NREMT EMT — All Questions

What is the recommended compression rate for adult CPR?

• a.60 to 80 per minute
• b.80 to 100 per minute
• c.140 to 160 per minute
• d.100 to 120 per minute✓

High-quality CPR uses a compression rate of 100 to 120 per minute. Rates that are too slow or too fast reduce cardiac output and coronary perfusion.

What is the correct compression-to-ventilation ratio for one-rescuer adult CPR?

• a.5:1
• b.10:2
• c.30:2✓
• d.15:2

Single-rescuer adult CPR uses 30 compressions to 2 breaths. This ratio maximizes chest compressions while still providing ventilation.

What is the minimum compression depth for an adult during CPR?

• a.About 3 inches (7.5 cm)
• b.About 1.5 inches (4 cm)
• c.At least 2 inches (5 cm)✓
• d.About 1 inch (2.5 cm)

Adult chest compressions should be at least 2 inches (5 cm) but not more than 2.4 inches (6 cm) deep. Adequate depth is essential to generate blood flow.

For two-rescuer CPR on a child, the compression-to-ventilation ratio is:

• a.30:2
• b.15:2✓
• c.5:1
• d.10:2

When two rescuers perform CPR on an infant or child, the ratio is 15:2. With a single rescuer, the child ratio is 30:2, the same as adults.

The single most important intervention to improve survival that an EMT can deliver for witnessed sudden cardiac arrest is:

• a.Rapid transport to the hospital before starting CPR
• b.Oxygen by non-rebreather mask before compressions
• c.A precordial thump followed by a pulse check
• d.Early defibrillation with an AED plus high-quality CPR✓

Early defibrillation combined with early high-quality CPR offers the best chance of survival in cardiac arrest from a shockable rhythm. Every minute of delay to defibrillation reduces survival. Loading and driving first only delays the shock, and a mask delivers no oxygen to the tissues while there is no circulation to carry it. A precordial thump is not part of EMT care and does not reliably convert a shockable rhythm.

When an AED advises 'no shock advised' but the patient remains pulseless, you should:

• a.Give a second analysis right away without CPR
• b.Wait 5 minutes before doing anything
• c.Immediately resume CPR starting with compressions✓
• d.Remove the pads and transport

A 'no shock advised' message means the rhythm is not shockable, so resume CPR immediately beginning with chest compressions. The AED will reanalyze after about two minutes of CPR.

How deep should chest compressions be for an infant?

• a.About 1 inch, because an infant chest is small
• b.At least 2 inches (5 cm), the depth used for adults
• c.About 1.5 inches (4 cm), roughly one third of chest depth✓
• d.3 inches, pressing as deeply as the chest allows

Infant compressions should be about 1.5 inches (4 cm), roughly one third the depth of the chest, delivered with two fingers or the two-thumb encircling technique. At least 2 inches (5 cm) is the adult depth and is too deep for an infant, while pressing only about an inch does not move enough blood, and pressing as hard as the chest allows risks injury without improving flow.

A conscious adult reports crushing chest pressure radiating to the left arm. After ensuring no contraindications, the EMT may assist with:

• a.Oral glucose
• b.Chewable aspirin✓
• c.A tourniquet
• d.Activated charcoal

For suspected acute coronary syndrome, EMTs may assist with chewable aspirin, which reduces clot formation, if the patient has no allergy or contraindication. Aspirin improves outcomes in heart attack.

Under a typical EMS protocol, before assisting a patient with their own prescribed nitroglycerin for chest pain, the EMT must confirm:

• a.That the chest pain has lasted longer than twenty minutes, since the drug is only for prolonged pain
• b.That the patient has no aspirin allergy, because aspirin is always given alongside nitroglycerin
• c.That the patient has eaten recently, because nitroglycerin irritates an empty stomach
• d.Adequate blood pressure (typically systolic above 90 to 100 mmHg) and no recent erectile dysfunction drugs✓

Nitroglycerin dilates blood vessels and can cause dangerous hypotension, so an adequate blood pressure must be confirmed first, and it is contraindicated after recent erectile dysfunction medication because the combination can drop pressure severely. How long the pain has lasted, whether the patient can tolerate aspirin, and when the patient last ate do not determine whether it is safe to assist with the dose.

During CPR, allowing the chest to fully recoil between compressions is important because it:

• a.Moves air in and out of the lungs, so fewer breaths are needed
• b.Lets the rescuer reach a faster compression rate with less effort
• c.Prevents broken ribs by lifting all pressure off the sternum
• d.Allows the heart to refill with blood, improving the next compression's output✓

Full chest recoil lets the heart refill with blood between compressions, so the next push moves more blood. Leaning on the chest reduces venous return and lowers CPR effectiveness. Recoil does not provide effective ventilation and does not replace rescue breaths, it does not make a faster rate the goal, and it does not prevent rib fractures.

If a patient in cardiac arrest has a transdermal medication patch on the chest where an AED pad must go, you should:

• a.Place the pad directly over the patch and press firmly
• b.Withhold defibrillation until a paramedic arrives
• c.Remove the patch and wipe the area before applying the pad✓
• d.Leave the patch in place and lower the shock energy

A medication patch under an AED pad can block energy delivery or cause a skin burn, so the patch is removed and the skin wiped before the pad goes on. Defibrillation should not be delayed waiting for a paramedic, and an automated external defibrillator selects its own energy, so there is no setting for the operator to turn down.

What is the compression rate for infant and child CPR?

• a.80 to 100 per minute
• b.60 to 80 per minute
• c.140 to 160 per minute
• d.100 to 120 per minute✓

The compression rate for infants and children is the same as for adults, 100 to 120 per minute. Consistent rate and depth are key to effective CPR at all ages.

The purpose of minimizing interruptions in chest compressions is to:

• a.Maintain coronary and cerebral blood flow✓
• b.Allow extra breaths between cycles
• c.Reduce the chance of breaking ribs
• d.Let the AED charge its capacitor faster

Blood flow generated by compressions falls quickly when compressions stop and takes time to rebuild. Minimizing interruptions keeps perfusion to the heart and brain as high as possible. Pausing to add breaths trades that perfusion for ventilation the arrested patient needs far less, and rib injury is not what the pause is meant to prevent. The AED charges on its own timer, which is why compressions continue while it charges.

A patient becomes unresponsive and pulseless while you are attaching monitoring equipment. Your immediate action is to:

• a.Give two rescue breaths first
• b.Begin high-quality chest compressions✓
• c.Search for a medical bracelet first
• d.Check blood glucose

For an unresponsive, pulseless adult, start chest compressions immediately following the compressions-airway-breathing sequence. Early compressions are the priority in cardiac arrest.

