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10 free Paramedic practice questions: ACLS Pharmacology and Electrical Therapy

These are real questions from the same bank the app draws from. Each one is written to the NREMT Paramedic content specifications and kept inside the Paramedic scope of practice. Pick an answer and you get the full rationale, including why the other three options are wrong.

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Question 1 of 10

A 66-year-old patient is in ventricular fibrillation. A firm rectangular device is palpable under the skin below the left clavicle with a healed scar over it. Compressions are in progress and the pads have not yet been placed. What placement is most appropriate?

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Correct answer · Place the pads at least 8 cm away from the device

This patient has an implanted pacemaker or defibrillator. The firm rectangular device under the skin below the left clavicle, with a healed scar over it, is the generator. The generator sits right where the standard front pad goes. A pad on top of the generator can block or scatter the current you are trying to deliver. Repeated shocks through the generator can also damage the device. Keep the pads at least 8 cm from the edge of the generator. Front to back pad placement is an easy way to get that distance. Do not wait to see if the implanted device treats the rhythm. Ventricular fibrillation is a pulseless shockable rhythm, and this patient needs a shock now.

Why the others are wrong

Place one pad directly over the device to shorten the path: A shorter path for the current sounds helpful. Current that runs through the generator is current that does not reach the heart muscle, and the device can be damaged too. Keeping the pads away from the generator gets the current to the heart and protects the device.

Place both pads on the right chest to avoid the device: Putting both pads on the right chest does keep them off the device. With both pads on one side, the heart is not in the path of the current. The pads have to sit on either side of the heart to defibrillate it.

Withhold the shock and let the implanted device deliver it: An implanted defibrillator is supposed to treat ventricular fibrillation by itself. This patient is still in ventricular fibrillation with the device in place, so the device is not going to fix this rhythm. Defibrillate with your own pads.

Question 2 of 10

A 5-year-old child weighing 18 kg is in ventricular fibrillation. Compressions are in progress, pediatric pads are in place, and the monitor is in manual mode. What energy should the first shock deliver?

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Correct answer · 36 joules, using 2 joules per kilogram

The first shock for this child is 36 joules. Pediatric manual defibrillation is dosed by weight. The first shock is 2 joules per kilogram, and this child weighs 18 kg. That works out to 36 joules. The second shock goes up to 4 joules per kilogram. Shocks after that are at least 4 joules per kilogram. They go up toward 10 joules per kilogram or the adult maximum, whichever comes first. In manual mode, you pick the energy yourself. An automated device would analyze the rhythm and advise for you.

Why the others are wrong

72 joules, using 4 joules per kilogram: Four joules per kilogram, or 72 joules here, is the dose for the second shock. Four joules per kilogram is also the lowest dose for every shock after the second. Starting there skips the first dose.

The adult biphasic setting of 200 joules: far too much energy for an 18 kg child. A child's energy is figured from weight until that number reaches the adult maximum.

18 joules, using 1 joule per kilogram: One joule per kilogram is in the pediatric cardioversion range, not the defibrillation range. At 18 joules, this child gets half the energy needed, and half is unlikely to stop ventricular fibrillation.

Question 3 of 10

A 22-year-old patient has been pulled from a lake onto the shore after an estimated 6 minutes underwater. The patient is unresponsive, apneic, and has no palpable carotid pulse. There is no report of diving and no evidence of injury. Two paramedics are on scene, and a BVM device with oxygen, suction, and a cardiac monitor are immediately available. What is the most appropriate approach to resuscitation?

Show the answer and rationale

Correct answer · Compressions and ventilations at a ratio of 30 to 2

This patient is in cardiac arrest from drowning. The patient was underwater for about 6 minutes before the arrest. A drowning arrest is different from a sudden collapse from a heart problem. In drowning, the vocal cords spasm shut and water gets breathed in, so oxygen stops getting into the blood. The heart muscle runs out of oxygen and stops. By the time there is no pulse, the blood in the body has no usable oxygen left. Compressions alone would only move blood with no oxygen in it. That's why ventilations have to be part of CPR from the very first cycle. With two paramedics and a BVM ready, give compressions and ventilations at 30:2. Thirty compressions to 2 ventilations is the standard adult ratio when the arrest was caused by a lack of oxygen.

