Diabetes insipidus (DI) is characterized by specific biochemical markers. One of these markers is a low urine osmolality, meaning that the concentration of solutes in the urine is lower than normal. In contrast, the serum osmolality, which measures the concentration of solutes in the blood, is high in individuals with DI. This combination of low urine osmolality and high serum osmolality is indicative of DI. Other common biochemical disturbances associated with DI include elevated plasma osmolality, polyuria (excessive urine production), and hypernatremia (high sodium levels in the blood). However, it is important to note that sodium levels can sometimes be within the normal range in individuals with DI. It is worth mentioning that conditions such as Addison’s disease, syndrome of inappropriate antidiuretic hormone secretion (SIADH), and primary polydipsia are associated with low serum osmolality and hyponatremia. Additionally, the use of selective serotonin reuptake inhibitors (SSRIs) can also lead to hyponatremia as a side effect.

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.

It is recommended to administer sodium chloride solution gradually over a period of 10-15 minutes. If the systolic does not respond adequately, the bolus dose may need to be repeated. It is important to note that patients with DKA often have a fluid deficit of more than 5 liters, which should be taken into consideration.

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.

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.

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.

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).

The patient is showing signs of confusion and restlessness. Upon examination, it is found that the patient has high blood pressure, a rapid pulse rate, increased respiration rate, and a high temperature. An ECG reveals rapid atrial fibrillation. Additionally, the patient exhibits crackling sounds in the lower parts of the lungs, pitting edema in both legs below the knee, and a mild yellowish tint in the sclera. The patient’s medical history is obtained from their GP office, which reveals that they have not renewed their prescription for carbimazole and bisoprolol on time. Based on these findings, the most probable diagnosis is a thyroid storm.

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.

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.

This patient has presented with an Addisonian crisis, which is a rare but potentially catastrophic condition if not diagnosed promptly. It is more commonly seen in women than men and typically occurs between the ages of 30 and 50.

Addison’s disease is caused by insufficient production of steroid hormones by the adrenal glands, affecting the production of glucocorticoids, mineralocorticoids, and sex steroids. The main causes of Addison’s disease include autoimmune adrenalitis (accounting for 80% of cases), bilateral adrenalectomy, Waterhouse-Friderichsen syndrome (hemorrhage into the adrenal glands), and tuberculosis.

The most common trigger for an Addisonian crisis in patients with Addison’s disease is the intentional or accidental withdrawal of steroid therapy. Other factors that can precipitate a crisis include infection, trauma, myocardial infarction, cerebral infarction, asthma, hypothermia, and alcohol abuse.

Clinical features of Addison’s disease include weakness, lethargy, hypotension (especially orthostatic hypotension), nausea, vomiting, weight loss, reduced axillary and pubic hair, depression, and hyperpigmentation (particularly in palmar creases, buccal mucosa, and exposed areas). In an Addisonian crisis, the main symptoms are usually hypoglycemia and shock, characterized by tachycardia, peripheral vasoconstriction, hypotension, altered consciousness, and even coma.

Biochemical markers of Addison’s disease typically include increased ACTH levels (as a compensatory response to stimulate the adrenal glands), elevated serum renin levels, hyponatremia, hyperkalemia, hypercalcemia, hypoglycemia, and metabolic acidosis. Confirmatory investigations may involve the Synacthen test, plasma ACTH level measurement, plasma renin level measurement, and testing for adrenocortical antibodies.

Management of Addison’s disease should be overseen by an Endocrinologist. Treatment usually involves the administration of hydrocortisone, fludrocortisone, and dehydroepiandrosterone. Some patients may also require thyroxine if there is concurrent hypothalamic-pituitary disease. Treatment is lifelong, and patients should carry a steroid card and MedicAlert bracelet to alert healthcare professionals about their condition and the potential for an Addisonian 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.

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.

The electrolyte imbalances that are commonly observed in individuals with Addison’s disease are decreased sodium levels, increased potassium levels, increased calcium levels, and decreased glucose levels. In cases of Addisonian crisis, which is a severe form of Addison’s disease, patients may also experience hyponatremia (low sodium levels), hyperkalemia (high potassium levels), hypercalcemia (high calcium levels), and hypoglycemia (low glucose levels). Additionally, these patients may often develop acidosis.

Further Reading:

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare disorder caused by the destruction of the adrenal cortex. This leads to reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. The deficiency of cortisol results in increased production of adrenocorticotropic hormone (ACTH) due to reduced negative feedback to the pituitary gland. This condition can cause metabolic disturbances such as hyperkalemia, hyponatremia, hypercalcemia, and hypoglycemia.

The symptoms of Addison’s disease can vary but commonly include fatigue, weight loss, muscle weakness, and low blood pressure. It is more common in women and typically affects individuals between the ages of 30-50. The most common cause of primary hypoadrenalism in developed countries is autoimmune destruction of the adrenal glands. Other causes include tuberculosis, adrenal metastases, meningococcal septicaemia, HIV, and genetic disorders.

