Poisonings

What is the first and most primary thing to do on PE when the patient can’t answer questions and isn’t stabilized?

ABCs; A = airway

What is a cardiac risk when combining a lot of substances

QT prolongation, can lead to Torsades

What determines the toxicity of all substances?

Toxicity of all substances is dose dependent

What are the mechanisms of harm with poisoning?

Alteration or inhibition of cellular functioning

What are the routes of poisoning?

Ingestion

What determines the duration of patient observation in poisoning?

Duration of patient observation varies based on toxin

Which poisoning cases require psychiatric referral?

All patients with intentional poisonings should have a psychiatric referral

Which poisoning cases may require a social work referral?

Pediatric poisonings may require a social work referral

What is a limitation of history in toxicology cases?

Frequently unreliable/incomplete

What should be asked about during history taking in toxicology?

Ask about any drugs taken

Who else should be interviewed in toxicology cases?

Interview bystanders

What items should be obtained during toxicology history?

Obtain drugs/bottles etc.

Who should be contacted based on drug labels in toxicology cases?

Call pharmacy or physician on drug label

What are the components of the physical exam in toxicology?

Airway, Breathing, Circulation, vitals

What additional assessments are needed in toxicology physical exam?

Core temperature, O2 sat, hypoglycemia

What substances are associated with an ETOH breath odor?

Ethanol, methanol, isopropanol

What substances are associated with a mothballs breath odor?

Naphthalene, camphor

What substance is associated with a tin of fruit salad breath odor?

Chloral hydrate

What substance is associated with an almonds breath odor?

Cyanide

What substance is associated with a carrots/raw parsnip breath odor?

Water Hemlock

What substances are associated with a garlic breath odor?

Organophosphates

What are the overall breath odors in the toxic patient?

ETOH, mothballs, tin or fruit salad, almonds, carrots/raw parsnip, garlic

What labs are included in the toxicology overall approach?

ABCs

What is the overall management of poisoning?

initial decontamination, antidote, hemodialysis, hemoperfusion, enhanced elimination

What emesis/suction methods are used in enteral decontamination?

Ipecac

What emesis/suction decontamination is no longer recommended?

Ipecac, because it started to become associated with EDs

What is orogastric lavage reserved for?

potential lethal poisonings

When is orogastric lavage contraindicated?

if airway is unprotected, ingestion of a caustic agent, or ingestion of pills that are too large to fit through the port

What binding method is used in the gut lumen during enteral decontamination?

Activated charcoal

What is the dosing for activated charcoal?

1gm/kg or 10:1 AC to drug ratio

What are the contraindications of activated charcoal?

if airway is unprotected, ingestion of caustic agent, ingestion of agent that does not bind to charcoal, or active vomiting

What methods enhance transit time in enteral decontamination?

Cathartics, Whole bowel irrigation

What is the dosing of cathartics?

70% sorbitol 1gm/kg or 10% mag citrate 4mg/kg

What are the CIs of cathartics?

< 5yrs, ingestion of caustic agents, ingestion of agents known to cause significant diarrhea, bowel obstruction, or renal failure

How is whole bowel irrigation done?

polyethylene glycol via NG tube until rectal effluent is clear

What are the early clinical presentations of salicylate toxicity?

Nausea

What are the late clinical presentations of salicylate toxicity?

Agitation

What are the s/sxs associated with mild (

tinnitus, hearing loss, dizziness, n/v

What are the s/sxs associated with moderate (150–300 mg/kg) salicylate toxicity?

Tachypnea

What are the s/sxs associated with severe (>300 mg/kg) salicylate toxicity?

Abnormal MS

What occurs in Phase 1 of salicylate acid/base disturbance?

Hyperventilation

What occurs in Phase 2 of salicylate acid/base disturbance?

Aciduria

What occurs in Phase 3 of salicylate acid/base disturbance?

Dehydration

What is the most popular OTC analgesic in the US?

Acetaminophen (APAP)

What is the primary metabolism route of acetaminophen (APAP)?

Liver >>> renal metabolism

How quickly are peak levels reached after acetaminophen (APAP) ingestion?

Rapid GI absorption results in peak levels within 2 hours

What are the metabolic pathways of acetaminophen (APAP)?

