CLINICAL LABORATORY TESTS USED IN THE EVALUATION OF DISEASE STATES AND INTERPRETATION OF TEST RESULTS OF SOME COMMONLY ORDERED LAB TESTS.pptx

It contains information about hematology, Renal function test, Pulmonary Function test, Thyroid Function test, Liver Function test

1. CLINICAL LABORATORY TESTS USED IN THE EVALUATION OF DISEASE STATES AND INTERPRETATION OF TEST RESULTS OF SOME COMMONLY ORDERED LAB TESTS

2. HAEMATOLOGICAL PARAMETERS

3. HAEMATOLOGICAL TEST A haematological test, also known as a blood test, is a diagnostic tool used to evaluate the components of blood . These tests help identify various conditions, including infections, anaemia, clotting disorders, and other systemic diseases .

4. Different tests in the evaluation of haematological disorders. Complete Blood Count (CBC): This test measures key blood components, including: 1. Red Blood Cell ( erythrocytes ) : A red blood cell (RBC) count is a blood test that tells you how many red blood cells you have. Normal range : 4.5 to 6.0 million cells per microliter (cells/ μL (or) x106/mm 3) for Men, 3.8 to 5.4 million cells per microliter (cells/ μL (or) x106/mm 3 ) for women. Abnormalities: Low: Anemia , blood loss, nutritional deficiencies. High: Polycythemia (increased level of HCT/ Hb ), dehydration.

5. 2. Haemoglobin ( Hb ) : it provide direct indication of the oxygen-transport capacity of the blood. It is also known as Oxygen-carrying protein. Normal range : 13 to 18 g/ dL for men 11.5 to 16.5 g/ dL for women. Low : Anaemia. High: Dehydration, smoking 3. Hematocrit , packed cell volume (HCT/PCV) : it is the percentage volume of blood that is composed of erythrocytes; it is also known as packed cell volume. (Percentage of RBCs in blood) Normal range : 47 to 62% for men and 40 to 54 % for women.

6. 4. White Blood Cell ( WBC/ TOTAL COUNT) : White blood cells, also known as leukocytes , are responsible for protecting your body from infection. As your white blood cells travel through your bloodstream and tissues, they locate the site of an infection and act as an army general to notify other white blood cells of their location to help defend your body from an attack of an unknown organism. Normal Range :- 4,000-11,000/μ L/// (x 103 cells/ mm 3) High : Infections, inflammation, leukemia . Low : Bone marrow suppression, viral infections

7. Differential Count (DC) A differential count, often measures the percentage of different types of white blood cells (WBCs) in the blood. It helps assess immune function, detect infections, and diagnose blood disorders like leukemia or allergies. 5. Neutrophils / Polymorphs (34-75%) Function : Fight bacterial and fungal infections via phagocytosis . High ( Neutrophilia ): Bacterial infections, Inflammation (e.g., appendicitis, arthritis). Stress, smoking, corticosteroid use. Low ( Neutropenia ): Viral infections, Bone marrow suppression (e.g., chemotherapy, aplastic anemia )

8. 6. Lymphocytes (20-45%) Key players in immune response; include B-cells, T-cells, and natural killer (NK) cells. High ( Lymphocytosis ): Viral infections (e.g., hepatitis). Chronic infections (e.g., tuberculosis). Low ( Lymphopenia ): Immunodeficiency (e.g., HIV/AIDS). Corticosteroid use chemotherapy.

9. 7. Eosinophils (1-6%) Fight parasitic infections ; involved in allergic reactions. High ( Eosinophilia ): Parasitic infections. Allergies (e.g., asthma, hay fever). Autoimmune diseases (e.g., eosinophilic esophagitis ). – Esophagus inflamation Low ( Eosinopenia ): Stress. Corticosteroid therapy

10. 8. Monocytes (2-11%) Remove debris and pathogens; precursors to macrophages. High ( Monocytosis ): Chronic infections (e.g., tuberculosis, syphilis). Inflammatory conditions (e.g., Crohn's disease). Leukemia . Low ( Monocytopenia ): Bone marrow suppression. Severe infections (sepsis)

11. 9. Basophils ( < 1%) Release histamine during allergic reactions; mediate inflammation. High ( Basophilia ): Allergic reactions. Chronic inflammation (e.g., ulcerative colitis). Leukemia . Low ( Basopenia ): Acute infections. Stress, hyperthyroidism.

12. 10. ERYTHROCYTE SEDIMENTATION RATE(ESR): Normal range: male: 0-15mm, female: 0-20mm Numerous physiological and disease states are associated with the rate at which erythrocytes settle from blood, termed the Erythrocyte Sedimentation Rate (ESR) { Measures inflammation by assessing the rate RBCs settle in a tube .} High ESR: Infections, autoimmune diseases (e.g., lupus), cancers. Low ESR: Polycythemia , sickle cell anaemia.

