robert J.; Traves D. Crabtree; Eugene F. Foley (2000). Surgical specialties. Hagerstwon, MD: Lippincott Williams & Wilkins. p. 3. ISBN 0-7817-2771-5.{{cite book}}: CS1 maint: multiple names: authors list (link)
  15. ^ Feringa HH, Bax JJ, van Waning VH; et al. (2006). "The long-term prognostic value of the resting and postexercise ankle-brachial index". Arch. Intern. Med. 166 (5): 529–35. doi:10.1001/archinte.166.5.529. PMID 16534039. {{cite journal}}: Explicit use of et al. in: |author= (help); Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)
  16. ^ Wild SH, Byrne CD, Smith FB, Lee AJ, Fowkes FG (2006). "Low ankle-brachial pressure index predicts increased risk of cardiovascular disease independent of the metabolic syndrome and conventional cardiovascular risk factors in the Edinburgh Artery Study". Diabetes Care. 29 (3): 637–42. doi:10.2337/diacare.29.03.06.dc05-1637. PMID 16505519. {{cite journal}}: Unknown parameter |month= ignored (help)CS1 maint: multiple names: authors list (link)

Ë

Retrieved from "https://en.wikipedia.org/w/index.php?title=Ankle–brachial_pressure_index&oldid=408925320"