Toxicology Flashcards
Typical metabolic abnormality or laboratory finding to expect in Beta-blocker toxicity or overdose
❌Catecholamine induced hepatic glucose production and glycogen breakdown▶Hypoglycemia
Which arterial blood gas result would you find in a carbon monoxide poisoning?
- Lactic acidosis→↓ bicarbonate, ↓pH (tissue hypoxia)
- ↑ Carboxyhemoglobin levels
Which finding do you expect to find in cell blood count in a patient with chronic carbon monoxide poisoning?
Kidney responds to tissue hypoxia→↑EPO→Secondary polycythemia
Treatment for anticholinergic toxicity
Physostigmine►cholinesterase inhibitor
Most common sources of exposure for cyanide intoxication
- Dermal: partial immersion in liquid cyanide or cyanide solutions or contact with molten cyanide salts
- Inhalational: Hydrogen cyanide, product of combustion from nitrogen-containing synthetic polymers (foam, cotton, paint, silk, etc)►Faster onset of symptoms
- Intestinal: ingestion of amygdalin (cyanogenic glucoside in apricot seeds), cyanide directly
Which empiric treatment should be done in unconscious victims of smoke inhalation?
Cyanide toxicity→Hydroxicobalamin►forms Cyanocobalamin; Sodium thiosulfate or Nitrites►induce methemoglobinemia
*Prevent cardiorespiratory arrest and permanent neurologic disability
Two major products of combustion in closed spaces
Hydrogen cyanide (HCN) and Carbon monoxide (CO)
Best initial management of altered mental status of unclear etiology (suspecting intoxication)
- Opiate antagonist→Naloxone (give immediately, opiate overdose is fatal)
- Dextrose
Keys on clinical presentation to diagnose aspirin overdose
- Tinnitus and hyperventilation
- Respiratory alcalosis
- Metabolic acidosis with ↑ Lactate
Best initial test when suspect tricyclic antidepressant toxicity and why?
EKG➡look for cardiac toxicity
- Widening of the QRS complex➡⬆risk ventricular arrhythmia
- Prolongs QT→Torsade de Pointes
Severe symptoms of carbon monoxide poisoning and most appropriate treatment
- Severe CO intoxication:
- Cerebral hypoxia: Drowsiness, confusion, seizures, syncope, coma
- Myocardial injury: Ventricular arrhythmia, myocardial ischemia, pulmonary edema (cardiac dysfunction or CO-induced alveolar damage)
- Lactic metabolic acidosis
- Treatment: Hyperbaric oxygen
*Not severe, treat with 100% Oxygen
Best initial and most effective therapy for Methemoglobinemia
- Best initial: 100% Oxygen
- Most Effective: Methylene blue (↓ half-life)
Treatment for Lead poisoning
- Oral: Succimer
- Parenteral: Ethylenediaminetetraacetic acid (EDTA) and dimercaprol (BAL)
Most accurate test and best initial test for Lead poisoning
- Most accurate: Lead level
- Best initial: Level of free erythrocyte protoporphyrin
Management for tricyclic antidepressant cardiac toxicity
Sodium bicarbonate for QRS widening (>100 msec) or ventricular arrhythmias
Most reliable sign of opioid intoxication. Which other clues you may find?
⬇Respiratory rate
- Bradycardia
- Acute change in mental status
- Miosis
- Hypotension
- Hypothermia
- Hypoactive bowel sounds
“BAM3H”
How do you suspect inhalant abuse acute intoxication?
- Brief transient euphoria and loss consciousness
- Highly lipid soluble➡immediate effects (typically last 15-45 minutes)
- Dermatitis due chemical exposure around the mouth or nostrils▶”glue sniffer’s rash”
- Chronic abuse of nitrous oxide➡vitamin B12 deficiency▶polyneuropathy
Remarkable and helpful laboratory finding to diagnose Ecstasy intoxication
Hyponatremia
Which etiology suggests a high anion gap metabolic acidosis with an osmolal gap?
- Poisoning with:
- Acute ethanol (most common)
- Acute Methanol
- Acute Ethylene glycol
Classical finding in acute ethylene glycol poisoning
- Rectangular, enveloped-shaped calcium oxalate crystals on urinalysis
- Most commonly antifreeze ingestion
Most common complication of acute ethylene glycol poisoning
Acute renal failure
Signs and symptoms of tricyclic antidepressant overdose or toxicity
- Hyperthermia
- Anticholinergic effects➡skin flushing, intestinal ileus, mydriasis, dry mouth, urinary retention
- Seizures
- Cardiac toxicity:
- ❌cardiac fast Na+ channels➡QRS prolongation▶⬆risk ventricular arrhythmia
- Hypotension➡can be refractory to tx➡major cause of mortality in TCA overdose
Treatment for cardiac toxicity by TCA overdose
Sodium bicarbonate➡improves systolic blood pressure, narrows QRS, ⬇incidence ventricular arrhythmia
*Alkalinization➡neutral form TCA is less available to bind Na channels