13. 11. Platelet Count : Normal Range; About 1,50,000 to 4,50,000 cells/ μL . Platelets, or Thrombocytes , are small, colourless cell fragments in our blood that form clots and stop or prevent bleeding. Platelets are made in our bone marrow, the sponge-like tissue inside our bones. Low: Thrombocytopenia (bleeding risk). High: Thrombocytosis (clotting risk).

14. 12.Mean Corpuscular Volume (MCV): (Size of RBCs) Normal Range : 76-97 fl MCV blood test measures the average size of your red blood cells It can be calculated by dividing the heamatocrit by the RBC count but is ordinarily determined by averaging the directly measured size of thousands of red blood cells ( HCT or PCV / RBC x 100) 13. Mean corpuscular Haemoglobin (MCH): (Haemoglobin per RBC.) Normal Range: 26-32pg/cell Mean corpuscular haemoglobin (MCH) is the amount of haemoglobin per RBC . It is calculated by dividing the Hb by the RBC count. ( Hb / RBC x 100) 14. Mean corpuscular Haemoglobin concentration (MCHC): Normal Range: 32-36 g/dl It indicates the average concentration of haemoglobin in a given volume of red blood cells (RBCs). MCHC is the haemoglobin is divided by the heamatocrit . ( Hb /HCT x 100)

15. Iron Studies Tests : Serum Iron : Amount of iron in blood. Normal: 60-170 μ g/ dL . Low: Iron deficiency. High: Hemochromatosis ./ excess iron/ iron overload Ferritin : Iron storage protein. Normal: 12-300 ng / mL (men),12-150 ng / mL (women). Low: Iron deficiency. High: Chronic disease, iron overload. TIBC: Capacity of blood to bind iron. Normal: 240-450 μ g/ dL . High: Iron deficiency. Low: Iron overload

16. Prothrombin Time (PT) and International Normalized Ratio (INR) Purpose: Measures how long blood takes to clot. Normal PT : 9-12 seconds. Normal INR : 0.9-1.3. High PT/INR : Liver disease, anticoagulant use, vitamin K deficiency. Low PT/INR : Risk of clotting. 2. Activated Partial Thromboplastin Time ( aPTT ) Purpose: Evaluates clotting factors in the intrinsic pathway. Normal Range: 15-45 seconds. High aPTT : Hemophilia , heparin therapy. Low aPTT : Hypercoagulable states.

17. Microcytic Anaemia Microcytic anaemia or anaemia with abnormally small erythrocytes is typically caused by iron deficiency . Decreased MCV is a late indicator of the deficiency. Daily requirements are approximately 1 mg of elemental iron for each 1 mL of RBCs produced, so daily requirements are approximately 20-25 mg for erythropoeisis . Most iron needed within the body is obtained by recycling metabolized haemoglobin. RBCs have a lifespan of approximately 120 days. When old or damaged erythrocytes are taken up by macrophages in the liver, spleen, and bone marrow, the haemoglobin molecule is broken down and iron is extracted and stored with proteins . Only about 5% of the daily requirement (1 mg) is newly absorbed to compensate for losses due to faecal and urinary excretion, sweat, and desquamated skin.

18. Other causes of iron deficiency include; Blood loss due to excessive menstrual discharge Peptic ulcer disease Gastritis due to the ingestion of alcohol, aspirin, and non steroidal anti-inflammatory drugs (NSAIDs)" Bacterial overgrowth of the small bowel Inflammatory bowel disease Occult bleeding from GI carcinoma Mean Corpuscular Volume (MCV): Typically less than 76 ( fL ). Hemoglobin and Hematocrit: Reduced levels due to smaller cell size. Peripheral Blood Smear: May show hypochromic (pale) and microcytic cells.

19. Macrocytic Anaemia : Macrocytic anaemia is a lowered haemoglobin value characterized by abnormally enlarged erythrocytes. The two most common causes are vitamin B12 deficiencies , Drugs that cause macrocytic anaemia mainly interfere with proper utilization, absorption, and metabolism of these vitamins. Vitamin B12 Deficiency Vitamin B12 is also known as cobalamin . The normal daily requirement of vitamin B12 is 2-5 mcg . It is stored primarily in the liver , which contains approximately 1 mcg of vitamin of liver tissue. Overall, the body has B12 stores of approximately 2-5 mg. Therefore, if vitamin B12 absorption suddenly ceased in a patient with normal liver stores, several years would pass before any abnormalities occurred due to vitamin deficiency.

20. The absorption of vitamin B, is complex, and the mechanisms responsible are still being defined. Cobalamin (vitamin B) is ingested in meats, eggs, and dairy products Mean Corpuscular Volume (MCV): Usually greater than 97 fL. Hemoglobin and Hematocrit: Can be lower due to fewer but larger cells. Peripheral Blood Smear: May show hyperchromic (larger and darker) and macrocytic cells.