Why the others are wrong

Abdominal thrusts to clear water before ventilating: Abdominal thrusts are for a responsive adult with a foreign body blocking the airway. Using them here assumes the lungs are full of water that needs to come out. In drowning, only a small amount of water is breathed in, and the water absorbs into the blood quickly. There is nothing to clear. Thrusts only delay compressions and ventilations, and they raise the chance of vomiting.

Continuous compressions without delivered ventilations: Compression-only CPR fits a witnessed sudden collapse from a heart problem. In that patient, the blood still carries oxygen for the first several minutes, so compressions alone can move that oxygen around. This patient was underwater for 6 minutes before the arrest. The oxygen was used up before the heart stopped. Without ventilations, compressions have no oxygen to move.

Suctioning of the airway until no further water returns: Suctioning is the right move when vomit, secretions, or blood are blocking the airway. Keep suction ready on every drowning call for that reason. Suctioning until no more water comes back goes after water that mostly is not there, because only a small amount gets breathed in. Every second spent suctioning is a second without compressions or oxygen.

Question 4 of 10

A 71-year-old patient reports the sudden onset of severe, constant abdominal pain that radiates into the back and began 1 hour ago. The patient has a history of hypertension and has smoked for 40 years. The abdomen is tender, and a pulsatile mass is palpated to the left of the midline above the umbilicus. The skin is pale, cool, and diaphoretic. The vital signs are BP 88/56, P 124, and R 24, with SpO₂ 95% on room air. What condition should the paramedic most strongly suspect as the cause of this emergency?

Show the answer and rationale

Correct answer · Abdominal aortic aneurysm

This patient has a leaking abdominal aortic aneurysm. A pulsatile mass sits to the left of the midline above the umbilicus. No other option produces a pulsatile mass. The patient also has high blood pressure and has smoked for 40 years. High blood pressure and smoking are the classic history for an abdominal aortic aneurysm. The aneurysm is leaking blood, and the pain goes straight through to the back. The pulse of 124, the blood pressure of 88/56, and the pale, cool, diaphoretic skin tell you the patient is losing blood. Handle this patient gently, and do not keep pressing on the mass. Start large bore IV access, but do not push fluid to bring the blood pressure back to normal. A higher pressure can push more blood out of the aneurysm. Transport right away to a hospital that has vascular surgery.

Why the others are wrong

Perforated peptic ulcer: A perforated peptic ulcer causes sudden, severe abdominal pain with a rigid abdomen. A perforated ulcer never produces a pulsatile mass, and the pulsatile mass points to the aorta.

Acute pancreatitis: gives severe upper abdominal pain that goes through to the back. Pancreatitis is common with alcohol use or gallstones, and nothing in this history points to either one. An inflamed pancreas also never gives you a pulsatile mass.

Renal colic: A kidney stone causes renal colic, with sudden, severe flank pain that moves toward the groin. Renal colic comes in waves, and this patient's pain is constant. A kidney stone does not explain the pulsatile mass above the umbilicus. A stone also does not drop the blood pressure to 88/56. That pressure, with a pulse of 124 and pale, cool, diaphoretic skin, means this patient is losing blood.

Question 5 of 10

A 6-year-old patient weighing 22 kilograms is unresponsive, apneic, and pulseless. Chest compressions have been started and positive pressure ventilations are being delivered. The monitor shows a coarse disorganized waveform with no identifiable QRS complexes, and the defibrillator pads are in place. Which initial defibrillation energy is most appropriate?

Show the answer and rationale

Correct answer · 2 joules per kilogram

This child is in ventricular fibrillation. The monitor shows a coarse, disorganized waveform with no QRS complexes, and the child has no pulse. Ventricular fibrillation is shockable at any age. In children, you set the shock by weight instead of using one fixed setting. Heart size and how much the chest resists the current change a lot as a child grows. The first shock is 2 joules per kilogram. For this 22 kilogram child, 2 joules per kilogram comes to about 44 joules. Starting at the lowest dose that works limits damage to the heart muscle and still stops ventricular fibrillation in most children. If the fibrillation keeps going, later shocks go up to 4 joules per kilogram and can go higher. Shocks never go above 10 joules per kilogram or the adult dose. Restart compressions right after every shock.