Under standard resuscitation guidance, AED pads for a small child when pediatric pads are unavailable should be:

• a.Cut down with trauma shears so the two pads fit without touching
• b.Placed using adult pads, one on the chest and one on the back if needed to avoid overlap✓
• c.Withheld entirely, because an adult shock dose is unsafe for a child
• d.Placed side by side on the upper chest so both stay off the abdomen

If pediatric pads or a pediatric setting are unavailable, adult pads may be used on a child, with one pad on the front of the chest and one on the back when that is what it takes to keep the pads from touching. Pads must not be cut or trimmed, because that changes the surface the current passes through, and defibrillation should not be withheld from a child in cardiac arrest.

Which is a classic sign that a patient may be having a heart attack in addition to chest pain?

• a.Sharp pain that worsens only when the chest wall is pressed
• b.Warm, dry, pink skin with a strong radial pulse
• c.Diaphoresis (heavy sweating), nausea, and shortness of breath✓
• d.Slow, deep, effortless breathing with normal skin color

Acute coronary syndrome often presents with heavy sweating, nausea, and shortness of breath alongside the chest discomfort, and recognizing those associated signs helps identify a heart attack when the chest pain itself is atypical. Pain reproduced by pressing on the chest wall more often points to a musculoskeletal cause, and warm, dry, pink skin with easy, unlabored breathing is not part of the classic picture.

Hands-only CPR by bystanders is encouraged for adults primarily because:

• a.Rescue breaths mostly fill the stomach and do more harm than good
• b.Continuous compressions maintain blood flow and bystanders are more willing to act✓
• c.Chest compressions alone restart the heart, so an AED is not needed
• d.Compression-only CPR is the preferred approach for young children too

For sudden cardiac arrest in an adult, continuous chest compressions keep blood moving and bystanders are far more willing to act when mouth-to-mouth is not required, which improves survival. Compressions do not restart the heart by themselves and do not replace defibrillation, and children in arrest more often need rescue breaths because the cause is usually respiratory.

Where should the heel of the hand be placed for adult chest compressions?

• a.On the upper sternum, just below the collarbones
• b.On the center of the chest, on the lower half of the sternum✓
• c.Over the left nipple, directly above the heart's apex
• d.On the upper abdomen just below the xiphoid process

Compressions are delivered on the lower half of the sternum in the center of the chest. Correct hand placement maximizes cardiac output and reduces injury. Compressing the upper sternum will not squeeze the ventricles effectively, and moving off to the left side pushes on ribs rather than on the sternum. Pressing on the upper abdomen compresses the liver and stomach instead of the heart and risks injury and regurgitation.

A conscious patient with a suspected heart attack should generally be placed in what position if no hypotension or altered mental status is present?

• a.Prone, to ease the work of breathing
• b.Flat and supine to rest the heart
• c.Head-down Trendelenburg position
• d.A position of comfort, often sitting up✓

A conscious cardiac patient who is not hypotensive is usually most comfortable sitting up, which can ease breathing and reduce the work of the heart. Lying flat, lying face down, or tipping the head down does not help and can make breathing harder. Keep the patient calm and limit exertion.

The main reason to switch compressors about every 2 minutes during CPR is to:

• a.Let the ventilator catch up on missed breaths
• b.Prevent rescuer fatigue that reduces compression quality✓
• c.Comply with the AED, which requires a new compressor
• d.Give the patient a rest from the pressure on the chest

Compression quality falls off with fatigue, often before the rescuer notices it, so compressors change about every two minutes, ideally during a rhythm check. The change is not driven by ventilations, not requested by the AED, and not a break for the patient.

After an AED delivers a shock, the rescuer should:

• a.Immediately resume chest compressions✓
• b.Wait for the AED to advise again before touching the patient
• c.Check for a pulse for 30 seconds
• d.Remove the pads

Immediately after a shock, resume CPR starting with compressions for about two minutes before the next rhythm analysis. This minimizes the pause in blood flow and improves outcomes.

For an unresponsive adult who is not breathing normally, how should you check for a pulse and for how long?

• a.Brachial pulse for up to 10 seconds
• b.Radial pulse for a full 30 seconds
• c.Apical pulse listened to for 60 seconds
• d.Carotid pulse for no more than 10 seconds✓

In an unresponsive adult, check the carotid pulse for no more than 10 seconds. If no definite pulse is felt within that time, begin chest compressions. The brachial site is the one used for an infant, and the radial pulse can be absent in a patient who still has a central pulse, so neither settles the question in an adult. Listening for an apical pulse takes equipment and time that a pulseless patient does not have.

A 58-year-old had chest pressure while shoveling snow that eased within about four minutes once he stopped and rested. He is now pain-free with normal vital signs. Which interpretation is most accurate?

• a.Chest pressure that stops with rest rules out myocardial infarction, so he can be told to see his own doctor this week.
• b.Being pain-free means no heart muscle was injured.
• c.Exertional chest pressure in a man of this age is diagnostic of an evolving myocardial infarction.
• d.This fits stable angina, but only hospital evaluation can exclude a heart attack.✓

Stable angina is brief, predictable, provoked by exertion and relieved by rest, which is exactly what he describes, but unstable angina and an early infarction can also ease temporarily and no field finding distinguishes them. The tempting claim that relief with rest rules out infarction is wrong for that reason: patients whose pain settles still turn out to have infarcted, which is why evaluation is needed rather than a clinic appointment days later. Nothing about the episode makes the diagnosis certain in either direction.

A 62-year-old man has 40 minutes of burning epigastric discomfort that he blames on a heavy meal. He is pale and sweating heavily and feels short of breath. He denies any chest pain at all. The EMT should:

• a.Withhold aspirin until a hospital electrocardiogram has confirmed that the problem is cardiac in origin.
• b.Treat the complaint as indigestion, since he denies any chest pain at all.
• c.Manage him as a possible acute coronary syndrome and assist with aspirin if not contraindicated.✓
• d.Offer an antacid and reassess in ten minutes.

Epigastric burning with diaphoresis and shortness of breath is a classic anginal equivalent, and older adults, women and people with diabetes often infarct without ever reporting chest pain, so the crew must work the case as an acute coronary syndrome. Waiting for the hospital electrocardiogram is the strongest competing choice and sounds cautious, but aspirin's benefit depends on being given early, the field cannot exclude infarction, and a single chewed dose carries little risk in a patient with no bleeding history or allergy. An antacid neither treats nor excludes an infarction and only delays transport.

