tox and environmental Flashcards
GHB overdose sx
slow: CNS depression, hypoventilation, bradycardia
fast: myoclonus, seizures
GHB withdrawal sx
agitation, delirium, seizures
beta-blocker overdose tx
fluids and pressors
insulin 1u/kg bolus
glucagon 5q10 x 3 doses
intralipid
CCB overdose tx
insulin 1u/kg bolus
calcium gluconate 3g
intralipid
dig overdose tx
Digibind 10-20 vials
heroin overdose tx (and when to use it)
opioid-naive: 0.4 mg IV
opioid-dependent: 0.04-0.1 mg (to prevent inducing withdrawal)
when to use it: obtunded, miotic, RR < 12, and O2 sat < 90% (all others can be observed)
*in all cases: may uptitrate to max 10 mg
organophosphate overdose tx
atropine 2 mg, double q5-30m until secretions controlled –> pralidoxime 1-2g over 15-30m
dig: 2 pathognomonic EKG findings
PAT w/block (rare)
bidirectional VT
dig: most common dysrhythmia
PVCs
dig: most common EKG change
Salvador Dali STs
regularized afib
dig toxicity
naloxone: onset of action
1-6 mins depending on route
naloxone: duration of effect
20-90 mins depending on route
naloxone gtt dose
2/3 wake-up dose
check this before giving physostigmine
EKG (for blocks, TCA)
Librium taper
6 50 mg tabs
- day 1: 1 tab TID
- day 2: 1 tab BID
- day 3: 1 tab
naloxone: full dose
2 mg
black widow vs brown recluse
black widow: neurotoxins (ACh and NE) > fake appy, neuroexcitation opioids and benzos, antivenin if severe
brown recluse: cytotoxic enzymes > local tissue necrosis (no antivenin)
cholinergic toxidrome
SLUDGE and killer Bs (bradycardia, bronchorrhea, bronchospasm)
dextromethorphan toxidrome
like PCP: CNS sx like visual hallucinations, rotary nystagmus, tachycardia (reliable), mydriasis, hyperthermia
APAP overdose mechanism
overdose overwhelms normal metabolic pathways (sulfation and glucuronidation), shunting the rest of of the APAP to the CYP450 pathway which generates NAPQI, which requires glutathione to detox it
rapid depletion of glutathione stores leads to NAPQI accumulation and hepatotoxicity
acute mountain sickness: tx
halt ascent, Diamox (except in sulfa allergy)
decompression sickness
gas bubbles go free > obstruct/inflame tissues/vasculature mins/hours after surfacing
- type 1: joints (“bends”), skin (mottling), extremity lymphatic obstruction
- type 2: cardiopulmonary (“chokes”), neuro (“staggers”), upper lumbar/lower thoracic spine pain
tx is like arterial air embolism: supine position, O2, increase tissue perfusion (IVF), recompression (hyperbaric)
When does pulmonary barotrauma occur?
ascent
When do sinus squeeze and inner ear barotrauma occur?
descent
VPA toxicity
N/V, encephalopathy, hyperammonemia
tx: charcoal, L-carnitine, HD
how to dose bicarb in TCA toxicity
50 mEq IV at a time until QRS narrows
then gtt @150 mEq in 1L D5W at 2-3xM
When do you stop cooling a hyperthermic pt?
39 degrees, to avoid overshoot
cyclosporine can cause
hyperK, hyperuricemia, HTN, nephrotoxicity
azathioprine can cause
marrow suppression, pancreatitis, hepatitis, jaundice
oil of wintergreen toxicity and blood gas
highly-concentrated ASA (deadly to a kid)
early resp alkalosis, later gap metabolic acidosis
myasthenia pathophysiology
autoantibody binds nicotinic ACh receptors > prevents ACh binding > neuromuscular weakness
tetanus toxin pathophysiology
prevention of presynaptic release of inhibitory neurotransmitters (GABA and glycine)
botulinum toxin pathophysiology
inhibition of presynaptic release of ACh > flaccid paralysis
NAC mechanism
restores glutathione
What dose of acetaminophen is typically required to cause significant liver damage?
150 mg/kg or greater
sudden sniffing death syndrome
hydrocarbon ingestion > catecholamine surge > ventricular dysrhythmia
avoid procainamide, sotalol, amio (classes IA and III)
calcium channel blocker toxicity tx
glucagon (although this works more w/beta-blocker toxicity)
calcium chloride
high-dose insulin
epinephrine
when to avoid rewarming in frostbite
if there’s a risk of refreezing
trench foot
prolonged wet/cold (but nonfreezing) exposure causing reversible neurovascular injury
just the toes = chilblains
symptom of early radiation exposure
vomiting
when to antibiose animal bites
cat bite
wound requiring closure
immunocompromised pt
hand/genitalia
danger of physostigmine
asystole
drugs associated with noncardiogenic pulmonary edema
meprobamate, opioids, Narcan, PCP, aspirin
isopropyl EtOH tx
supportive, sometimes HD
methanol tx
fomepizole
ethylene glycol tx
fomepizole
methylene chloride toxicity mimics
CO poisoning
electrolyte abnormality that worsens dig toxicity
HYPOkalemia