21. LIVER FUNCTION TESTS { LFT }

22. A Liver Function Test (LFT) is a group of blood tests used to assess the health and functionality of the liver. These tests measure various enzymes, proteins, and substances in your blood that are produced, processed, or excreted by the liver. They help detect liver damage, disease, or dysfunction

23. 1. Alanine Aminotransferase ( ALT): SGPT ( Serum glutamic pyruvic transaminase ) Normal Range: male: < 50U/L, Female: <35 U/L ALT is an enzyme mainly found in liver cells. Elevated ALT levels indicate liver cell damage or inflammation, often seen in conditions like hepatitis or fatty liver disease . 2. Aspartate Aminotransferase ( AST): SGOT serum glutamic-oxaloacetic transaminase Normal Range: male: < 50U/L, Female: <35 U/L AST is an enzyme found in the liver, heart, muscles, and other tissues. Elevated AST levels can suggest liver damage or injury , but they are less specific to the liver compared to ALT.

24. 3. Alkaline Phosphatase (ALP): Normal Range: 30-120 IU/L ALP is an enzyme present in liver cells, bones, and other tissues. Elevated ALP levels can indicate liver or bone disorders, and it's particularly useful in detecting conditions like obstructive jaundice. 4. Gamma- Glutamyl Transferase (GGT): Normal Range: 0-30 U/L GGT is an enzyme found in the liver and biliary system. Elevated GGT levels are associated with liver and bile duct disorders, alcohol use, and certain medications.

25. 5. Total Bilirubin: Normal Range: 0.3-1.2 mg/ dL Bilirubin is a waste product from the breakdown of red blood cells.(RBC) Elevated levels can cause jaundice and indicate liver dysfunction or other issues affecting bilirubin metabolism. 6. Direct (Conjugated) Bilirubin: Normal Range: Less than 0.2 mg/ dL Direct bilirubin represents the fraction of bilirubin that has been processed by the liver and excreted into bile . Elevated levels can suggest problems with bile flow. 7. Indirect ( Unconjugated ) Bilirubin: Normal Range: 0.2-0.8 mg/ dL Indirect bilirubin is the unconjugated form before it undergoes liver processing. Some bilirubin is bound to a certain protein (albumin) in the blood. Elevated levels may indicate increased breakdown of red blood cells or other issues affecting bilirubin metabolism.

26. 8. Albumin: Normal Range: 3.5-5.0 g/ dL Albumin is a protein produced by the liver that helps maintain blood volume and transport substances . Low levels can indicate liver dysfunction or nutritional issues . 9. Total Protein: Normal Range: 6.0-8.3 g/ dL Total protein measures the sum of albumin and other proteins in the blood. Changes in total protein levels can reflect liver or kidney disease, or nutritional status.

27. 9. Prothrombin Time (PT) and International Normalized Ratio (INR) Purpose: Measures how long blood takes to clot. Normal PT : 9-12 seconds. Normal INR : 0.9-1.3. High PT/INR : Liver disease, anticoagulant use, vitamin K deficiency. Low PT/INR : Risk of clotting. 10. Activated Partial Thromboplastin Time ( aPTT ) Purpose: Evaluates clotting factors in the intrinsic pathway. Normal Range: 15-45 seconds. High aPTT : Hemophilia , heparin therapy. Low aPTT : Hypercoagulable states.

28. RENAL FUNCTION TESTS { RFT }

29. Renal function tests are essential laboratory tests that provide insights into how well the kidneys are functioning . The kidneys play a vital role in filtering waste products, maintaining electrolyte balance, and regulating fluid levels in the body. Abnormal results from renal function tests can indicate various kidney conditions and other health issues. Here are the clinical implications of commonly ordered renal function tests:

30. SERUM CREATININE: Normal Range: 0.72-1.18 mg/ dL for Males 0.55 – 1.02 mg/ dL for females Creatinine is a waste product generated from muscle metabolism and is normally filtered by the kidneys. Clinical Implications: Increased levels: Acute kidney injury (AKI),Chronic kidney disease (CKD),Dehydration or shock Obstruction (e.g., kidney stones or tumors ) Decreased levels: Low muscle mass, Advanced liver disease

31. 2. Blood Urea Nitrogen (BUN): Normal Range: 8-24 mg/ dL BUN is a by-product of protein metabolism that the kidneys eliminate. Clinical Implications: Increased levels: Dehydration, AKI or CKD, High protein intake, Gastrointestinal bleeding Decreased levels: Low protein intake, Severe liver disease

32. Clinical Implications: Decreased GFR: Indicator of CKD (classified into stages based on GFR), Acute kidney injury, Age-related decline in renal function

33. Glomerular Filtration Rate (GFR): Normal Range: 90 - 120 mL /min/1.73 m² (varies with age) GFR estimates the rate at which the kidneys filter blood . A decreased GFR indicates reduced kidney function, which can be due to various conditions, including CKD. GFR is used to stage CKD and determine the severity of kidney impairment. Cockcroft- Gault equation is often used as a method of estimating GFR (although it was developed as a method predicting creatinine clearance) from knowledge of serum creatinine, age and weight.

