Endocrine Disorders: Addison’s Disease, Cushing Syndrome, and Conn Syndrome

Addison’s Disease:
Addison’s disease, or primary hypoadrenalism, is a condition characterized by chronic adrenal insufficiency. It is most commonly caused by autoimmune destruction of the adrenals in the UK, while tuberculosis is the most common cause worldwide. Other causes include long-term exogenous steroid use, cancer, or hemorrhage damage. Symptoms develop gradually, but patients can present in Addisonian crisis if there is a sudden deterioration in adrenal function or a physiological stress that the residual adrenal function cannot cope with. Treatment is with long-term replacement of corticosteroids and aldosterone.

Cushing Syndrome:
Cushing syndrome is a result of excess corticosteroid. It can be caused by exogenous steroids, primary hyperadrenalism, or secondary hyperadrenalism. Signs and symptoms include weight gain with moon facies and buffalo hump, hypertension, hyperglycemia, mood changes, hirsutism, baldness, and sleep disturbance.

Conn Syndrome:
Conn syndrome, also known as primary hyperaldosteronism, is caused most commonly by adrenal hyperplasia or adenomas. It results in excess aldosterone release, causing difficult-to-treat hypertension, hypernatremia, and hypokalemia.

Other Disorders:
Hypoglycemia occurs in insulinoma, but the other features are absent. Peutz-Jeghers syndrome is an autosomal dominant condition characterized by perioral freckling and small bowel polyps, which may present with vomiting secondary to intussusception from the small polyps but does not explain the hypoglycemia.

Thyroid storm is a medical emergency that can occur in patients with hyperthyroidism, such as those with Graves’ disease. It is characterized by symptoms such as high fever, rapid heartbeat, jaundice, and altered mental status. In such cases, IV beta-blockers, such as propranolol, are the first-line treatment to inhibit the peripheral adrenergic effects of excess thyroid hormone. However, propranolol should not be used in patients with asthma or reversible COPD, and caution should be exercised in patients with heart failure. Lugol’s solution can also be used to inhibit the release of stored thyroid hormone, but it is usually delayed until after antithyroid therapy has been initiated. Therapeutic plasma exchange may be considered for patients who do not respond to medical therapy. In this case, the patient’s jaundice is likely due to her hyperthyroid crisis, and there is no evidence of biliary disease or cholecystitis. Therefore, IV co-amoxiclav, which is the first-line antibiotic for community-acquired pneumonia, would be appropriate for this patient. If propranolol is contraindicated, a cardiac-specific beta-blocker or calcium-channel blocker may be used instead. However, in this patient, IV propranolol should be used as the first-line treatment.

Understanding Thyroid Storm

Thyroid storm is a rare but serious complication of thyrotoxicosis, which is characterized by an overactive thyroid gland. It is usually seen in patients who already have thyrotoxicosis and is not typically the first symptom. It is important to note that an excess of thyroxine caused by medication does not usually lead to thyroid storm.

There are several events that can trigger thyroid storm, including surgery, trauma, infection, and exposure to iodine, such as through CT contrast media. The clinical features of thyroid storm include fever, tachycardia, confusion, nausea, vomiting, hypertension, heart failure, and abnormal liver function tests.

The management of thyroid storm involves treating the underlying cause and providing symptomatic relief. This may include medications such as beta-blockers, anti-thyroid drugs, Lugol’s iodine, and dexamethasone. Paracetamol may also be used to manage fever.

In summary, thyroid storm is a serious complication of thyrotoxicosis that requires prompt medical attention. Understanding the triggers and clinical features of thyroid storm can help with early diagnosis and effective management.

Differential Diagnosis of Endocrine Disorders: Symptoms and Treatment Options

Hypothyroidism, adrenal insufficiency, Cushing syndrome, primary hypoparathyroidism, and secondary hypoparathyroidism are all endocrine disorders that can present with various symptoms. Hypothyroidism may cause cerebellar ataxia, myxoedema, and congestive cardiac failure, and is treated with replacement of thyroid hormone. Adrenal insufficiency may cause tiredness, weakness, and postural hypotension, among other symptoms. Cushing syndrome may present with central obesity, skin and muscle atrophy, and osteoporosis. Primary hypoparathyroidism may cause hypocalcaemia symptoms, while secondary hypoparathyroidism may also present with hypocalcaemia symptoms. Treatment options vary depending on the specific disorder.

