Radiology / Emergency Flashcards
when is contrast head CT the best answer?
AV malformations
primary or metastatic tumors
when is abdominal pelvic CT the best answer
to evaluate retroperitoneal structures (pancreas, colon, prostate, testicular or renal)
when is high resolution CT scan of chest the best answer?
evaluate parenchymal lung disease and bony structures
who should NOT get a CT scan w/ contrast?
pt with renal dz (Cr > 1.5)
pt with multiple myeloma
what drug should be discontinued prior to doing a CT scan w/ contrast?
metformin
- do not resume until 48 hours after scan
test of choice for evaluating demyelinating dz
MRI
when is HIDA scan the answer?
- biliary obstruction vs. acute cholecystitis
- biliary leaks post-op
- congenital biliary atresia
when is a bone scan the answer?
- metastatic bone lesions (NOT Lytic)
- delayed fractures
- osteomyelitis
- avascular necrosis of femoral head
when is adrenal scan the answer?
test of choice to localize pheochromocytoma when MRI/CT scan is not diagnostic
initial test of choice to evaluate pulmonary embolism
V/Q scan
who should not get a V/Q scan
pts with COPD or extensive lung dz
when is a gallium scan the answer?
localizing abscesses
staging lymphomas and melanomas
pt presents to ED with acute mental status change - what do you do?
- give naloxone, thiamine and dextrose
- give O2 and saline
- check toxicology screen
- CBC, chemistry, urinalysis
- psych consult - if suicide attempt
- charcoal
when can gastric emptying be used
only within first hour of overdose
antidote - acetaminophena
N acetyl cysteine
- can give charcoal too
- prevents liver toxicity for up to 24 hours after ingestion
antidote - aspirin
bicarb to alkalinize the urine
antidote - BDZs
do NOT give flumazenil; may precipitate a seizure
antidote - carbon monoxide
100% Oxygen
antidote - digoxin
digoxin binding antibodies
- use if CNS or cardiac abnormalities
antidote - ethylene glycol/ methanol
fomepizole or ethanol
antidote - methemoglobinemia
methylene blue
- also give 100% oxygen
antidote - neuroleptic malignant syndrome
bromocriptine, dantrolene
antidote - TCAs
bicarb (protects the heart)
features of ASA o/d
- metabolic acidosis, increase AG
- respiratory alkalosis (hyperventilation)
- tinnitus
- renal insufficiency
- elevated prothrombin time
- CNS symptoms
- fever
what should you order on CCS if suspected ASA o/d?
CBC chem panel ABG PT/INR/PTT ASA (salicylate) level
how do you alkalinize the urine in ASA o/d
D5W with 3 amps bicarbonate
what drug o/d is alkalinization of the urine useful for?
ASA
TCAs
phenobarbital
chlorpropamide
what three things should be ordered on all overdose patients
ASA, acetaminophen and alcohol levels
management of BDZ overdose in ED
move the clock forward on CCS - o/d is not fatal and will resolve with time.
routine tx. of CO poisoning
100% supp O2 via non rebreathing mask
when do you use hyperbaric O2 for management of CO poisoning?
carboxy Hb > 25%
LOC
ph < 7.1
what drug can result in cyanide toxicity?
nitroprusside - esp. if pt has CRF or is receiving a high dose/prolonged infusion of nitroprusside
pt presents with N/V/D, blurred vision with yellow halos around objects and an arrhythmia with PR prolongation. Labs show hyperkalemia - what did he o/d on?
digoxin
meds/things that can cause digoxin toxicity
CCB (verapamil) quinidine amiodarone spironolactone hypokalemia
unique findings with ethylene glycol toxicity
- renal insufficiency
- kidney stones - calcium oxalate stones
- hypocalcemia - from precipitate of oxalic acid with calcium
unique findings with methanol toxicity
- visual disturbance
2. retinal hyperemia - toxicity of formic acid
what things in the pts history will make you consider methemoglobinemia?
history of nitrate, anesthetics, dapsone or other oxidants and any drug ending in caine
diagnosis of methemoglobinemia
normal pO2 on ABG with chocolate-brownish blood; methemoglobin level
pt is cyanotic with normal pO2 - what do you think of?
methemoglobinemia
Tx. heat exhaustion (sweating, NV)
normal saline IV
remove from hot environment
Tx. heat stroke (dry skin, altered mental status)
cooling measures - ice baths/packs
cardiotoxic effects of TCAs
QRS prolongation
re-entrant arrhythmias –> VT, Vfib, Torsades
Tx. TCAs toxicity
NaHCO3
lidocaine - for arrhythmias
next step in pt with TCA toxicity and wide QRS prolongation
give bicarb and transfer to ICU
CF: black widow spider bite
abdominal pain w/o tenderness, rigidity and hypocalcemia
Tx. black widow bite
antivenin
CF: brown recluse spider bite
local necrosis, bullae and dark lesions
Tx. brown recluse spider bite
debridement
most important step for any pt who has been in a fire
100% supp O2
in a pt who was in a fire - who should be intubated?
hoarseness, wheezing or stridor
burns inside the nose or mouth
which agents should be avoided in burn patients for sedation?
succinylcholine and other depolarizing agents
- increase K+ can be lethal
what pain/sedative meds do you give a burn pt?
morphine - 10 mg/hr
diazepam
Parkland formula for fluids in burn pt
4 ml x kg x %BSA
- give over 24 hours; first half in first 8 hours
first step to perform in hypothermic pt
EKG - J waves of osborn
best initial therapy for acute angle closure glaucoma
pilocarpine drops
management: unknown dry chemical powder on skin
always brush off powder first - once the visible powder is removed, then the area should be irrigated with copious amounts of low pressure water