34. Chronic Kidney Disease (CKD) is classified into five stages based on the Glomerular Filtration Rate (GFR), a measure of kidney function. Stage 1: Kidney Damage with Normal or Increased GFR GFR: ≥ 90 mL /min/1.73 m² Kidneys function normally, but there may be structural damage (e.g., protein in urine, abnormalities in imaging). Management: Control risk factors (e.g., blood pressure, blood sugar), monitor kidney health

35. Stage 2: Mild Reduction in GFR GFR: 60–89 mL /min/1.73 m² Mild loss of kidney function with evidence of kidney damage. Management: Monitor progression, manage co morbidities, and lifestyle modifications. Stage 3 : Moderate Reduction in GFR GFR: 30–59 mL /min/1.73 m² Stage 3a : GFR 45–59 mL /min/1.73 m² Stage 3b : GFR 30–44 mL /min/1.73 m² Kidney function is moderately reduced, and symptoms such as fatigue, swelling, and changes in urination may begin. Management: Address complications (e.g., anemia , bone disease), manage blood pressure and diabetes

36. Stage 4 : Severe Reduction in GFR GFR: 15–29 mL /min/1.73 m² Severe kidney function decline; symptoms such as swelling, nausea, and itching are more pronounced. Management: Prepare for renal replacement therapy (dialysis or transplant), continue strict management of risk factors. Stage 5: Kidney Failure (End-Stage Renal Disease - ESRD) GFR: < 15 mL /min/1.73 m² Kidneys can no longer meet the body’s needs; dialysis or transplant is required. Management: Initiate renal replacement therapy, manage symptoms and quality of life.

37. Serum Electrolytes (Sodium, Potassium, Calcium, Phosphate): Kidneys play a role in maintaining electrolyte balance. Abnormal electrolyte levels can result from kidney dysfunction and affect various bodily functions, including nerve transmission, muscle contraction, and bone health. Sodium: 133-152 mmol /L Potassium: 3.5-5.5 mmol /L Calcium: 8.8-10.2 mmol /L Phosphate: 2.4-4.5 mmol /L Abnormal electrolyte levels can indicate kidney dysfunction, affecting nerve function, muscle contraction, and bone health. Electrolyte imbalances require prompt attention.

38. THYROID FUNCTION TEST

39. Why would I need thyroid function tests? Thyroid gland has an important role in controlling your  metabolism . Hormones made by your thyroid gland influence your: Heart rate Blood pressure Body temperature Weight A Thyroid function test (TFT) commonly refers to the appraise of thyroid stimulating hormone (TSH) and circulating thyroid hormones in serum to assess the ability of the thyroid gland to produce and regulate thyroid hormone production

40. Production of thyroid hormone by the thyroid gland is controlled by the pituitary , another endocrine gland in the brain. The pituitary releases Thyroid Stimulating Hormone (abbreviated TSH) into the blood to stimulate the thyroid to make more thyroid hormone. The amount of TSH that the pituitary sends into the bloodstream depends on the amount of thyroid hormone in the body . If the pituitary senses low thyroid hormone, then it produces more TSH to tell the thyroid gland to produce more. Once the T4 in the bloodstream goes above a certain level, the pituitary’s production of TSH is shut off. In this way, the pituitary senses and controls thyroid gland production of thyroid hormone. Endocrinologists use a combination of thyroid hormone and TSH testing to understand thyroid hormone levels in the body.

41. Thyroid hormone exists in two main forms: Thyroxine (T4 ) and Triiodothyronine (T3). T4 is the primary form of thyroid hormone circulating in the blood ( about 95%). To exert its effects, T4 is converted to T3 by the removal of an iodine atom; this occurs mainly in the liver and in certain tissues where T3 acts, such as in the brain. T3 normally accounts for about 5% of thyroid hormone circulating in the blood. Most thyroid hormone in the blood is bound by protein , while only a small fraction is " free" to enter tissues and have a biologic effec t. Thyroid tests may measure total (protein bound and free) or free hormone levels.

42. Signs Of  Hyperthyroidism Sensitivity to heat Weight loss Fast heartbeat Nervousness Sweating Signs Of  Hypothyroidism   Tiredness Weakness Weight gain Muscle aches Constipation Slow heart rate Sensitivity to cold

43. Thyroid Stimulating Hormone [TSH]:- A high TSH level indicates that the thyroid gland is not making enough thyroid hormone ( hypothyroidism ). On the other hand, a low TSH level usually indicates that the thyroid is producing too much thyroid hormone ( hyperthyroidism ). Occasionally, a low TSH may result from an abnormality in the pituitary gland, which prevents it from making enough TSH to stimulate the thyroid (hypothyroidism). In most healthy individuals, a normal TSH value means that the thyroid is functioning properly. Normal value: 0.4- 4.0 mIU / mL Increased: - Thyrotropin producing tumor , hypothyroidism, Hashimoto's Syndrome. Decreased -Hyperthyroidism, Grave's disease, Euthyroid sick syndrome.