Understanding Glycosylated Haemoglobin (HbA1c) in Diabetes Mellitus

Glycosylated haemoglobin (HbA1c) is a commonly used measure of long-term blood sugar control in diabetes mellitus. It is produced when glucose attaches to haemoglobin in the blood at a rate proportional to the glucose concentration. The level of HbA1c is influenced by the lifespan of red blood cells and the average blood glucose concentration. However, certain conditions such as sickle-cell anaemia, GP6D deficiency, and haemodialysis can interfere with accurate interpretation of HbA1c levels.

HbA1c is believed to reflect the blood glucose levels over the past 2-4 weeks, although it is generally thought to represent the previous 3 months. It is recommended that HbA1c be checked every 3-6 months until stable, then every 6 months. The Diabetes Control and Complications Trial (DCCT) has studied the complex relationship between HbA1c and average blood glucose. The International Federation of Clinical Chemistry (IFCC) has developed a new standardised method for reporting HbA1c in mmol per mol of haemoglobin without glucose attached.

Understanding HbA1c is crucial in managing diabetes mellitus and achieving optimal blood sugar control.

In the management of DKA, it is important to continue the patient’s regular long-acting insulin while stopping their short-acting insulin. Fixed-rate insulin and fluids should also be administered. Continuing short-acting insulin may lead to hypoglycaemia, so it should be stopped until the patient is stable. Increasing the dose of both long-acting and short-acting insulin is not recommended.

Diabetic ketoacidosis (DKA) is a serious complication of type 1 diabetes mellitus, accounting for around 6% of cases. It can also occur in rare cases of extreme stress in patients with type 2 diabetes mellitus. However, mortality rates have decreased from 8% to under 1% in the past 20 years. DKA is caused by uncontrolled lipolysis, resulting in an excess of free fatty acids that are ultimately converted to ketone bodies. The most common precipitating factors of DKA are infection, missed insulin doses, and myocardial infarction. Symptoms include abdominal pain, polyuria, polydipsia, dehydration, Kussmaul respiration, and acetone-smelling breath. Diagnostic criteria include glucose levels above 13.8 mmol/l, pH below 7.30, serum bicarbonate below 18 mmol/l, anion gap above 10, and ketonaemia.

Management of DKA involves fluid replacement, insulin, and correction of electrolyte disturbance. Most patients with DKA are depleted around 5-8 litres, and isotonic saline is used initially, even if the patient is severely acidotic. Insulin is administered through an intravenous infusion, and correction of electrolyte disturbance is necessary. Long-acting insulin should be continued, while short-acting insulin should be stopped. DKA resolution is defined as pH above 7.3, blood ketones below 0.6 mmol/L, and bicarbonate above 15.0mmol/L. Complications may occur from DKA itself or the treatment, such as gastric stasis, thromboembolism, arrhythmias, acute respiratory distress syndrome, acute kidney injury, and cerebral oedema. Children and young adults are particularly vulnerable to cerebral oedema following fluid resuscitation in DKA and often need 1:1 nursing to monitor neuro-observations.

The primary treatment for hypercalcaemia is IV fluid therapy.

Managing Hypercalcaemia

Hypercalcaemia is a condition where there is an excess of calcium in the blood. The initial management of hypercalcaemia involves rehydration with normal saline, typically 3-4 litres per day. This helps to flush out the excess calcium from the body. Once rehydration is achieved, bisphosphonates may be used to further lower the calcium levels. These drugs take 2-3 days to work, with maximal effect being seen at 7 days.

Calcitonin is another option for managing hypercalcaemia. It works quicker than bisphosphonates but is less commonly used due to its short duration of action. Steroids may be used in sarcoidosis, a condition that can cause hypercalcaemia.

Loop diuretics such as furosemide may also be used in hypercalcaemia, particularly in patients who cannot tolerate aggressive fluid rehydration. However, they should be used with caution as they may worsen electrolyte derangement and volume depletion.

In summary, the management of hypercalcaemia involves rehydration with normal saline followed by the use of bisphosphonates or other medications depending on the underlying cause of the condition. It is important to monitor electrolyte levels and adjust treatment accordingly to prevent complications.

On the day of surgery, it is recommended to omit the morning dose of gliclazide for patients taking sulfonylureas. However, if the patient takes BD, they can have the afternoon dose. Metformin should be taken as usual on the day before and on the day of elective surgery, except for lunchtime dose if taken three times a day.

