January Revision 2024-2025

[Audio] Good morning everyone, welcome to our January revision update for 2024-2025. Today, we will be discussing some key changes and updates in our field. Let's get started..

[Audio] The individuals in the image are seated around a table, focused on their discussion or meeting. Their expressions show they are attentive and engaged, indicating a productive exchange of ideas. The atmosphere appears calm and respectful, with no signs of tension or conflict. This scene could depict various settings, including a business meeting, conference, or social gathering. It is evident that these individuals are dedicated to their conversation and are working together towards a shared objective..

Section A.

[Audio] Cirrhosis of the liver can be caused by various factors, including autoimmune primary biliary cirrhosis, alpha1-antitrypsin deficiency, and haemochromatosis. All three conditions have been linked to the development of cirrhosis, making them potential causes..

[Audio] Aminotransferases are the most sensitive markers of liver injury. They are enzymes released into the bloodstream when there is damage to the liver cells. The levels of these enzymes can increase rapidly in response to liver injury, making them useful indicators of liver damage..

[Audio] Stellate cells are the primary effector cells responsible for the development of liver fibrosis. They play a crucial role in the deposition of collagen and other extracellular matrix proteins, leading to the formation of scar tissue. In response to liver injury, stellate cells undergo activation and differentiation into myofibroblasts, which then produce and secrete excessive amounts of collagen, leading to the development of fibrosis..

[Audio] Troponin I is a specific cardiac biomarker of myocardial infarction..

[Audio] The blood cholesterol levels in heterozygotes with primary hypercholesterolaemia exceed 7.8 millimoles per liter..

[Audio] Hepatocyte ballooning is a feature of NASH, and so is steatosis. Lymphoid follicles are not typically seen in NASH, whereas perisinusoidal inflammation is a common finding in NASH. Therefore, option c) lymphoid follicles is the correct answer..

[Audio] Decreases in intracellular free cholesterol result in decreased HMG CoA reductase activity, leading to increased production of mevalonate, which then leads to increased cholesterol biosynthesis. Conversely, increases in intracellular free cholesterol result in decreased HMG CoA reductase activity, thereby decreasing cholesterol biosynthesis. This negative feedback mechanism helps maintain cellular cholesterol homeostasis..

[Audio] The patient, a 4-year-old child, was reviewed at a children's hospital due to hepatosplenomegaly and mental retardation. Upon biopsy, it was discovered that the child had accumulation of sphingomyelin. This led to the question of what disease the child has. The possible options include Gaucher's, Niemann Pick's, Krabbe's, and Tay Sach's..

[Audio] Metformin, thiazolidinediones, and sulfonylureas are all treatment options for type II diabetics. These medications help regulate blood sugar levels by increasing insulin sensitivity, reducing glucose production in the liver, and stimulating insulin secretion. By combining these therapies, healthcare providers can develop personalized treatment plans tailored to each patient's unique needs..

[Audio] Haemoglobin A1C reflects glycaemia over the last two months. This means that it provides information about blood glucose levels during this period..

[Audio] Statins are first-line drugs for lowering LDL-cholesterol, and their major mechanism of action is inhibiting HMG CoA reductase inhibitors. This means they decrease the production of mevalonate, a precursor molecule necessary for the biosynthesis of cholesterol. By doing so, statins reduce the amount of cholesterol produced by the liver, leading to lower levels of low-density lipoprotein (LDL) cholesterol in the blood..

[Audio] When the body's respiratory system increases its removal of carbon dioxide from the blood, respiratory alkalosis occurs, resulting in lower than normal levels of pCO2. This can happen if the lungs take in more oxygen than usual, such as during exercise or at high altitudes. Consequently, the body's pH becomes more alkaline, or basic..

[Audio] With age, the body's ability to maintain proper pH levels through kidney function declines. This decline is primarily due to a reduction in the number of functioning nephrons, which reduces the kidneys' capacity to excrete excess hydrogen ions and retain bicarbonate ions. This change in renal function impairs the body's ability to regulate pH levels, leading to potential imbalances..

