Adrenocortical disorders By AbdAlAziz AbdAllah, MD The adrenal gland is divided into two parts, adrenal cortex and medulla. The adrenal cortex secretes androgen, mineralocorticoids (eg, aldosteron) and glucocorticoids (eg, crtisol). The adrenal medulla secretes catecholamines (eg, epinephrine, norepinephrine, dopamine). Aldosteron is primarily involved with fluid and electrolyte balance. Aldosteron secretion causes sodium reabsorption in the distal renal tubule in exchange for potassium and hydrogen ions. The net effects are, fluid retention, decrease in plasma potassium and metabolic alkalosis. Aldosteron secretion is stimulated by; -Renin-angiotensin system. -ACTH. -Hyperkalemia. -Hypovolemia. -Hypotension. -congestive heart failure. -Surgery. Glucocorticoids are essential for life and have mutiple pysiological effects. Metabolic actions include enhanced gluconeogenesis and inhibition of peripheral glucose utilization. Glucocorticoids are required for vascular and bronchial smooth muscle to be responsive to catecholamines. Glucocorticoids are structurly related to aldosteron, so they have aldosteron like action. ACTH is the principal regulator of Glucocorticoids secretion. Secretion of ACTH and glucocorticoids exhibit a diurnal rhythm, stimulated by stress and inhibited by circulating glucocorticoids. Endogenous production of cortisol averages 20 mg \ day. Mineralocorticoid excess I- 1ry hyper-aldosteronism (Conn syndrome): Conn syndrome is characterized by increased aldosterone secretion from the adrenal glands, it was first described in 1955 by J. W. Conn in a patient who had an aldosterone-producing adenoma. Pathophysiology Primary hyperaldosteronism is caused by increased aldosterone excretion from the adrenals, which results primarily from 2 major subtypes: (1) unilateral aldosterone-producing adenoma , Conn syndrome, (50-60% of cases) (2) idiopathic hyperaldosteronism (IHA) or bilateral adrenal hyperplasia (40-50% of cases). (3) Rarely, aldosterone can be secreted by adrenocortical carcinomas and ovarian tumors. Aldosterone, by inducing renal distal tubular reabsorption of sodium, enhances secretion of potassium and hydrogen ions, causing hypernatremia, hypokalemia, and metabolic alkalosis. Frequency: Prevalence for Conn syndrome; 0.05-2% of the population. Mortality/Morbidity: The morbidity and mortality associated with Conn syndrome, are primarily related to; 1- Hypertension, especially if left untreated for many years, can lead to many complications, including heart disease (eg, coronary artery disease, congestive heart failure), stroke, and intracerebral hemorrhage (with very high blood pressure). 2-Hypokalemia, especially if severe, causes cardiac arrhythmias, which can be fatal Age Peak incidence occurs in the third to sixth decades of life. Sex Primary hyperaldosteronism is twice as common in women as in men. II- 2ry hyperaldosteronism: There is increased renin-angiotensin with increased aldosteron secretion; -CHF -Liver cirrhosis and ascitis -Nephrotic syndrome -Renal artery stenosis Clinical manifestations -Hypertension; -Hypokalemia; patients with severe hypokalemia report fatigue, muscle weakness, cramping, headaches, and palpitations. They can also have polydipsia and polyuria from hypokalemia-induced nephrogenic diabetes insipidus. -Metabolic alkalosis; will lower ionized calcium levels and can cause tetany. Investigations: Laboratory Studies -hypernatremia -Hypokalemia; normokalemia does not exclude primary hyperaldosteronism. Several studies have shown that 7-38% of patients with primary hyperaldosteronism have normal baseline serum levels of potassium -metabolic alkalosis -Renin levels are suppressed to less than 1 ng/mL/h in patients with primary hyperaldosteronism. -A 24-hour aldosterone excretion rate of greater than 14 ug is diagnostic of primary hyperaldosteronism Imaging Studies -CT scanning -MRI Treatment Medical medical therapy is used preoperatively to prevent the morbidity and mortality associated with hypertension and hypokalemia, thus decreasing surgical risk. - Sodium-restricted diet (<80 mEq or <2 g of sodium per day. -Potassium-sparing agent (first-step agent) such as spironolactone100 mg initially, increase to 400 mg/d for control of blood pressure. -Potassium supplementation should not be routinely administered with spironolactone because of the potential for the development of hyperkalemia. -Second-step agents include thiazides diuretics, ACE inhibitors, calcium channel