Before assisting a patient with suspected acute coronary syndrome with aspirin, which finding under most EMS protocols would lead the EMT to withhold it?

• a.A blood pressure of 96/60, because aspirin lowers the pressure further in a patient who is already hypotensive.
• b.A previous heart attack treated with a coronary stent and daily clopidogrel.
• c.Active gastrointestinal bleeding or a known aspirin allergy.✓
• d.A heart rate of 52 beats per minute.

Aspirin is withheld for hypersensitivity to it and for active or recent bleeding, because its only meaningful hazards are allergic reaction and bleeding. The patient already taking clopidogrel is the tempting exclusion, since it feels like doubling up on blood thinners, but existing antiplatelet therapy is not a contraindication and protocols still direct the aspirin dose for a new suspected infarction. Aspirin has no effect on blood pressure or heart rate, so neither vital sign has any bearing on the decision.

Under a typical EMS protocol, aspirin for a patient with suspected acute coronary syndrome is given as:

• a.Two 325 mg enteric-coated tablets swallowed whole with water to protect the stomach.
• b.One 81 mg tablet swallowed whole, with the rest given later at the hospital.
• c.160 to 325 mg of chewable aspirin, chewed.✓
• d.A single 650 mg dose, repeated once after fifteen minutes.

Protocols call for roughly 160 to 325 mg, and the tablets are chewed rather than swallowed because chewing speeds absorption and platelet inhibition when minutes of clot growth matter. An enteric coating is designed to delay dissolution in the stomach, which is the opposite of what is wanted here, and swallowing whole tablets has the same drawback. Splitting the dose or repeating it in fifteen minutes is not part of the prehospital regimen.

A man with chest pain has his own prescribed nitroglycerin and a systolic blood pressure of 132 mmHg. He mentions he took tadalafil (Cialis) last night. Under most EMS protocols the EMT should:

• a.Assist with the nitroglycerin, since the blood pressure is well within the range the protocol requires.
• b.Withhold the nitroglycerin because of the risk of severe, prolonged hypotension.✓
• c.Assist with half of the usual dose to blunt the drop in blood pressure.
• d.Have him lie flat and take the nitroglycerin.

Nitrates combined with an erectile-dysfunction drug of this class can cause profound hypotension that does not respond well to treatment; protocols exclude nitroglycerin within roughly 24 hours of sildenafil or vardenafil and roughly 48 hours of the longer-acting tadalafil. An adequate starting blood pressure is the tempting reason to proceed, but the pressure being acceptable now is exactly the situation in which the combined vasodilation causes the crash. There is no half-dose provision for this interaction, and lying the patient flat does not prevent it.

Under a typical EMS protocol that lets an EMT assist a patient with his own nitroglycerin for chest pain, what must happen before each additional dose?

• a.Nothing further is needed, because the pressure was checked before the first dose and the doses are five minutes apart.
• b.The blood pressure is rechecked and must still meet the protocol's minimum.✓
• c.The patient must be given oxygen by nonrebreather mask before each further dose.
• d.The patient must stand up to show he tolerates the drug.

Every dose dilates veins and can drop the blood pressure, so the pressure is measured again before each dose and the dose is withheld if it has fallen below the protocol's threshold; typical protocols allow up to three doses about five minutes apart on that condition. Relying on the pre-first-dose reading is the tempting shortcut, but it tells the crew nothing about what the drug has already done. Oxygen is given for hypoxia rather than as a prerequisite, and standing a patient up after a nitrate invites syncope.

A patient's chest pain eases substantially a few minutes after one dose of his own prescribed nitroglycerin. What does this response tell the EMT about the cause of the pain?

• a.It confirms the pain is cardiac, since nitroglycerin relieves only pain from narrowed coronary arteries.
• b.It shows the artery has reopened, so he can be transported without further reassessment.
• c.It rules out a heart attack and points to stable angina.
• d.Very little about the cause of the pain.✓

Nitroglycerin relaxes smooth muscle generally, so it can ease esophageal spasm and other noncardiac pain, while a genuine infarction may improve for a while and then return; response to the drug is not a diagnostic test in either direction. The claim that it confirms a cardiac cause is the most tempting because that is how the drug is described to patients, but it is a vasodilator rather than a coronary-specific one. Whatever the response, the patient needs continued monitoring and transport.

A patient with long-standing heart failure has marked swelling of both ankles and distended neck veins, but his lungs are clear on both sides and he speaks in full sentences. This pattern points to:

• a.Left-sided heart failure, because the left ventricle is the chamber that fails first in most patients.
• b.Right-sided heart failure with systemic venous congestion.✓
• c.Early acute pulmonary edema, before crackles become audible.
• d.Cardiac tamponade from a pericardial effusion.

When the right side of the heart fails, blood backs up into the systemic veins, producing jugular distention, dependent swelling of the ankles and an enlarged, tender liver, with the lungs staying clear. Left-sided failure is the tempting choice because it is more common, but it backs blood up into the lungs and would produce crackles and breathlessness, which this patient does not have. Tamponade also distends the neck veins, but it develops acutely with hypotension and muffled heart sounds rather than over years of ankle swelling.

A 74-year-old fainted while sitting at dinner with no warning symptoms at all. She is alert again and says she feels fine; her pulse is 38 and regular and her blood pressure is 104/62. The EMT should recognize that:

• a.Because she has recovered fully and her blood pressure is adequate, she can safely refuse transport.
• b.Sudden syncope with a very slow pulse suggests a cardiac cause and needs monitored transport.✓
• c.The slow pulse is a normal vagal after-effect of fainting and will settle on its own.
• d.Fainting while seated is typical of a simple vasovagal episode.

A vasovagal faint usually happens while standing and gives warning, such as nausea, sweating, tunnel vision or lightheadedness; collapse with no warning while seated, together with a heart rate that is still profoundly slow afterward, suggests a dysrhythmia such as heart block. The vagal after-effect explanation is the strongest competing answer, because vagal tone genuinely does slow the heart during a faint, but that slowing is transient and resolves once the patient is supine and awake, not a persistent rate of 38. Feeling well proves nothing when the underlying rhythm can stop again.

