The plasma osmolality for this patient can be calculated by multiplying the sodium concentration by 2, adding the glucose concentration, and then adding the urea concentration. In this case, the calculation would be (2 x 146) + 38 + 21.

Further Reading:

Hyperosmolar hyperglycaemic state (HHS) is a syndrome that occurs in people with type 2 diabetes and is characterized by extremely high blood glucose levels, dehydration, and hyperosmolarity without significant ketosis. It can develop over days or weeks and has a mortality rate of 5-20%, which is higher than that of diabetic ketoacidosis (DKA). HHS is often precipitated by factors such as infection, inadequate diabetic treatment, physiological stress, or certain medications.

Clinical features of HHS include polyuria, polydipsia, nausea, signs of dehydration (hypotension, tachycardia, poor skin turgor), lethargy, confusion, and weakness. Initial investigations for HHS include measuring capillary blood glucose, venous blood gas, urinalysis, and an ECG to assess for any potential complications such as myocardial infarction. Osmolality should also be calculated to monitor the severity of the condition.

The management of HHS aims to correct dehydration, hyperglycaemia, hyperosmolarity, and electrolyte disturbances, as well as identify and treat any underlying causes. Intravenous 0.9% sodium chloride solution is the principal fluid used to restore circulating volume and reverse dehydration. If the osmolality does not decline despite adequate fluid balance, a switch to 0.45% sodium chloride solution may be considered. Care must be taken in correcting plasma sodium and osmolality to avoid complications such as cerebral edema and osmotic demyelination syndrome.

The rate of fall of plasma sodium should not exceed 10 mmol/L in 24 hours, and the fall in blood glucose should be no more than 5 mmol/L per hour. Low-dose intravenous insulin may be initiated if the blood glucose is not falling with fluids alone or if there is significant ketonaemia. Potassium replacement should be guided by the potassium level, and the patient should be encouraged to drink as soon as it is safe to do so.

Complications of treatment, such as fluid overload, cerebral edema, or central pontine myelinolysis, should be assessed for, and underlying precipitating factors should be identified and treated. Prophylactic anticoagulation is required in most patients, and all patients should be assumed to be at high risk of foot ulceration, necessitating appropriate foot protection and daily foot checks.

If a person has symptoms or signs that indicate diabetes, a random venous plasma glucose concentration of 11.1 mmol/l or higher is considered to be indicative of diabetes mellitus. However, it is important to note that a diagnosis should not be made based solely on one test. A second test should be conducted to confirm the diagnosis. It is also worth mentioning that temporary high blood sugar levels may occur in individuals who are experiencing acute infection, trauma, circulatory issues, or other forms of stress that are not related to diabetes.

Further Reading:

Diabetes Mellitus:
– Definition: a group of metabolic disorders characterized by persistent hyperglycemia caused by deficient insulin secretion, resistance to insulin, or both.
– Types: Type 1 diabetes (absolute insulin deficiency), Type 2 diabetes (insulin resistance and relative insulin deficiency), Gestational diabetes (develops during pregnancy), Other specific types (monogenic diabetes, diabetes secondary to pancreatic or endocrine disorders, diabetes secondary to drug treatment).
– Diagnosis: Type 1 diabetes diagnosed based on clinical grounds in adults presenting with hyperglycemia. Type 2 diabetes diagnosed in patients with persistent hyperglycemia and presence of symptoms or signs of diabetes.
– Risk factors for type 2 diabetes: obesity, inactivity, family history, ethnicity, history of gestational diabetes, certain drugs, polycystic ovary syndrome, metabolic syndrome, low birth weight.

Hypoglycemia:
– Definition: lower than normal blood glucose concentration.
– Diagnosis: defined by Whipple’s triad (signs and symptoms of low blood glucose, low blood plasma glucose concentration, relief of symptoms after correcting low blood glucose).
– Blood glucose level for hypoglycemia: NICE defines it as <3.5 mmol/L, but there is inconsistency across the literature.
– Signs and symptoms: adrenergic or autonomic symptoms (sweating, hunger, tremor), neuroglycopenic symptoms (confusion, coma, convulsions), non-specific symptoms (headache, nausea).
– Treatment options: oral carbohydrate, buccal glucose gel, glucagon, dextrose. Treatment should be followed by re-checking glucose levels.

Treatment of neonatal hypoglycemia:
– Treat with glucose IV infusion 10% given at a rate of 5 mL/kg/hour.
– Initial stat dose of 2 mL/kg over five minutes may be required for severe hypoglycemia.
– Mild asymptomatic persistent hypoglycemia may respond to a single dose of glucagon.
– If hypoglycemia is caused by an oral anti-diabetic drug, the patient should be admitted and ongoing glucose infusion or other therapies may be required.

Note: Patients who have a hypoglycemic episode with a loss of warning symptoms should not drive and should inform the DVLA.

Thyroid storm is a rare condition that affects only 1-2% of patients with hyperthyroidism. However, it is crucial to diagnose it promptly because it has a high mortality rate of approximately 10%. Thyroid storm is often triggered by a physiological stressor, such as stopping antithyroid therapy prematurely, recent surgery or radio-iodine treatment, infections (especially chest infections), trauma, diabetic ketoacidosis or hyperosmolar diabetic crisis, thyroid hormone overdose, pre-eclampsia. It typically occurs in patients with Graves’ disease or toxic multinodular goitre and presents with sudden and severe hyperthyroidism. Symptoms include high fever (over 41°C), dehydration, rapid heart rate (greater than 140 beats per minute) with or without irregular heart rhythms, low blood pressure, congestive heart failure, nausea, jaundice, vomiting, diarrhea, abdominal pain, confusion, agitation, delirium, psychosis, seizures, or coma.

To diagnose thyroid storm, various blood tests should be conducted, including a full blood count, urea and electrolytes, blood glucose, coagulation screen, CRP, and thyroid profile (T4/T3 and TSH). A bone profile/calcium test should also be done as 10% of patients develop hypocalcemia. Blood cultures should be taken as well. Other important investigations include a urine dipstick/MC&S, chest X-ray, and ECG.

The management of thyroid storm involves several steps. Intravenous fluids, such as 1-2 liters of 0.9% saline, should be administered. Airway support and management should be provided as necessary. A nasogastric tube should be inserted if the patient is vomiting. Urgent referral for inpatient management is essential. Paracetamol (1 g PO/IV) can be given to reduce fever. Benzodiazepines, such as diazepam (5-20 mg PO/IV), can be used for sedation. Steroids, like hydrocortisone (100 mg IV), may be necessary if there is co-existing adrenal suppression. Antibiotics should be prescribed if there is an intercurrent infection. Beta-blockers, such as propranolol (80 mg PO), can help control heart rate. High-dose carbimazole (45-60 mg/day) is recommended.