Preparation for surgery varies depending on whether the patient is undergoing an elective or emergency procedure. For elective cases, it is important to address any medical issues beforehand through a pre-admission clinic. Blood tests, urine analysis, and other diagnostic tests may be necessary depending on the proposed procedure and patient fitness. Risk factors for deep vein thrombosis should also be assessed, and a plan for thromboprophylaxis formulated. Patients are advised to fast from non-clear liquids and food for at least 6 hours before surgery, and those with diabetes require special management to avoid potential complications. Emergency cases require stabilization and resuscitation as needed, and antibiotics may be necessary. Special preparation may also be required for certain procedures, such as vocal cord checks for thyroid surgery or bowel preparation for colorectal cases.

Individuals with sickle cell anaemia and other haemoglobinopathies may have inaccurate HbA1c readings due to the shortened lifespan of their red blood cells, resulting in lower than actual levels. Conversely, conditions such as splenectomy, iron-deficiency anaemia, B12 deficiency, and alcoholism can lead to falsely elevated HbA1c levels. The accuracy of HbA1c as a measure of average blood glucose concentration is dependent on the lifespan of red blood cells.

Understanding Glycosylated Haemoglobin (HbA1c) in Diabetes Mellitus

Glycosylated haemoglobin (HbA1c) is a commonly used measure of long-term blood sugar control in diabetes mellitus. It is produced when glucose attaches to haemoglobin in the blood at a rate proportional to the glucose concentration. The level of HbA1c is influenced by the lifespan of red blood cells and the average blood glucose concentration. However, certain conditions such as sickle-cell anaemia, GP6D deficiency, and haemodialysis can interfere with accurate interpretation of HbA1c levels.

HbA1c is believed to reflect the blood glucose levels over the past 2-4 weeks, although it is generally thought to represent the previous 3 months. It is recommended that HbA1c be checked every 3-6 months until stable, then every 6 months. The Diabetes Control and Complications Trial (DCCT) has studied the complex relationship between HbA1c and average blood glucose. The International Federation of Clinical Chemistry (IFCC) has developed a new standardised method for reporting HbA1c in mmol per mol of haemoglobin without glucose attached.

Understanding HbA1c is crucial in managing diabetes mellitus and achieving optimal blood sugar control.

Based on the presence of thyrotoxic symptoms, goitre, and anti-thyroid peroxidase antibodies, the likely diagnosis is

Graves’ Disease: Common Features and Unique Signs

Graves’ disease is the most frequent cause of thyrotoxicosis, which is commonly observed in women aged 30-50 years. The condition presents typical features of thyrotoxicosis, such as weight loss, palpitations, and heat intolerance. However, Graves’ disease also exhibits specific signs that are not present in other causes of thyrotoxicosis. These include eye signs, such as exophthalmos and ophthalmoplegia, as well as pretibial myxoedema and thyroid acropachy. The latter is a triad of digital clubbing, soft tissue swelling of the hands and feet, and periosteal new bone formation.

Autoantibodies are also present in Graves’ disease, including TSH receptor stimulating antibodies in 90% of patients and anti-thyroid peroxidase antibodies in 75% of patients. Thyroid scintigraphy can also aid in the diagnosis of Graves’ disease, as it shows diffuse, homogenous, and increased uptake of radioactive iodine.

Overall, Graves’ disease presents with both typical and unique features that distinguish it from other causes of thyrotoxicosis. Early diagnosis and treatment are crucial to prevent complications and improve outcomes for patients.

Cholestasis can be caused by sulphonylureas.

Understanding Drug-Induced Liver Disease

Drug-induced liver disease is a condition that occurs when certain medications or drugs cause damage to the liver. This condition is generally divided into three categories: hepatocellular, cholestatic, or mixed. However, there is often overlap between these categories, as some drugs can cause a range of changes to the liver.

Hepatocellular drug-induced liver disease is characterized by damage to the liver cells. Some of the drugs that tend to cause this type of damage include paracetamol, sodium valproate, phenytoin, MAOIs, halothane, anti-tuberculosis medications, statins, alcohol, amiodarone, methyldopa, and nitrofurantoin.

Cholestatic drug-induced liver disease, on the other hand, is characterized by a reduction in bile flow from the liver. Some of the drugs that tend to cause this type of damage include the combined oral contraceptive pill, antibiotics such as flucloxacillin, co-amoxiclav, and erythromycin, anabolic steroids, testosterones, phenothiazines such as chlorpromazine and prochlorperazine, sulphonylureas, fibrates, and rare reported causes such as nifedipine. Methotrexate, methyldopa, and amiodarone can cause both hepatocellular and cholestatic damage.

It is important to note that drug-induced liver disease can be a serious condition and can lead to liver cirrhosis if left untreated. Therefore, it is important to be aware of the potential risks associated with certain medications and to seek medical attention if any symptoms of liver damage occur.