Toxicology: Ross--> check quizlet Flashcards
Goals of general Management
- Get the Exposure: EMS history
- Get the time of ingestion
- Substance and Amount Pill –Bottles in order to count
- Why the ingestion?
- History from patient in a quiet setting without peers
- Be a detective, ask the same question in different ways to family/friends
- What symptoms?
Criteria for Nontoxic Ingestion
- Only one substance
- Must have absolute identification
- Exposure is unintentional
-Symptom free for obs period
Easy follow up
Overdose deaths (#1 cause?)
Opioids= #1 Sedative /hypnotics/antipsychotics Cardiovascular Stimulants Alcohols Acetaminophen Antidepressants
Listen for red flags
Hx:
- suicide attempt–> Concern: Multiple substances, delayed action
- Tricyclic antidepressant–> high morbidity and mortality
- Beta blocker or CCB
- Vomiting with LOC–> airway compromise
- Lithium, aspirin. theophyline, toxic alcohols–> may require dialysis
- Muschroom or acetominophen ingestion –> High morbidity and mortality
Vitals: (questions?)
- Brady or tachy?
- hyper pr hypotension?
- Temp?
- must undress
Bradycardia/hypotension is caused by:
-b blockers calcium channel blockers, Digoxin, clonidine, organophosphates, ethanol opioids
Tachy/ Hypertension caused by?
sympathomimetics, anticholinergics, theophylline, nicotine , thyroid
Hyperthermia caused by?
-salicylates, anticholinergics, sympathomimetic, withdrawal states, NMS and serotonin syndrome
Bradypnea caused by?
Sedatives, ethanol, opiods
Tachypnea caused by?
Salicylates,metabolic acidosis, paraquat,chemical pneumonitis
Physical Exam:
- eyes?
- Skin?
- RR?
Eyes: state pupillary size and reaction to light
Skin: wet or dry (check armpits/groin)
RR
Neurological : muscle tone and conscious state
Bowel function: hyper/hypo
Bladder: retention
Increased muscle tone–> associated with which drug class?
amphetamines, phencyclidine, antipsycotics, ssri
Flaccid tone:
-assoc with?
sedative-hypnotics, narcotics, clonidine
Rigid tone: assoc with?
haloperidol, phencyclidine,strychnine,NMS
Tremor:
-associated with?
lithium, nicotine stimulant overdose or sedative-hypnotic withdrawal
Seizures:
-associated w?
TCA, amphetamines, phenothiazines,lindane,isoniazid,pesticides
Absorption:
-describe first pass?
first pass metabolism hepatic portal circulation through liver greatly reduces bio-availability
Distribution=
how substance is transported to tissue
**volume of distribution
Elimination=
Elimination: excreted or biotransformation with kidneys and liver primarily responsible
Supportive Management:
-includes assessment of ______
- *Mental Status and Ability to continue respiratory function is KEY
- Airway and central function of breathing
- During the first hours patient needs multiple re-evaluations of respiratory function
- Does patient need a reversal agent, how can we enhance elimination
SAGE=
Supportive care: ABC
antidotes: “coma cocktail” and table 47-10
gastric decontamination: removal (ipecac, lavage, and charcoal)
Elimination: dialysis, urinary excretion, hemofiltration
Altered Mental Status:
AEIOU TIPSS
KNOW
Alcohol,electrolyte,insulin,oxygen,opiate,uremia,trauma,infection, psychosis,stroke,seizure
Coma Cocktail:
(contains?) KNOW
Coma cocktail= DONT D-dextrose (D50) O- Oxygen N- Naloxone (0.1mg-0.4 mg, IV, IM, SQ) -Thiamine- 100mg IV
Pitfall of Naloxone
-We said earlier many opioid ingestions are coupled with benzodiazepine
Naloxone will reverse opioid but NOT benzo
-so potential to reverse opioid possibly put in mild withdrawal state but still sedated from Benzo.