Hyperglycemia is a common occurrence in patients with phaeochromocytoma. This is primarily due to the excessive release of catecholamines, which suppress insulin secretion from the pancreas and promote glycogenolysis. Calcium levels in phaeochromocytoma patients can vary, with hypercalcemia being most frequently observed in cases where hyperparathyroidism coexists, particularly in MEN II. However, some phaeochromocytomas may secrete calcitonin and/or adrenomedullin, which can lower plasma calcium levels and lead to hypocalcemia. While not typical, potassium disturbances may occur in patients experiencing severe vomiting or acute kidney injury. On the other hand, anemia is not commonly associated with phaeochromocytoma, although there are rare cases where the tumor secretes erythropoietin, resulting in elevated hemoglobin levels and hematocrit.

Further Reading:

Phaeochromocytoma is a rare neuroendocrine tumor that secretes catecholamines. It typically arises from chromaffin tissue in the adrenal medulla, but can also occur in extra-adrenal chromaffin tissue. The majority of cases are spontaneous and occur in individuals aged 40-50 years. However, up to 30% of cases are hereditary and associated with genetic mutations. About 10% of phaeochromocytomas are metastatic, with extra-adrenal tumors more likely to be metastatic.

The clinical features of phaeochromocytoma are a result of excessive catecholamine production. Symptoms are typically paroxysmal and include hypertension, headaches, palpitations, sweating, anxiety, tremor, abdominal and flank pain, and nausea. Catecholamines have various metabolic effects, including glycogenolysis, mobilization of free fatty acids, increased serum lactate, increased metabolic rate, increased myocardial force and rate of contraction, and decreased systemic vascular resistance.

Diagnosis of phaeochromocytoma involves measuring plasma and urine levels of metanephrines, catecholamines, and urine vanillylmandelic acid. Imaging studies such as abdominal CT or MRI are used to determine the location of the tumor. If these fail to find the site, a scan with metaiodobenzylguanidine (MIBG) labeled with radioactive iodine is performed. The highest sensitivity and specificity for diagnosis is achieved with plasma metanephrine assay.

The definitive treatment for phaeochromocytoma is surgery. However, before surgery, the patient must be stabilized with medical management. This typically involves alpha-blockade with medications such as phenoxybenzamine or phentolamine, followed by beta-blockade with medications like propranolol. Alpha blockade is started before beta blockade to allow for expansion of blood volume and to prevent a hypertensive crisis.

SIADH is characterized by hyponatremia, which is a condition where there is a low level of sodium in the blood. This occurs because the body is unable to properly excrete excess water, leading to a dilution of sodium levels. SIADH is specifically classified as euvolemic, meaning that there is a normal amount of fluid in the body, and hypotonic, indicating that the concentration of solutes in the blood is lower than normal.

Further Reading:

Syndrome of inappropriate antidiuretic hormone (SIADH) is a condition characterized by low sodium levels in the blood due to excessive secretion of antidiuretic hormone (ADH). ADH, also known as arginine vasopressin (AVP), is responsible for promoting water and sodium reabsorption in the body. SIADH occurs when there is impaired free water excretion, leading to euvolemic (normal fluid volume) hypotonic hyponatremia.

There are various causes of SIADH, including malignancies such as small cell lung cancer, stomach cancer, and prostate cancer, as well as neurological conditions like stroke, subarachnoid hemorrhage, and meningitis. Infections such as tuberculosis and pneumonia, as well as certain medications like thiazide diuretics and selective serotonin reuptake inhibitors (SSRIs), can also contribute to SIADH.

The diagnostic features of SIADH include low plasma osmolality, inappropriately elevated urine osmolality, urinary sodium levels above 30 mmol/L, and euvolemic. Symptoms of hyponatremia, which is a common consequence of SIADH, include nausea, vomiting, headache, confusion, lethargy, muscle weakness, seizures, and coma.

Management of SIADH involves correcting hyponatremia slowly to avoid complications such as central pontine myelinolysis. The underlying cause of SIADH should be treated if possible, such as discontinuing causative medications. Fluid restriction is typically recommended, with a daily limit of around 1000 ml for adults. In severe cases with neurological symptoms, intravenous hypertonic saline may be used. Medications like demeclocycline, which blocks ADH receptors, or ADH receptor antagonists like tolvaptan may also be considered.

It is important to monitor serum sodium levels closely during treatment, especially if using hypertonic saline, to prevent rapid correction that can lead to central pontine myelinolysis. Osmolality abnormalities can help determine the underlying cause of hyponatremia, with increased urine osmolality indicating dehydration or renal disease, and decreased urine osmolality suggesting SIADH or overhydration.

In an elderly patient with a history of gradual decline accompanied by high blood sugar levels, excessive thirst, and recent infection, the most likely diagnosis is hyperosmolar hyperglycemic state (HHS). This condition can be life-threatening, with a mortality rate of approximately 50%. Common symptoms include dehydration, elevated blood sugar levels, altered mental status, and electrolyte imbalances. About half of the patients with HHS also experience hypernatremia.

To calculate the serum osmolality, the formula is 2(K+ + Na+) + urea + glucose. In this case, the serum osmolality is 364 mmol/l, indicating a high level. It is important to discontinue the use of metformin in this patient due to the risk of metformin-associated lactic acidosis (MALA). Additionally, an intravenous infusion of insulin should be initiated.

The treatment goals for HHS are to address the underlying cause and gradually and safely:
– Normalize the osmolality
– Replace fluid and electrolyte losses
– Normalize blood glucose levels

If significant ketonaemia is present (3β-hydroxybutyrate is more than 1 mmol/L), it indicates a relative lack of insulin, and insulin should be administered immediately. However, if significant ketonaemia is not present, insulin should not be started.

Patients with HHS are at a high risk of thromboembolism, and it is recommended to routinely administer low molecular weight heparin. In cases where the serum osmolality exceeds 350 mmol/l, full heparinization should be considered.

In this scenario, a 48-year-old patient presents to the emergency department with severe headache, excessive sweating, and episodes of blurred vision. The patient’s triage observations reveal a significantly elevated blood pressure of 234/138 mmHg. The patient also mentions that they are awaiting the results of a 24-hour urine collection for hypertension investigation, specifically for catecholamines, metanephrines, and normetanephrines, as there is suspicion of phaeochromocytoma.