While assessing a patient who called for an ankle injury, an EMT records a blood pressure of 192/108. She feels well, with no headache, visual change, chest pain or neurologic deficit. The EMT should understand that:

• a.A high reading without end-organ symptoms is not an emergency.✓
• b.The reading is almost certainly an artifact of a cuff that is too small and can be disregarded.
• c.Nitroglycerin should be offered to bring the pressure down before transport.
• d.This is a hypertensive emergency, and the crew should arrange an intercept to have the pressure lowered en route.

A hypertensive emergency is defined by acute end-organ dysfunction accompanying the high pressure, such as chest pain, neurologic change, severe headache with visual disturbance or pulmonary edema, not by the number alone; this reading is documented, reported and rechecked. A cuff that is too small does inflate readings, which is why the crew should confirm with a correctly sized cuff, but that is a reason to remeasure rather than to dismiss the value. Lowering blood pressure is not an EMT intervention, and nitroglycerin is neither carried for this nor prescribed to her.

A crew finds a man unresponsive and cold in an unheated garage. His jaw is rigid and there is dependent purple discoloration along his back where he lies. Under a typical EMS protocol, the crew should:

• a.Begin CPR and apply the AED, because lividity and rigor are unreliable in a cold environment.
• b.Begin CPR while a supervisor is asked to confirm the findings before it is stopped.
• c.Move him to the ambulance and transport with compressions.
• d.Withhold resuscitation and follow the protocol for a death scene.✓

Rigor mortis together with dependent lividity is one of the definitive signs of death that protocols list as grounds for withholding resuscitation, alongside decapitation, decomposition and injury incompatible with life. The cold-environment objection is the strongest competing answer, and it is true that a severely hypothermic patient can feel stiff and look dead, but that stiffness is generalized cold rigidity without settled pooling of blood in the dependent tissues, which takes a prolonged period of no circulation to appear. Starting compressions and then hunting for permission to stop only exposes the crew and the scene to unnecessary disruption.

An adult is found in cardiac arrest lying in the middle of a soft bed. As compressions are started, the EMT should:

• a.Begin compressions on the mattress and accept a shallower depth, since any delay is more harmful.
• b.Move him to the floor or slide a backboard under him.✓
• c.Raise the bed to waist height and compress while kneeling on the mattress.
• d.Deflate the mattress and compress with the arms bent to add force.

A soft mattress absorbs part of every compression, so the chest is squeezed far less than the rescuer's hand travel suggests and cardiac output falls; a firm surface, gained by moving the patient down or sliding a board underneath, takes only seconds. Accepting a shallower depth is the tempting trade, but shallow compressions generate little forward flow, so the few seconds spent are repaid immediately. Kneeling on the mattress makes the sinking worse, and bent arms tire the rescuer and reduce depth rather than adding force.

An EMT is alone with a 7-year-old in cardiac arrest until the rest of the crew reaches her. What compression-to-ventilation ratio should she use?

• a.15 compressions to 2 breaths, the pediatric ratio at every stage of a child resuscitation.
• b.30 compressions to 2 breaths, changing to 15:2 when a second rescuer arrives.✓
• c.Continuous compressions with no pauses for breaths.
• d.5 compressions to 1 breath.

A single rescuer uses 30:2 for a child or infant, the same ratio as for an adult, because one person cannot switch between the chest and the airway often enough to sustain 15:2; the ratio drops to 15 compressions to 2 breaths only once a second trained rescuer is working. The 15:2 answer is the strongest distractor because that ratio is genuinely pediatric, but it is defined for two rescuers. Compressions without breaths are not the recommendation in children, whose arrests are usually caused by a breathing problem.

Two EMTs are resuscitating a 3-month-old in cardiac arrest. Which compression technique should be used?

• a.Two thumbs with the hands encircling the chest.✓
• b.The heel of one hand on the lower half of the sternum, as for a small child.
• c.Both thumbs side by side over the upper sternum, above the nipple line.
• d.Two fingers on the sternum, the infant technique whatever the number of rescuers.

With two rescuers the two-thumb encircling-hands technique is preferred for an infant: it produces more consistent depth and force and lets the compressor stay in position while the partner ventilates. The two-finger technique is the correct choice for a lone rescuer, which is why it is tempting, but it delivers less consistent depth when a second pair of hands is available. Whichever technique is used, the compression site is the lower half of the sternum, just below the nipple line, not the upper sternum.

A 79-year-old woke gasping for breath and has crackles throughout both lungs and pink-tinged frothy sputum. Her blood pressure is 168/96 and she is alert and anxious. Under most EMS protocols, initial EMT care includes:

• a.Laying her flat with the legs raised to improve blood return to the heart and support the pressure.
• b.Assisting her with a friend's furosemide tablet to draw fluid off the lungs.
• c.Encouraging her to cough forcefully.
• d.Sitting her upright with the legs dependent, plus oxygen.✓

This is acute pulmonary edema from left-sided heart failure; sitting the patient upright with the legs hanging down lets fluid settle away from the upper lungs and reduces the volume of blood returning to an overloaded heart, while oxygen treats the hypoxia. Laying her flat with the legs raised is the reflex for a shock patient and is the most tempting wrong answer, but here it pushes still more blood into a heart that cannot move it and worsens the flooding of the lungs. An EMT may never give a medication prescribed to someone else, and coughing does not clear fluid out of the alveoli.

Where the EMT's scope permits placing a supraglottic airway, how does adult CPR change once that airway is in place?

• a.Compressions still pause every 30 compressions for two breaths, since pausing keeps the ventilations effective.
• b.Ventilation stops once the airway is in place.
• c.Continuous compressions with a breath every 2 seconds.
• d.Compressions become continuous, with one breath every 6 seconds.✓

Once an advanced airway seals the airway, breaths no longer have to be synchronized with compressions, so the compressor works continuously while the other rescuer delivers about 10 breaths per minute, one every 6 seconds. Continuing to pause after every 30 compressions is the tempting habit carried over from bag-mask CPR, but those pauses drop coronary perfusion pressure that then takes several compressions to rebuild. A breath every 2 seconds is 30 per minute, which raises pressure inside the chest, impedes venous return and reduces the output the compressions generate.

A bystander asks why hands-only CPR, which is encouraged for adults, is not what is recommended for a child. The best explanation is:

• a.Hands-only CPR is only approved for rescuers with formal training.
• b.A child's chest is too flexible for compressions alone to move blood, so breaths replace the missing circulation.
• c.Compressions may fracture a child's ribs, so ventilations reduce the number of compressions needed.
• d.Most pediatric arrests begin with a breathing problem, so ventilations matter more.✓

Adults usually arrest from a sudden rhythm problem with oxygenated blood still in the chest, whereas children usually arrest at the end of a respiratory or shock process, so their blood is already oxygen-depleted and rescue breaths are a necessary part of the resuscitation. Breaths do not create circulation, however, so describing them as replacing compressions is wrong, and a flexible chest makes compressions more effective rather than less. A bystander who is unwilling or unable to ventilate should still do compressions rather than nothing.