[Audio] Chronic alcoholics are known to have a high risk of developing hypomagnesaemia because of their poor diet and increased urinary excretion of magnesium. The other options do not necessarily increase the risk of hypomagnesaemia..

[Audio] The haemoglobin buffer system plays a crucial role in maintaining the body's acid-base balance by buffering changes in pH caused by fluctuations in plasma pCO2 levels. When the plasma pCO2 is rising or falling, the haemoglobin buffer system helps to stabilize the pH by binding to excess hydrogen ions or releasing them as needed. This ensures that the body's pH remains within a narrow range, even in the face of changing environmental conditions..

[Audio] a) An 8-month-old with a fever of 40oC and diarrhoea is at a higher risk of developing an electrolyte imbalance because children under the age of five are more susceptible to dehydration due to their small body size and immature regulatory mechanisms. This can lead to an imbalance of essential electrolytes such as sodium, potassium, and chloride. The presence of fever and diarrhoea further increases this risk..

[Audio] Metabolic acidosis is a condition characterized by an accumulation of hydrogen ions in the body, leading to a decrease in blood pH. This occurs when the patient misses his dialysis treatment, resulting in the buildup of acidic waste products in the blood. Symptoms include nausea, vomiting, headache, fatigue, and muscle weakness..

[Audio] Compensated metabolic alkalosis occurs when the body attempts to correct an elevated serum bicarbonate level by increasing respiratory rate, thereby reducing pCO2 levels. This is evident in option d) high pCO2, high bicarbonate, high pH, where the increased pCO2 is being offset by the elevated bicarbonate level, resulting in a high pH. The other options do not demonstrate this compensatory mechanism. Therefore, option d is the correct answer..

[Audio] Renal failure does not typically cause hypokalaemia. Instead, it often leads to hyperkalaemia due to impaired potassium excretion by the kidneys. This means that option a) renal failure is incorrect, and the correct answer is one of the other options. The other options are excessive aldosterone secretion, metabolic alkalosis, and the use of diuretic medications, which can all cause hypokalaemia..

[Audio] Potassium levels above normal range are seen in conditions such as Addison's disease, where there is an increase in aldosterone production, leading to increased potassium retention. In this case, a patient with Addison's disease would have a potassium level of 5.5. The other options do not typically cause potassium levels to rise above the normal range..

[Audio] None of the above alternatives are specific for cirrhosis. Cirrhosis can present with various liver function tests depending on the underlying cause and severity of the disease..

[Audio] In the differential diagnosis of cholestatic or hepatocellular (hepatic) jaundice, all three biochemical measurements - alkaline phosphatase, γ-Glutamyl transpeptidase, and aspartate aminotransferase - are important. These enzymes can help distinguish between cholestatic and hepatocellular causes of jaundice. Alkaline phosphatase is elevated in cholestasis, while γ-Glutamyl transpeptidase is more specific for bile duct obstruction. Aspartate aminotransferase is typically elevated in hepatocellular damage. By considering these enzyme levels, clinicians can narrow down the differential diagnosis and guide further testing and treatment..

[Audio] Creatine kinase is not a specific marker of myocardial infarction. Troponin I is the most useful cardiac biomarker of myocardial infarfection..

[Audio] Type I diabetes is characterized by the presence of islet cell autoantibodies. This is a hallmark feature of the disease, indicating an autoimmune response against the pancreatic beta cells. The destruction of these cells leads to a loss of insulin production, resulting in hyperglycemia and other complications..

[Audio] The oral glucose tolerance test is used to diagnose diabetes when the blood glucose level at 2 hours after the test is above 11 millimoles per liter. This indicates that the body is unable to regulate blood sugar levels effectively, which is a hallmark of diabetes..