Phaeochromocytoma is a rare tumor that arises from the adrenal glands and can cause excessive release of catecholamines, such as adrenaline and noradrenaline. This leads to symptoms like severe hypertension, headache, sweating, and palpitations.

Given the patient’s presentation and suspicion of phaeochromocytoma, the most appropriate medication choice to lower the blood pressure would be phentolamine. Phentolamine is an alpha-adrenergic antagonist that blocks the effects of catecholamines on blood vessels, resulting in vasodilation and a decrease in blood pressure.

Hydralazine, magnesium sulfate, and glyceryl trinitrate are not the most appropriate choices in this scenario. Hydralazine is a direct vasodilator that acts on smooth muscle to relax blood vessels, but it does not specifically target the effects of catecholamines. Magnesium sulfate is commonly used for conditions like preeclampsia and eclampsia, but it does not directly address the underlying cause of hypertension in phaeochromocytoma. Glyceryl trinitrate, also known as nitroglycerin, is primarily used for the management of angina and does not specifically target the effects of catecholamines.

Diazepam is a benzodiazepine that has sedative and anxiolytic properties but does not directly lower blood pressure or address the underlying cause of hypertension in phaeochromocytoma.

Further Reading:

A hypertensive emergency is characterized by a significant increase in blood pressure accompanied by acute or progressive damage to organs. While there is no specific blood pressure value that defines a hypertensive emergency, systolic blood pressure is typically above 180 mmHg and/or diastolic blood pressure is above 120 mmHg. The most common presentations of hypertensive emergencies include cerebral infarction, pulmonary edema, encephalopathy, and congestive cardiac failure. Less common presentations include intracranial hemorrhage, aortic dissection, and pre-eclampsia/eclampsia.

The signs and symptoms of hypertensive emergencies can vary widely due to the potential dysfunction of every physiological system. Some common signs and symptoms include headache, nausea and/or vomiting, chest pain, arrhythmia, proteinuria, signs of acute kidney failure, epistaxis, dyspnea, dizziness, anxiety, confusion, paraesthesia or anesthesia, and blurred vision. Clinical assessment focuses on detecting acute or progressive damage to the cardiovascular, renal, and central nervous systems.

Investigations that are essential in evaluating hypertensive emergencies include U&Es (electrolyte levels), urinalysis, ECG, and CXR. Additional investigations may be considered depending on the suspected underlying cause, such as a CT head for encephalopathy or new onset confusion, CT thorax for suspected aortic dissection, and CT abdomen for suspected phaeochromocytoma. Plasma free metanephrines, urine total catecholamines, vanillylmandelic acid (VMA), and metanephrine may be tested if phaeochromocytoma is suspected. Urine screening for cocaine and/or amphetamines may be appropriate in certain cases, as well as an endocrine screen for Cushing’s syndrome.

The management of hypertensive emergencies involves cautious reduction of blood pressure to avoid precipitating renal, cerebral, or coronary ischemia. Staged blood pressure reduction is typically the goal, with an initial reduction in mean arterial pressure (MAP) by no more than 25% in the first hour. Further gradual reduction to a systolic blood pressure of 160 mmHg and diastolic blood pressure of 100 mmHg over the next 2 to 6 hours is recommended. Initial management involves treatment with intravenous antihypertensive agents in an intensive care setting with appropriate monitoring.

The healthcare provider should also assess the insulin infusion rate. It is important to note that the recommended minimum rate is 0.05 units per kilogram per hour. In this case, the patient weighs 60 kilograms and is currently receiving 3 units of Actrapid® insulin per hour, which is equivalent to 0.05 units per kilogram per hour. Therefore, the patient is already on the lowest possible dose. However, if the patient was on a higher dose of 0.1 units per kilogram per hour, it can be reduced once the glucose level falls below 14 mmol/l.

Further Reading:

Diabetic ketoacidosis (DKA) is a serious complication of diabetes that occurs due to a lack of insulin in the body. It is most commonly seen in individuals with type 1 diabetes but can also occur in type 2 diabetes. DKA is characterized by hyperglycemia, acidosis, and ketonaemia.

The pathophysiology of DKA involves insulin deficiency, which leads to increased glucose production and decreased glucose uptake by cells. This results in hyperglycemia and osmotic diuresis, leading to dehydration. Insulin deficiency also leads to increased lipolysis and the production of ketone bodies, which are acidic. The body attempts to buffer the pH change through metabolic and respiratory compensation, resulting in metabolic acidosis.

DKA can be precipitated by factors such as infection, physiological stress, non-compliance with insulin therapy, acute medical conditions, and certain medications. The clinical features of DKA include polydipsia, polyuria, signs of dehydration, ketotic breath smell, tachypnea, confusion, headache, nausea, vomiting, lethargy, and abdominal pain.

The diagnosis of DKA is based on the presence of ketonaemia or ketonuria, blood glucose levels above 11 mmol/L or known diabetes mellitus, and a blood pH below 7.3 or bicarbonate levels below 15 mmol/L. Initial investigations include blood gas analysis, urine dipstick for glucose and ketones, blood glucose measurement, and electrolyte levels.

Management of DKA involves fluid replacement, electrolyte correction, insulin therapy, and treatment of any underlying cause. Fluid replacement is typically done with isotonic saline, and potassium may need to be added depending on the patient’s levels. Insulin therapy is initiated with an intravenous infusion, and the rate is adjusted based on blood glucose levels. Monitoring of blood glucose, ketones, bicarbonate, and electrolytes is essential, and the insulin infusion is discontinued once ketones are below 0.3 mmol/L, pH is above 7.3, and bicarbonate is above 18 mmol/L.

Complications of DKA and its treatment include gastric stasis, thromboembolism, electrolyte disturbances, cerebral edema, hypoglycemia, acute respiratory distress syndrome, and acute kidney injury. Prompt medical intervention is crucial in managing DKA to prevent potentially fatal outcomes.

Hyperosmolar hyperglycaemic state (HHS) is a condition characterized by extremely high blood sugar levels, dehydration, and increased osmolality without significant ketosis. In this patient, the symptoms are consistent with HHS as they have high blood sugar levels without significant ketoacidosis (pH is above 7.3 and ketones are less than 3 mmol/L). Additionally, they show signs of dehydration with low blood pressure and a fast heart rate. The osmolality is calculated to be equal to or greater than 320 mosmol/kg, indicating increased concentration of solutes in the blood.

