Master the Boards: Emergency Medicine Flashcards
Should ipecac be used in the ED?
No
What are cathartic agents and what is an example?
Are they appropriate for use in a toxic ingestion?
They speed up GI transit time e.g. sorbitol
They are not appropriate, it can still be absorbed
Is forced diuresis acceptable in toxic ingestion, why?
No. There is a greater risk of pulmonary edema
Is whole bowel irrigation acceptable after a toxic ingestion?
Almost never. There are few isolated reasons it would be allowed.
(e.g. GoLytely)
When a patient comes to the ED with a toxic ingestion and altered mental status what is the best initial management (2 items)?
Give naloxone and dextrose
*Opioid ingestion and diabetes are two common causes of altered mental status and they’re reversible
What do you give for an opioid overdose?
How about BZD overdose?
Opioid: naloxone
BZD: nothing (BZD OD is often not fatal; flumazenil can be used for withdrawal)
How often should charcoal be used in the setting of a pill overdose?
Often. It is benign and relatively harmless, it should be given to all. Has even been shown to reduce levels of some toxins after they’ve been absorbed.
If a toxic amount of acetaminophen has been ingested what should be provided?
What if the overdose was > 24 hours ago?
N-acetylcysteine
If >24 hours then no specific therapy
*N-acetylcysteine is not contraindicated with charcoal
Tinnitus
Respiratory alkalosis
Metabolic acidosis
All caused by _____ OD.
Aspirin
What is the main treatment for aspirin OD?
Alkalinization of urine to increase excretion
A patient OD’d on multiple agents today, including lorazepam for the first time today. You give him flumazenil and he immediately seizes. What was the other drug OD’d on?
TCA
BZD and TCAs often taken together and BZDs prevent the seizures from TCA toxicity which can be reversed when flumazenil is given.
What effect does bicarbonate have in a TCA overdose?
It protects the heart from arrhythmias. It does not increase TCA excretion.
What arrhythmia do TCAs lead to?
Prolonged QT and eventually torsades de pointes
Caustic or acidic ingestions are best managed how?
Copious flushing.
*DO NOT give alkali or acids. An exothermic reaction will ensue.
Carboxyhemoglobin due to CO poisoning is functionally the same as _______.
an anemia
What acid base disturbance occurs in CO poisoning?
Lactic acidosis due to impaired oxygen utilization
What is the appropriate management of carbon monoxide poisoning?
Give 100% oxygen and if symptoms are severe enough (e.g. CNS or cardiac involvement, metabolic acidosis) then hyperbaric oxygen
How can you use color of the blood to distinguish carboxyhemoglobin (CO poisoning) from methemoglobinemia?
Carboxyhemoglobin: blood is abnormally red bc hemoglobin won’t let go of oxygen in presence of CO
Methemoglobinemia: blood is brown because Hb is oxidized and doesn’t have any oxygen bound
Most effective therapy in methemoglobinemia?
Methylene blue
100% oxygen
Why does hypokalemia predispose to digoxin toxicity?
K+ and digoxin both vie for the same binding site
Downsloping of ST segment on EKG is an indication of _____ toxicity.
Digoxin
What is the best initial test to determine lead toxicity?
Increased level of free erythrocyte protoporphyrin
What is the most accurate test of a sideroblastic anemia and how does it work?
Prussian blue stain
Detects iron build up in mitochondria
What are chelating agents used for lead toxicity?
Succimer (oral)
EDTA and dimercaprol (parenteral)
Patient presents after a toxic ingestion with SOB identified as interstitial fibrosis, hallucinations, nervousness, and a twitch. What was the ingestion?
Tx?
Mercury
May use Dimercaprol and succimer
What is the treatment for both methanol and ethylene glycol toxicity?
Fomepizole and dialysis
Hypocalcemia and envelope shaped crystals in the urine may be a sign of what toxic ingestion?
Ethylene glycol
How is the serum osmolality calculated?
2Na + BUN/2.8 + glucose/18
Do snake bites often deposit venom in the bloodstream?
How do hemolytic toxin and neurotoxin contribute to mortality?
No, it’s usually only local deposition.
Hemolytic toxin: hemolysis and DIC
Neurotoxin: respiratory paralysis, diplopia, dysphagia
How can calcium level help distinguish a black widow vs brown recluse spider bite?