[Audio] The biochemical investigation of Graves' disease, hyperthyroidism, and hypothyroidism requires thyroid stimulating hormone (TSH), tri-iodothyronine (T3), and thyroxine (T4) measurements. These hormones play crucial roles in regulating thyroid function, and their levels can help diagnose and monitor these conditions. TSH measures the pituitary gland's ability to stimulate the thyroid gland, while T3 and T4 assess the production of thyroid hormones. By analyzing these hormone levels, healthcare professionals can identify abnormalities and develop effective treatment plans..

[Audio] The results indicate a homozygotic form of hypercholesterolaemia. Tendon xanthoma is a characteristic feature of homozygous familial hypercholesterolemia, a rare genetic disorder caused by mutations in the LDLR gene. The extremely high plasma cholesterol level also supports this diagnosis..

[Audio] Cholesterol is transported from extra hepatic tissue to the liver by high-density lipoprotein, specifically HDL..

[Audio] The majority of mutations occur within the EGF precursor homology domain..

[Audio] Diabetic ketoacidosis is a life-threatening condition characterized by high blood sugar levels, metabolic acidosis, and electrolyte imbalances. The presence of ketones in the patient's urine indicates that their body is breaking down fat for energy due to insulin deficiency, leading to the accumulation of ketone bodies in the bloodstream. This condition requires immediate medical attention, as it can lead to serious complications if left untreated. Treatment typically involves fluid replacement, insulin administration, and correction of electrolyte imbalances..

[Audio] Chronic diarrhoea leads to a significant loss of bicarbonate ions from the body, ultimately resulting in metabolic acidosis. The gut is unable to absorb sufficient amounts of bicarbonate ions, leading to a decrease in serum bicarbonate levels. This impairs the body's buffering capacity, causing the pH of the blood to become acidic. Untreated metabolic acidosis can lead to serious complications such as seizures, coma, and even death. Prompt medical attention is required. Treatment typically involves correcting fluid and electrolyte imbalances, administering bicarbonate supplements, and addressing any underlying causes of the diarrhoea..

[Audio] Sodium and potassium are the major contributors to the osmolarities of both the extracellular fluid and the intracellular fluid. They have significant concentrations in these fluids. Sodium is present in high amounts in the extracellular fluid, while potassium is found primarily within cells. Both ions play crucial roles in maintaining proper fluid balance and regulating various physiological processes..

[Audio] The patient has a blood pH of 7.2, indicating an acidic state. The HCO3 level is 17 mmol/L, which suggests that there is some buffering capacity remaining. However, the pCO2 is only 20 mm Hg, indicating a respiratory component to the acid-base disorder. Given these findings, the most likely diagnosis is metabolic acidosis. This is because the patient's pH is low, but not extremely low, and the HCO3 level is not severely decreased. The presence of a respiratory component, as indicated by the low pCO2, suggests that the patient may have a mixed acid-base disorder, but the primary problem is still metabolic acidosis..

[Audio] Potassium level of 2.2. The ECG findings of ST wave depression, inverted T wave, and prominent U wave are consistent with hypokalemia, which is caused by a low potassium level. Other analytes such as magnesium and phosphorus do not typically cause these specific ECG changes..

[Audio] The compounds H2CO3, H2PO4- and NH4+ can all act as acids when dissolved in water because they have hydrogen ions that can dissociate into protons and release electrons, making them acidic..

[Audio] Respiratory acidosis is suggested by the patient's symptoms of difficulty breathing and a feeling of tightness in her chest. This is consistent with the definition of respiratory acidosis, which is characterized by an increase in carbon dioxide levels in the blood due to impaired ventilation. A severe respiratory infection, such as pneumonia, may have caused the patient's prolonged coughing and inability to breathe, leading to respiratory acidosis. Therefore, option c) respiratory acidosis is the most likely correct answer..

[Audio] During respiratory acidosis, the chemoreceptors monitor the pCO2 levels in the plasma and cerebrospinal fluid. Normally, this would trigger a decrease in pulmonary ventilation rates, allowing the body to compensate for the increased CO2 levels. This response helps to restore the balance of pH in the blood..

