Emergency Med Flashcards
What should the first step be in treating a patient with a very recent pill overdose of unknown type?
gastric lavage, which is most useful in the first hour but can be helpful up to two hours after ingestion
When is gastric lavage indicated and contraindicated?
- indicated within the first two hours of a toxic ingestion
- contraindicated for those with altered mental status or a caustic ingestion
Describe the role of gastric emptying in the treatment of poisoning/overdose.
- gastric lavage can be useful in the first two hours
- whole bowel irrigation is only useful for massive iron ingestion, lithium overdose, and ingestion of drug-filled packets (e.g. smuggling)
- ipecac, cathartics, and forced diuresis are never helpful
- gastric emptying is always wrong with altered mental status, caustic ingestion, and acetaminophen overdose
What are the indications for whole bowel irrigation?
massive iron ingestion, lithium overdose, and ingestion of drug-filled packets (i.e. smuggling)
Gastric emptying should never be used in what circumstances?
- patients with altered mental status
- caustic ingestions
- acetaminophen overdose
What are the two most common causes of death by overdose?
aspirin and acetaminophen
What is the best initial management of altered mental status of unclear etiology?
give naloxone and glucose; these work instantly, have no adverse effects, and treat very common etiologies
What roll does charcoal play in treating overdose?
it is benign and occasionally helpful so should be given to anyone with a pill overdose
What are two circumstances in which flumazenil should not be given?
- anyone who chronically uses benzodiazepines as this may induce an acute, fatal withdrawal
- anyone who also took TCAs as benzodiazepines may be preventing seizures in those with a TCA overdose
How should acetaminophen overdose be managed?
- if a clearly toxic amount (more than 8-10 grams) was ingested within the last 24 hours, give n-acetylcysteine
- if an unknown about was taken, get a drug level
When is n-acetylcysteine ineffective for the treatment of acetaminophen overdose?
when the ingestion was more than 24 hours ago
How does charcoal affect the effectiveness of N-acetylcysteine?
it doesn’t and the two can be given together
Describe the presentation, including ABG, and treatment of aspirin overdose.
- presents with tinnitus, altered mental status, renal toxicity, hyperventilation, and an anion gap metabolic acidosis
- hyperventilation produces a respiratory alkalosis and inhibition of oxidative phosphorylation produces a lactic acidosis
- typical ABG has a nearly normal pH as these two negate one another
- treat with alkalinization of the urine to increase excretion
Describe the presentation and management of TCA overdose.
- presents with anticholinergic effects, seizures, and arrhythmias
- management should start with an ECG and treatment with sodium bicarbonate to protect the heart against arrhythmia
How should caustic ingestion be managed?
- do not attempt to reverse acids or bases
- flush out caustics with high volumes of water and perform an endoscopy to assess the injury
Describe the pathophysiology, presentation, ABG, diagnosis, and treatment of carbon monoxide poisoning.
- CO binds oxygen and prevents the release of O2 into peripheral tissues, causing a functional anemia
- presents with dyspnea, lightheadedness, confusion, seizures, and ultimately death from MI
- ABG demonstrates a lactic acidosis predominating over a respiratory alkalosis
- PaO2 and SaO2 will be normal, so diagnosis requires a carboxyhemoglobin level
- treat with 100% in most cases; use hyperbaric oxygen for those with CNS symptoms, cardiac symptoms, or a metabolic acidosis
Describe the pathophysiology, etiology, presentation, diagnosis, and treatment of methemoglobinemia.
- oxidation of hemoglobin produces ferric iron which cannot carry oxygen
- this is most often secondary to benzocaine and other anesthetics, nitrites, nitroglycerin, or dapsone exposure
- presents with dyspnea, cyanosis, headache, confusion, seizures, and metabolic acidosis
- PaO2 is likely normal because this is a measure of unbound oxygen and SaO2 is ~85%, so diagnosis requires a methemoglobin level
- the best initial therapy is 100% oxygen and the most effective is methylene blue
Cyanosis in the presence of a normal PaO2 is suggestive of what illness?
methemoglobinemia
What is the best initial step in treating organophosphate poisoning?
atropine
What is the best initial step in treating nerve gas exposure?
atropine because it inhibits the metabolism of acetylcholine and produces cholinergic poisoning
Organophosphates and nerve gas cause death due to what?
bronchospasm, bronchorrhea, and respiratory arrest
Describe the presentation, diagnosis, and treatment of digoxin toxicity.
- most commonly presents in those with hypokalemia because potassium is a competitive inhibitor of digoxin
- presents with GI upset, hyperkalemia, visual disturbance, confusion, and arrhythmia
- the best initial test is a potassium level and an ECG, which will show downslopping of the ST segment
- the most accurate test is a digoxin level
- treat with potassium regulation and digoxin-specific antibodies
Describe the presentation, diagnosis, and treatment of lead poisoning.
- presents with abdominal pain, acute tubular necrosis, sideroblastic anemia, peripheral neuropathies, and memory loss/confusion
- the best initial test is a free erythrocyte protoporphyrin but the most accurate is a venous lead level
- treat with succimer if level is > 45, dimercaprol and EDTA if greater than 70
Describe the presentation and treatment of mercury poisoning.
- it presents with neurologic problems if orally ingested and interstitial fibrosis if vapors are inhaled
- chelating agents like dimercaprol and succimer are effective at limiting neurologic toxicity and preventing progression of pulmonary disease, but the fibrosis is irreversible