Metabolism through sulfation and glucuronidation >>> oxidation by cytochrome P450

What toxic metabolite is produced by cytochrome P450 oxidation of acetaminophen (APAP)?

NAPQI

What constitutes a single ingestion toxic exposure to acetaminophen (APAP)?

>10g or 200 mg/kg

What constitutes toxic exposure to acetaminophen over 24 hrs (APAP)?

>10g or >200 mg/kg

What constitutes toxic exposure to acetaminophen over 2 days (APAP)?

>6g or >150mg/kg per 24 hr

What is the 140s rule in acetaminophen toxicity?

140mg/kg toxic

What occurs in Stage 1 of acetaminophen toxicity?

The first 24 hr following exposure: Anorexia, nausea, vomiting, malaise

What occurs in Stage 2 of acetaminophen toxicity?

Days 2-3: Same as stage 1

What occurs in Stage 3 of acetaminophen toxicity?

Days 3-4: Progression to fulminant hepatic failure

What occurs in Stage 4 of acetaminophen toxicity?

Up to week 2: Recovery

What is included in the evaluation of acetaminophen toxicity?

Ingestion history

What are the management steps for acetaminophen toxicity?

ABCs

How is N-acetylcysteine administered?

140 mg/kg loading dose PO or NG tube within 24–36 hours, then 17 mg/kg q4° for 17 doses

What are the characteristics of N-acetylcysteine?

IV dosing also available

What are the types of caustic exposures?

Intentional exposures

What are desiccants and their effect?

Desiccants: Extract water, destroy cell

What is the effect of acids (pH

Hydrogen ions released cause coagulation necrosis, cell death, and eschar formation

What are examples of industrial acids?

hydrochloric, sulfuric, hydrofluoric, formic

What are examples of home acids?

sulfuric, hydrochloric, formic, acetic, hydrofluoric

What is the effect of alkali (pH>11)?

Hydroxide causes liquefaction necrosis

What are examples of industrial alkali?

sodium hydroxide, potassium hydroxide, calcium hydroxide, lithium hydroxide

What is an example of a home alkali?

sodium hydroxide

What are the caustic substances?

desiccants, acids, alkali

What are the laryngotracheal injury symptoms of caustic exposure?

Dysphonia

What are the gastrointestinal injury symptoms of caustic exposure?

Dysphagia

What are the stages of esophageal injuries in caustic exposure?

Stage 1: edema and hyperemia

What is helpful for resuscitation?

two IVs

What shouldn't be given in caustic management?

no activated charcoal, no ipecac

What is usually the best approach to any type of poisoning?

dilution

What are examples of barbiturates?

Phenobarbital

What are the effects of barbiturates?

Depress nervous and musculoskeletal function

What are examples of benzodiazepines?

Diazepam, alprazolam

What do benzodiazepines affect?

the GABA receptor to make neurons less excitable

What are benzodiazepines associated with?

morbidity and mortality is low

What are examples of nonbenzodiazepine sedatives and their characteristics?

Ex Buspirone, Chloral hydrate

What are the clinical presentations of barbiturate toxicity?

Drowsiness

What are the clinical presentations of benzodiazepine toxicity?

Drowsiness

What is characteristic of non-benzodiazepine sedative poisonings?

Non-benzodiazepine sedative poisonings have a wide assortment of features.

What is the antidote for benzodiazepine toxicity?

Flumazenil

What can you give for agitation in anticholinergic management?

benzodiazepines, first thing to do because agitation is dangerous

What properties do opioids possess?

analgesic and sedative properties

What nerves do opioids affect?

afferent nerves in the CNS, PNS, and GI tract

What receptors do opioids act as agonists for?

mu, kappa, and delta

How are opioids metabolized?

metabolized mostly through the liver

What is the absorption pattern of opioids?

rapid absorption with peak levels between 30–60 minutes

What are the most commonly involved opioids?

Heroin

What are the clinical features of opioid toxicity?

CNS depression

What is the opioid syndrome triad?

Coma

What are the clinical features of opioid withdrawal?

Anxiety

What are the complications of methadone?

prolonged QT predisposing to torsades de pointes

What are the complications of propoxyphene?

prolonged QT, widened QRS, heart block, ventricular bigeminy, seizures

What are the complications of tramadol?

agitation, hypertension, seizures

What are the complications of heroin?

acute lung injury