Why the others are wrong

10 joules per kilogram: Ten joules per kilogram is the highest a child's shocks can go. Later shocks can reach that dose if the fibrillation keeps coming back. Starting at the top gives the heart more energy than the first shock needs. The extra energy damages heart muscle the child still needs after the rhythm is fixed.

4 joules per kilogram: Four joules per kilogram is the right dose for the second shock and every shock after it. The question asks for the first shock, and the first shock is half that dose, 2 joules per kilogram.

The manufacturer's adult setting: The adult setting is what an AED without a pediatric attenuator delivers. Using the adult setting is far better than not shocking a child in ventricular fibrillation at all. The adult setting is a backup for when you are missing equipment. This crew has a manual defibrillator with pads on and a known weight of 22 kilograms, so you can dose by weight.

Question 6 of 10

A 68-year-old patient reports palpitations and lightheadedness. The patient is drowsy and answers questions slowly, and the skin is pale, cool, and diaphoretic. The cardiac monitor shows a regular wide-complex rhythm at 168 with no identifiable P waves. The vital signs are BP 78/46, P 168, R 20, SpO₂ 94% on room air. An intravenous line is in place, and the paramedic prepares for synchronized cardioversion. Which initial energy setting is most appropriate?

Show the answer and rationale

Correct answer · 100 joules

This patient is in an unstable regular wide-complex tachycardia. The monitor shows a regular wide rhythm at 168 with no identifiable P waves. The blood pressure is 78/46, the patient is drowsy, and the skin is pale, cool, and diaphoretic. A regular wide-complex tachycardia with a pulse is usually monomorphic ventricular tachycardia. An organized, regular rhythm takes less energy to convert than a chaotic, irregular one. Synchronized cardioversion for a regular wide-complex tachycardia starts at 100 joules. The shock is timed to the R wave so the shock does not land on the T wave and cause ventricular fibrillation. If the first shock does not work, go up in energy on the next shock instead of repeating the same setting.

Why the others are wrong

50 joules: Some protocols start a regular narrow-complex tachycardia, like SVT, as low as 50 joules. This rhythm is wide with no visible P waves, not narrow. A regular wide rhythm starts at 100 joules. At 50 joules the shock is likely too weak to work. A failed shock costs time in a patient who is already hypotensive and drowsy.

360 joules: A 360 joule shock is the monophasic dose for defibrillation. Defibrillation is unsynchronized and used on a pulseless patient in ventricular fibrillation or pulseless ventricular tachycardia. This patient has a pulse and a blood pressure of 78/46. The shock has to be synchronized and start at the dose for this rhythm.

200 joules: A 200 joule shock is a starting dose for an irregular narrow-complex rhythm like atrial fibrillation. Atrial fibrillation needs more energy because the activity in the atria is chaotic. This monitor shows a regular wide rhythm, and a regular wide rhythm starts at 100 joules.

Question 7 of 10

A 24-year-old patient is lethargic 90 minutes after swallowing a large number of amitriptyline tablets. The pupils are dilated, the skin is warm and dry, and the mouth is dry. The vital signs are BP 96/58, P 124, R 16, SpO₂ 97% on room air. The 12-lead ECG shows a sinus tachycardia with a QRS duration of 0.16 seconds and a tall terminal R wave in lead aVR. An intravenous line is in place. Which medication should the paramedic administer first?

Show the answer and rationale

Correct answer · Sodium bicarbonate 1 mEq/kg intravenously

This is tricyclic antidepressant toxicity, and the patient needs sodium bicarbonate. Amitriptyline is a tricyclic. Tricyclics block the fast sodium channels the ventricles use to depolarize. Blocked sodium channels widen the QRS past 0.10 seconds, and here the QRS is 0.16 seconds. Blocked sodium channels also cause the tall terminal R wave in lead aVR. Those two ECG findings together mean the sodium channels are blocked. As the drug level climbs, the same blockade will cause ventricular dysrhythmias, seizures, and hypotension. Sodium bicarbonate works two ways. The extra sodium pushes more current through the blocked channels. Making the blood more alkaline also makes more of the drug bind to protein, so less of the drug is free to block the channels. When the bicarbonate is working, the QRS gets narrower. The dilated pupils, dry skin, dry mouth, and fast heart rate fit the overdose, but you are not treating those findings.