An adult in cardiac arrest has a hard lump under the skin below the left collarbone with a small surgical scar over it, consistent with an implanted pacemaker or defibrillator. The EMT should:

• a.Withhold the AED, because the implanted device will deliver its own shocks and an external shock could destroy it.
• b.Place the pad directly over the device so the shock reaches the heart.
• c.Place the pad about an inch clear of the device and use the AED normally.✓
• d.Turn the implanted device off first.

The pad is positioned about an inch, or 2.5 cm, away from the generator so that current is not shunted around the device or the heart, and the AED is then used exactly as usual. Withholding the shock is the dangerous temptation, since the patient is pulseless and the implanted device has plainly failed to restore a rhythm; an external shock may damage it, but that is a repairable problem in a survivor. An EMT has no means of switching the implant off, and a pad directly over it wastes energy on the metal can.

A man is pulled from a swimming pool in cardiac arrest onto a wet pool deck. Regarding AED use, the EMT should:

• a.Wait until he is completely dry from head to toe before attaching the pads, since surface water conducts the shock.
• b.Move him clear of standing water and dry the chest.✓
• c.Attach the pads at once without drying, because a little water does not affect the shock.
• d.Move him onto a rubber mat and shock without wiping the chest.

Standing water can carry current to rescuers, and a film of water on the chest lets the shock track across the skin between the pads instead of through the heart, so the patient is moved clear of pooled water and the chest is wiped dry before the pads go on. Drying him from head to toe is the tempting overcorrection, but it costs minutes of defibrillation delay for no added safety once he is off the wet surface and the pad sites are dry. A mat does not solve the problem of a wet chest between the pads.

A patient re-arrests in the back of an ambulance that is moving at highway speed, and the AED needs to analyze the rhythm. The crew should:

• a.Keep driving and let the AED analyze, because the device filters out vehicle vibration automatically.
• b.Keep driving and rely on chest compressions alone until arrival at the hospital.
• c.Disconnect the pads while the ambulance is moving.
• d.Stop the vehicle so the AED can analyze without motion artifact.✓

Road vibration and compressions both create artifact that an AED can misread as an organized rhythm or as a shockable one, so the standard practice is to bring the ambulance to a stop for the few seconds of analysis and, if advised, the shock. Trusting the device to filter the motion out is the tempting answer, but AED filtering is designed for a stationary patient, which is why every operating instruction says to stop movement during analysis. Giving up on defibrillation entirely abandons the only definitive treatment for ventricular fibrillation.

After a shock, a patient in cardiac arrest regains a strong palpable carotid pulse but remains unresponsive and is breathing about 6 shallow breaths per minute. The EMT should:

• a.Give high-flow oxygen by nonrebreather mask.
• b.Remove the AED pads and place him in the recovery position, then transport and check the pulse every five minutes.
• c.Resume chest compressions, because his breathing is inadequate.
• d.Leave the pads attached, ventilate with a bag-valve mask, and reassess frequently.✓

Return of circulation is fragile and re-arrest is common, so the pads stay on and the pulse and breathing are rechecked often, while breathing this slow and shallow is inadequate and must be assisted with positive pressure. A nonrebreather mask is the closest competing answer, but it only enriches the air a patient draws in himself, and 6 shallow breaths a minute do not move enough volume for that to matter. Compressions are not restarted while a pulse is present, and removing the pads throws away the ability to shock immediately if the rhythm deteriorates again.

What is the practical implication of the chain of survival for an EMS system responding to out-of-hospital cardiac arrest?

• a.Defibrillation is the only link that changes outcome, so the other links matter mainly for documentation.
• b.The links are carried out by hospital staff, so out-of-hospital care is only a transport function.
• c.Each link can make up for a weak link earlier in the chain.
• d.Survival depends on every link, so a delay at any one step lowers survival even when the other steps are done well.✓

The metaphor's whole point is dependency: recognition and activation, immediate CPR, rapid defibrillation, advanced resuscitation, post-arrest care and recovery each depend on the ones before, so excellent defibrillation cannot rescue an arrest that went ten minutes without compressions. That is also why later links cannot compensate for earlier failures. The first links belong to bystanders and dispatchers rather than to the hospital, which is why systems invest in bystander CPR training and public access defibrillators.

A patient with an hour of crushing chest pain is gray and clammy, with crackles at both lung bases, a blood pressure of 76/50 and a pulse of 120. He has nitroglycerin prescribed to him and asks for it. Under most EMS protocols the EMT should:

• a.Assist with the nitroglycerin, because relieving the pain will reduce the strain on the failing heart.
• b.Withhold the nitroglycerin, support oxygenation and transport rapidly.✓
• c.Lay him completely flat and raise both legs to bring the blood pressure up first.
• d.Have him chew a second aspirin.

This is cardiogenic shock: the infarcting heart cannot maintain output, which is why the pressure is low and fluid is backing into the lungs. Nitroglycerin protocols set a minimum systolic pressure, commonly around 100 to 110 mmHg, and a pressure of 76 is far below any of them, so the drug is withheld however severe the pain. Raising the legs is the strongest competing answer because it is right for hypovolemic shock, but the problem here is a pump that has already failed to move the blood it has, and adding preload worsens the pulmonary edema.

A 66-year-old has sudden severe chest pain that he describes as tearing and that radiates through to between his shoulder blades. Which additional finding would most suggest an acute aortic dissection rather than a myocardial infarction?

• a.Pain that worsens when he leans forward and eases when he sits still and breathes shallowly.
• b.Nausea, vomiting and heavy sweating with the pain.
• c.Pain radiating into the left jaw.
• d.A large difference in blood pressure between the two arms.✓

A dissection can extend into the origin of a subclavian artery, so the pulse and pressure on one side fall and the arms read very differently, which is why blood pressure is checked in both arms when the description is tearing pain radiating to the back. Nausea and diaphoresis accompany both conditions and cannot separate them, and jaw radiation is the classic pattern of an infarction rather than a dissection. Pain that changes with position and breathing points instead toward pericarditis or a musculoskeletal cause.

During a resuscitation the team leader says, 'Ken, take over compressions at the next rhythm check.' Which response reflects closed-loop communication?

