Ischemia

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Ischaemia
)
Ischemia
Other namesischaemia, ischæmia
Vascular ischemia of the toes with characteristic cyanosis
Pronunciation
SpecialtyVascular surgery

Ischemia

hypoxia in a part of a body resulting from constriction (such as vasoconstriction, thrombosis, or embolism
).

Ischemia causes not only insufficiency of oxygen, but also reduced availability of nutrients and inadequate removal of metabolic wastes. Ischemia can be partial (poor perfusion) or total blockage. The inadequate delivery of oxygenated blood to the organs must be resolved either by treating the cause of the inadequate delivery or reducing the oxygen demand of the system that needs it. For example, patients with myocardial ischemia have a decreased blood flow to the heart and are prescribed with medications that reduce chronotrophy and ionotrophy to meet the new level of blood delivery supplied by the stenosed vasculature so that it is adequate.

Signs and symptoms

The signs and symptoms of ischemia vary, as they can occur anywhere in the body and depend on the degree to which blood flow is interrupted.

pulseless, paresthesia, paralysis, and poikilothermia.[7]

Without immediate intervention, ischemia may progress quickly to tissue

neuropathy may persist after revascularization and may be permanent.[8]

Cardiac ischemia

Main articles: Coronary ischemia and Coronary artery disease

Cardiac ischemia may be asymptomatic or may cause chest pain, known as

myocardium, receives insufficient blood flow.[9] This most frequently results from atherosclerosis, which is the long-term accumulation of cholesterol-rich plaques in the coronary arteries. In most Western countries, Ischemic heart disease is the most common cause of death in both men and women, and a major cause of hospital admissions.[10][11]

Bowel

Main article: Intestinal ischemia

Both large and small intestines can be affected by ischemia. The blockage of blood flow to the

mesenteric ischemia.[13]

Brain

Main articles:
Ischemic stroke

ischemic stroke is a neurological emergency typically caused by a blood clot blocking blood flow in a vessel in the brain.[14] Chronic ischemia of the brain may result in a form of dementia called vascular dementia.[15] A sudden, brief episode (symptoms lasting only minutes) of ischemia affecting the brain is called a transient ischemic attack (TIA), often called a mini-stroke.[16] TIAs can be a warning of future strokes, with approximately 1/3 of TIA patients having a serious stroke within one year.[16][17]

Limb

Main articles: Acute limb ischaemia and Chronic limb threatening ischemia

Inadequate blood supply to a limb may result in acute limb ischemia or chronic limb threatening ischemia.

Cutaneous

See also: Cyanosis and Gangrene

Reduced blood flow to the skin layers may result in

mottling
or uneven, patchy discoloration of the skin.

Kidney ischemia

Kidney ischemia is a loss of blood flow to the kidney cells. Several physical symptoms include shrinkage of one or both kidneys,[18] renovascular hypertension,[19] acute renal failure,[18] progressive azotemia,[18] and acute pulmonary edema.[18] It is a disease with high mortality rate and high morbidity.[20] Failure to treat could cause chronic kidney disease[21] and a need for renal surgery.[22]

Causes

Ischemia is a

thrombi are prone to develop.[8]

Occlusion

The

peripheral arterial disease (PAD).[8]

Trauma

iatrogenic arterial injury (e.g., after angiography).[8]

Other

An inadequate flow of blood to a part of the body may be caused by any of the following:

Pathophysiology

Native records of contractile activity of the left ventricle of isolated rat heart perfused under Langendorff technique. Curve A - contractile function of the heart is greatly depressed after ischemia-reperfusion. Curve B - a set of short ischemic episodes (ischemic preconditioning) before prolonged ischemia provides functional recovery of contractile activity of the heart at reperfusion.
Main article: Ischemic cascade

Ischemia results in tissue damage in a process known as

enzymes into the cell and surrounding tissues.[25]

Restoration of blood supply to ischemic tissues can cause additional damage known as

cardiac arrhythmias and also accelerates cellular self-destruction. The restored blood flow also exaggerates the inflammation response of damaged tissues, causing white blood cells to destroy damaged cells that may otherwise still be viable.[26]