The diagnosis of Addison’s disease is often suspected based on low cortisol levels and electrolyte abnormalities. The adrenocorticotropic hormone stimulation test is commonly used for confirmation. Other investigations may include adrenal autoantibodies, imaging scans, and genetic screening.

Addisonian crisis is a potentially life-threatening condition that occurs when there is an acute deficiency of cortisol and aldosterone. It can be the first presentation of undiagnosed Addison’s disease. Precipitating factors of an Addisonian crisis include infection, dehydration, surgery, trauma, physiological stress, pregnancy, hypoglycemia, and acute withdrawal of long-term steroids. Symptoms of an Addisonian crisis include malaise, fatigue, nausea or vomiting, abdominal pain, fever, muscle pains, dehydration, confusion, and loss of consciousness.

There is no fixed consensus on diagnostic criteria for an Addisonian crisis, as symptoms are non-specific. Investigations may include blood tests, blood gas analysis, and septic screens if infection is suspected. Management involves administering hydrocortisone and fluids. Hydrocortisone is given parenterally, and the dosage varies depending on the age of the patient. Fluid resuscitation with saline is necessary to correct any electrolyte disturbances and maintain blood pressure. The underlying cause of the crisis should also be identified and treated. Close monitoring of sodium levels is important to prevent complications such as osmotic demyelination syndrome.

Subclinical hypothyroidism is a condition where the thyroid-stimulating hormone (TSH) levels are higher than normal, but the levels of free thyroxine (T4) are still within the normal range. On the other hand, subclinical hyperthyroidism is a condition where the TSH levels are lower than normal, but the levels of free triiodothyronine (T3) and free thyroxine (T4) are still within 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.

Myxoedema coma is a condition characterized by severe hypothyroidism, leading to a state of metabolic decompensation and changes in mental status. Patients with myxoedema coma often experience electrolyte disturbances such as hypoglycemia and hyponatremia. In addition, laboratory findings typically show elevated levels of TSH, as well as low levels of T4 and T3. Other expected findings include hypoxemia and hypercapnia.

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.

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).

Patients who have myxoedema coma usually show symptoms such as lethargy, bradycardia, hypothermia, worsening mental state, seizures, and/or coma. This patient has hypothyroidism and takes thyroxine regularly, which aligns with the signs and symptoms of myxoedema coma. It is worth noting that infections often act as a trigger, and this patient has developed a cough in the last week.

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 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.

Hypertension, hyperglycemia, weight gain, truncal obesity, supraclavicular fat pads, and striae are characteristic symptoms of a Cushing syndrome.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

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.

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.

Cushing syndrome is most commonly caused by the use of external glucocorticoids. However, when it comes to endogenous causes, pituitary adenoma, also known as Cushing’s disease, is the leading culprit.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

This patient is displaying symptoms and signs that are consistent with a diagnosis of phaeochromocytoma. Phaeochromocytoma is a rare functional tumor that originates from chromaffin cells in the adrenal medulla. There are also less common tumors called extra-adrenal paragangliomas, which develop in the ganglia of the sympathetic nervous system. Both types of tumors secrete catecholamines, leading to symptoms and signs associated with hyperactivity of the sympathetic nervous system.

The most common initial symptom is hypertension, which can be either sustained or paroxysmal. Other symptoms tend to be intermittent and can occur frequently or infrequently. As the disease progresses, these symptoms usually become more severe and frequent.

In addition to hypertension, patients with phaeochromocytoma may experience the following clinical features: headache, profuse sweating, palpitations or rapid heartbeat, tremors, fever, nausea and vomiting, anxiety and panic attacks, a sense of impending doom, epigastric or flank pain, constipation, hypertensive retinopathy, postural hypotension due to volume contraction, cardiomyopathy, and café au lait spots.

To confirm a suspected diagnosis of phaeochromocytoma, elevated levels of metanephrines (catecholamine metabolites) can be measured in the blood or urine. This can be done through methods such as a 24-hour urine collection for free catecholamines, vanillylmandelic acid (VMA), and metanephrines, high-performance liquid chromatography for catecholamines in plasma and/or urine, or radioimmunoassay (RIA) for urinary/plasma metanephrines.

Once the diagnosis of phaeochromocytoma is biochemically confirmed, imaging methods can be used to locate the tumor. The first imaging modality to be used is a CT scan, which has an overall sensitivity of 89%. An MRI scan is the most sensitive modality for identifying the tumor, especially in cases of extra-adrenal tumors or metastatic disease, with an overall sensitivity of 98%. In cases where CT or MRI does not show a tumor, a nuclear medicine scan such as MIBG scintigraphy can be useful.