Further Reading:

Hyperosmolar hyperglycaemic state (HHS) is a syndrome that occurs in people with type 2 diabetes and is characterized by extremely high blood glucose levels, dehydration, and hyperosmolarity without significant ketosis. It can develop over days or weeks and has a mortality rate of 5-20%, which is higher than that of diabetic ketoacidosis (DKA). HHS is often precipitated by factors such as infection, inadequate diabetic treatment, physiological stress, or certain medications.

Clinical features of HHS include polyuria, polydipsia, nausea, signs of dehydration (hypotension, tachycardia, poor skin turgor), lethargy, confusion, and weakness. Initial investigations for HHS include measuring capillary blood glucose, venous blood gas, urinalysis, and an ECG to assess for any potential complications such as myocardial infarction. Osmolality should also be calculated to monitor the severity of the condition.

The management of HHS aims to correct dehydration, hyperglycaemia, hyperosmolarity, and electrolyte disturbances, as well as identify and treat any underlying causes. Intravenous 0.9% sodium chloride solution is the principal fluid used to restore circulating volume and reverse dehydration. If the osmolality does not decline despite adequate fluid balance, a switch to 0.45% sodium chloride solution may be considered. Care must be taken in correcting plasma sodium and osmolality to avoid complications such as cerebral edema and osmotic demyelination syndrome.

The rate of fall of plasma sodium should not exceed 10 mmol/L in 24 hours, and the fall in blood glucose should be no more than 5 mmol/L per hour. Low-dose intravenous insulin may be initiated if the blood glucose is not falling with fluids alone or if there is significant ketonaemia. Potassium replacement should be guided by the potassium level, and the patient should be encouraged to drink as soon as it is safe to do so.

Complications of treatment, such as fluid overload, cerebral edema, or central pontine myelinolysis, should be assessed for, and underlying precipitating factors should be identified and treated. Prophylactic anticoagulation is required in most patients, and all patients should be assumed to be at high risk of foot ulceration, necessitating appropriate foot protection and daily foot checks.

Patients with primary hyperaldosteronism typically present with hypertension and hypokalemia. This is due to the fact that aldosterone encourages the reabsorption of sodium and the excretion of potassium, leading to an imbalance in these electrolytes. Additionally, hypernatremia, or high levels of sodium in the blood, is often observed in these patients.

Further Reading:

Hyperaldosteronism is a condition characterized by excessive production of aldosterone by the adrenal glands. It can be classified into primary and secondary hyperaldosteronism. Primary hyperaldosteronism, also known as Conn’s syndrome, is typically caused by adrenal hyperplasia or adrenal tumors. Secondary hyperaldosteronism, on the other hand, is a result of high renin levels in response to reduced blood flow across the juxtaglomerular apparatus.

Aldosterone is the main mineralocorticoid steroid hormone produced by the adrenal cortex. It acts on the distal renal tubule and collecting duct of the nephron, promoting the reabsorption of sodium ions and water while secreting potassium ions.

The causes of hyperaldosteronism vary depending on whether it is primary or secondary. Primary hyperaldosteronism can be caused by adrenal adenoma, adrenal hyperplasia, adrenal carcinoma, or familial hyperaldosteronism. Secondary hyperaldosteronism can be caused by renal artery stenosis, reninoma, renal tubular acidosis, nutcracker syndrome, ectopic tumors, massive ascites, left ventricular failure, or cor pulmonale.

Clinical features of hyperaldosteronism include hypertension, hypokalemia, metabolic alkalosis, hypernatremia, polyuria, polydipsia, headaches, lethargy, muscle weakness and spasms, and numbness. It is estimated that hyperaldosteronism is present in 5-10% of patients with hypertension, and hypertension in primary hyperaldosteronism is often resistant to drug treatment.

Diagnosis of hyperaldosteronism involves various investigations, including U&Es to assess electrolyte disturbances, aldosterone-to-renin plasma ratio (ARR) as the gold standard diagnostic test, ECG to detect arrhythmia, CT/MRI scans to locate adenoma, fludrocortisone suppression test or oral salt testing to confirm primary hyperaldosteronism, genetic testing to identify familial hyperaldosteronism, and adrenal venous sampling to determine lateralization prior to surgery.

Treatment of primary hyperaldosteronism typically involves surgical adrenalectomy for patients with unilateral primary aldosteronism. Diet modification with sodium restriction and potassium supplementation may also be recommended.

Nephrogenic diabetes insipidus may develop in a certain percentage of individuals who take lithium.

Further Reading:

Diabetes insipidus (DI) is a condition characterized by either a decrease in the secretion of antidiuretic hormone (cranial DI) or insensitivity to antidiuretic hormone (nephrogenic DI). Antidiuretic hormone, also known as arginine vasopressin, is produced in the hypothalamus and released from the posterior pituitary. The typical biochemical disturbances seen in DI include elevated plasma osmolality, low urine osmolality, polyuria, and hypernatraemia.

Cranial DI can be caused by various factors such as head injury, CNS infections, pituitary tumors, and pituitary surgery. Nephrogenic DI, on the other hand, can be genetic or result from electrolyte disturbances or the use of certain drugs. Symptoms of DI include polyuria, polydipsia, nocturia, signs of dehydration, and in children, irritability, failure to thrive, and fatigue.

To diagnose DI, a 24-hour urine collection is done to confirm polyuria, and U&Es will typically show hypernatraemia. High plasma osmolality with low urine osmolality is also observed. Imaging studies such as MRI of the pituitary, hypothalamus, and surrounding tissues may be done, as well as a fluid deprivation test to evaluate the response to desmopressin.

Management of cranial DI involves supplementation with desmopressin, a synthetic form of arginine vasopressin. However, hyponatraemia is a common side effect that needs to be monitored. In nephrogenic DI, desmopressin supplementation is usually not effective, and management focuses on ensuring adequate fluid intake to offset water loss and monitoring electrolyte levels. Causative drugs need to be stopped, and there is a risk of developing complications such as hydroureteronephrosis and an overdistended bladder.

Congenital adrenal hyperplasia (CAH) is a group of inherited disorders that are caused by autosomal recessive genes. The majority of affected patients, over 90%, have a deficiency of the enzyme 21-hydroxylase. This enzyme is encoded by the 21-hydroxylase gene, which is located on chromosome 6p21 within the HLA histocompatibility complex. The second most common cause of CAH is a deficiency of the enzyme 11-beta-hydroxylase. The condition is rare, with an incidence of approximately 1 in 500 births in the UK. It is more prevalent in the offspring of consanguineous marriages.