44. T4 Tests A  Total T4 { TT4}  test measures the bound and free thyroxine (T4) hormone in the blood. A  Free T4[ FT4]  measures what is not bound and able to freely enter and affect the body tissues . What does it mean if T4 levels are abnormal? Importantly, Total T4 levels are affected by medications and medical conditions that change thyroid hormone binding proteins. Estrogen , oral contraceptive pills, pregnancy, liver disease, and hepatitis C virus infection are common causes of  increased  thyroid hormone binding proteins and will result in a high Total T4. Testosterone or androgens and anabolic steroids are common causes of  decreased   thyroid hormone binding proteins and will result in a low Total T4

45. Thyroxine (T4) Normal: 4-12-5 mcg/ dL Increased: ↑ TBG( Thyroxine Binding Globulin) Hyperthyroidism Decreased: hypothyroidism, decreased TBG FT4 Normal:- 0.8-1.8ng/ dL Increased: Grave's disease drugs like amiodarone , aspirin, Furosemide Decreased: All kinds/degree of hypothyroidism TT4- [Total thyroxine ]. Normal : 1.4-12.5 mcg/ dL Increased - Hyperthyroidism, thyrotoxicosis (release excess amount of thyroid hormone in short period ), Hepatitis ( inflamation of the liver) Decreased: Hypothyroidism, myoedema , drugs like Salicylates Is testosterone.

46. T3Tests T3 tests measure Triiodothyronine (T3) levels in the blood. A Total T3 [ TT3] test measures the bound and free fractions of Triiodothyronine . T3 tests can be used to support a diagnosis of hyperthyroidism and can determine the severity . In some thyroid diseases, the proportions of T3 and T4 in the blood change and can provide diagnostic information. A pattern of excess production of T3  vs  T4 is characteristic of Graves’ disease. On the other hand, medications like steroids and amiodarone , and severe illness can decrease the amount of thyroid hormone the body converts from T4 to T3 (active form) resulting in a lower proportion of T3

47. T3 – [ Thyronine ] Normal – 79-165ng/ dL Increased: Anxiety, sweating, irritability, Hyperactivity, Decreased: Thyroiditis ( inflamation of thyroid) TT3 [Total tri- iodo thyronine ] Normal- 80-220ng/ dL Increased- Hyperthyroidism acute thyroiditis Decreased- Hypothyroidism, Hepatic & renal disease Drugs :- Amiodarone , anabolic steroid & corticosteroids FT3 (Free tritodo thyronine ] Normal- 4-7.4 pmol /L Increased: Hyperthyroidism, Thyrotoxicosis Decreased: Graves disease, Hypothyroidism.

48. IMPORTANCE OF TFT A thyroid function test is a critical diagnostic tool used to evaluate how well your thyroid gland is working. The thyroid gland produces hormones that regulate essential body processes, including metabolism, energy levels, heart rate, and temperature regulation . Here’s why thyroid function tests are important

49. 1. Diagnosing Thyroid Disorders Hypothyroidism: Low levels of thyroid hormones can lead to fatigue, weight gain, depression, and cold sensitivity. Hyperthyroidism: Excessive thyroid hormones can cause weight loss, anxiety, rapid heartbeat, and heat intolerance. 2. Monitoring Treatment For individuals on medication for thyroid disorders, these tests help assess the effectiveness of treatment and guide dosage adjustments

50. 3. Assessing Overall Health Thyroid dysfunction can affect other body systems, including the heart, reproductive system, and mental health. Testing ensures these risks are managed proactively. 4. Identifying Underlying Causes A thyroid function test can help detect autoimmune conditions like Hashimoto's thyroiditis or Graves' disease, which affect thyroid performance. 5. During Pregnancy Thyroid hormones are crucial for fetal development. Regular monitoring in pregnant women can prevent complications such as preeclampsia, preterm birth, or developmental delays in the baby .

51. ELECTROLYTES

52. Electrolytes are critical for the body’s homeostasis and play key roles in maintaining fluid balance, nerve transmission, and muscle function. Imbalances in electrolytes can have profound clinical consequences, making their measurement and correction essential in medical practice. Electrolytes are minerals in the body that have an electric charge . Its present in blood, urine and body fluids Maintenance of electrolyte balance in the body is essential for normal function of our cells and organs.