Why the others are wrong

Lidocaine 1 mg/kg intravenously: Lidocaine is a ventricular antidysrhythmic, and the complexes here are wide. Lidocaine is also a sodium channel blocker. Giving lidocaine adds to the same blockade that is widening the QRS. Sodium channel blockers like lidocaine are specifically avoided in tricyclic toxicity.

Amiodarone 150 mg intravenously over 10 minutes: Amiodarone is for a stable wide-complex tachycardia, a fast ventricular rhythm you are trying to slow down. This rhythm is a sinus tachycardia with a QRS widened by the drug. Amiodarone also blocks sodium channels and prolongs the QT interval. Giving amiodarone stacks a second conduction problem on top of the one the overdose caused.

Calcium chloride 1 g intravenously: Calcium chloride is for calcium channel blocker toxicity, beta-blocker toxicity that does not respond to other treatment, and hyperkalemia. Amitriptyline does not block calcium channels. The QRS of 0.16 and the terminal R wave in aVR point to the sodium channels. Sodium bicarbonate is the drug that treats sodium channel blockade.

Question 8 of 10

A 74-year-old patient reports a racing heartbeat that began 1 hour ago. The patient is confused and answers questions slowly, and the skin is pale, cool, and diaphoretic. Crackles are heard at both lung bases. The vital signs are BP 78/50, P 168, R 24, SpO₂ 93% on room air. The cardiac monitor shows an irregularly irregular narrow-complex rhythm at 168 with no discernible P waves. An intravenous line is in place and the patient has received sedation. Which action is most appropriate?

Show the answer and rationale

Correct answer · Synchronized cardioversion at 120 joules

This patient is unstable from atrial fibrillation and needs synchronized cardioversion at 120 joules. The patient is confused, the blood pressure is 78/50, and there are crackles at both lung bases. Those findings come from a heart rate of 168, so you shock instead of giving a drug. The patient has a pulse, so the shock has to be synchronized to the QRS complex. Synchronizing keeps the shock from landing on the T wave. A shock on the T wave can turn a perfusing rhythm into ventricular fibrillation. The energy depends on the shape of the rhythm. An irregularly irregular narrow rhythm with no P waves is atrial fibrillation. The starting biphasic energy for a narrow irregular rhythm is 120 to 200 joules. A narrow regular rhythm starts lower, at 50 to 100 joules. Atrial fibrillation needs more energy because the atria have many wavefronts firing at once instead of one circuit.

Why the others are wrong

Synchronized cardioversion at 50 joules: has the right mode and the wrong energy. Starting at 50 joules is right for a regular narrow-complex tachycardia, like supraventricular tachycardia or atrial flutter. Those rhythms run on one reentry circuit, and low energy is enough to break that circuit. This rhythm is irregularly irregular with no P waves, so this rhythm is atrial fibrillation, and atrial fibrillation needs 120 to 200 joules. A shock that is too weak will probably fail. A failed shock costs time and adds one more painful shock for a patient who is already confused and hypotensive.

Unsynchronized shock at 120 joules: An unsynchronized shock at 120 joules has the right energy and the wrong mode, and the wrong mode is the more dangerous mistake. Unsynchronized means the shock fires the moment you press the button, wherever the heart is in its cycle. Current that lands on the T wave can throw a perfusing rhythm into ventricular fibrillation. Unsynchronized shocks are for pulseless rhythms, and this patient has a pulse.

Unsynchronized shock at 200 joules: An unsynchronized shock at 200 joules is wrong on both counts. Dropping synchronization carries the same risk of causing ventricular fibrillation in a patient with a pulse. For a narrow irregular rhythm, 200 joules is the top of the range, not the starting point. Start at 120 joules and go up in steps if the shock fails.

Question 9 of 10

A 58-year-old patient is in cardiac arrest, and no bystander cardiopulmonary resuscitation was performed before EMS arrival. High-quality chest compressions have been in progress for 22 minutes, an endotracheal tube is in place, the rhythm has been asystole throughout, and epinephrine has been given every 4 minutes. There is no history of kidney failure and no suspected overdose, and the blood glucose level is 104 mg/dL. Which action is most appropriate?

