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Jun 24, 2024 · A guide to interpreting blood tests, including how to approach blood test interpretation, principles of interpretation, reference ranges, identifying safety critical results and clinical reasoning.
Nov 1, 2020 · Electrodiagnostic testing (traditionally but less accurately called electromyography) consists of 2 distinct but related procedures typically performed together to interrogate the peripheral nervous system: nerve conduction studies and needle electrode examination.
- Matthew R. Ginsberg, John A. Morren, Kerry Levin
- 2020
- Introduction
- Why Check Lfts?
- Reference Ranges
- Alt / Ast
- Alp / GGT
- Bilirubin
- Albumin
- LFT Interpretation Method
- Further Investigations
- References
Liver function tests(LFTs) are among the most commonly ordered blood tests and include: 1. Alanine transaminase (ALT) 2. Aspartate aminotransferase (AST) 3. Alkaline phosphatase (ALP) 4. Gamma-glutamyltransferase (GGT) 5. Bilirubin 6. Albumin This guide gives an overview of LFTsand a structured approachto their interpretation.
LFTs can be requested for multiple reasons:1 1. To investigate patients with suspected liver disease 2. To monitor patients with confirmed liver disease (e.g. cirrhosis) 3. To monitor the effects of potentially hepatotoxic medications LFTs are often sent as part of a ‘baseline’ screening panel of investigations for patients presenting with a wide r...
Table 1. Liver function test reference ranges These reference ranges can varybetween laboratories, so always check local guidelines.
Alanine aminotransferase (ALT) andaspartate aminotransferase(AST) are enzymes found within liver cells at high concentrations. Raised ALT / AST levels in the blood occur in pathologies that cause liver cell (hepatocyte) inflammation or damage. Therefore, raised ALT / AST levels are a marker of hepatocellular injury. Common causes of hepatocellular ...
Serumalkaline phosphatase (ALP) is derived from biliary epithelial cells (cells lining the biliary tract) and bones.3 Raised ALP levels can therefore be caused by cholestasis orbone disease. Gamma-glutamyltransferase (GGT) is found in hepatocytes and also biliary epithelial cells.2 It is a non-specific buthighly sensitivemarker of liver damage and ...
Bilirubin is a waste product of haemoglobin breakdown. It is predominantly metabolised and excreted by the liver. Raised levels of bilirubin in the blood will lead to a yellowing of the skin, known as jaundice. Hint: Jaundice is usually absent until the bilirubin level exceeds 50 micromol/L.
Albumin is synthesised in the liver and helps to bind water, cations, fatty acids and bilirubin. It also plays a crucial role in maintaining the oncotic pressure of blood. Albumin is used as a non-specific marker of the synthetic functionof the liver. Albumin levels can fall due to: 1. Decreased albumin production: malnutrition, severe liver diseas...
Determine the pattern of LFT derangement
The pattern of ALT to ALP risecan indicate whether the pathology is primarily cholestatic or hepatocellular: 1. A greater than 10-fold increase in ALT and a less than 3-fold increase in ALP suggests a predominantly hepatocellular injury 2. Aless than 10-fold increase in ALT and a more than 3-fold increase in ALP suggests cholestasis 3. It is possible to have a mixed picture involving both hepatocellular injury and cholestasis An isolated ALP rise without a GGT rise should raise your suspicion...
Assess the bilirubin
Bilirubin is a marker of severity in acute cholestatic pathology and acute hepatocellular liver injuries. The presence of clinical jaundice is generally an indication of severe diseaserequiring urgent referral to secondary care for prompt assessment and management. An isolated bilirubin risewithout further LFT derangement suggests pre-hepatic jaundice or Gilbert’s disease.
Assess synthetic function
In severe hepatocellular injuries, the synthetic functions of the liver also become impaired, leading to decreased albumin. Coagulation studiesmay show prolonged prothrombin time, and in very severe disease, serum blood glucose may be low due to impaired gluconeogenesis. Hint: In chronic hepatocellular pathology (e.g. cirrhosis), the ALT / AST may return to within the normal range, however synthetic function of the liver can be markedly impaired.
Once the pattern of LFT derangement has been established, it is essential to determine the underlying cause. If cholestasis is suspected, an ultrasound should be arranged to assess the biliary tree for a potential site/cause of biliary obstruction. If hepatocellular injury is suspected, a liver ultrasound is generally arranged to assess for any str...
Coates P. Liver Function Tests. Australian Family Physician. March 2011. Available at [LINK].UpToDate. Approach to the patient with abnormal liver biochemical and function tests. May 2023. Available at [LINK].Patient.info Professional. Abnormal Liver Function Tests. July 2019. Available at [LINK].UpToDate. Bilirubin metabolism. October 2022. Available at [LINK].Oct 2, 2019 · The main reasons for performing a coagulation screen are: To confirm a suspected coagulopathy. To monitor the coagulation status of a patient on long/short term anti-coagulants. To assess a patients coagulation status prior to surgery. To assess the synthetic function of the liver.
Sep 12, 2024 · mL: milliliter. mmol/L: millimoles per liter. ng/mL: nanograms per milliliter. pg (picograms): one-trillionth of a gram. People worried about their health can also use the free Ada app to carry out a symptom assessment. Or find out more about how our symptom checker works before you try it for yourself.
Aug 15, 2023 · Thromboelastography (TEG) is a viscoelastic hemostatic assay that measures the global viscoelastic properties of whole blood clot formation under low shear stress. TEG shows the interaction of platelets with the coagulation cascade (aggregation, clot strengthening, fibrin cross-linking and fibrinolysis)
Oct 28, 2011 · This review analyses the most commonly used tests and signs for knee examination, outlining the correct way to perform the test, the correct interpretation of a positive test and the best management for evaluating an injured knee both in the acute and delayed timing. Peer Review reports. Introduction.