[Audio] Respiratory acidosis occurs when there is a delay in the elimination of carbon dioxide from the body, leading to an accumulation of this gas in the blood. This causes the pH of the blood to decrease, resulting in a respiratory acid-base disorder..

[Audio] The kidneys respond by increasing the rate of hydrogen ion secretion when a normal pulmonary response does not reverse respiratory acidosis. This is because the body needs to maintain its acid-base balance, and the kidneys play a crucial role in this process. By secreting more hydrogen ions, the kidneys help to reduce the amount of excess hydrogen ions in the blood, thereby reversing the respiratory acidosis..

[Audio] Metabolic alkalosis is often caused by conditions such as prolonged vomiting, hypokalemia, and hyperaldosteronism. However, hypoaldosteronism is actually associated with metabolic acidosis, not alkalosis. Therefore, option d) hypoaldosteronism is correct. This condition is characterized by a deficiency in aldosterone, leading to impaired sodium reabsorption and potassium secretion, resulting in metabolic acidosis..

[Audio] Metabolic acidosis is associated with a decreased blood pCO2. This occurs because a decrease in pCO2 leads to a decrease in bicarbonate levels, resulting in an increase in hydrogen ions and a decrease in pH. The other options are incorrect associations with metabolic acidosis. A raised plasma HCO3- is actually a characteristic of metabolic alkalosis, whereas hyperaldosteronism can cause metabolic alkalosis or respiratory alkalosis, but not metabolic acidosis. An anion gap may be increased in metabolic acidosis, but it is not always normal..

[Audio] In addition to the lipid profile, other essential factors to consider when assessing a patient's overall cardiovascular risk include age, gender, smoking status, diabetic status, blood pressure, and personal and family history of cardiovascular disease. These variables can significantly impact an individual's likelihood of developing cardiovascular disease, and it is crucial to take them into account when evaluating their risk..

[Audio] The laboratory tests used to assess glomerular filtration rate (GFR) include exogenous markers such as inulin, iohexol, and EDTA chromium-51. These markers are cleared by the kidneys and their clearance can be measured to estimate GFR. The formula for calculating GFR using these markers is clearance equals urinary concentration multiplied by urinary flow divided by plasma concentration. In addition to these exogenous markers, there are also several equations that can be used to estimate GFR based on serum creatinine and other factors. These equations include the Cockcroft-Gault equation, the Modification of Diet in Renal Disease (MDRD) study equation, and the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. However, all of these methods have limitations. For example, the accuracy of the measurements may vary depending on the marker used and the method of measurement. Additionally, the equations may not accurately reflect changes in GFR over time. Therefore, it is important to consider the hierarchy of GFR testing, which takes into account both the accuracy and practicality of each test. This allows healthcare providers to choose the most appropriate test for each individual patient..

[Audio] Insulin plays a crucial role in regulating blood sugar levels by facilitating glucose uptake in peripheral tissues such as muscle and fat cells. In the absence of insulin, or when its action is impaired, glucose remains in the bloodstream, leading to hyperglycemia. This triggers a cascade of metabolic changes that ultimately result in the development of diabetic ketoacidosis. The primary mechanism underlying this process involves the activation of counter-regulatory hormones, including glucagon, cortisol, and epinephrine. These hormones stimulate the breakdown of stored glycogen to glucose, increasing glucose production in the liver. Simultaneously, they promote the release of free fatty acids from adipose tissue, which are then converted into ketone bodies through the process of lipolysis. As a result, the concentration of ketone bodies in the blood increases, leading to acidosis and potentially life-threatening complications if left untreated. The presence of ketones in the urine, known as ketonuria, serves as a diagnostic indicator of diabetic ketoacidosis. Treatment options for type 1 diabetes focus on restoring normoglycemia and alleviating the symptoms of diabetic ketoacidosis. Insulin replacement therapy is the cornerstone of management, with short-acting, medium-acting, and long-acting insulins used to synchronize eating and insulin administration. Additionally, metformin, thiazolidinediones, and sulfonylureas may be prescribed to improve insulin sensitivity and reduce glucose production in the liver. In terms of dietary modifications, patients with type 1 diabetes are advised to follow a balanced diet that restricts total carbohydrates, proteins, and fats. Lipid-lowering diets have been shown to be effective in reducing cardiovascular risk factors in these individuals. Evidence from the Diabetes Control and Complications Trial (DCCT) has demonstrated the importance of tight glycemic control in preventing microvascular complications. By understanding the metabolic changes that occur during diabetic ketoacidosis and implementing appropriate treatment strategies, healthcare providers can effectively manage this condition and improve patient outcomes..