The deficiency of 21-hydroxylase leads to a deficiency of cortisol and/or aldosterone, as well as an excess of precursor steroids. As a result, there is an increased secretion of ACTH from the anterior pituitary, leading to adrenocortical hyperplasia.

The severity of CAH varies depending on the degree of 21-hydroxylase deficiency. Female infants often exhibit ambiguous genitalia, such as clitoral hypertrophy and labial fusion. Male infants may have an enlarged scrotum and/or scrotal pigmentation. Hirsutism, or excessive hair growth, occurs in 10% of cases.

Boys with CAH often experience a salt-losing adrenal crisis at around 1-3 weeks of age. This crisis is characterized by symptoms such as vomiting, weight loss, floppiness, and circulatory collapse.

The diagnosis of CAH can be made by detecting markedly elevated levels of the metabolic precursor 17-hydroxyprogesterone. Neonatal screening is possible, primarily through the identification of persistently elevated 17-hydroxyprogesterone levels.

In infants presenting with a salt-losing crisis, the following biochemical abnormalities are observed: hyponatremia (low sodium levels), hyperkalemia (high potassium levels), metabolic acidosis, and hypoglycemia.

Boys experiencing a salt-losing crisis will require fluid resuscitation, intravenous dextrose, and intravenous hydrocortisone.

Affected females will require corrective surgery for their external genitalia. However, they have an intact uterus and ovaries and are capable of having children.

The long-term management of both sexes involves lifelong replacement of hydrocortisone (to suppress ACTH levels).

After the fluid restriction period, the urine is checked to determine if it remains relatively dilute (less than 600 mOsm/kg). If it does, desmopressin is administered and the urine is rechecked to see if it responds and becomes more concentrated.

If the urine osmolality significantly increases after desmopressin, it indicates that the kidneys have responded appropriately to the medication and the urine has concentrated. This suggests that the patient is not producing ADH in response to water loss, indicating cranial DI.

It is important to note that some units may use a lower cut-off of greater than 600 mOsm/kg instead of 800 mOsm/kg.

Further Reading:

Diabetes insipidus (DI) is a condition characterized by either a decrease in the secretion of antidiuretic hormone (cranial DI) or insensitivity to antidiuretic hormone (nephrogenic DI). Antidiuretic hormone, also known as arginine vasopressin, is produced in the hypothalamus and released from the posterior pituitary. The typical biochemical disturbances seen in DI include elevated plasma osmolality, low urine osmolality, polyuria, and hypernatraemia.

Cranial DI can be caused by various factors such as head injury, CNS infections, pituitary tumors, and pituitary surgery. Nephrogenic DI, on the other hand, can be genetic or result from electrolyte disturbances or the use of certain drugs. Symptoms of DI include polyuria, polydipsia, nocturia, signs of dehydration, and in children, irritability, failure to thrive, and fatigue.

To diagnose DI, a 24-hour urine collection is done to confirm polyuria, and U&Es will typically show hypernatraemia. High plasma osmolality with low urine osmolality is also observed. Imaging studies such as MRI of the pituitary, hypothalamus, and surrounding tissues may be done, as well as a fluid deprivation test to evaluate the response to desmopressin.

Management of cranial DI involves supplementation with desmopressin, a synthetic form of arginine vasopressin. However, hyponatraemia is a common side effect that needs to be monitored. In nephrogenic DI, desmopressin supplementation is usually not effective, and management focuses on ensuring adequate fluid intake to offset water loss and monitoring electrolyte levels. Causative drugs need to be stopped, and there is a risk of developing complications such as hydroureteronephrosis and an overdistended bladder.

Addison’s disease occurs when the adrenal glands do not produce enough steroid hormones. This includes glucocorticoids, mineralocorticoids, and sex steroids. The most common cause is autoimmune adrenalitis, which accounts for about 70-80% of cases. It is more prevalent in women and typically occurs between the ages of 30 and 50.

The clinical symptoms of Addison’s disease include weakness, lethargy, low blood pressure (especially when standing up), nausea, vomiting, weight loss, reduced hair in the armpits and pubic area, depression, and hyperpigmentation (darkening of the skin in certain areas like the palms, mouth, and exposed skin).

Biochemically, Addison’s disease is characterized by increased levels of ACTH (a hormone that tries to stimulate the adrenal glands), low sodium levels, high potassium levels, high calcium levels, low blood sugar, and metabolic acidosis.

People with Addison’s disease have a higher risk of developing type 1 diabetes, Hashimoto’s thyroiditis, Grave’s disease, premature ovarian failure, pernicious anemia, vitiligo, and alopecia.

Management of Addison’s disease should be overseen by an Endocrinologist. Treatment typically involves taking hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also need thyroxine if there is hypothalamic-pituitary disease present. Treatment is lifelong, and patients should carry a steroid card and a MedicAlert bracelet in case of an Addisonian crisis.

Cerebral edema is the most significant complication of diabetic ketoacidosis (DKA), leading to death in many cases. It occurs in approximately 0.2-1% of DKA cases. The high blood glucose levels cause an osmolar gradient, resulting in the movement of water from the intracellular fluid (ICF) to the extracellular fluid (ECF) space and a decrease in cell volume. When insulin and intravenous fluids are administered to correct the condition, the effective osmolarity decreases rapidly, causing a reversal of the fluid shift and the development of cerebral edema.

Cerebral edema is associated with a higher mortality rate and poor neurological outcomes. To prevent its occurrence, it is important to slowly normalize osmolarity over a period of 48 hours, paying attention to glucose and sodium levels, as well as ensuring proper hydration. Monitoring the child for symptoms such as headache, recurrent vomiting, irritability, changes in Glasgow Coma Scale (GCS), abnormal slowing of heart rate, and increasing blood pressure is crucial.

If cerebral edema does occur, it should be treated with either a hypertonic (3%) saline solution at a dosage of 3 ml/kg or a mannitol infusion at a dosage of 250-500 mg/kg over a 20-minute period.

In addition to cerebral edema, there are other complications associated with DKA in children, including cardiac arrhythmias, pulmonary edema, and acute renal failure.