• a.The leader repeats the instruction until someone starts compressions.
• b.Ken nods and moves into position without speaking, so the noise level stays down.
• c.Whoever is closest to the patient calls out 'I've got it' and takes over.
• d.Ken answers, 'Taking compressions at the next check.'✓

Closed-loop communication means the person named repeats the assignment back out loud so the leader knows it was heard, understood and accepted by that specific person. A silent nod is the most tempting alternative because the task does get done, but a leader who is watching the monitor or timing the rhythm check never sees it and cannot confirm the loop is closed. An anonymous volunteer leaves the leader unsure who holds which role, and repeating an order into the noise is an open loop rather than a closed one.

Several sites in the heart can generate their own electrical impulses, yet in a healthy adult the sinoatrial node sets the heart rate. What explains that?

• a.The sinoatrial node is the only cardiac tissue that can generate an impulse without a nerve signal reaching it first
• b.The sinoatrial node lies in the left atrium, where each cardiac cycle begins before spreading to the right side
• c.The sinoatrial node alone receives a sympathetic nerve supply, so only its rate can be driven upward
• d.The sinoatrial node depolarizes at a faster intrinsic rate than the other pacemaker sites, so it reaches threshold and fires before they do✓

Every pacemaker site has its own intrinsic rate — the sinoatrial node fastest, the atrioventricular junction slower, the ventricles slowest — and the fastest site drives the heart because it resets the others before they can fire on their own. The idea that the sinoatrial node is the only tissue with automaticity is the common misconception: the junction and the ventricles both take over when the node fails, just at a slower escape rate. The node sits in the right atrium, not the left, and both sympathetic and parasympathetic fibers reach far more of the heart than the node alone.

Impulses arriving from the atria are briefly held up at the atrioventricular node before passing on to the ventricles. What does that delay accomplish in a normal beat?

• a.It lets the atria finish emptying into the ventricles before the ventricles contract✓
• b.It gives the ventricular muscle time to repolarize fully so that the next impulse is not blocked
• c.It slows conduction enough for the coronary arteries to fill with blood while the atria are contracting
• d.It blocks impulses that arrive from the atria too quickly

The pause at the atrioventricular node lasts only a fraction of a second, and in that time the atria squeeze their remaining volume into the ventricles, adding to the stroke volume before ventricular contraction begins. The node does limit how many impulses reach the ventricles when the atria fire very fast, which makes the blocking answer tempting, but that protection is a consequence of the same slow conduction rather than the purpose of the normal beat-to-beat delay. Coronary filling occurs during ventricular relaxation and is not produced by the nodal delay, and ventricular repolarization is governed by the muscle's own refractory period.

An adult trauma patient has a strong carotid pulse but no palpable radial pulse at either wrist. Which conclusion is best supported by that finding alone?

• a.The systolic pressure is between 60 and 80 mmHg, the range in which the radial pulse disappears
• b.Perfusion at the periphery is poor and a blood pressure must actually be measured✓
• c.The arm is injured; the blood pressure is normal
• d.This finding by itself establishes decompensated shock

A carotid pulse with no radial pulse tells the EMT that blood is being shunted centrally, which is a real warning of poor peripheral perfusion — but it is a sign, not a number, and the pressure still has to be measured with a cuff. The old teaching that carotid, femoral and radial pulses correspond to systolic pressures of roughly 60, 70 and 80 mmHg has been tested against measured pressures and was found to overestimate them, so it should not be used to assign a value. Shock is staged from the whole picture, including mental status and an actual blood pressure, rather than from one missing pulse, and an isolated arm injury would not explain central shunting in both arms.

A crew checks capillary refill on the fingernail of an adult found outdoors on a cold night. Which statement about that finding is correct?

• a.Cold surroundings slow refill on their own, so it must be read alongside the rest of the perfusion picture✓
• b.Refill time is the single most reliable indicator of perfusion in adults, so a delayed result confirms shock whatever the conditions
• c.A refill time over two seconds in an adult establishes that the patient is hypovolemic
• d.Refill is more useful in adults than in young children

Capillary refill is slowed by cold ambient temperature, by age and by peripheral vascular disease, so on a cold night a delayed result may say more about the environment than about cardiac output; it belongs in the perfusion picture beside skin color and temperature, mental status, pulse quality and blood pressure. Treating it as the single most reliable adult indicator is the tempting error — it is one of the better bedside signs in young children and least reliable in exactly the setting described here. The two-second figure is a rough guide rather than a threshold that establishes hypovolaemia on its own.

A patient with a very large upper arm is assessed with the standard adult cuff, the only size carried on the ambulance. The reading is 168/96, although she feels well and has never been told she has high blood pressure. What is the most likely explanation?

• a.The reading is accurate and simply reflects the extra work of perfusing a larger body
• b.A cuff that is too small leaks pressure as it deflates, so the true pressure is higher than the reading shown
• c.Arm circumference does not affect the reading as long as the bladder is centered over the brachial artery
• d.The cuff is too small for her arm, which pushes the reading up✓

A cuff whose bladder is too narrow for the arm has to be inflated to a higher pressure before it compresses the brachial artery, so it reads falsely high; a cuff that is too large for the arm reads falsely low. The reading should be repeated with a large adult cuff before hypertension is reported or acted on. Centring the bladder over the artery does matter, but it does not cancel out the wrong cuff size, and body size by itself does not produce a genuinely elevated pressure in a well patient.

In some patients the Korotkoff sounds fade out just below the true systolic pressure and reappear again lower down — an auscultatory gap. If the cuff is not inflated above that silent interval, what happens to the reading, and what prevents the error?

• a.The diastolic pressure is underestimated; deflating the cuff more slowly through the lower range prevents it
• b.The pulse pressure is exaggerated; switching to a wider cuff and repeating the measurement prevents it
• c.The systolic reading comes out too low; palpating the systolic first prevents it✓
• d.Neither number is affected; the gap only delays the reading

If the cuff is inflated only into the silent interval, the first sound heard on deflation is the return of sounds below the gap, so the systolic pressure is recorded lower than it truly is. Palpating the radial pulse, noting the pressure at which it disappears and then inflating roughly 30 mmHg above that point puts the cuff safely above the gap before deflation begins. An auscultatory gap tends to make the diastolic value read high rather than low, and cuff width is a separate source of error that does not create the silent interval.

A 30-year-old struck in the abdomen has a heart rate of 124, a blood pressure of 116/94, cool moist skin, and is anxious and repeatedly asking what happened. How should the EMT read this set of numbers?