antagonists, and angiotensin II blockers. Surgical Care Surgery is the main therapy for Conn syndrome. A laparoscopic adrenalectomy is favored, when possible Anesthetic considerations Preoperative correction of hypertension, CHF and volume and electrolytes imbalance specially potassium is mandatory. Mineralocorticoid deficiency -Hypo-aldosteronism Atrophy or destruction of both adrenal glands results in a combined deficiency of Mineralocorticoid and glucocorticoid ( addison disease) . -Isolated Mineralocorticoid deficiency; -Unilateral adrenalectomy -DM -Heparine therapy -congenital C\P *Hypotension; due to hypovolemia *Metabolic acidosis *Hyperkalemia; any increase in s. potassium without renal impairment, hypoaldosteronism should be considered. *hyponatremia Anesthetic management Preoperative preparation includes; *correction of fluid and electrolyte imbalance *exogenous mineralocorticoid, fludrocortison 0.1-0.3 mg\ day. Glucocorticoid excess Cushing syndrome Cushing syndrome is caused by prolonged exposure to elevated levels of either endogenous glucocorticoids or exogenous glucocorticoids Causes: -Exogenous steroid administration Symptoms of glucocorticoid excess generally occur with the administration of oral steroids; however, occasionally injections of steroids into joints and the use of steroid inhalers can cause Cushing syndrome. Patients at risk to develop cushing syndrome includes: -rheumatological, pulmonary, neurological, and nephrologic diseases that respond to steroid therapy. -Patients who have undergone organ transplants due to exogenous steroids required as part of graft antirejection medication regimens. Endogenous glucocorticoid administration -ACTH-producing pituitary adenoma ( Cushing disease). -Primary adrenal lesions; Overproduction of glucocorticoids may be due to an adrenal adenoma, adrenal carcinoma, or macronodular or micronodular adrenal hyperplasia. -Ectopic ACTH is sometimes secreted by oat cell or small-cell lung tumors or by carcinoid tumors Frequency Most cases of Cushing syndrome are due to exogenous glucocorticoids. Endogenous Cushing syndrome has been estimated at 13 cases per million individuals. Age The peak incidence of Cushing syndrome due to either an adrenal or pituitary adenoma is in persons aged 25-40 years Ectopic ACTH production due to lung cancer occurs later in life Sex The female-to-male incidence ratio is approximately 5:1 for Cushing syndrome due to an adrenal or pituitary tumor Mortality/Morbidity *Morbidity and mortality associated with Cushing syndrome are related primarily to the effects of excess glucocorticoids. However, a large primary pituitary tumor may cause panhypopituitarism and visual loss. *adrenocortical carcinomas are associated with a 5-year survival rate of 30% or less. * multiple medical problems, including hypertension, obesity, osteoporosis, fractures, impaired immune function, impaired wound healing, glucose intolerance, and psychosis. * adrenal crisis C\p Obesity -moon facies -buffalo hump -Central obesity, increased waist-to-hip ratio greater than 1 in men and 0.8 in women Skin Facial plethora abdominal striae lanugo facial hair Hirsutism and Steroid acne Cardiovascular and renal Hypertension and possibly edema may be present due to cortisol activation of the mineralocorticoid receptor leading to sodium and water retention Gastroenterologic Peptic ulceration may occur with or without symptoms. endocrine Galactorrhea and menstrual disturbances decreased libido and impotence in men. Skeletal/muscular Proximal muscle weakness Osteoporosis and osteopenia Avascular necrosis of the hip Neuropsychological emotional liability, fatigue, and depression Visual-field defects, often bitemporal, and blurred vision Adrenal crisis Investigations Laboratory Studies Hyperglycemia Hypokalemic metabolic alkalosis Biochemical evaluation of Cushing syndrome: 1-Urinary free cortisol excretion over 150 ug\ day. 2- dexamethasone suppression test; glucocorticoids inhibit secretion of hypothalamic CRH and pituitary ACTH but do not directly affect adrenal cortisol production. The overnight 1-mg dexamethasone suppression test requires administration of 1 mg of dexamethasone at 11 PM with subsequent measurement of cortisol level at 8 am.4 In healthy individuals, the serum cortisol level should be less than 2-3 ug/dL. 3-loss of circadian rhythm of cortisol secretion Normal values, 10-25 ug\ml in the morning, 2-10 ug\ml in the evening, elevated serum cortisol at 11 PM can be an early finding. Recently, measuring salivary cortisol level has gained interest, as it is a simple and convenient way of obtaining a nighttime sampl. levels less than 1.3-1.5 ng/mL exclude Cushing syndrome. 