-*AIRWAY NIGHTMARE
Have airway adjuncts or think about intubations
For gastric Decontamination will Ipecac work?
nope
_____ is better for decontamination
charcoal**
The general thinking is Not to use _____ (this product) ever
- *Ipecac
- Does more harm than good
- Needs to be administered immediately to do any good takes about 20 min to work
- Possible role in Prehospital setting with a serious Iron, Lithium
Gastric Decontamination: Lavage
“Pump the Stomach
- This procedure should never be done alone
- Many complications
- Indications are rare to never
- -Fatal ingestions that arrive within 60 min of ingestion AND are not absorbed by charcoal
- -Such as…. Iron, Lithium, Large amounts of salicylate, ingestion of sustained release products,
Enhance Elimination:
-when is charcoal useful?
**Useful for up to 1-2 hours post ingestion unless the drug is enteric coated or a slow release then 2nd doses needed
-Prevents absorption of drug and in acetaminophen enhances elimination through the enterohepatic pathway
Charcoal:
-how good is it?
=BEST form of decontamination
-low risk
Describe Charcoal
- highly porous substance which absorbs toxins
- **best given < 60 min of ingestion no longer routine management
Contraindications for charcoal include:
- Decreased Mental Status
- Very lethal if aspirated so the patient must be able to drink or consider intubation
- Hydrocarbon ingestions
- Corrosives
Charcoal:
-adverse effects?
- Adversely can cause nausea so always give with an anti-emetic, ex. Zofran
- Contraindicated when there is a suspicion of GI perforation such as ingestion of a corrosive, hydrocarbons
- Dose is 1g/kg with sorbitol, subsequent doses are without sorbitol.
Charcoal:
Multiple doses with sorbitol are not beneficial unless one of these folks
—THESE PATIENTS SHOULD DRINK CHARCOAL QUICKLY
THEOPHYLLINE, PHENOBARBITAL SALICYLATES, DAPSONE CARBAMAZEPINE QUINIDINE
Charcoal
Not helpful for :
Iron
Lithium
Lead
Or other small molecules
Whole Bowel Irrigation
copious
iron
lithium
packers
Enhancing Elimination : Hemodialysis
- low protein binding
- small volume of distribution
-Good for these OD:
salicylate, lithium, methanol, isopropanol, ethylene glycol, theophylline
Systematic Evaluation:
-what do you do first?
Respiratory Function First, Vital Signs next, MS
Systematic Evaluation:
-Has the PT ingested a lethal dose?
=**LD50
-is there an antidote?
- Decontamination Principles:
- -Toxicity depends of absorbed dose of toxin
- -does this pt need charcoal/WBI/dialysis?
Who should you always call?
CALL your LOCAL Poison Center
ROCKY MOIUNTAIN POISON CONTROL
Labs to order for overdose cases
Labs: BMP, Mag level, alcohol level, tylenol , ASA
Utox??
Does not measure a lot of substances
exrohypnol, or MDNA
Labs:
-common false positives
Amphetamines: pseudophedrine
TCA: diphenhydramine
PCP: ketamine, dextromethorphan
Labs:
-common false negatives?
- dilute urine
- Rohypnol: benzo
Treatments for absorption:
-Decrease absorption
-charcoal,wbi
Treatments for absorption:
-enhance elimination?
- Alkalinizing with bicarbonate
- Salicylate-urine
- Dialysis
Treatments for absorption:
-Prevent peripheral Effects
Antidotes: Narcan, Digi-bind, Fab fragments, chelation therapy, amyl nitrate
General Management
Unknown Ingestion
-Toxidrome: table 47.2 :
(NEED TO KNOW THESE)
-Sympathomimetic (SNS also called adrenergic)
-Opioid
-Anti-Cholinergic ( anti-parasympathetic)
-Salicylate
-Hypoglycemia
Serotonin Syndrome
-If unknown agent look for a pattern within the vital signs and physical exam to tease out an agent
Toxidrome: Anticholinergic
- Presentation?
- V/S changes?
- Causative agents?
- Delirium, Flushed skin, dilated pupils, **Hot as a hare, Dry as a bone, Red as a beet, Blind as a bat*
- V/S changes: Tachy, Hyperthermia, HTN
- Antihistamines, Scopolamine, Jimson weed, Benzotropine, TCAs, atropine
Toxidrome: Opiate/narcotic
- Presentation?
- V/S changes?
- Causative agents?