• a.Adequate perfusion, since the systolic pressure is within the normal adult range and he is awake and talking
• b.Compensated shock, with the narrow pulse pressure showing that vasoconstriction is holding the systolic up✓
• c.Decompensated shock, since a diastolic above 90 marks the point where compensation has failed
• d.Anxiety alone, which raises both the pulse and the diastolic pressure

Vasoconstriction raises the diastolic pressure while the systolic is defended, so the pulse pressure narrows — here 116 minus 94 leaves 22 mmHg — and that narrowing, together with tachycardia, cool moist skin and anxiety, is the picture of compensated shock. A systolic of 116 looks reassuring, which is precisely the trap: in decompensated shock the systolic falls, and waiting for that means waiting until compensation has already failed. No diastolic number defines decompensation, and anxiety alone does not produce cool, moist skin after abdominal trauma.

A 74-year-old, two days after a heart attack, is confused, with a blood pressure of 78/56, a heart rate of 118, cold grey skin, and crackles heard part way up both lung fields. Under a typical EMS protocol, what does this patient need from the EMT?

• a.Supine with the legs raised, the standard response to any patient whose systolic pressure is below 90
• b.Assisting him with his own nitroglycerin, since reducing the heart's workload is the priority in cardiogenic shock
• c.Oxygen titrated to his saturation, a position that eases his breathing, and rapid transport✓
• d.Warm blankets and a flat position while ALS is awaited

This is cardiogenic shock: the damaged pump cannot maintain output, so pressure falls while blood backs up into the lungs. EMT care is supportive — oxygen guided by the saturation, a position the patient can breathe in, warmth, and fast transport to a facility that can treat the pump, with an ALS intercept where one is available. Raising the legs is the tempting move because the pressure is low, but in a patient whose lungs are already wet it pushes more volume back toward a failing left ventricle, and nitroglycerin lowers the pressure further and is contraindicated at this blood pressure.

A patient thrown from a motorcycle cannot move his legs. His blood pressure is 84/60, his heart rate is 58, and his skin is warm and dry below the nipple line. Which explanation fits the findings best?

• a.A faint brought on by pain, which lifts once he is lying flat
• b.Hypovolemic shock from an unrecognised abdominal bleed, since hemorrhage is by far the commonest cause of hypotension after trauma
• c.Spinal shock, the temporary loss of reflexes and movement below the level of injury
• d.Neurogenic shock, in which lost sympathetic tone leaves the vessels dilated and prevents the usual rise in heart rate✓

Warm, dry skin below the injury, hypotension without tachycardia, and a motor deficit point to neurogenic shock, where the injury has interrupted sympathetic outflow so the vessels dilate and the heart cannot speed up to compensate. Occult hemorrhage is the strong competing answer and must still be assumed and treated in any thrown rider — but bleeding produces cool, pale, sweaty skin and a fast pulse, and the picture here is the opposite. Spinal shock names the loss of reflex activity below a cord injury and is not a circulatory diagnosis, and a simple faint does not leave a patient hypotensive and paralysed.

Which pairing of a type of shock with the skin findings usually seen early in it is correct?

• a.Cardiogenic shock — warm, dry, flushed skin produced by blood backing up behind the failing heart
• b.Hypovolemic shock — flushed skin produced by stored red cells released from the spleen
• c.Septic shock — skin that is warm and flushed early, turning cool and mottled later✓
• d.Anaphylactic shock — cold, pale, dry skin from the histamine release

Septic shock, like the other distributive shocks, begins with widespread vasodilation, so the skin is often warm, flushed and dry early on and only becomes cool and mottled as the patient deteriorates — which is why a warm patient can still be in profound shock. Cardiogenic and hypovolemic shock both drive intense vasoconstriction and give the cold, pale, sweaty skin that most candidates associate with shock in general. Anaphylaxis is also distributive, so it typically flushes the skin and adds hives rather than making it cold and dry.

An 80-year-old is dizzy and nearly fainting when she sits up. Her pulse is regular at 38 and her blood pressure is 82/50. No cardiac monitor is available. Under a typical EMS protocol, what should the EMT do?

• a.Keep her supine, give oxygen if she is hypoxic, and request ALS✓
• b.Walk her to the ambulance, since activity raises the heart rate through the sympathetic response
• c.Apply the AED, which will pace the heart once the pads are attached
• d.Withhold treatment unless the rate falls below 30, the point at which bradycardia becomes symptomatic

A regular rate of 38 with hypotension and near-syncope is symptomatic bradycardia, and the EMT's part is supportive — supine positioning, oxygen if the saturation is low, close reassessment — plus getting her to definitive care or to a paramedic crew, since the drugs and pacing that treat the rhythm sit above the EMT scope in essentially every system. Applying the AED is the tempting action because it is the cardiac device on the truck, but an automated external defibrillator analyzes for shockable rhythms and has no pacing function. Bradycardia is called symptomatic because of the symptoms rather than because the rate crosses a set figure, and making a hypotensive patient stand invites a syncopal fall.

A 40-year-old says her heart suddenly started racing while she sat watching television. The radial pulse is regular and too fast to count reliably; a carotid count gives about 190. She is alert, with a blood pressure of 108/70, no fever, no pain, no blood loss and no exertion. Without a monitor, what should the EMT suspect?

• a.Sinus tachycardia from anxiety, which commonly drives an adult resting heart rate to around 190
• b.Atrial fibrillation, which characteristically produces a rapid but perfectly regular pulse at the wrist
• c.A normal finding, since she is alert with an acceptable blood pressure
• d.A supraventricular tachycardia, given the abrupt onset at rest and the very high rate✓

An abrupt onset at rest and a regular rate near 190 in an adult with no fever, pain, bleeding or exertion fit a supraventricular tachycardia; sinus tachycardia has an identifiable cause, comes on gradually and rarely reaches that rate at rest in an adult of this age. Anxiety is the strong competing answer and certainly produces a fast pulse, but the switch-on-while-sitting-quietly history and the rate itself argue against it. Atrial fibrillation gives an irregularly irregular pulse, and a rate near 190 is not a normal finding even in a patient who currently looks well; EMT care here is oxygen if indicated, a position of comfort and transport with ALS where available.

A hiker is dug out of a snowdrift, unresponsive, with no breathing and no pulse detected over a careful 45-second check. He is profoundly cold and stiff, with no rigor mortis, no lividity and no obviously lethal injury. Under most EMS protocols, how does the crew's approach differ from an ordinary cardiac arrest?

