Biochemical and Metabolic Profiles in Basic Blood Investigations: A Primer for Healthcare Professionals
A biochemical and metabolic profile is a comprehensive assessment of the body’s metabolic function and overall health status. It is typically obtained through basic blood investigations and includes several key components:
Complete Blood Count (CBC)
The CBC provides information about the haematological system and many other organ systems. It includes parameters such as haemoglobin concentration, haematocrit, red cell indices (MCV, MCH, MCHC), white cell count and differential, and platelet count. Abnormalities can indicate a variety of disease states including anaemia, infection, inflammation, bleeding disorder or malignancy.
Electrolytes
Electrolytes (sodium, potassium, chloride, bicarbonate) are crucial for maintaining homeostasis within the body, including acid-base balance, osmotic pressure and function of cells and nerves. Abnormal levels can occur in many conditions including renal disease, acid-base disturbances, endocrine disorders and in patients on certain medications.
Kidney Function Tests
Urea and creatinine are waste products filtered by the kidneys and their levels in the blood can indicate how well the kidneys are functioning. Elevated levels can suggest renal impairment, which can be due to a variety of causes including dehydration, renal obstruction, glomerulonephritis or tubulointerstitial disease.
Liver Function Tests
Liver function tests include alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), total protein, albumin, bilirubin and coagulation tests. These can indicate hepatocellular damage, biliary obstruction, liver synthetic function and haemostasis.
Blood Glucose
Blood glucose is a key test in the diagnosis and monitoring of diabetes. It can also be important in the assessment of patients with infections, sepsis, metabolic disturbances, and various endocrine disorders.
Lipid Profile
The lipid profile (total cholesterol, LDL cholesterol, HDL cholesterol, triglycerides) is used in the assessment of cardiovascular risk. It can also be relevant in patients with pancreatitis, liver disease, and certain endocrine disorders.
Thyroid Function Tests
Thyroid function tests (TFTs) include thyroid-stimulating hormone (TSH) and thyroxine (T4), and sometimes triiodothyronine (T3). TFTs can diagnose hypothyroidism and hyperthyroidism and monitor response to treatment.
Cardiac Enzymes
Cardiac enzymes, such as troponin, are released into the blood when there is damage to the heart muscle, such as a heart attack. Measuring these can help diagnose a heart attack.
These tests provide a wealth of information about a patient’s health and can help diagnose a wide range of conditions. They are a crucial part of preventive healthcare, as many diseases can be treated more effectively if caught early.
For a deeper understanding of blood test reference ranges and to gain insights into what’s considered normal and what’s not, we highly recommend the article “Understanding Blood Test Reference Ranges: What’s Normal and What’s Not” on the Professional Development UK (PDUK) website. This resource provides valuable information that complements the knowledge shared in this piece and can be an excellent guide for healthcare professionals seeking to enhance their understanding of blood investigations. Check it out here.
Healthcare professionals who need to expand their expertise in this field can also find several excellent short courses on the Practitioner Development website. These courses are very popular, so we suggest that you book your place as soon as possible.
References
Bishop, M.L., Fody, E.P. and Schoeff, L., 2018. Clinical chemistry: principles, techniques, and correlations. Wolters Kluwer Health.
Burtis, C.A., Ashwood, E.R. and Bruns, D.E., 2012. Tietz fundamentals of clinical chemistry and molecular diagnostics. Elsevier Health Sciences.
McPherson, R.A. and Pincus, M.R., 2016. Henry’s clinical diagnosis and management by laboratory methods. Elsevier Health Sciences.
Rifai, N., Horvath, A.R. and Wittwer, C.T. eds., 2018. Tietz textbook of clinical chemistry and molecular diagnostics. Elsevier Health Sciences.
Strasinger, S.K., Di Lorenzo, M.S. and Leong, K., 2014. Urinalysis and body fluids. FA Davis.