Endocrinology

Question 1

Life threatening causes of polydispsia? (List 3)

Answer 1

DI (central and nephrogenic), DM, primary polydipsia

Question 2

DDx of polydipsia?

Answer 2

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

Question 3

Clinical features of DKA

Answer 3

polyuria, polydipsia, dehydration, nausea/vomiting, abdo pain, tachypnea - Kussmaul breathing, fruity acetone breath, altered mental status

Question 4

Definition of DKA?

Answer 4

1. Random BG > 11.1
2. pH < 7.3 or bicarb < 15
3. urine/serum ketones

Question 5

Fluid management in DKA?

Answer 5

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

Question 6

Risk factors for cerebral edema (list 4)?

Answer 6

Elevated BUN
Low PCO2 (initial acidosis)
Treatment with bicarb
Failure of measured Na to rise with treatment
Age < 3 years
New-onset diabetes

Question 7

Hypoglycemia WITHOUT ketones is consistent with?

Answer 7

hyperinsulinism or FAO (ex. MCAD)

Question 8

Components of critical sample?

Answer 8

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

Question 9

Definition of hypoglycemia?

Answer 9

Blood glucose < 3.3 WITH symptoms (altered LOC, confusion, seizures)

or blood glucose < 2.7 WITHOUT symptoms

Question 10

Symptoms of hypoglycemia?

Answer 10

• Adrenergic: palpitation, anxiety, tremors, hunger, sweating
• Neuroglycopenic: irritability, headache, confusion, fatigue, seizure, LOC

Question 11

Management of hypoglycemia?

Answer 11

• 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)

Question 12

Which toxins cause hypoglycemia?

Answer 12

ethanol, beta-blockers, oral hypoglycemics (sulfonylureas)

Question 13

How does growth hormone (GH) deficiency present in infants?

Answer 13

hypoglycemia and micropenis (< 2 cm stretched penile length)

Question 14

Lab findings in adrenal insufficiency?

Answer 14

hyponatremia, hypoglycemia, hyperkalemia, metabolic acidosis, possible hypercalcemia; low cortisol (can also do ACTH stim test)

Question 15

Treatment of adrenal insufficiency?

Answer 15

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

Question 16

3 common presentations of CAH?

Answer 16

ambiguous genitalia
acute salt wasting crisis (infants)
precocious puberty (virilization)

Salt wasting occurs after 2 weeks of life (usually 2-5 weeks old)

Question 17

Most common cause of CAH?

Answer 17

21-hydroxylase deficiency

Question 18

Stress dose steroids in CAH?

Answer 18

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)

Question 19

Clinical presentation of pheochromocytoma?

Answer 19

episodic headache, palpitations, sweating, flushing, tachycardia, HTN (paroxysmal, occurs when symptomatic)

Question 20

How to treat HTN in pheochromocytoma?

Answer 20

alpha-blocker (ie. Prazosin, sodium nitroprusside IV).

*Unopposed beta-blockade should be avoided as it can cause severe hypertension.

Question 21

Lab workup of suspected pheochromocytoma?

Answer 21

elevated urine catecholamines and plasma metanephrines – then find the mass with CT or MRI

Question 22

Clinical presentation of diabetes insipidus?

Answer 22

Polyuria, enuresis, polydipsia, signs of dehydration with “normal” urine output

Question 23

Lab findings of diabetes insipidus?

Answer 23

High serum Osm (> 300) and sodium (> 145) in presence of dilute urine (Osm < 600 mOsm/L)

Blood glucose normal; Cr normal.

Question 24

Causes of diabetes insipidus?

Answer 24

1. 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
2. Nephrogenic DI: sex linked recessive, renal disease, PCKD, chronic pyelonephritis, lithium, SCD, idiopatic

Question 25

Lab criteria for diagnosing SIADH?

Answer 25

1. Hyponatremia (Na< 125), low serum Osm
2. High urine osmolarity (> 100)
3. Higher than appropriate urine Na
4. Normal renal/adrenal/TSH, absence of volume depletion

Question 26

Symptoms of hyponatremia

Answer 26

anorexia, headache, lethargy, N/V, disorientation, seizures, coma

Question 27

Causes of SIADH?

Answer 27

bacterial meningitis (50%), PPV (20%), RMSF (70%), mod/severe illness, nausea, pain

Question 28

Symptoms of severe/ symptomatic hyponatremia?

Answer 28

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)

Question 29

Symptoms of hypercalcemia?

Answer 29

Bone pain, abdominal pain (peptic ulcer), constipation, psychiatric
In neonate –> hypotonia, listlessness, constipation, vomiting, resp distress, apnea
Cardiac: HTN, short QTc

Question 30

Xray findings of hyperparathyroidism?

Answer 30

demineralization and bone resorption, osteitis fibrosis cystica

Question 31

Manifestations of hypocalcemia?

Answer 31

• 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

Question 32

What are Chvostek and Trousseau signs?

Answer 32

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)

Question 33

Clinical manifestations of rickets?

Answer 33

bowed legs, limb pain and swelling, seizures, failure to thrive (RTA), hypocalcemia, radiographic

Question 34

Radiologic features of rickets?

Answer 34

widening and irregularity of epiphyseal plates, cupper metaphyses, fractures and bowing of weight-bearing limbs

Question 35

Signs and symptoms of thyroid storm?

Answer 35

fever (often as high as 41 degrees), tachycardia, bounding pulses (wide pulse pressure) , HTN, goiter, exophthalmos, tremulous, restless, mania/delirium, psychosis

Question 36

Treatment of thyroid storm?

Answer 36

B-adrenergic antagonist (propranolol or esmolol); lower body temperature with sponging, cooling blanket and acetaminophen, Methimazole, steroids

Question 37

Clinical presentation of neonatal thyrotoxicosis?

Answer 37

newborns born to mothers with history of hyperthyroidism

FTT, tachycardia, CHF, goiter and exophthalmos

Question 38

Symptoms of congenital hypothyroidism?

Answer 38

constipation, prolonged jaundice, large posterior fontanelle, umbilical hernia, coarse cry, poor feeding, hypotonia, hypothermia –> impaired neurologic development if treatment delayed past 1 month