53. TYPES OF ELECTROLYTES CATION SODIUM POTASSIUM CALCIUM MAGNESIUM ANIONS CHLORIDE PHOSPHATE

54. Electrolytes regulate Nerve and muscle function Body's hydration Blood pH Blood pressure Rebuilding of damaged tissues Water balance

55. Sodium (Na⁺) Normal Range : 133–152 mEq /L or mmol /L Functions : Regulates extracellular fluid (ECF) volume, Maintains osmotic balance and blood pressure, Essential for nerve impulse transmission and muscle contractions. Clinical Significance: Hyponatremia (<133 mEq /L): Causes: Excess fluid intake, heart failure, liver cirrhosis. Symptoms : Nausea, headache, confusion, seizures, and coma. Drugs:- Diurectics , Heparin and NSAIDS Hypernatremia (>152 mEq /L): Causes : Dehydration, diabetes insipidus , Symptoms: weakness, irritability, lethargy, seizures Drugs:- corticosteroids, Sodium bicarbonate, lactulose .

56. Potassium (K⁺) Normal Range : 3.5–5.5 mEq /L Functions: Essential for muscle contraction, especially cardiac muscles. Involved in acid-base balance, osmotic pressure. It is the principle ion in the ICF and primary buffer within the cell. Clinical Significance: Hypokalemia (<3.5 mEq /L): Causes: diarrhoea, vomiting, alkalosis ( too much alkali) Symptoms: Muscle weakness, cramps, paralysis. Drugs: Gentamycin , aldosterone , corticosteroids, Diuretics, insulin. Hyperkalemia (>5.0 mEq /L): Causes: Renal failure, acidosis(too much acid) Symptoms: Fatigue, muscle weakness, cardiac arrhythmias Drugs: ACE inhibitors, Digoxin , Heparin, potassium-sparing diuretics

57. Calcium (Ca²⁺) Normal Range: 8.8–10.2 mg/ dL Functions : Structural component of bones and teeth. Muscle contraction and neurotransmitter release. Blood clotting (cofactor for clotting factors). Regulates enzyme activity. Clinical Significance: Hypocalcemia (<8.8 mg/ dL ): Causes: Hypoparathyroidism , vitamin D deficiency, chronic kidney disease, pancreatitis. Symptoms: Paresthesia (abnormal sensation), muscle spasms, tetany (intermittent muscular spasms), seizures Drugs: Phneytoin , Furosemide , Phenobarbitol Hypercalcemia (>10.8 mg/ dL ): Causes: Hyperparathyroidism, malignancy, excessive vitamin D or calcium intake. Symptoms: Renal Stones, Bone Pain, Abdominal Pain, Confusion Drugs: Hydrochlorothiazide, Diuretics, Lithium

58. Key Regulators of Calcium Metabolism Parathyroid Hormone (PTH): Released by the parathyroid glands in response to low blood calcium. Functions: Increases calcium resorption from bones. Enhances calcium reabsorption in the kidneys. Stimulates activation of vitamin D (to increase calcium absorption in the gut). 2. Vitamin D ( Calcitriol ): Enhances calcium absorption in the intestines. Promotes bone mineralization and calcium reabsorption in the kidneys. 3. Calcitonin : Secreted by the thyroid gland in response to high blood calcium. Reduces calcium levels by inhibiting bone resorption and increasing calcium excretion. 4. Phosphorus: Interacts closely with calcium. An imbalance in phosphorus levels can affect calcium metabolism.

59. Magnesium (Mg²⁺) Normal Range : 1.7–2.2 mg/ dL Functions : Regulates neuromuscular excitability ( the ability of muscle fibers to generate electrical impulses in response to stimuli ). Carbohydrate metabolism, protein synthesis Clinical Significance: Hypomagnesemia (<1.7 mg/ dL ): Causes: Alcoholism, Malabsorption ,, Diarrhea . Symptoms: Tetany , Seizures, Arrhythmias Drugs:- Aminoglycocide , Diuretics, PPI Hypermagnesemia (>2.2 mg/ dL ): Causes: Renal failure, excessive magnesium intake Symptoms: Hypotension, Bradycardia , Respiratory Depression, Cardiac Arrest Drugs: Lithium, psychotropic, antacids or laxatives

60. Chloride ( Cl ⁻) Normal Range : 96–106 mEq /L Functions: Maintains ECF osmolality and acid-base balance. Essential for gastric acid ( HCl ) production. Clinical Significance: Hypochloremia (<96 mEq /L): Causes: Vomiting, metabolic alkalosis ( an acid-base disorder that occurs when the pH of tissue is elevated due to increased bicarbonate concentrations or decreased hydrogen ion concentration ) Symptoms: Muscle hyperexcitability , shallow breathing, alkalosis. Drugs - diuretics Hyperchloremia (>106 mEq /L): Causes: Dehydration, metabolic acidosis, excessive saline administration. Symptoms: Weakness, lethargy, deep breathing Drugs – Spironolactone , Amphotericin B

61. Phosphate (PO₄³⁻) Normal Range : 2.5–4.5 mg/ dL Functions: Integral for ATP production and energy metabolism. Bone and teeth mineralization. Clinical Significance: Hypophosphatemia (<2.5 mg/ dL ): Causes: Alcoholism, hyperparathyroidism. Symptoms: Weakness, bone pain, respiratory failure. Hyperphosphatemia (>4.5 mg/ dL ): Causes: Renal failure, hypoparathyroidism , tumor lysis syndrome. Symptoms: Bone and joint pain, Itchy skin or rash, Muscle cramps