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Correct answer · Continue compressions and epinephrine dosing

This patient is in asystole, and the arrest is already being treated correctly. Continue compressions and keep giving epinephrine on schedule. Buffers and electrolytes only help an arrest when there is a specific cause for them. This question rules out each of those causes. There is no kidney failure, no suspected overdose, and the blood glucose is 104 mg/dL. Routine bicarbonate can also make the acidosis worse. Bicarbonate turns into carbon dioxide. During compressions, blood flow through the lungs is a fraction of normal, so the lungs cannot get rid of that carbon dioxide. The carbon dioxide moves back into the cells and makes the acidosis inside the cells worse. Keep compressions going without interruptions and keep ventilations controlled. Continue the resuscitation, or consider your termination criteria.

Why the others are wrong

Administer sodium bicarbonate 1 mEq/kg: Sodium bicarbonate has real uses in cardiac arrest. Those uses are a sodium channel blocker overdose, like a tricyclic, and known or suspected hyperkalemia. This question rules out both. There is no history of kidney failure and no suspected overdose. Bicarbonate given routinely for acidosis has not improved survival or neurologic outcome. Bicarbonate can also make the acidosis worse, and giving bicarbonate takes effort away from compressions.

Administer calcium chloride 1 g: Calcium chloride is for hyperkalemia, calcium channel blocker toxicity, and magnesium toxicity. You would suspect those causes from a dialysis history or a pill bottle. This patient has neither. Routine calcium in an arrest with no known cause has not improved outcome and may worsen reperfusion injury.

Increase the ventilation rate to correct acidosis: Ventilating faster does blow off carbon dioxide, and blowing off carbon dioxide is how the body normally makes up for acidosis. In cardiac arrest, fast ventilation raises the pressure inside the chest. Higher pressure in the chest means less blood returns to the heart, and coronary perfusion pressure drops. The acidosis in cardiac arrest comes from poor blood flow, and high-quality compressions are what improve blood flow.

Question 10 of 10

A 61-year-old patient being monitored during transport for chest discomfort suddenly slumps forward and becomes unresponsive. The patient is apneic and has no palpable carotid pulse. Defibrillation pads are already attached, and the monitor shows a chaotic waveform with no organized complexes. Which action is most appropriate?

Show the answer and rationale

Correct answer · Defibrillate as soon as the device is charged

This patient just went into ventricular fibrillation in front of you. The patient slumped forward during transport, has no pulse, and the monitor shows a chaotic waveform with no organized complexes. The pads are already on. The biggest factor in surviving ventricular fibrillation is the time from the start of the rhythm to the first shock. Here that time can be almost zero. The heart muscle still has oxygen, and the fibrillation is still coarse. A shock is more likely to stop the rhythm right now than at any later point. Every minute you wait lowers the chance the shock works. Do compressions while the device charges so blood keeps moving, but do not delay the shock to do compressions. Charge, clear, shock, and restart compressions right after.

Why the others are wrong

Confirm the rhythm in a second lead before shocking: Checking a second lead is the right habit for asystole. A flat line can come from a lead that came off, poor contact, or fine ventricular fibrillation seen from the wrong angle. Calling a flat line wrong means you hold a shock the patient needed. A chaotic waveform with no organized complexes in a patient with no pulse is clearly ventricular fibrillation. A second lead gives you nothing new and uses up the seconds when the shock works best.

Perform 2 minutes of compressions before shocking: Two minutes of compressions before the shock comes from the older CPR-first approach. CPR-first was for an arrest nobody saw, with a long down time. Compressions first could get blood to a heart muscle that had run out of oxygen and make a shock more likely to work. This arrest happened on the monitor moments ago, so the heart muscle has not run out of oxygen yet.

Administer epinephrine 1 mg before shocking: Epinephrine belongs in this resuscitation after the first shock, then every 3 to 5 minutes. Epinephrine improves blood flow to the heart during compressions. No drug stops ventricular fibrillation. With the pads already on and a shockable rhythm, the shock goes first.

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