Toxicology Flashcards
What are the top 3 medications that can be given to a patient in a coma that wont hurt them and might fix it?
What is the triad of opioid overdose?
Whats first line medication for seizure?
Glucose
Naloxone (Narcan)
Thiamine
Triad of opioid overdose:
- CNS depression
- Resp depression
- Miosis (constriction)
Seizure med: diazepam, if this fails give phenobarbital
Decontamination:
- when is emesis indicated?
- which medication can be used to induce vomiting?
- when is emesis CI?
Emesis indicated:
- only in patiens with intact gag reflex
- must be within 1hr of ingestion
- for drugs not absorbed by charcoal
Medication used to induce vomiting = ipecac
CI:
- if caustic or low viscosity hydrocarbons have been ingested
- rapid acting convulsants have been ingested (amphetamines, cocaine, cyclic antidepressants, strychnine)
Decontamination:
-gastric lavage indications
- activated charcoal
- -MOA
- -dosage
- -why do we mix with sorbitol?
- what toxins does it not work on?
- bowel irrigation
- -indications
- -medication used
Gastric lavage indications:
- suspected serious ingestions when emesis has failed
- pts are lethargic or uncooperative
- gag-reflex is markedly depressed
ACTIVATED CHARCOAL:
-MOA: binds most poisons, great absorption
- Dosage: if ingested poison is known, give at least 10x that weight in activated charcoal.
- Mix with sorbital to improve tasste and provide cathartic action (speeds up GI transit, but gives you lots of pain)
- PAIL
- -potassium
- -alcohol
- -iron
- -lithium
Bowel Irrigation:
- indications: useful with sustained release and enteric coated labs.
- med: golytely
Toxicology:
-initial studies
lab studies:
- ABGs
- Chem 7 (BMP)
- EKG
- CXR
- Flat plate Xray
- urine tox
- tox screens for indicated substances.
Toxicology Kinetics:
- what is first order kinetics?
- what is zero order kinetics?
- Toxins with large volumes of distribution are effeciently/not effectiently removed by dialysis or diuresis?
-hemodialysis is effective at eliminating toxins with what property? examples.
Hemoperfusion is effective at elminating toxins with what properties? examples/
First order = a fixed % of the toxin is removed per unit time
Zero order = a fixed amount of toxin is removed per unit time
ARE NOT EFFICIENTLY
Hemodialysis is effective at eliminating toxins that are water-soluble and not highly protein bound. Ex: MELS -methanol -ethylene glycol -lithium -salicylate
Hemoperfusion is effective at eliminating toxins with poor water solubility, lipid soluble, and highly protein bound. Ex. TRI PEP-TD -TCA -paraquat -ethchlorvynol -phenobarbital -theophylline -digitoxin
What is the antidote for:
- acetaminophen
- anticholinergics
- benzos
- cyanide
- methanol/polyeth/ glycol
- narcotics
Acetaminophen: acetylcysteine
Anticholinergics: physostigmine
Benzos: Flumazenil
Cyanide: Na nitrite and Na thiosulfate
Methanol/polyeth. glycol : ethanol
Narcotics: naloxone
What is the MC cause of a change in osmolar gap greater than 30?
Acetaminophen:
- max dose?
- toxic dose?
- how long does it take for hepatotoxicity to develop?
- when is the best time to draw an acetaminophen level?
- tx of toxicity
ethanol
Acetaminophen:
- max dose: 3g
- toxic dose: 6g or greater than 140mg/kg
delayed hepatotoxicity 24-72hrs post ingestion
Best to draw acetaminophel level within 4 hrs post-ingestion
Toxicity:
- give activated charcoal
- acetylcysteine (must be given EARLY!! within 8-16hrs)
Acetaminophen Toxicity:
- sx at each of the following time intervals:
- -4hrs
- -24-48hrs
- -3-5days
- -one week out
4hrs: anorexia, n/v, sweating, may be asymptomatic
24-48hrs: abnornormalities in LFT, abd pain
3-5d: jaundice, hypoglycemia, coagulopathies, encephalopathies, renal failure
One weeK: if they make it this far they start to come back to normal.