Amiodarone, a medication used to treat heart rhythm problems, can have effects on the thyroid gland. It can either cause hypothyroidism (low thyroid hormone levels) or hyperthyroidism (high thyroid hormone levels). Amiodarone is a highly fat-soluble drug that accumulates in various tissues, including the thyroid. Even after stopping the medication, its effects can still be seen due to its long elimination half-life of around 100 days.

The reason behind amiodarone impact on the thyroid is believed to be its high iodine content. In patients with sufficient iodine levels, amiodarone-induced hypothyroidism is more likely to occur. On the other hand, in populations with low iodine levels, amiodarone can lead to a condition called iodine-induced thyrotoxicosis, which is characterized by hyperthyroidism.

The mechanism of amiodarone-induced hypothyroidism involves the release of iodide from the drug, which blocks the uptake of further iodide by the thyroid gland and hampers the production of thyroid hormones. Additionally, amiodarone inhibits the conversion of the inactive thyroid hormone T4 to the active form T3.

Amiodarone-induced hyperthyroidism, on the other hand, is thought to occur in individuals with abnormal thyroid glands, such as those with nodular goiters, autonomous nodules, or latent Graves’ disease. In these cases, the excess iodine from amiodarone overwhelms the thyroid’s normal regulatory mechanisms, leading to hyperthyroidism.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma. hypotension, hypoventilation, altered mental state, seizures and/or coma.

In the UK, the most prevalent cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. On a global scale, hypothyroidism is primarily caused by iodine deficiency. However, in areas where iodine levels are sufficient, such as the UK, hypothyroidism and subclinical hypothyroidism are most commonly attributed to autoimmune thyroiditis. This condition can manifest with or without a goitre, known as atrophic thyroiditis.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

The most probable diagnosis in this case is primary hyperaldosteronism, which is caused by either an adrenal adenoma (Conn’s syndrome) or bilateral idiopathic adrenal hyperplasia. Conn’s syndrome is likely in a patient who has difficult-to-control hypertension, low levels of potassium (hypokalaemia), and elevated or high normal levels of sodium. If the aldosterone:renin ratio is raised (>30), it further suggests primary hyperaldosteronism. CT scanning can be used to differentiate between an adrenal adenoma and adrenal hyperplasia. Treatment for hyperaldosteronism caused by an adenoma typically involves 4-6 weeks of spironolactone therapy followed by surgical removal of the adenoma. Adrenal hyperplasia usually responds well to potassium-sparing diuretics alone, such as spironolactone or amiloride.

Renal artery stenosis could also be suspected in a case of resistant hypertension, but it would be expected to cause a decline in renal function when taking a full dose of an ACE inhibitor like ramipril. However, in this case, the patient’s renal function is completely normal.

Phaeochromocytoma is associated with symptoms such as headaches, palpitations, tremors, and excessive sweating. The hypertension in phaeochromocytoma tends to occur in episodes. Since these symptoms are absent in this patient, a diagnosis of phaeochromocytoma is unlikely.

Cushing’s syndrome is characterized by various other clinical features, including weight gain, central obesity, a hump-like accumulation of fat on the back (buffalo hump), muscle wasting in the limbs, excessive hair growth (hirsutism), thinning of the skin, easy bruising, acne, and depression. Since this patient does not exhibit any of these features, Cushing’s syndrome is unlikely.

White coat syndrome is an unlikely diagnosis in this case because the initial diagnosis of hypertension was made based on ambulatory blood pressure monitoring.

Diabetic amyotrophy, also referred to as proximal diabetic neuropathy, is the second most prevalent form of diabetic neuropathy. It typically begins with discomfort in the buttocks, hips, or thighs and is often initially experienced on one side. The pain may start off as mild and gradually progress or it can suddenly manifest, as seen in this case. Subsequently, weakness and wasting of the proximal muscles in the lower limbs occur, making it difficult for the patient to transition from sitting to standing without assistance. Reflexes in the affected areas can also be impacted. Good control of blood sugar levels, physiotherapy, and lifestyle adjustments can reverse diabetic amyotrophy.

Peripheral neuropathy is the most common type of diabetic neuropathy and typically manifests as pain or loss of sensation in the feet or hands.

Autonomic neuropathy leads to changes in digestion, bowel and bladder function, sexual response, and perspiration. It can also affect the cardiovascular system, resulting in rapid heart rates and orthostatic hypotension.

Focal neuropathy causes sudden weakness in a single nerve or group of nerves, resulting in pain, sensory loss, or muscle weakness. Any nerve in the body can be affected.

Thyroid storm is a rare condition that affects only 1-2% of patients with hyperthyroidism. However, it is crucial to diagnose it promptly because it has a high mortality rate of approximately 10%. Thyroid storm is often triggered by a physiological stressor, such as stopping antithyroid therapy prematurely, recent surgery or radio-iodine treatment, infections (especially chest infections), trauma, diabetic ketoacidosis or hyperosmolar diabetic crisis, thyroid hormone overdose, pre-eclampsia. It typically occurs in patients with Graves’ disease or toxic multinodular goitre and presents with sudden and severe hyperthyroidism. Symptoms include high fever (over 41°C), dehydration, rapid heart rate (greater than 140 beats per minute) with or without irregular heart rhythms, low blood pressure, congestive heart failure, nausea, jaundice, vomiting, diarrhea, abdominal pain, confusion, agitation, delirium, psychosis, seizures, or coma.

To diagnose thyroid storm, various blood tests should be conducted, including a full blood count, urea and electrolytes, blood glucose, coagulation screen, CRP, and thyroid profile (T4/T3 and TSH). A bone profile/calcium test should also be done as 10% of patients develop hypocalcemia. Blood cultures should be taken as well. Other important investigations include a urine dipstick/MC&S, chest X-ray, and ECG.

The management of thyroid storm involves several steps. Intravenous fluids, such as 1-2 liters of 0.9% saline, should be administered. Airway support and management should be provided as necessary. A nasogastric tube should be inserted if the patient is vomiting. Urgent referral for inpatient management is essential. Paracetamol (1 g PO/IV) can be given to reduce fever. Benzodiazepines, such as diazepam (5-20 mg PO/IV), can be used for sedation. Steroids, like hydrocortisone (100 mg IV), may be necessary if there is co-existing adrenal suppression. Antibiotics should be prescribed if there is an intercurrent infection. Beta-blockers, such as propranolol (80 mg PO), can help control heart rate. High-dose carbimazole (45-60 mg/day) is recommended.