Addison’s disease, also known as adrenal insufficiency, is characterized by a gradual onset of symptoms over several weeks, although it can sometimes occur suddenly. The diagnosis of Addison’s disease can be challenging as its symptoms, such as fatigue, muscle pain, weight loss, and nausea, are non-specific. However, a key feature is low blood pressure. The disease is associated with changes in pigmentation, ranging from increased pigmentation due to elevated ACTH levels to the development of vitiligo caused by the autoimmune destruction of melanocytes.

Patients with Addison’s disease often exhibit hyponatremia (low sodium levels) and hyperkalemia (high potassium levels). If the patient is dehydrated, this may be reflected in elevated urea and creatinine levels. While hypercalcemia (high calcium levels) and hypoglycemia (low blood sugar levels) can occur in Addison’s disease, they are less common than hyponatremia and hyperkalemia.

In contrast, diabetes insipidus, characterized by normal or elevated sodium levels, does not cause pigmentation changes. Cushing’s syndrome, which results from excess steroid production, is almost the opposite of Addison’s disease, with hypertension (high blood pressure) and hypokalemia (low potassium levels) being typical symptoms. Phaeochromocytoma, on the other hand, is associated with episodes of high blood pressure and hyperglycemia (high blood sugar levels).

Further Reading:

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare disorder caused by the destruction of the adrenal cortex. This leads to reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. The deficiency of cortisol results in increased production of adrenocorticotropic hormone (ACTH) due to reduced negative feedback to the pituitary gland. This condition can cause metabolic disturbances such as hyperkalemia, hyponatremia, hypercalcemia, and hypoglycemia.

The symptoms of Addison’s disease can vary but commonly include fatigue, weight loss, muscle weakness, and low blood pressure. It is more common in women and typically affects individuals between the ages of 30-50. The most common cause of primary hypoadrenalism in developed countries is autoimmune destruction of the adrenal glands. Other causes include tuberculosis, adrenal metastases, meningococcal septicaemia, HIV, and genetic disorders.

The diagnosis of Addison’s disease is often suspected based on low cortisol levels and electrolyte abnormalities. The adrenocorticotropic hormone stimulation test is commonly used for confirmation. Other investigations may include adrenal autoantibodies, imaging scans, and genetic screening.

Addisonian crisis is a potentially life-threatening condition that occurs when there is an acute deficiency of cortisol and aldosterone. It can be the first presentation of undiagnosed Addison’s disease. Precipitating factors of an Addisonian crisis include infection, dehydration, surgery, trauma, physiological stress, pregnancy, hypoglycemia, and acute withdrawal of long-term steroids. Symptoms of an Addisonian crisis include malaise, fatigue, nausea or vomiting, abdominal pain, fever, muscle pains, dehydration, confusion, and loss of consciousness.

There is no fixed consensus on diagnostic criteria for an Addisonian crisis, as symptoms are non-specific. Investigations may include blood tests, blood gas analysis, and septic screens if infection is suspected. Management involves administering hydrocortisone and fluids. Hydrocortisone is given parenterally, and the dosage varies depending on the age of the patient. Fluid resuscitation with saline is necessary to correct any electrolyte disturbances and maintain blood pressure. The underlying cause of the crisis should also be identified and treated. Close monitoring of sodium levels is important to prevent complications such as osmotic demyelination syndrome.

Phaeochromocytoma is characterized by certain clinical features, including paroxysmal hypertension, palpitations, headache, tremor, and profuse sweating. This patient exhibits paroxysmal symptoms that align with phaeochromocytoma, such as high blood pressure (systolic readings exceeding 220 mmHg are common), headache, sweating, and feelings of anxiety and fear. It is important to note that individuals with conditions like congenital adrenal hyperplasia, diabetes insipidus, and Addisonian crisis typically experience low 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.

The recommended diagnostic tests for Cushing’s syndrome include the 24-hour urinary free cortisol test, the 1 mg overnight dexamethasone suppression test, and the late-night salivary cortisol test. In this case, the patient exhibits symptoms of Cushing syndrome such as a moon face, abdominal striae, and hirsutism. These symptoms may be caused by Cushing’s disease, which is Cushing syndrome due to a pituitary adenoma. The patient also experiences headaches and visual disturbances, which could potentially be caused by high blood sugar levels. It is important to note that Cushing syndrome caused by an adrenal or pituitary tumor is more common in females, with a ratio of 5:1. The peak incidence of Cushing syndrome caused by an adrenal or pituitary adenoma occurs between the ages of 25 and 40 years.

Further Reading:

Cushing’s syndrome is a clinical syndrome caused by prolonged exposure to high levels of glucocorticoids. The severity of symptoms can vary depending on the level of steroid exposure. There are two main classifications of Cushing’s syndrome: ACTH-dependent disease and non-ACTH-dependent disease. ACTH-dependent disease is caused by excessive ACTH production from the pituitary gland or ACTH-secreting tumors, which stimulate excessive cortisol production. Non-ACTH-dependent disease is characterized by excess glucocorticoid production independent of ACTH stimulation.