• a.Move him quickly and vigorously into the warm ambulance so that rewarming can begin at once
• b.Withhold resuscitation, since a cold and pulseless patient recovered from snow meets the usual criteria for obvious death
• c.Start compressions and ventilations, handle him gently, and continue while he is rewarmed during transport✓
• d.Compress at half the usual rate to match his slowed metabolism

Severe hypothermia slows metabolism enough that a pulse and respirations can be undetectable in a patient who is still salvageable, so resuscitation is started and continued with active rewarming, and the decision to stop is generally deferred to the hospital. Withholding care is tempting because the patient is cold and stiff, but stiffness from cold is not rigor mortis and none of the usual signs of irreversible death are present here. A profoundly cold heart is irritable and rough handling can precipitate ventricular fibrillation, and compressions are still delivered at the standard rate and depth.

A child is pulled from a lake unresponsive, not breathing and pulseless. Compared with a witnessed adult collapse from a suspected cardiac cause, what does the drowning change about the resuscitation?

• a.Nothing changes; compression-only CPR is preferred after drowning just as it is for a witnessed adult collapse
• b.Ventilations matter more, because the arrest follows a period of hypoxia✓
• c.The AED is left off because the chest is wet
• d.Abdominal thrusts are given first to clear water from the lungs before compressions begin

Drowning kills by hypoxia, so the blood is already desaturated by the time the heart stops and rescue breaths are an essential part of the resuscitation rather than an optional extra — compressions combined with ventilations, not compression-only CPR, are what this child needs. Trying to expel water first is the classic error: water in the lungs cannot be drained out, and abdominal thrusts delay compressions and invite vomiting and aspiration. The AED is still applied; the chest is simply dried before the pads go on.

A woman who appears to be near term collapses in cardiac arrest in a shop. Two rescuers are present. Besides high-quality CPR and rapid transport, what does the pregnancy add?

• a.Tilt the whole backboard about 30 degrees to the left, which is preferred to manual displacement because it frees a rescuer
• b.Have one rescuer manually displace the uterus to her left while compressions continue✓
• c.Hold defibrillation until after delivery, because the shock can reach the fetus
• d.Compress over the xiphoid to reach the displaced heart

Near term the uterus compresses the inferior vena cava when the patient is supine, cutting off the venous return that chest compressions depend on, so a dedicated rescuer holds the uterus displaced to the patient's left throughout. Tilting the board is the older technique and is the tempting answer, but a tilted torso makes effective compressions much harder, so continuous manual displacement on a flat, firm surface is now preferred. Defibrillation is delivered in the usual way, and compressions are given on the lower half of the sternum rather than over the xiphoid process.

A service equips some of its ambulances with a mechanical chest-compression device. Which statement reflects current guidance on how such a device should be used?

• a.Applying it takes priority over starting manual compressions, since it delivers a consistent depth and rate from the first minute
• b.It has been shown to improve survival with good neurological recovery compared with high-quality manual compressions
• c.Once it is running, ventilations are no longer needed because it moves enough air on its own
• d.It is a reasonable alternative to manual compressions in particular situations✓

Trials comparing mechanical compression devices with high-quality manual CPR have not shown better survival or better neurological outcome, so guidelines treat them as a reasonable alternative in specific circumstances — a moving ambulance, a prolonged resuscitation, too few rescuers, or a place where a rescuer cannot kneel safely — rather than as a routine upgrade. Because of that, manual compressions begin at once and the device is fitted with only a brief planned pause. The device compresses the chest; it does not ventilate the patient, so ventilations continue as the protocol directs.

Cardiac arrest in children usually develops differently from arrest in adults. What follows from that for an EMT at the side of an unresponsive, pulseless 5-year-old?

• a.Compressions must be paired with effective ventilations, because the arrest usually began with hypoxia✓
• b.Compression-only CPR is preferred for children too, since pausing to ventilate lowers the perfusion pressure
• c.The AED should go on before compressions, because a shockable rhythm is the commonest cause of arrest at this age
• d.Ventilations alone are given until a pulse returns

Most pediatric arrests are the end point of respiratory failure or shock rather than a sudden rhythm problem, so the child is profoundly hypoxic by the time the pulse is lost and oxygen has to be put back in: compressions together with ventilations, at the ratio local guidelines set for one or two rescuers. That is why compression-only CPR, a reasonable option for an untrained bystander at an adult collapse, is not the preferred approach here. A shockable rhythm is uncommon at this age, so the defibrillator does not come ahead of compressions, and ventilations alone cannot circulate the oxygen once the pulse is gone.

A crew is shown a signed POLST form for a nursing-home resident who is in cardiac arrest. In most states, how does a POLST form differ from a traditional do-not-resuscitate order?

• a.It is a statement of the patient's wishes written by the patient or family, which the crew may honour only after medical direction agrees
• b.It applies only inside the facility that issued it
• c.It is a portable medical order covering several treatment decisions, not only resuscitation✓
• d.It authorises the crew to withhold comfort measures as well as resuscitation

In most states a POLST — also called a MOLST or POST — is a portable medical order signed by a physician or other authorised clinician that travels with the patient and addresses more than code status, recording decisions about intubation, other interventions and sometimes transport, whereas a traditional do-not-resuscitate order addresses resuscitation alone. Which forms are valid, whose signature is required and whether the original must be produced are set by state law and local protocol, so crews follow their own state's rules. The form is a clinician's order rather than a family's statement of wishes, it follows the patient between settings, and comfort care is given whatever the form says.

A crew finds an unresponsive man with no pulse and no breathing, cool skin, a stiff jaw and stiff limbs, and dark purple discolouration along the back where he lies. Under the resuscitation policies used in most states, what is appropriate?

• a.Begin CPR and continue until a physician orders it stopped, since only a physician may declare a patient dead
• b.Begin CPR, since rigor and lividity are unreliable in a cool room and the arrest may be recent
• c.Withhold resuscitation and follow local policy for a death on scene✓
• d.Begin CPR and stop only after the AED has advised no shock on three consecutive analyzes

Rigor mortis together with dependent lividity are among the signs of irreversible death that EMS protocols in most states allow a crew to recognize without starting resuscitation; the crew then preserves the scene, makes the notifications its policy requires and supports the family. Beginning CPR is the safe default and is the right choice whenever the findings are equivocal, which is what makes that answer tempting — but here two independent signs of prolonged death are present together. Who may pronounce death, and who may authorise stopping a resuscitation once it has begun, are matters of state law and local protocol, and neither is settled by counting AED analyzes.