62. PULMONARY FUNCTION TESTS

63. PULMONARY FUNCTION TESTS Pulmonary Function Test (PFT) is to identify how well the lungs are working while it measure lung volume, lung capacity, rates of flow and, gas exchange. There are 2 types of pulmonary disorder- Obstructive (block) [air has troubled flowing out of the lungs due to airway resistance] Restrictive [lung tissue and chest muscle can't expand]

64. 1. Lung Volumes 1. Tidal volume [TV] Total amount of air in a normal breathing. 2. Inspiratory Reserve Volume [IRV]:- The extra volume of air that can be inhaled into the lungs during maximal inspiration (or) inhalation 3. Expiratory Reserve volume [ERV] :- The largest volume air which can be  expelled from the lungs during maximum exhalation . 4. Residual volume [RV]:- The amount of air remaining in the lungs after exhalation.

65. 2. Lung Capacities 1.Vital Capacity[VI] : Amount of air that can be exhaled after a maximal inhalation. 2.Inspiratory capacity [IC] : The amount of air that can be inspired with the maximal effort 3.Functional Residual Capacity (FRC) The amount of air remaining in the alveoli & air passage at the end of normal exhalation. 4.Total Lung Capacity [TLC]: The total volume of the lungs when filled with as much air as possible.

66. Types of PFT'S SPIROMETRY: It is a test that measures various aspects of breathing and lung function. It's performed by a person breathe out into a tube [mouth piece] connected to a machine [ spirometer ]; that measure the amount of air exhaled.

67. Procedure Spirometer is a metal container with 2 chambers The outer chamber has a floating drum and it is immersed in the water in an inverted position. The drum is counter balanced by the weight attached in the top by means of a string attached to the weight. The inner chamber inverted with a small hole and attached with a long metal tube at the end with a mouth piece. During the spirometry attach a nose-clip to minimize the exhalation or minimize air loss.

68. The patient may sit (or) stand during the test. The spirometey determines the effectiveness of various mechanical forces included in the lung & chest wall movement Spirometry routinely assess - vital capacity, forced expiratory volume Advantages Helps to identify implied pharmacotherapy, response is before and during administration of of bronchodilator to see response with spirometry a test result will be measured. Before and after in the medication regimen of bronchodilator.  Disadvantages: Residual volume, functional residual capacity & TLC can't be measured.

69. MICROBIAL CULTURE SENSITIVITY TESTS

70. Microbial culture sensitivity tests, also known as antimicrobial susceptibility testing , It is essential for determining the effectiveness of antibiotics against specific microorganisms. These tests help guide appropriate antibiotic treatment and prevent the development of antibiotic resistance. Different methods are used to perform microbial culture sensitivity tests. Here are some common methods:

71. MINIMUM INHIBITORY CONCENTRATION : The minimum inhibitory concentration ( MIC ) is the lowest concentration of a chemical, usually a drug, which prevents visible in vitro growth of bacteria or fungi. MIC testing is performed in both diagnostic and drug discovery laboratories. The MIC is determined by preparing a dilution series of the chemical, adding agar or broth, then inoculating with bacteria or fungi, and incubating at a suitable temperature. The value obtained is largely dependent on the susceptibility of the microorganism and the antimicrobial potency of the chemical, but other variables can affect results too. The MIC is often expressed in micrograms per millilitre ( μg / mL ) or milligrams per litre (mg/L).

72. DISK DIFFUSION METHOD This method involves placing paper disks containing different antibiotics on a culture plate inoculated with the target microorganism . As the antibiotics diffuse into the agar, they create a concentration gradient . The zone of inhibition (clear area around the disk where bacterial growth is inhibited) is measured and compared to standardized tables to determine the microorganism's susceptibility to the antibiotics.

73. Advantages: Simple, cost-effective, and easy to perform. Limitations: Limited accuracy in determining exact minimum inhibitory concentration (MIC), variations in results due to factors like media, incubation conditions, and disk content.

74. BROTH DILUTION METHOD: This method involves preparing a series of liquid broth cultures with increasing concentrations of antibiotics . The microorganism is inoculated into each broth, and growth is observed after incubation. The lowest concentration that inhibits visible growth is the MIC. Advantages: Provides accurate MIC (Minimum inhibitory concentration) values, suitable for testing multiple antibiotics simultaneously. Limitations: Requires more time, equipment, and expertise.

75. E-Test (Gradient Diffusion Method): The E-test combines features of both the disk diffusion and broth dilution methods. It uses plastic strips with a gradient of antibiotic concentrations . The strip is placed on an agar plate, and the intersection point of the zone of inhibition with the strip indicates the MIC . Advantages: Provides quantitative MIC values with simplicity similar to disk diffusion. Limitations: Limited number of antibiotics on a single strip.

