Endocrinology Flashcards
Life threatening causes of polydispsia? (List 3)
DI (central and nephrogenic), DM, primary polydipsia
DDx of polydipsia?
o Diabetes mellitus
o Diabetes insipidus (ADH deficiency - CNS causes vs. nephrogenic)
o Sickle cell
o Less common: electrolyte imbalance, catecholamine excess, cystinosis, medications (lithium, methylxanthines, diuretics, other nephrotoxins)
o Primary polydipsia: ingestion of water in excess of that needed to maintain water balance
o Bartter syndrome
o Catecholamine excess – pheochromocytoma, neuroblastoma, ganglioneuroma
Clinical features of DKA
polyuria, polydipsia, dehydration, nausea/vomiting, abdo pain, tachypnea - Kussmaul breathing, fruity acetone breath, altered mental status
Definition of DKA?
- Random BG > 11.1
- pH < 7.3 or bicarb < 15
- urine/serum ketones
Fluid management in DKA?
o Initial fluid resuscitation: 10ml/kg NS bolus over 30 minutes, can repeat if ongoing hypoperfusion or tachycardia
If not in shock - 5-7 mm/kg over 1 hour
o Ongoing fluids: 4-6ml/kg/hr (max 250ml/hr), initial NS, D10 if glucose <15 or <25 and dropping by 5. Add 40mmol/L KCl if K <5/5.5 and pt voided.
o Insulin 0.1U/kg/hour after first hour
Risk factors for cerebral edema (list 4)?
Elevated BUN Low PCO2 (initial acidosis) Treatment with bicarb Failure of measured Na to rise with treatment Age < 3 years New-onset diabetes
Hypoglycemia WITHOUT ketones is consistent with?
hyperinsulinism or FAO (ex. MCAD)
Components of critical sample?
blood glucose, gas, lactate, ammonia, electrolytes, insulin, growth hormone, free fatty acids, cortisol, acyl carnitine, amino acids beta-hydroxybutyrate, urine ketones, urine organic acid, C- peptide
Definition of hypoglycemia?
Blood glucose < 3.3 WITH symptoms (altered LOC, confusion, seizures)
or blood glucose < 2.7 WITHOUT symptoms
Symptoms of hypoglycemia?
- Adrenergic: palpitation, anxiety, tremors, hunger, sweating
- Neuroglycopenic: irritability, headache, confusion, fatigue, seizure, LOC
Management of hypoglycemia?
- Initial step: Rule of 50’s: IV/IO 0.5 g/kg = 5 ml/kg D10, 2 ml/kg D25, 1 ml/kg D50; no access can give glucagon 0.03 mg/kg (max 1mg) IM/SC
- Then D10 NS infusion 1.5 maintenance (GIR 6-8 mg/kg/min)
Which toxins cause hypoglycemia?
ethanol, beta-blockers, oral hypoglycemics (sulfonylureas)
How does growth hormone (GH) deficiency present in infants?
hypoglycemia and micropenis (< 2 cm stretched penile length)
Lab findings in adrenal insufficiency?
hyponatremia, hypoglycemia, hyperkalemia, metabolic acidosis, possible hypercalcemia; low cortisol (can also do ACTH stim test)
Treatment of adrenal insufficiency?
o Hydrocortisone 50-100 mg/m2 IV (if no BSA give 1-2 mg/kg); continue high dose steroids 48 hours
o IV fluids – NS boluses, then D10W NS with no K
o treat hyperkalemia if cardiac ECG changes (peaked T waves, prolonged QRS, Vfib)
o hypoglycemia - dextrose and steroids
o treat infection or precipitating factor
3 common presentations of CAH?
ambiguous genitalia
acute salt wasting crisis (infants)
precocious puberty (virilization)
Salt wasting occurs after 2 weeks of life (usually 2-5 weeks old)
Most common cause of CAH?
21-hydroxylase deficiency
Stress dose steroids in CAH?