Treatment

Early treatment is essential to keep the affected organ viable. The treatment options include injection of an

unfractionated heparin has been the traditional agent of choice.[8]

If the condition of the ischemic limb is stabilized with

thrombolytic agents work directly to resolve the clot over a period of 24 to 48 hours.[8]

Direct

anticoagulation to prevent further acute arterial ischemic episodes.[8]

Decrease in body temperature reduces the aerobic metabolic rate of the affected cells, reducing the immediate effects of

hypoxia. Reduction of body temperature also reduces the inflammation response and reperfusion injury. For frostbite injuries, limiting thawing and warming of tissues until warmer temperatures can be sustained may reduce reperfusion injury
.

Ischemic stroke is at times treated with various levels of statin therapy at hospital discharge, followed by home time, in an attempt to lower the risk of adverse events.[27][28]

Society and culture

The Infarct Combat Project (ICP) is an international

ischemic heart diseases through education and research.[29]

Etymology and pronunciation

The word ischemia (/ɪˈskiːmiə/) is from Greek ἴσχαιμος iskhaimos 'staunching blood', from ἴσχω iskhο 'keep back, restrain' and αἷμα haima 'blood'.

See also

References

  1. OED
    2nd edition, 1989.
  2. ^ Entry "ischemia" in Merriam-Webster Online Dictionary.
  3. ^ Merck & Co. Occlusive Peripheral Arterial Disease, The Merck Manual Home Health Handbook website, revised and updated March 2010. Retrieved March 4, 2012.
  4. ^ a b "Chronic Limb-Threatening Ischemia (CLTI) – Vascular Cures". Archived from the original on 2021-10-29. Retrieved 2021-10-27.
  5. ^ Zhai Y, Petrowsky H, Hong JC, et al: Ischaemia-reperfusion injury in liver transplantation—From bench to bedside. Nat Rev Gastroenterol Hepatol 2013; 10:79–89
  6. ^ Perico N, Cattaneo D, Sayegh MH, et al: Delayed graft function in kidney transplantation. Lancet 2004; 364:1814–1827
  7. PMID 28722881
    , retrieved 2021-10-27
  8. ^ a b c d e f g Lewis. S.L (2008). Medical-Surgical Nursing (7th ed.). Vascular disorder. pp. 907–908.
  9. ^ "Myocardial ischemia - Symptoms and causes". Mayo Clinic. Retrieved 2021-10-27.
  10. ISBN 92-4-156371-0
    .
  11. ^ "Coronary Artery Disease". medlineplus.gov. Retrieved 2021-10-27.
  12. ^ "Ischemic colitis - Symptoms and causes". Mayo Clinic. Retrieved 2021-10-27.
  13. ^ "Acute Mesenteric Ischemia - Digestive Disorders". Merck Manuals Consumer Version. Retrieved 2021-10-27.
  14. ^ "Ischemic Stroke". medlineplus.gov. Retrieved 2021-10-27.
  15. PMID 30177276. Archived from the original
    on 2021-08-28. Retrieved 2018-09-07.
  16. ^ a b "Transient Ischemic Attack". medlineplus.gov. Retrieved 2021-10-27.
  17. ^ "What is a TIA". www.stroke.org. Retrieved 2021-10-27.
  18. ^ a b c d "Ischemic renal disease: an emerging cause of chronic renal... : Journal of Hypertension". LWW. Retrieved 2020-12-20.
  19. ^ "Renovascular hypertension: MedlinePlus Medical Encyclopedia". medlineplus.gov. Retrieved 2020-12-20.
  20. S2CID 32234965
    .
  21. PMID 26768243
    .
  22. PMID 21288330
    .
  23. PMID 29261879
    . Retrieved 23 July 2023.
  24. S2CID 18769752
    .
  25. S2CID 2552899
    .
  26. PMID 19751827
    .
  27. PMID 28242176
    .
  28. S2CID 11252336
    .
  29. ^ Infarct Combat Project website; accessed October 26, 2015.

Bibliography

Look up ischemia in Wiktionary, the free dictionary.
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