The most common cause of Cushing’s syndrome is exogenous steroid use. Pituitary adenoma is the second most common cause and the most common endogenous cause. Cushing’s disease refers specifically to Cushing’s syndrome caused by an ACTH-producing pituitary tumor.

Clinical features of Cushing’s syndrome include truncal obesity, supraclavicular fat pads, buffalo hump, weight gain, moon facies, muscle wasting and weakness, diabetes or impaired glucose tolerance, gonadal dysfunction, hypertension, nephrolithiasis, skin changes (such as skin atrophy, striae, easy bruising, hirsutism, acne, and hyperpigmentation in ACTH-dependent causes), depression and emotional lability, osteopenia or osteoporosis, edema, irregular menstrual cycles or amenorrhea, polydipsia and polyuria, poor wound healing, and signs related to the underlying cause, such as headaches and visual problems.

Diagnostic tests for Cushing’s syndrome include 24-hour urinary free cortisol, 1 mg overnight dexamethasone suppression test, and late-night salivary cortisol. Other investigations aim to assess metabolic disturbances and identify the underlying cause, such as plasma ACTH, full blood count (raised white cell count), electrolytes, and arterial blood gas analysis. Imaging, such as CT or MRI of the abdomen, chest, and/or pituitary, may be required to assess suspected adrenal tumors, ectopic ACTH-secreting tumors, and pituitary tumors. The choice of imaging is guided by the ACTH result, with undetectable ACTH and elevated serum cortisol levels indicating ACTH-independent Cushing’s syndrome and raised ACTH suggesting an ACTH-secreting tumor.

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.

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.

The first-line treatment for Addisonian (adrenal) crisis is hydrocortisone. This patient displays symptoms that indicate an Addisonian crisis, and the main components of their management involve administering hydrocortisone and providing intravenous fluids for resuscitation.

Further Reading:

Addison’s disease, also known as primary adrenal insufficiency or hypoadrenalism, is a rare disorder caused by the destruction of the adrenal cortex. This leads to reduced production of glucocorticoids, mineralocorticoids, and adrenal androgens. The deficiency of cortisol results in increased production of adrenocorticotropic hormone (ACTH) due to reduced negative feedback to the pituitary gland. This condition can cause metabolic disturbances such as hyperkalemia, hyponatremia, hypercalcemia, and hypoglycemia.

The symptoms of Addison’s disease can vary but commonly include fatigue, weight loss, muscle weakness, and low blood pressure. It is more common in women and typically affects individuals between the ages of 30-50. The most common cause of primary hypoadrenalism in developed countries is autoimmune destruction of the adrenal glands. Other causes include tuberculosis, adrenal metastases, meningococcal septicaemia, HIV, and genetic disorders.

The diagnosis of Addison’s disease is often suspected based on low cortisol levels and electrolyte abnormalities. The adrenocorticotropic hormone stimulation test is commonly used for confirmation. Other investigations may include adrenal autoantibodies, imaging scans, and genetic screening.

Addisonian crisis is a potentially life-threatening condition that occurs when there is an acute deficiency of cortisol and aldosterone. It can be the first presentation of undiagnosed Addison’s disease. Precipitating factors of an Addisonian crisis include infection, dehydration, surgery, trauma, physiological stress, pregnancy, hypoglycemia, and acute withdrawal of long-term steroids. Symptoms of an Addisonian crisis include malaise, fatigue, nausea or vomiting, abdominal pain, fever, muscle pains, dehydration, confusion, and loss of consciousness.

There is no fixed consensus on diagnostic criteria for an Addisonian crisis, as symptoms are non-specific. Investigations may include blood tests, blood gas analysis, and septic screens if infection is suspected. Management involves administering hydrocortisone and fluids. Hydrocortisone is given parenterally, and the dosage varies depending on the age of the patient. Fluid resuscitation with saline is necessary to correct any electrolyte disturbances and maintain blood pressure. The underlying cause of the crisis should also be identified and treated. Close monitoring of sodium levels is important to prevent complications such as osmotic demyelination syndrome.

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.

When patients with diabetic ketoacidosis (DKA) are treated with insulin infusion, it is expected that their plasma bicarbonate levels will increase by at least 3 mmol/L per hour. Insulin therapy is aimed at correcting both hyperglycemia and ketoacidosis. However, if capillary ketones are not decreasing by at least 0.5 mmol/L per hour, venous bicarbonate is not rising by at least 3 mmol/L per hour, or plasma glucose is not decreasing by at least 3 mmol/L per hour, the insulin infusion rate should be reevaluated.

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.

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.