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
How is osmolar gap calculated?
it is the difference between measured and calculated serum osmolality:
calculated = 2(Na) + BUN/2.8 + glucose/18
Describe the etiology, presentation, and diagnosis of methanol poisoning.
- methanol exposure is typically from wood alcohol, cleaning solutions, or paint thinner
- toxicity results from the toxic metabolite formaldehyde
- presents with intoxication, ocular toxicity, metabolic acidosis with an anion and osmolar gap
- treat with fomepizole and dialysis
Describe the etiology, presentation, and diagnosis of ethylene glycol poisoning.
- exposure is typically from antifreeze and toxicity results from the toxic metabolite oxalate
- presents with intoxication, renal toxicity, hypocalcemia, and a metabolic acidosis with anion and osmolar gap
- treat with fomepizole and dialysis
Why are methanol and ethylene glycol poisoning treated with fomepizole and dialysis?
- fomepizole inhibits alcohol dehydrogenase to prevent the formation of toxic metabolites
- dialysis is required to remove any remaining substance from the body
What is the presentation and treatment for black widow spider bites?
- present with abdominal pain, muscle pain, and hypocalcemia
- treat with calcium and antivenin
What is the presentation and treatment for brown recluse spider bites?
- present with local skin necrosis, bullae, and blebs
- treat with debridement, steroids, and dapsone
Describe the general presentation and treatment of snake bites.
- the most common injury is a local wound
- some snakes produce a hemolytic toxin causing hemolysis and DIC while others produce a neurotoxin that cause respiratory paralysis
- treat with pressure, immobilization, and antivenin
- do not place tourniquets or ice and do not perform I&D
Describe the etiology and treatment of dog, cat, and human bites.
- human: Eikenella corrodens
- dog/cat: Pasteurella multocida
- treat all with amoxicillin and clavulanate
- give a tetanus booster if more than 5 years since the last injection and a rabies vaccine if the animal had altered mental status or cannot be observed
Under what circumstances is stress ulcer prophylaxis with PPI indicated?
- head trauma
- burns
- ET intubation
- coagulopathy with respiratory failure
What is the best initial therapy for burn victims? Who should be intubated?
- best initial therapy is 100% oxygen
- intubate for stridor, hoarseness, wheezing, or burns inside the nasopharynx or oropharynx
Describe the fluid, volume, and rate for fluid replacement in burn victims.
- replace with LR
- total for 24 hours = 4 mL x kg x %BSA burned
- give half in the first 8 hours and half over the next 16
Describe the management of burn victims.
- best initial therapy is 100% oxygen
- intubate for stridor, hoarseness, wheezing, or burns inside the nasopharynx or oropharynx
- replace fluids with LR with total volume = 4 x kg x %BSA burned
- apply prophylactic topical antibiotics
How can percent of body surface area burned be calculated?
- rule of 9’s
- one patient hand equals 1% of total body area
What is the best initial step when managing hypothermia?
get an ECG
What is the characteristic ECG finding for those with hypothermia?
J waves are produced by a QRS that hits the ST segment and hypothermia results in marked elevation of the J point
What is high altitude pulmonary edema, how does it present, and how is it treated?
- it is pulmonary edema in the setting of a normal ejection fraction which occurs at elevations above 2500 meters
- presents with two symptoms (dyspnea, cough, weakness, and chest tightness) and two signs (crackles, wheezing, cyanosis, tachypnea, tachycardia)
- treat with oxygen, rapid descent, and either steroids, nifedipine, or sildenafil
How should jelly fish stings be treated?
- wash the wound with seawater
- scrape off the stingers
- inactivated the toxin with hot water
- apply topical steroids and antihistamines for symptoms
When should a “precordial thump” be given?
for cardiac arrest with onset in the last ten minutes with no defibrillator avilable
What are the four major causes of sudden loss of pulse?
- asystole
- ventricular fibrillation
- ventricular tachycardia
- pulseless electrical activity
What is the best initial management for pulselessness?
CPR
What is the proper treatment for asystole?
CPR and epinephrine, which shunts blood to critical organs
Unsynchronized cardioversion is only indicated for what two arrhythmias?
ventricular tachycardia and ventricular fibrillation
How should ventricular fibrillation be managed?
- begin CPR
- unsynchronized cardioversion
- epinephrine
- unsynchronized cardioversion
- amiodarone or lidocaine
- unsynchronized cardioversion
- repeat drug then cardioversion cycle
How should ventricular tachycardia be managed?
- if hemodynamically stable: start with amiodarone, then lidocaine, then procainamide; if unsuccessful, cardiovert
- if hemodynamically unstable: cardiovert several times and then try amiodarone, lidocaine, and procainamide
- if pulseless: manage like VFib, alternating unsynchronized cardioversion with epinephrine, amiodarone, and lidocaine
How is hemodynamic instability defined in those with rhythm disturbances?
- hypotension
- confusion
- dyspnea
- chest pain
How should afib be treated in the post-CABG patient?
- in this case it is a common and usually self-limited
- rate control with beta-blockers or amiodarone is best in these cases lasting less than 24 hours
- antigoculation and/or cardioversion should only be used for cases that persist for longer than 24 hours
What is the difference between atrial flutter and atrial fibrillation?
fluter is a regular rhythm that tends to return to sinus or deteriorate into fibrillation which is an irregularly irregular rhythm
Describe the management of atrial fibrillation.
- for hemodynamically unstable patients, the first step is synchronized electroconversion
- for acute but stable patients with an exogenous cause (post-CABG, cocaine, alcohol, etc.), rate control is all that is necessary; most cases with spontaneously revert
- chronic cases (lasting >48 hours) should be managed with rate control first (beta-blockers, CCBs, or digoxin) and then started on anticoagulation (NOACs preferred in most cases, warfarin for mitral stenosis or metal valves, aspirin for CHADS-VASC less than 2)
How should SVT be managed?
- begin with vagal maneuvers
- give adenosine if these don’t work
- beta-blockers, CCBs, and digoxin are a last resort
What are signs of Wolff-Parkinson-White syndrome?
- SVT alternating with ventricular tachycardia
- SVT that gets worse with diltiazem or digoxini
- delta waves present on EKG
How is Wolff-Parkinson-White syndrome treated?
- for acute therapy, use procainamide or amiodarone for both atrial and ventricular arrhythmias if WPW is present
- for chronic therapy, use an EP to identify the anatomic defect then perform radio frequency catheter ablation
What is the best first step for a patient with asymptomatic bradycardia?
get an ECG to distinguish sinus brady from other causes
What is the treatment for sinus bradycardia?
- nothing if asymptomatic
- for symptoms, atropine is the best initial therapy followed by pacemaker as the most effective for chronic treatment
What is the treatment for 1st degree AV block?
the same as sinus bradycardia: if symptomatic, atropine followed by pacemaker for long-term control
What is the treatment for second-degree AV block?
- for Mobitz I, treat like sinus bradycardia: nothing if asymptomatic but atropine and pacemaker if symptoms arise
- for Mobitz II, treat like 3rd degree: pacemaker regardless of symptoms
If a patient is post-MI and develops ventricular tachycardia, what is the best management?
arrhythmias from ischemia should be corrected by correcting the underlying ischemia so perform angiography or bypass