76. Agar Dilution Method: Similar to broth dilution, but antibiotics are incorporated into agar plates. The MIC is determined by observing growth or absence thereof on agar containing varying concentrations of antibiotics. Advantages: Provides MIC values, allows simultaneous testing of multiple antibiotics. Limitations: Requires preparation of antibiotic-containing agar plates, time-consuming.

77. CARDIAC MARKERS

78. Cardiac markers are biomarkers measured in blood that help in the diagnosis and management of heart-related conditions, especially myocardial infarction (heart attack). These markers are released into the blood stream when there is an injury or stress to the heart muscle

79. BIOCHEMICAL CARDIAC MARKERS 1. TROPONINS Troponins are regulatory proteins found in cardiac muscle. They are released into the bloodstream when cardiac muscle cells are damaged. Highly specific for cardiac injury . Composed of three subunits : Troponin C, Troponin I, and Troponin T. Of these, Troponin I (<1.5ng/ml) and Troponin T (<0.1ng/ml ) are specific to cardiac tissue. Time Course : Rises : 3–6 hours after myocardial injury . Peaks : 12–24 hours . Returns to baseline: 7–14 days

80. Clinical Use : Diagnosis of Myocardial Infarction (MI): The gold standard biomarker for acute coronary syndromes (ACS). Troponin elevation above the 99th percentile with a rising or falling pattern confirms myocardial damage . Chronic Conditions: May be mildly elevated in heart failure, chronic kidney disease . Limitations: Elevated levels can also occur in non-ischemic cardiac injury, e.g., sepsis, pulmonary embolism, and chronic kidney disease

81. 2. CREATINE KINASE Creatinine kinase is an enzyme that stimulate High Energy Phosphate groups. It is found in myocardium, skeletal muscle and brain. Creatine kinase (CK), also known as creatine phosphokinase (CPK), is an enzyme that plays a key role in energy production in muscle cells and other tissues. It catalyzes the conversion of creatine and adenosine triphosphate (ATP) to phosphocreatine and adenosine diphosphate ( ADP). This reaction helps provide energy for cellular processes, particularly during high-intensity activities or muscle contraction. NORMAL RANGE : Male: 52-336IU/L Female : 38-176 U/L CK exists as three iso -enzymes: CK-MM (skeletal muscle), CK-BB (brain), and CK-MB (heart).

82. Creatine Kinase -MB (CK-MB) NORMAL RANGE: <25 U/L CK-MB is an iso -enzyme of creatine kinase predominantly found in cardiac muscle. It leaks into the bloodstream following myocardial cell damage . Less specific than troponins due to its presence in skeletal muscle . Time Course : Rises : 3–6 hours after myocardial injury . Peaks : 12–24 hours . Returns to baseline: 2–3 days

83. Clinical Use : Used for detecting reinfarction : CK-MB levels return to baseline faster than troponins . Monitoring cardiac injury during surgery. Limitations: Elevated in skeletal muscle injury, making it less specific than troponins .

84. 3. MYOGLOBIN A small heme protein found in both cardiac and skeletal muscle. Myoglobin is a small, oxygen-binding protein found in muscle tissue, where it stores oxygen and facilitates its transport to mitochondria during muscle contraction . Structurally similar to hemoglobin . It is released very early during muscle injury, including myocardial infarction . Normal Range : Men : 28–72 ng / mL Women : 25–58 ng /m

85. Time Course: Rises: 1–4 hours after injury. Peaks: 6–12 hours. Returns to baseline: Within 24 hours . Clinical Use: Early detection of myocardial infarction (first marker to rise). High sensitivity, but very low specificity since it can be elevated in any muscle injury (e.g., trauma, rhabdomyolysis ).

86. 4. LACTATE DEHYDROGENASE (LDH) Lactate Dehydrogenase (LDH) is an enzyme found in nearly all body tissues, where it plays a critical role in energy production. LDH is involved in the conversion of lactate to pyruvate during anaerobic metabolism. It is released into the bloodstream when cells are damaged, making it a useful marker for tissue injury Normal LDH Levels Adults : 120–250 U/L LDH Isoenzymes There are five LDH isoenzymes , each associated with specific tissues : LDH-1 : Heart, red blood cells, and kidneys . LDH-2 : Reticuloendothelial system (e.g., lymph nodes ). LDH-3 : Lungs and other tissues . LDH-4 : Liver and skeletal muscle . LDH-5 : Liver and skeletal muscle.

87. Elevated LDH levels can indicate damage or disease in various tissues. Specific causes include : 1 . Heart Conditions Myocardial infarction (heart attack): Increased LDH-1 and LDH-2 Time Course: Rises: 12–24 hours after injury. Peaks : 48–72 hours. Returns to baseline: 7–10 days. Clinical Use: Detect and monitor tissue damage . Support the diagnosis of heart attacks, hemolysis , or liver disease . Monitor cancer progression or treatment efficacy