4- A plasma ACTH of less than 5 pg/mL is suggestive of a primary adrenal tumor. An ACTH level greater than 10-20 pg/mL is consistent with ACTH-dependent Cushing syndrome. Imaging studies CT or MRI brain and abdomen Treatment *Hypopysectomy for pituitary tumors, or adrenalectomy for adrenal tumors. *Pituitary irradiation is employed when transsphenoidal surgery is not successful or not possible *Patients with endogenous Cushing syndrome who undergo resection of pituitary, adrenal, or ectopic tumors should receive stress doses of glucocorticoid in the intraoperative and immediate postoperative period *lifelong glucocorticoid and mineralocorticoid replacement is necessary in those patients who undergo bilateral adrenalectomy. Anesthetic considerations Preoperative management From the C\P those pt. Tend to be volume overloaded, hypertensive and hypokalemic, so Preoperative correction of these factors are essential by potassium and spironolactone. Intaoperative Patients with osteoprosis are at risk for fracture during positioning. Preoperative weakness may indicate an increased sensitivity to muscle relaxants. Supplemental steroids are indicated for; -patients with Cushing syndrome due to exogenous glucocorticoids -patients undergoing adrenalectomy Dose; I.V. hydrocortisone succinate 100 mg every 8 h beginning the evening before surgery or on the morning of surgery. Other complications of adrenalectomy include significant blood loss and unintentional pneumothorax. Pseudo-Cushing Syndrome In 1976, Smalls and associates described 3 alcoholic patients who had the physical and biochemical abnormalities of Cushing syndrome. Most of the abnormalities disappeared with 1-3 weeks of alcohol abstinence. About 30 cases have been reported. Pathophysiology The mechanism remains unclear. Most evidence suggests central stimulation of a corticotropinreleasing hormone, either at the hypothalamic or suprahypothalamic level. Persistence of abnormalities may lead to complications such as hypertension, glucose intolerance, diabetes mellitus, and osteoporosis. The most important part of the history is the extent and duration of alcohol abuse. Glucocorticoid deficiency Addison Disease Thomas Addison first described the clinical presentation of primary adrenocortical insufficiency (Addison disease) in 1855 in his classic paper, On the Constitutional and Local Effects of Disease of the Supra-Renal Capsules. Pathophysiology Addison disease is adrenocortical insufficiency due to the destruction or dysfunction of the entire adrenal cortex. It affects glucocorticoid and mineralocorticoid function. The onset of disease usually occurs when 90% or more of both adrenal cortices are dysfunctional or destroyed. Frequency The prevalence of Addison disease is 40-60 cases per 1 million population. Causes 1- idiopathic autoimmune adrenocortical insufficiency. 2- Chronic granulomatous diseases; TB, sarcoidosis, histoplasmosis. 3- Hematologic malignancies; as Hodgkin and non-Hodgkin lymphoma and leukemia. 4- Metastatic malignant disease; as metastatic cancer of the lung, breast, colon or renal cell carcinoma. 5-Infiltrative metabolic disorders; Amyloidosis and hemochromatosis. 6- AIDS. Age The most common age at presentation in adults is 30-50 years. Sex Idiopathic autoimmune Addison disease tends to be more common in females and children. Secondary adrenal insufficiency is a result of inadequate ACTH secretion by the pituitary, the most common cause of secondary adrenal insufficiency is iatrogenic, the result of the administration of exogenous glucocorticoids. C\P Patients usually present with features of both glucocorticoid and mineralocorticoid deficiency. The predominant symptoms vary depending on the duration of disease. -Hyperpigmentation of the skin and mucous membranes due to high ACTH. - vitiligo, which most often is seen in idiopathic autoimmune Addison disease. -clinical manifestations due to aldosteron deficiency; hyponatremia, hypovolemia, hypotension, hyperkalemia and metabolic acidosis -clinical manifestations due to cortisol deficiency; weakness, fatigue, hypoglycemia, hypotension, and weight loss. -Prominent gastrointestinal symptoms may include nausea, vomiting, and occasional diarrhea. - Patients with secondary adrenal