The tibial nerve has three main sensory branches that provide sensory function. These branches include the medial plantar nerve, which supplies the skin on the medial sole and the medial three and a half toes. The lateral plantar nerve supplies the skin on the lateral sole and the lateral one and a half toes. Lastly, the medial calcaneal branches of the tibial nerve supply the skin over the heel. Overall, these branches play a crucial role in providing sensory supply to the sole of the foot.

The following provides a summary of common causes for different acid-base disorders.

Respiratory alkalosis can be caused by hyperventilation, such as during periods of anxiety. It can also be a result of conditions like pulmonary embolism, CNS disorders (such as stroke or encephalitis), altitude, pregnancy, or the early stages of aspirin overdose.

Respiratory acidosis, on the other hand, is often associated with chronic obstructive pulmonary disease (COPD), life-threatening asthma, pulmonary edema, sedative drug overdose (such as opiates or benzodiazepines), neuromuscular disease, obesity, or other respiratory conditions.

Metabolic alkalosis can occur due to vomiting, potassium depletion (often caused by diuretic usage), Cushing’s syndrome, or Conn’s syndrome.

Metabolic acidosis with a raised anion gap can be caused by lactic acidosis (such as in cases of hypoxemia, shock, sepsis, or infarction), ketoacidosis (such as in diabetes, starvation, or alcohol excess), renal failure, or poisoning (such as in late stages of aspirin overdose, methanol or ethylene glycol ingestion).

Lastly, metabolic acidosis with a normal anion gap can be a result of conditions like diarrhea, ammonium chloride ingestion, or adrenal insufficiency.

The levels of thyroid stimulating hormone (TSH) and thyroxine (T4) are both below the normal range.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

Thyroid storm, also known as thyrotoxic crisis, is a rare and dangerous complication of hyperthyroidism. The initial management of this condition involves the use of specific medications. These medications include a beta blocker, a corticosteroid, an antithyroid drug, and an iodine solution.

The beta blocker used is typically propranolol, which is administered intravenously at a dose of 1 mg over 1 minute. If a beta blocker is contraindicated, a calcium channel blocker such as diltiazem may be used instead, at a dose of 0.25 mg/kg over 2 minutes.

For corticosteroids, hydrocortisone is commonly used and given intravenously at a dose of 200 mg. Alternatively, dexamethasone can be used at a dose of 2 mg intravenously.

The antithyroid drug used is usually propylthiouracil, which is given orally, through a nasogastric tube, or rectally, at a dose of 200 mg.

An iodine solution, specifically Lugol’s iodine, is also part of the initial management. However, it should not be administered until at least 1 hour after the antithyroid drug has been given. This is because iodine can exacerbate thyrotoxicosis by stimulating thyroid hormone synthesis. Propylthiouracil, on the other hand, inhibits the normal interactions of iodine and peroxidase with thyroglobulin, preventing the formation of T4 and T3. Therefore, it is given first and allowed time to take effect before iodine is administered.

Further Reading:

The thyroid gland is an endocrine organ located in the anterior neck. It consists of two lobes connected by an isthmus. The gland produces hormones called thyroxine (T4) and triiodothyronine (T3), which regulate energy use, protein synthesis, and the body’s sensitivity to other hormones. The production of T4 and T3 is stimulated by thyroid-stimulating hormone (TSH) secreted by the pituitary gland, which is in turn stimulated by thyrotropin-releasing hormone (TRH) from the hypothalamus.

Thyroid disorders can occur when there is an imbalance in the production or regulation of thyroid hormones. Hypothyroidism is characterized by a deficiency of thyroid hormones, while hyperthyroidism is characterized by an excess. The most common cause of hypothyroidism is autoimmune thyroiditis, also known as Hashimoto’s thyroiditis. It is more common in women and is often associated with goiter. Other causes include subacute thyroiditis, atrophic thyroiditis, and iodine deficiency. On the other hand, the most common cause of hyperthyroidism is Graves’ disease, which is also an autoimmune disorder. Other causes include toxic multinodular goiter and subacute thyroiditis.

The symptoms and signs of thyroid disorders can vary depending on whether the thyroid gland is underactive or overactive. In hypothyroidism, common symptoms include weight gain, lethargy, cold intolerance, and dry skin. In hyperthyroidism, common symptoms include weight loss, restlessness, heat intolerance, and increased sweating. Both hypothyroidism and hyperthyroidism can also affect other systems in the body, such as the cardiovascular, gastrointestinal, and neurological systems.

Complications of thyroid disorders can include dyslipidemia, metabolic syndrome, coronary heart disease, heart failure, subfertility and infertility, impaired special senses, and myxedema coma in severe cases of hypothyroidism. In hyperthyroidism, complications can include Graves’ orbitopathy, compression of the esophagus or trachea by goiter, thyrotoxic periodic paralysis, arrhythmias, osteoporosis, mood disorders, and increased obstetric complications.

Myxedema coma is a rare and life-threatening complication of severe hypothyroidism. It can be triggered by factors such as infection or physiological insult and presents with lethargy, bradycardia, hypothermia, hypotension, hypoventilation, altered mental state, seizures and/or coma.

Of all the medications mentioned in this question, only pioglitazone is known to be a potential cause of hypoglycemia. Glucagon, on the other hand, is specifically used as a treatment for hypoglycemia. The remaining medications mentioned are antidiabetic drugs that do not typically lead to hypoglycemia when used alone.

Addison’s disease can be attributed to various underlying causes. The most common cause, accounting for approximately 80% of cases, is autoimmune adrenalitis. This occurs when the body’s immune system mistakenly attacks the adrenal glands. Another cause is bilateral adrenalectomy, which involves the surgical removal of both adrenal glands. Additionally, Addison’s disease can be triggered by a condition known as Waterhouse-Friderichsen syndrome, which involves bleeding into the adrenal glands. Tuberculosis, a bacterial infection, is also recognized as a potential cause of this disease. Lastly, although rare, congenital adrenal hyperplasia can contribute to the development of Addison’s disease.

The correct answer is 10-15%. This means that out of all phaeochromocytoma cases, approximately 10-15% occur outside of the adrenal glands.

Further Reading:

Phaeochromocytoma is a rare neuroendocrine tumor that secretes catecholamines. It typically arises from chromaffin tissue in the adrenal medulla, but can also occur in extra-adrenal chromaffin tissue. The majority of cases are spontaneous and occur in individuals aged 40-50 years. However, up to 30% of cases are hereditary and associated with genetic mutations. About 10% of phaeochromocytomas are metastatic, with extra-adrenal tumors more likely to be metastatic.

