Medicine_MUST KNOW

Question 1

What does CREST (syndrome) stand for?

Answer 1

Calcinosis
Rayaud's phenomenon
Esophageal dysmotility
Sclerodactyly
Telangiectasia

• • ass’d w/ anti-Centromere antibody
• • limited skin involvement, often confined to fingers & face. More benign clinical course.

Question 2

Petechiae vs. Ecchymoses vs. Purpura

Answer 2

< 5mm = Petechiae

> 5mm, < 1cm = Purpura

> 1cm = Echymosis

Question 3

Pathophysiology:

Myasthenia Gravis vs. Lambert-Eaton Myasthenic Syndrome

Answer 3

MG = autoantibodies to postsynaptic ACh receptor (block, do NOT destroy receptors)

LEMS = Autoantibodies to presynaptic Ca(2+) channel –> dec’d ACh release

Question 4

Cholinomimetic Direct Agonists?

Answer 4

Bethanechol, Carbachol, Pilocarpine, Methacholine

Question 5

Acetylcholinesterase-inhibitors?

Answer 5

Neostigmine, Pyridostigmine, Physostigmine (CNS), Edrophonium, Donepezil

Question 6

Muscarinic Antagonists?

Answer 6

Atropine (eye), Benztropine (CNS), Scopolamine (CNS), Ipra/Tiotropium (resp), Oxybutynin (G/U), Glycopyrrolate (GI/resp)

Question 7

NE: effect on MAP & HR?

Answer 7

inc’d MAP
dec’d HR

(all but β-2 agonist)

Question 8

Isoproterenol: effect on MAP & HR?

Answer 8

dec’d MAP
inc’d HR

(β-1 & 2 agonist)

Question 9

Clonidine - MOA?

Answer 9

centrally acting α-2 agonist

dec’s central symp outflow

Question 10

Clonidine - clinical use?

Answer 10

Hypertension, esp. w/ renal disease b/c no decrease in BF to kidneys

Question 11

α-methyldopa - clinical use?

Answer 11

Hypertension, esp. w/ renal disease b/c no decrease in BF to kidneys

Question 12

α-methyldopa - clinical use?

Answer 12

centrally acting α-2 agonist

dec’s central symp outflow

Question 13

Phenoxybenzamine vs. Phentolamine?

Answer 13

Phenoxybenzamine = irreversible, used for Pheochromocytomas before removing tumor

Phentolamine = reversible, give to patients on MAO inhibitors who eat tyramine-containing foods

Question 14

Common triggers/characteristics of Vasovagal (neurocardiogenic) Syncope?

Answer 14

Triggers = Prolonged standing, Emotional distress, Painful stimuli

Prodromal Sx = Nausea, warmth, diaphoresis, dizziness

• • due to excessively inc’d vagal tone
• • excellent prognosis

Question 15

Type of Syncope?

- Prodromal Sx of nausea, dizziness, warmth, diaphoresis

Answer 15

Vasovagal (neurocardiogenic)

Question 16

Type of Syncope?

Hypokalemia, Hypomagnesemia, meds that cause inc’d QT interval

Answer 16

Torsades de Pointes

acquired long QT syndrome

Question 17

Type of Syncope?

Sinus pauses on monitor, prolonged PR interval or QRS duration

Answer 17

Sick Sinus Syndrome,
Bradyarrhythmias,
AV-block

Question 18

Myasthenic Crisis Tx?

Answer 18

• Endotracheal intubation
• w/draw acetylcholinesterase-inhibitors
• ABX if 2/2 infection (most commonly is)
• Plasmapheresis or IVIG can also be given to hasten recovery of the MG crisis

Question 19

Serum Anion Gap calculation

Answer 19

= [Na+] − ([Cl-] + [HCO3−])

Question 20

Osmol Gap calculation

Answer 20

OG = measured serum osmolality − calculated osmolality

Calculated osmolality = 2 x [Na mmol/L] + [glucose mg/dL] / 18 + [BUN mg/dL] / 2.8 + [Ethanol/3.7]

(NB: divisor 18 respectively 2.8 to convert mg/dL into mmol/L)

A normal osmol gap is < 10 mOsm/kg

Question 21

Urine Anion Gap

Answer 21

UAG = Urine (Na + K - Cl)

Normal UAG = 20-90

In metabolic acidosis, kidneys secrete NH4+, usually paired w/ Cl-, so a neg UAG means high urine Cl-, which means high NH4 being secreted by kidneys (i.e. met acidosis 2/2 diarrhea)

• normal UAG in met acidosis suggests a distal RTA (also a met acidosis w/ a persistent urine pH above 5.5 suggests dRTA)