insufficiency have a history of tacking cortisol. - acute adrenal crisis Investigations Laboratory Studies -ACTH stimulation test; In patients with Addison disease, both cortisol and aldosterone show minimal or no change in response to ACTH. -hyponatremia Hyperkalemia metabolic acidosis -elevated (BUN) and creatinine due to the hypovolemia with decreased glomerular filtration rate. -Hypoglycemia -adrenal autoantibodies may be present Imaging study Chest x-ray TB CT abdomen Treatment The goals of pharmacotherapy are to reduce morbidity and to prevent complications e.g adrenal crisis; 1- corticosteroid: Prednisone 5-7.5 mg PO qd in am or 5 mg PO qd in am and 2.5 mg PO qd at 45 pm. 2- mineralocorticoid: Fludrocortisone 0.05-0.1 mg PO qd; some patients may only require alternate-day dosing. Anesthetic considerations Preoperative management *ensure adequate replacement therapy *correct fluid and electrolytes disturbaces *for all patients who have received potentially suppressive doses of steroids, the daily equivalent of 5 mg of prednisone, by any route of administration- topical, inhalational or oral-, for a period of more than 2 weeks any time in the previous 12 months may be unable to respond appropriately to surgical stress. Adults normally secrete 20mg of cortisol daily, this may increase to over 300 mg under maximal stress. - 100 mg of hydrocortisone phosphate every 8 h beginning the evening before or on the morning of surgery. -an alternative low dose regimen, 25 mg of hydrocortisone phosphate at the time of induction followed by an infusion of 100 mg during the subsequent 24 h, and this might be appropriate for diabetic pt. Intaoperative ensure adequate fluid. Postoperative Continue the stress dose of steroids to gard against acute adrenal crisis. 11- beta Hydroxylase Deficiency Congenital adrenal hyperplasia (CAH) is a general term used to describe a group of inherited disorders in which a defect in cortisol biosynthesis is present with consequent overproduction of (ACTH) and secondary adrenal hyperplasia as a consequence. Causes An autosomal recessive disease. Patients with 11-beta-hydroxylase deficiency present with features of androgen excess, including masculinization of female newborns and precocious puberty in male children. Approximately two thirds of patients also have hypertension, which may or may not be associated with mineralocorticoid excess, hypokalemia, hypernatremia and metabolic alkalosis. The hypertension is initially responsive to glucocorticoid replacement, but it may become a chronic condition subsequently requiring standard antihypertensive therapy. Addison Disease and Pregnancy -Before glucocorticoid replacement therapy became available, pregnancy in patients with adrenal insufficiency was associated with a maternal mortality rate of 35-45%. -The usual glucocorticoid and mineralocorticoid replacement dosages are continued throughout pregnancy. Some patients may require slightly more glucocorticoid in the third trimester. During labor, adequate saline hydration and 25 mg of intravenous cortisol (ie, hydrocortisone sodium succinate) should be administered every 6 hours. At the time of delivery or if the labor is prolonged, high-dose parenteral hydrocortisone should be administered (100 mg q6h or as a continuous infusion). After delivery, the dosage can be quickly tapered to a maintenance dose in 3 days. Cushing Syndrome and Pregnancy The risk of maternal morbidity and a poor fetal outcome is significant when Cushing syndrome coexists with pregnancy. Maternal hypertension may antedate the pregnancy but becomes worse in two thirds of patients. Preeclampsia or pregnancy-induced hypertension is noted in approximately 10% of patients. Gestational DM occurs in approximately one third. Congestive heart failure associated with severe hypertension occurs in 10%. Wound breakdown after surgery is possible. Severe proximal myopathy and mental problems ranging from emotional lability to profound psychosis should be added to the list of medical problems that may occur. Primary Hyperaldosteronism and Pregnancy Patients present with hypertension, hypokalemia, and elevated urine potassium levels. The goals of medical therapy should be adequate control of blood pressure and replacement of potassium spironolactone and angiotensin-converting enzyme inhibitors, are contraindicated in patients who are pregnant. Methyldopa, beta-blockers, and calcium channel blockers have been used with variable outcomes