- AMS, Unresponsive, Miosis, shock
- Shallow respirations, slow resp rate, brady, hypothermia
-Opiates, Dextromethorphan
Toxidrome:
Cholinergic
?
Toxidrome:
Sympathomimetic
?
Unknown OD:
-LOOK FOR anion ____
**gap acidosis: VBG and BMP
MUDPILES
Methanol, uremia, DKA, propylene glycol, INH iron,lactic acidosis,ethylene glycol,ethanol (alcoholic keto acidosis), rhabdo, salicyclates
CHIPES
Chloral hydrate, Calcium carbonate Heavy metals Iron Psychotropic, packets,potassium Enteric-coated and slow release Solvents
THESE all have radiopaquents visible
Osmolar gap=
measured -calculated
Dont memorize this:
Calculated osmols= 2(na) + glucose/18+ bun/2.8+etoh/4.6
be able to calculate anion gap?
?
Opiote antidote=
naloxone
Organophosphates (antidote)=
atropine
Cyanide (antidote)=
Sodium Nitrite and sodium thiosulfate
Benzodiazepine= (antidote?)
flumazinil(rarely given)
Flumazenil is really only intended for ?
single intoxicant and with kids
- avoid in general
- mixed intoxicants really avoid
-complication includes intractable seizures
Toxidrome: Sympathomimetic
- Sx?
- Tx?
-Sx: Stimulants, HTN, Tachycardic, Seizures
-Amphetamines activate the adrenergic system with with alpha and beta receptor activity
increases release of norepinephrine, epinephrine, dopamine and serotonin
-TX: Benzodiazapines**
and intubate possibly
WHAT DO YOU NOT GIVE a person that overdosed on sympathomimetic? (stimulants)
DO NOT GIVE THEM BETA BLOCKERS
-**Treatment Pitfall: Beta blockade gives un-opposed alpha activity
Ex’s of stimulants
- cocaine
- amphetamines )ie ecstasy, bath salts, smokeable meth
MDMA=
- describe
- tx for overdose?
=Molly “molecular” or Ecstasy, Hallucinogen --releases large amount of serotonin serotonin triggers oxytocin and vasopressin the love trust and empathy hormones also amphetamine like affect
-Hyperthermia, psychomotor agitation, delirium
tx=cooling and benzodiazepines
19y/o college student
Doesn’t “feel well” has runny nose, cough x 2 days. Roommate states he hasn’t been acting right for about 4 hours. no drugs or etoh
otc meds
Anxious, agitated
WHAT DO YOU WANT TO KNOW?
Is he maintaining his airway? What are his vitals? 140/70, 138, 20, 97%, 100.1
GET VITALS, AIRWAY
Pt with anti-cholinergic overdose will have what Sx?
**hot as hell, blind as a bat, dry as a bone, red as beet, mad as a hatter Tachycardia, hyperthermia Mydriasis, can’t accommodate Dry skin and mucus membranes also Urinary retention, decreased bowel sounds AMS Wide QRS Hallucinations: to agitated delirium
anticholinergic cardiac toxicity: **usually tachycardias only
-Wide complex tachycardia, sodium channel blockade: tx?
sodium bicarbonate
Torsades de points: tx?
magnesium
Ventricular Dysrhythmia: tx?
lidocaine
What med can treat any anti cholinergic OD?
physostigmine* can reverse all sx BUT, you must make sure there are no other drugs on board
Major S/E of physostigmine=
seizures**
OD DDx:
- encephalitis
- head trauma
- withdrawal
Management of the Agitated Patient who you believe is in a Substance abuse psychosis or just plain psychotic
Vital sign check is important
-Hx as much as feasible: AMPLE
-approach in SAFEST manner
space, appearance, focus, exchange, stabilize and treat
test Question:
if alcoholics are in withdrawal and very agitated: tx?
benzos
-give antiipsychotic if they arent in withdrawal
Test question:
- amphetamine OD:
- Anticholinergic OD:
BENZOS= tx
Test question: CNS depressant( ie alcohol) OD: tx?