The clinical features of phaeochromocytoma are a result of excessive catecholamine production. Symptoms are typically paroxysmal and include hypertension, headaches, palpitations, sweating, anxiety, tremor, abdominal and flank pain, and nausea. Catecholamines have various metabolic effects, including glycogenolysis, mobilization of free fatty acids, increased serum lactate, increased metabolic rate, increased myocardial force and rate of contraction, and decreased systemic vascular resistance.

Diagnosis of phaeochromocytoma involves measuring plasma and urine levels of metanephrines, catecholamines, and urine vanillylmandelic acid. Imaging studies such as abdominal CT or MRI are used to determine the location of the tumor. If these fail to find the site, a scan with metaiodobenzylguanidine (MIBG) labeled with radioactive iodine is performed. The highest sensitivity and specificity for diagnosis is achieved with plasma metanephrine assay.

The definitive treatment for phaeochromocytoma is surgery. However, before surgery, the patient must be stabilized with medical management. This typically involves alpha-blockade with medications such as phenoxybenzamine or phentolamine, followed by beta-blockade with medications like propranolol. Alpha blockade is started before beta blockade to allow for expansion of blood volume and to prevent a hypertensive crisis.

An Addisonian crisis is characterized by several distinct features. These include experiencing pain in the legs and abdomen, as well as symptoms of vomiting and dehydration. Hypotension, or low blood pressure, is also commonly observed during an Addisonian crisis. Confusion and psychosis may also occur, along with the presence of a fever. In some cases, convulsions may be present as well. Additionally, individuals experiencing an Addisonian crisis may also exhibit hypoglycemia, hyponatremia, hyperkalemia, hypercalcemia, eosinophilia, and metabolic acidosis.

The first step in managing hypertension in patients with phaeochromocytoma is to use alpha blockade, usually with a medication called phenoxybenzamine. This is followed by beta blockade. Before undergoing surgery to remove the phaeochromocytoma, patients need to be on both alpha and beta blockers. Alpha blockade is typically achieved by giving phenoxybenzamine intravenously at a dose of 10-40 mg over one hour, and then switching to an oral form (10-60 mg/day in divided doses). It is important to start alpha blockade at least 7 to 10 days before surgery to allow for an increase in blood volume. Beta blockade is only considered once alpha blockade has been achieved, as starting beta blockers too soon can lead to a dangerous increase in blood pressure.

Further Reading:

Phaeochromocytoma is a rare neuroendocrine tumor that secretes catecholamines. It typically arises from chromaffin tissue in the adrenal medulla, but can also occur in extra-adrenal chromaffin tissue. The majority of cases are spontaneous and occur in individuals aged 40-50 years. However, up to 30% of cases are hereditary and associated with genetic mutations. About 10% of phaeochromocytomas are metastatic, with extra-adrenal tumors more likely to be metastatic.

The clinical features of phaeochromocytoma are a result of excessive catecholamine production. Symptoms are typically paroxysmal and include hypertension, headaches, palpitations, sweating, anxiety, tremor, abdominal and flank pain, and nausea. Catecholamines have various metabolic effects, including glycogenolysis, mobilization of free fatty acids, increased serum lactate, increased metabolic rate, increased myocardial force and rate of contraction, and decreased systemic vascular resistance.

Diagnosis of phaeochromocytoma involves measuring plasma and urine levels of metanephrines, catecholamines, and urine vanillylmandelic acid. Imaging studies such as abdominal CT or MRI are used to determine the location of the tumor. If these fail to find the site, a scan with metaiodobenzylguanidine (MIBG) labeled with radioactive iodine is performed. The highest sensitivity and specificity for diagnosis is achieved with plasma metanephrine assay.

The definitive treatment for phaeochromocytoma is surgery. However, before surgery, the patient must be stabilized with medical management. This typically involves alpha-blockade with medications such as phenoxybenzamine or phentolamine, followed by beta-blockade with medications like propranolol. Alpha blockade is started before beta blockade to allow for expansion of blood volume and to prevent a hypertensive crisis.

To diagnose diabetic ketoacidosis (DKA), all three of the following criteria must be present: ketonaemia (≥3 mmol/L) or ketonuria (> 2+ on urine dipstick), blood glucose > 11 mmol/L or known diabetes mellitus, and blood pH <7.3 or bicarbonate < 15 mmol/L. It is important to note that plasma osmolality and anion gap, although typically elevated in DKA, are not included in the diagnostic criteria. Further Reading: Diabetic ketoacidosis (DKA) is a serious complication of diabetes that occurs due to a lack of insulin in the body. It is most commonly seen in individuals with type 1 diabetes but can also occur in type 2 diabetes. DKA is characterized by hyperglycemia, acidosis, and ketonaemia. The pathophysiology of DKA involves insulin deficiency, which leads to increased glucose production and decreased glucose uptake by cells. This results in hyperglycemia and osmotic diuresis, leading to dehydration. Insulin deficiency also leads to increased lipolysis and the production of ketone bodies, which are acidic. The body attempts to buffer the pH change through metabolic and respiratory compensation, resulting in metabolic acidosis. DKA can be precipitated by factors such as infection, physiological stress, non-compliance with insulin therapy, acute medical conditions, and certain medications. The clinical features of DKA include polydipsia, polyuria, signs of dehydration, ketotic breath smell, tachypnea, confusion, headache, nausea, vomiting, lethargy, and abdominal pain. The diagnosis of DKA is based on the presence of ketonaemia or ketonuria, blood glucose levels above 11 mmol/L or known diabetes mellitus, and a blood pH below 7.3 or bicarbonate levels below 15 mmol/L. Initial investigations include blood gas analysis, urine dipstick for glucose and ketones, blood glucose measurement, and electrolyte levels. Management of DKA involves fluid replacement, electrolyte correction, insulin therapy, and treatment of any underlying cause. Fluid replacement is typically done with isotonic saline, and potassium may need to be added depending on the patient’s levels. Insulin therapy is initiated with an intravenous infusion, and the rate is adjusted based on blood glucose levels. Monitoring of blood glucose, ketones, bicarbonate, and electrolytes is essential, and the insulin infusion is discontinued once ketones are below 0.3 mmol/L, pH is above 7.3, and bicarbonate is above 18 mmol/L. Complications of DKA and its treatment include gastric stasis, thromboembolism, electrolyte disturbances, cerebral edema, hypoglycemia, acute respiratory distress syndrome, and acute kidney injury. Prompt medical intervention is crucial in managing DKA to prevent potentially fatal outcomes.