Cocaine/Amphetamines:
- overdose sx and signs
- tx of overdose
signs and sx:
-htn
- bradycardia
- ventricular arrhythmias
- seizures & hyperthermia may cause rhabdo and myoglobinuria
- euphoria
- excitement
- restlessness
- toxic psychosis
- MI
Tx:
- GI decontamination
- tx seizure with diazepam
- DBP greater than 120 or HTN encephalopathy = nitroprusside
- EKC
- CT of head
Anticholinergics:
- examples
- sx
- tx
Examples:
-scopolomine, belladona, antihistamines, tcas, nightshade (makes you sleepy), atropine
Sx: -delerium -blurred vision -mydriasis (dilation) -hallucinations -coma -dry mucous membranes -inhibition of sweating -hyperthermia -tachycardia "Hot as a hare, red as a beet, dry as a bone, blind as a bat, and mad as a hatter" (crazy)
Tx:
- supportive
- GI decontamination
- physostigmine IV only if SEVERE!
Anticoagulants: WARFARIN:
- works on which clotting factors?
- tx
Clotting factors: II, VII, IX, X
Tx:
- supportive/GI decontamination
- baseline PT/INR
- VIt K
- FFP in a bleeding emergency
Arsenic:
- sources
- types of toxicity
- -sx of each type
- -tx
Sources:
- shellfish*
- insecticides
- in the soil
Types:
-Acute, Chronic, and Gas toxicity
Sx:
- Acute ingestion:
- -crampy abd pain, vomiting, profuse watery diarrhea, burning mucosa, conjuncitivits, tremor, seizures
- -garlic order may be present on breath
- -periorbital edema after 1-2days
- Chronic ingestion:
- -peripheral and sensory neuropathy, malaise, anorexia, alopecia, anemia, stomatitis
- Arsine Gas:
- -intravascular hemolysis and renal failure
Tx:
-acute: GI decontamination w/ GI lavage and charcoal
- chronic: penicillamine
- arsine gas: blood transfusion may be necessary, adequate hydration to prevent renal hgb.
Carbon Monoxide:
- sx
- can we trust a pulse oximiter for an accurate hgb sat reading?
- tx
Sx:
- wake up with a HA and it gets better at work
- minimal sx, no loss of consciousness
- fatigue
- malaise
- nausea, confsion, dizziness
- paresthesias
- lethargy
- chest pain, MI, hypotension, cardiac arre
NO! pulse oximetry cannot be used to access oxygenation b/c the device confuses COHgb for O2Hgb and gives falsely high values.
Tx:
-100% FiO2 for 4 hours (half life of COhgb is 4h on RA and 60mins when breaing 100% FiO2 and 15mins with 100% FiO2 at 2.5 atm w/ HBO)
HBO indicated if AMS, abnormal neuro exam, coma, myocardial ischemia, pregnant, thermal/chemical burns.
Digitalis:
- MOA on CV?
- sx
- EKG findings
- what electrolyte abnormalities is associated with digatalis overdose?
MOA:
- enhance cardiac contractility
- slow AV conduction
- enhances automaticity
Sx:
- anorexia
- nausea
- vomiting
- diarrhea
- abd pain
- blurred vision
- color vision disturbance
EKG findings: 3rd degree AV block, bradycaria, ventricular ectopy, or paroxysmal atrial tachycardia with AV block
Hyperkalemia is associated with acute in gestion of an overdose of digitalis.
Digitalis:
-tx
Tx:
-if hyperkalemia (greater than 7) treat with glucose + insulin thereapy
- symptomatic bradycardia, 2nd/3rd degree AV block = atropine and maybe pacing
- Ventricular ectopy use lidocaine
- Fab fragments (Digibind)**