If unwell - 50 mg/m2 hydrocortisone IM/IV
If well appearing (but fever)– give usual dose PO but given TID (3X daily dose), or HC 50 mg/m2 div TID (given PO)
Clinical presentation of pheochromocytoma?
episodic headache, palpitations, sweating, flushing, tachycardia, HTN (paroxysmal, occurs when symptomatic)
How to treat HTN in pheochromocytoma?
alpha-blocker (ie. Prazosin, sodium nitroprusside IV).
*Unopposed beta-blockade should be avoided as it can cause severe hypertension.
Lab workup of suspected pheochromocytoma?
elevated urine catecholamines and plasma metanephrines – then find the mass with CT or MRI
Clinical presentation of diabetes insipidus?
Polyuria, enuresis, polydipsia, signs of dehydration with “normal” urine output
Lab findings of diabetes insipidus?
High serum Osm (> 300) and sodium (> 145) in presence of dilute urine (Osm < 600 mOsm/L)
Blood glucose normal; Cr normal.
Causes of diabetes insipidus?
- Central = AHD deficiency: head injury, meningitis, idiopathic, suprasellar tumors and treatment by surgery and/or radiotherapy (craniopharyngioma/optic nerve glioma), midline cleft palate, septic optic dysplasia, Wolfram syndrome, histiocyostis X
- Nephrogenic DI: sex linked recessive, renal disease, PCKD, chronic pyelonephritis, lithium, SCD, idiopatic
Lab criteria for diagnosing SIADH?
- Hyponatremia (Na< 125), low serum Osm
- High urine osmolarity (> 100)
- Higher than appropriate urine Na
- Normal renal/adrenal/TSH, absence of volume depletion
Symptoms of hyponatremia
anorexia, headache, lethargy, N/V, disorientation, seizures, coma
Causes of SIADH?
bacterial meningitis (50%), PPV (20%), RMSF (70%), mod/severe illness, nausea, pain
Symptoms of severe/ symptomatic hyponatremia?
Usually asymptomatic until Na < 125
3% saline, 3 ml/kg every 10-20 min, consider Lasix + NS infusion. Treat underlying cause. Anti-epileptics if needed for ongoing choices (fosphenytoin/ phenytoin good choices as they inhibit ADH release)
Symptoms of hypercalcemia?
Bone pain, abdominal pain (peptic ulcer), constipation, psychiatric
In neonate –> hypotonia, listlessness, constipation, vomiting, resp distress, apnea
Cardiac: HTN, short QTc
Xray findings of hyperparathyroidism?
demineralization and bone resorption, osteitis fibrosis cystica
Manifestations of hypocalcemia?
- neuromuscular instability/tetany
- paresthesias to perioral region hands and feet, muscle cramps
- seizures, laryngospasm, bronchospasm
- Trousseau’s sign
- Chvostek’s sign
- Cardio: hypotension, congestive heart failure, prolonged QT, dysrhythmia.
- Papilledema
What are Chvostek and Trousseau signs?
Seen in hypocalcemia
- Trousseau’s sign: carpopedal spasm with inflation of a BP cuff for >3 minutes
- Chvostek’s sign: contraction of the ipsilateral facial muscle induced by tapping of the facial nerve in front of the ear (present in 10% of normal people)
Clinical manifestations of rickets?
bowed legs, limb pain and swelling, seizures, failure to thrive (RTA), hypocalcemia, radiographic
Radiologic features of rickets?
widening and irregularity of epiphyseal plates, cupper metaphyses, fractures and bowing of weight-bearing limbs
Signs and symptoms of thyroid storm?
fever (often as high as 41 degrees), tachycardia, bounding pulses (wide pulse pressure) , HTN, goiter, exophthalmos, tremulous, restless, mania/delirium, psychosis
Treatment of thyroid storm?
B-adrenergic antagonist (propranolol or esmolol); lower body temperature with sponging, cooling blanket and acetaminophen, Methimazole, steroids
Clinical presentation of neonatal thyrotoxicosis?
newborns born to mothers with history of hyperthyroidism
FTT, tachycardia, CHF, goiter and exophthalmos
Symptoms of congenital hypothyroidism?
constipation, prolonged jaundice, large posterior fontanelle, umbilical hernia, coarse cry, poor feeding, hypotonia, hypothermia –> impaired neurologic development if treatment delayed past 1 month