- antipsychotic med (HALDOL) or 2nd gen Planzapine –> these meds can prolong QT
- BUT Must know what their QT is
B52=
commonly used,
it’s a combo of benzo 5mg and haldol 2mg
Agitated Delirium=
=Paranoia, Hallucinations and Disorientation
-Hyperthermia
- Seemingly superhuman strength
- -unclear pathophys: Hyper K, and cpk with positional asphyxia
-chronic drug abuse (stimulants)
Agitated Delirium: tx?
benzo and check electrolytes
28 yo male biba after “friend” found him asleep in his room and could not arouse him. On arrival EMS noted shallow respirations as well as miosis. Pt had gone to work the day prior and seemed “ok”. No other hx known.
PMH: back pain post mva 1 yr ago
meds: unk
110/50,99,8,90% and 96.8, lethargic with minimal response to pain.
pt has an iv started and no meds
Steps:
- IV O2 monitor
- Naloxone
ask questions:
-is this suicide?
-is this someone trying to get high
-
CNS depression, Hypothermia, Bradycardia, Miosis=
Toxidrome= CNS depression
OPIOIDS!!!!!
Deaths are most commonly from methadone, oxycodone and morphine.
Usually associated with diversion and provider shopping.
Acetaminophen OD is due to the build up of which toxic metabolite?
- n-acetyl-p-benzoquinoneimine (NAPQI)
- causes hepatocellular necrosis
Acetaminophen OD: tx?
repletion of glutathione stores with N-Acetylcysteine NAC (precursor to glutathione)
po and **iv forms
4 Phases of Acetaminophen OD toxicity:
0-24 hours: stage one; GI symptoms n/v
24-48 Quiet stage: asymptomatic; rise of transaminases, liver tenderness
72-96 hours stage 3: Jaundice and Hepatic encephalopathy, death
4 days to ?? May survive with liver failure or resolution of symptoms RING OF FIRE Stage
Rumack-Matthew nomogram
for toxicity:
use within first 24 hrs of acetaminophen toxicity (plasma levels)
Acetaminophen OD:
-rule of 4’s (but just got changed to 150)
- 150 mg/kg= toxic dose
- 4 hour level greater than 150 ug/mL= toxicity
-150 mg/kg of N-Acetylcysteine (NAC) mucomyst PO or IV : loading dose then a 2 and 3rd doses
Acetaminophen OD:
-decontaminate w/?
- charcoal**
- tx if NAC with levels >20
**BUT NAC is useful even after 24 hours after toxicity
ASA overdose: bottom line?
Pts develop a severe metabolic acidosis with a respiratory alkalosis**
-and tinnitus
THINGS TO KNOW:
ethanol : drink with ethyl: no acidosis (unless starved)
methanol: windshield wiper, paint strippers
acidosis (it forms formic acid) with large osmolar gap: blind
isopropyl: rubbing alcohol
ketosis with no acidosis
ethylene glycol: antifreeze, de-icers–> acidosis with gap: renal failure, urine crystals
Serotonin Syndrome:
-
most often with therapeutic doses of SSRI
Cognitive, neuromuscular and autonomic dysfunction rigidity, lethargy and fever
Similar presentation to NMS 9less severe) with Hyperthermia, muscle rigidity with clonus, hyper-reflexia, shakes and cognitive dysfunction
difference is hyperreflexia and clonus
Precipitated by med increase or administration of serotonergic drugs (merperidine)
SSRI : serotonin syndrome
tx?
**Cyprohepatidine is an H1 receptor antagonist but also blocks serotonin at the 5-HT1A and 5-HT2A receptor
Things that Kill Peds in Small Doses
TCA Camphor Methyl salicylate (wintergreen oil) Calcium channel blockers **Sulfonylureas: oral hypoglycemics Clonidine Lomital Vision: alpha 2 agonist
Sulfonylureas
=children can become proudly hypoglycemic
-need admission to watch
-do not autonomically give glucose (this will cause the release of insulin) if glucose is
low then give
Neuroleptic Malignant Syndrome=
tetrad of distinct clinical features:
**fevers
**rigidity: will lead to elevated CPK
**mental status changes
autonomic instability
(hyperthermia will kill them if they are left untreated)
-caused by antipsychotics**
Tx: dantroline**