[Audio] Separation is key when it comes to accurately reporting plasma potassium levels. Failure to properly separate the plasma from the cells can lead to pseudohyperkalaemia, a condition where there appears to be an excess of potassium in the blood due to potassium leaking from cells into the plasma. This can have serious consequences if not properly interpreted. Pseudohyperkalaemia can also occur in rare cases of hereditary spherocytosis, a genetic condition where there are defects in red blood cell membranes. Additionally, conditions like thrombocytosis and leucocytosis can also cause pseudohyperkalaemia. It's important to beware of contamination issues as well, such as using potassium-EDTA tubes instead of lithium heparin tubes for collecting blood samples for potassium testing. On the other hand, pseudohyponatraemia can be caused by indirect readings from ISE machines, raised total protein levels, or raised lipids. Laboratory investigations for this condition include looking at the EDTA pattern for potassium, which can be affected by the chelation of magnesium and calcium, and can also impact potassium levels. Additionally, the drip arm pattern and serum indices should be evaluated for any signs of haemolysis. And when it comes to sodium levels, it's important to measure total protein and lipids, and to compare direct and indirect ISE readings. Finally, plasma osmolality should also be taken into consideration. In conclusion, while both pseudohyperkalaemia and pseudohyponatraemia can cause misleading results in laboratory testing, each has its own distinct set of causes and investigations that must be carefully considered in order to accurately interpret results and ensure the safety of patients..

[Audio] Abnormal liver function test results have significant implications for patient care. The interpretation of these results requires careful consideration of various factors including patient's clinical history, symptoms, risk factors, drug history, and alcohol history. This information helps clinicians to determine the real cause of abnormal liver function test results. Furthermore, the results of liver function tests enable clinicians to identify the type of liver damage, which guides further diagnostic testing and treatment decisions. In some cases, repeating liver function tests may be necessary to exclude temporary increases in liver enzymes caused by non-specific causes. Additionally, looking beyond individual components of liver function tests is crucial, as multiple enzymes can be elevated simultaneously in certain liver conditions. This comprehensive approach ensures accurate diagnoses and effective management of liver-related disorders..

[Audio] Urinary albumin, or microalbumin, is a biomarker of chronic kidney disease. The microalbumin test, also known as the albumin-to-creatinine ratio, detects early signs of kidney damage by measuring the small amount of albumin present in urine. This test is more sensitive than a urine dipstick test, which only detects larger amounts of protein in the urine. In a healthy individual, the kidneys filter waste products from the blood and excrete them in the urine. Proteins are reabsorbed and reused by the body. However, when kidney function is impaired, proteins begin to leak into the urine. Albumin is one of the first proteins to appear in the urine when kidney damage occurs. Patients with an albumin-to-creatinine ratio greater than 2.5 milligrams per millimole in males and greater than 3.5 milligrams per millimole in females require repeated testing to confirm microalbuminuria. It's essential to note that aside from kidney damage, there are few other reasons why microalbuminuria may occur, such as uncontrolled hypertension, urinary tract infections, heart failure, menstrual contamination, and strenuous exercise, among others..