Endocrinology
4.1 Acute Adrenal Insufficiency
Cause: Primary adrenal insufficiency (Addison’s disease) can be atrophic in nature as seen in idiopathic or autoimmune with suppressor T-cell defect; or it can be characterized as destructive as seen in primary or metastatic cancer (Ann Hematol 1999;78:151); antiphospholipid syndrome (Chest 1998;113:1136); infection, especially in TB or in peds with sepsis (Arch Dis Child 1999;80:51); and meningococcemia with Friderichsen-Waterhouse syndrome; in amyloidosis; or in severe hemorrhage with hypotension (Arch Surg 1999;134:394). Secondary adrenal insufficiency occurs in those who may be panhypopit, those who are on chronic steroids—including the possibility of inhaled beclomethasone (J Allergy Clin Immunol 1999;103:956), or those who have just come off of corticosteroids and are now under stress; or autoimmune disorders in general (Clin Endocrinol (Oxf) 1998;49:779). Also seen in HIV in AIDS patients.
Epidem: In Addison’s Disease, peak incidence age 20-40 yr. Associated with HLA-B8 and DR 3/4, and thereby with pernicious anemia, myasthenia gravis, islet cell antibody IDDM, myxedema, vitiligo, alopecia, and primary gonadal failure.
Pathophys: 80% of gland must be destroyed to get symptoms. ACTH and MSH similar, hence increased pigmentation; both mineralocorticoid and glucocorticoid deficiencies create si/sx.
Sx: Loss of sense of well-being; nausea, vomiting, and diarrhea; salt craving and weight loss; galactorrhea, rarely; increased pigmentation if chronic.
Si: Hypotension; cachexia; hyperpigmentation, vitiligo, longitudinal nail pigment streaks if chronic; diminished axillary and pubic hair; remember not to rely on abdominal exam for acute abdomen if patient is on exogenous steroids.
Crs: 40% of those with Addison’s disease will develop other glandular failure (especially thyroid and gonadal).
Hyporeninemic hypoaldosteronism: hyperkalemia and metabolic acidosis due to depressed prostaglandin synthesis.
Adrenoleukodystrophy: in boys, a sex-linked abnormality of fatty acid metabolism.
Lab: Chemistry profile with low Na+, low HCO3, elevated K+, order a cortisol level—if < 15 µgm%, then diagnosis most likely; check TSH (J Clin Endocrinol Metab 2000;85:1388), CBC with diff looking for eosinophilia (Lancet 1999;353:1675), consider steroid-21-hydroxylase antibody and very long chain fatty acids serum levels looking for elevation for diagnosis of idiopathic (J Clin Endocrinol Metab 1998;83:3163), consider pan culture and other ID evaluation for hypotension; EKG; Graded ACTH stimulation test diagnostic (J Endocrinol Invest 2000;23:163).
Emergency Management:
IVF with 20 cc/kg bolus.
Hydrocortisone 100 mg iv (and may repeat in 6 hr) (Mil Med 1996;161:624).
Methylprednisolone 1-2 mg/kg iv if additional glucocorticoid boost needed (respiratory distress, hypotension).
4.2 Diabetic Ketoacidosis
Cause: IDDM with noncompliance and/or secondary infection most likely.
Epidem: Approximately 5% mortality (Med J Aust 1989;151:439,441,442)
Pathophys: Coma from CSF acidosis, hence rarer in metabolic than respiratory acidosis because CO2 crosses blood-brain barrier easily; HCO3 treatment may paradoxically induce/worsen coma. Atrial natriuretic peptide suppressed in children to maintain fluid and sodium (J Peds 1987;111:329).
Sx: Malaise, confusion, nausea, vomiting, abdominal pain.
Si: Kussmaul’s respirations; stupor; coma; hypotension; dehydration.
Crs: Onset over 2-3 d.
Cmplc: Cerebral edema leading to coma with 90% mortality 6-10 hr after starting treatment—especially in children (Nejm 1967;276:665) with low PaCO2 and high serum BUN (Nejm 2001;344:264). Secondary infection with Pseudomonas pseudomallei (Melioidosis), ubiquitous in Asia (Arch IM 1972;130:268).
Diff Dx: Hypoglycemia; infection; drug intoxication; appendicitis; acute renal failure; Non-ketotic, nonacidotic hyperosmolar coma—seen in the elderly with NIDDM.
Lab: Chemistry profile and blood gas, specifically looking for bicarb < 10 and pH < 7.2 (Ped Emerg Care 1996;12:347). Look for anion gap (AG) > 15 calculating the following: Na − (Cl + CO2) = AG (Nejm 1977;297:814). ABG vs venous blood gas—venous just as useful (Ann EM 1998;31:459). CBC with diff, and > 10% bandemia warrants search for secondary infection (Am J EM 1987;5:1). UA as quick test for ketones and hydration status and if secondary UTI. Consider pan culture and other ID evaluation
if source or febrile. Consider serum ketones or acetone level (Diabetes 1986;35:668). Consider measured and/or calculated osmoles—calculated osmoles = glucose/18 + 2 × Na + BUN/2.8.
if source or febrile. Consider serum ketones or acetone level (Diabetes 1986;35:668). Consider measured and/or calculated osmoles—calculated osmoles = glucose/18 + 2 × Na + BUN/2.8.
Emergency Management:
Adults with iv NS with 1 L bolus then 1 L per hr.
Peds with 20 cc/kg IVF bolus and may repeat × 1 before maintenance rate if needed; studies that call into question the use of IVF because of cerebral edema are just selecting those that are the sickest who required the most fluid resuscitation and these patients have increased water diffusion in the brain (J Peds 2004;145:164).
Regular insulin 0.33-0.44 U/kg iv push, then 7 U/hr iv continuous until glucose < 250 mg%; then 2-6 U/hr iv until glucose < 150 mg%; then routine maintenance (Arch IM 1977;137:1377); check K+ before infusing insulin unless EKG changes such as wide QRS.Related posts:
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