HY lecture notes:
Tx cystitis with nitrofurantoin; notably the answer in pregnant women; but there’s also a Q on one of the 2CK NBMEs where it’s the answer in a non-pregnant patient.
Osteoporosis –> Ca, PO4, PTH, and ALP are all normal.
In renal failure, secondary hyperparathyroidism –> low Ca, high PO4.
Primary hyperparathyroidism is due to adenoma –> high Ca, low PO4. Diffuse hyperplasia can be seen in MEN1 or MEN2A, but may also be adenoma.
Urinary cAMP is increased if PTH is high.
Urinary calcium is increased, not decreased, in primary PTH, despite the renal reabsorption of Ca. Why? Because blood calcium is high, so urine calcium is already high.
Evaluation of thyroid:
Palpate the thyroid gland first. (Sounds obvious and weird, but it’s an answer on the FM forms, even though, yes, this is an IM lecture).
If nodule palpated, do TSH (in real life you’d also order T3 and T4, but the USMLE assesses management in terms of TSH).
Cancer is cold, meaning it doesn’t secrete thryoid hormone.
So if TSH is normal or elevated, the patient is not hyperthyroid, so the nodule you palpated is clearly not hyper-secreting and could be cancer –> you do fine-needle aspiration (FNA) as next best step. It’s technically an ultrasound-guided FNA, but on the exam, if they ask you FNA vs USS, choose FNA.
If the TSH is low, then the patient is hyperthyroid (secondary hypothyroidism is due to decreased TSH, but the USMLE won’t go there with this type of Q because they’re genuinely looking to see if you can manage thyroid nodule without the gymnastics).
Because the patient is hyperthyroid, you do uptake scan next. You want to see if the nodule is a toxic adenoma (isolated nodule uptake) or if the nodule is part of toxic multinodular goiter (elderly; multiple nodules) or Graves (diffuse uptake).
So palpate thyroid gland –> nodule present.
Do TSH.
If TSH normal or high –> FNA.
If TSH low –> radioiodine uptake scan.
Criteria for pathologic jaundice in peds IM:
- Any jaundice on the first day of life period, regardless as to the supposed cause.
- Any jaundice present after one week if term, or after two weeks if pre-term.
- Total bilirubin >15 mg/dL.
- Direct/conjugated bilirubin >10% of total, even if total is <15.
- Rate of change of increase of total bilirubin >0.5 mg/dL/hour.
If pathologic, do phototherapy first to Tx. If insufficient and neonate getting worse –> exchange transfusion is the answer. Despite being pedantic about criteria for pathologic jaundice, the USMLE does not care about the exact guidelines for commencing phototherapy (that might be Qbank). They will merely give you a case of pathologic jaundice and then want you to choose phototherapy as the correct Tx modality, followed by exchange transfusion.
Breastfeeding jaundice –> pathologic jaundice due to increased enterohepatic circulation in the absence of adequate feeding. –> Assist with neonate’s ability to attach to breast.
Breastmilk jaundice –> pathologic jaundice due to increased enterohepatic circulation due to hormonal effects of breastmilk.