Black widow spider bite associated with hypocalcemia
Tx for black widow spider bite?
Tx for brown recluse spider bite?
Black widow: calcium, antivenin
Brown recluse: debridement, steroids, dapsone
How do the presenting features differ for a black widow vs brown recluse spider bite?
Black widow: abdominal and muscular pain
Brown recluse: local skin necrosis, bullae, and blebs
What is the treatment of all human, cat, or dog bites?
What vaccine may be regiven?
What is the common agent in dogs/cats?
How about humans?
Amoxicillin/clavulanate
Tdap if more than 5 years
Dogs/cats: Pasteurella multocida
Humans: Eikenella corrodens
In what cases should a rabies vaccine be given after an animal bite?
Animal has altered mental status/bizarre behavior
Animal cannot be observed or diagnosed
In those suffering from burns what are the immediate management measures to reduce mortality?
100% oxygen, intubate (especially in setting of an airway burn)
Replace fluids
What is the most common cause of mortality one week after a burn?
What is used for ppx?
Infection
Topical antibx are used e.g. silver sulfadiazine
J waves are seen where the QRS segment hits the ST segment. What may commonly cause this abnormality?
Hypothermia
Drowning should be managed first with what ventilation setting?
What is the difference between salt and fresh water drowning?
Intubation and positive pressure ventilation
Salt water drowning is like CHF with wet, heavy lungs
Fresh water drowning causes hemolysis due to hypotonic solution
What is the best initial management of all forms of pulselessness?
CPR
Therapy for asystole is what two items?
CPR
Epinephrine
Unsynchronized cardioversion =
Defibrillation
Unsynchronized cardioversion (defibrillation) is only used on two rhythms. What are they?
Vfib
Vtach without a pulse
You defibrillate a patient with Vfib to no avail. You continue CPR immediately after. What should you prepare to give prior to the next shock to increase the likelihood of bringing back the rhythm?
Epinephrine
If defib and then epi are unsuccessful to correct Vfib what is the next drug you should try?
Amiodarone or lidocaine
What is the management of Vtach?
Hint: it is different if pulseless and depending on hemodynamic stability
Pulseless: defib
Hemodynamically stable: Amiodarone/lidocaine/procainamide. If fails cardiovert
Hemodynamically unstable: Cardioversion followed by amiodarone/lidocaine/procainamide.
What are the causes of pulseless electrical activity (normal EKG but no pulse)?
Hypoxia, hypothermia, hydrogen ions, hypovolemia, hypoglycemia, hypo/hyperkalemia
Tension ptx, tamponade, toxins, PE
In hemodynamically unstable atrial arrhythmias what is the appropriate management?
What if the arrhythmia is afib, how will treatment change if it is acute or chronic?
Synchronized cardioversion
Acute: synchronized cardioversion
Chronic: anticoagulate and then synchronized cardioversion
What is the best initial therapy in the management of chronic afib? (2 steps)
1) Control the HR (beta blocker, CCB, digoxin)
2) Anticoagulate
*Routine cardioversion is not recommended
If patients have afib with a low CHADS score (
Aspirin may be acceptable in these patients. Placing them at risk of major bleeding with warfarin is not indicated
Palpitations in a hemodynamically stable patient is often SVT. What is the stepwise approach to management (3 steps)?
1) Vagal maneuvers
2) Adenosine
3) Rate control: Beta-blockers, CCB, or digoxin
SVT which gets worse after diltiazem or digoxin may suggest what disorder?
WPW
What is the most accurate test for WPW?
Electrophysiology studies (shows where chronic ablation can be used to target the alternate pathway)
Why are digoxin and CCBs dangerous in WPW?
They block the normal AV node and will force conduction down the alternate pathway
Multifocal atrial tachycardia are often in association with what disease?
As such, what medication should be avoided in these patients?
COPD
Beta-blockers
In symptomatic bradycardia what is the best initial therapy?
What is the most effective therapy?
Initial: Atropine
Most effective: pacemaker
Tx of Mobitz type II heart block?
Pacemaker placement because it may deteriorate into third degree heart block
Gastric lavage after a toxic ingestion is rarely used. How long after an ingestion can it be used?
Should you lavage a patient with altered mental status or a caustic ingestion?
Can be used within 2 hours after ingestion (50% received at one hour and 15% at two hours)
No. Aspiration risk or esophagitis risk, respectively.
