I85PREP
⌘ K
AHA ACLS Provider study materials
AHA ACLS Provider study resources

AHA ACLS Provider practice questions

One question at a time. Build your AHA ACLS Provider understanding.

First 50 of 200 questions. Each one lists the choices, the correct answer, and an explanation. The checker at the top of this page saves progress in this browser when it is available.

Continue in the practice tool above to load more questions, 50 at a time.

Question 1Rhythm recognition and ECG interpretation

A rhythm strip is 6 seconds long and contains 8 QRS complexes. What is the approximate ventricular rate?

  1. 80 beats/min Correct answer.
  2. 100 beats/min
  3. 48 beats/min
  4. 60 beats/min

Explanation

The 6-second method multiplies the number of QRS complexes in a 6-second strip by 10 to estimate the rate. Eight complexes times 10 equals 80 beats/min. This method is preferred when the rhythm is irregular and the R-R interval varies.

Question 2Rhythm recognition and ECG interpretation

A monitor shows a regular rhythm at 42/min with an upright P wave before every QRS, a PR interval of 0.16 second, and a narrow QRS. Which rhythm is this?

  1. Sinus bradycardia Correct answer.
  2. Junctional rhythm
  3. First-degree AV block
  4. Sinus arrhythmia

Explanation

A rhythm with upright sinus P waves preceding every QRS at a rate below 60/min is sinus bradycardia. The normal PR interval excludes an AV conduction delay, and the regularity excludes sinus arrhythmia.

Question 3Rhythm recognition and ECG interpretation

The monitor shows a chaotic, irregular, undulating waveform with no identifiable P waves, QRS complexes, or T waves. Which rhythm is this?

  1. Ventricular fibrillation Correct answer.
  2. Coarse atrial fibrillation
  3. Polymorphic ventricular tachycardia
  4. Asystole

Explanation

Ventricular fibrillation produces disorganized electrical activity with no recognizable complexes because ventricular myocardium is depolarizing chaotically. It is a shockable arrest rhythm requiring CPR and immediate defibrillation. Any organized QRS activity, even if irregular, argues against VF.

Question 4Rhythm recognition and ECG interpretation

Which of these rhythms is managed with high-quality CPR and epinephrine but is not an indication for defibrillation?

  1. Asystole Correct answer.
  2. Ventricular fibrillation
  3. Torsades de pointes
  4. Pulseless ventricular tachycardia

Explanation

Asystole is a non-shockable arrest rhythm, so treatment consists of high-quality CPR, epinephrine, and a search for reversible causes. Shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia, including the polymorphic form.

Question 5Rhythm recognition and ECG interpretation

A stable patient has a regular, narrow-complex tachycardia at 186/min with no visible P waves. Which rhythm is most likely?

  1. Ventricular tachycardia
  2. Atrial flutter with 2:1 conduction
  3. Sinus tachycardia
  4. SVT Correct answer.

Explanation

A regular narrow-complex tachycardia faster than about 150/min without discernible P waves is characteristic of supraventricular tachycardia. Sinus tachycardia usually shows P waves and rarely sustains rates near 190/min in a resting adult. Wide QRS complexes would raise concern for ventricular tachycardia instead.

Question 6Rhythm recognition and ECG interpretation

A 12-lead ECG shows a regular rhythm at 70/min. Every P wave is followed by a QRS, and the PR interval is 0.28 second. What is the interpretation?

  1. First-degree AV block Correct answer.
  2. Third-degree AV block
  3. Normal sinus rhythm
  4. Second-degree AV block, type I

Explanation

A PR interval longer than 0.20 second with every P wave conducted to a QRS defines first-degree AV block. There are no dropped beats, so it is not a second-degree block, and the atrial and ventricular rates are linked, so it is not complete block.

Question 7Rhythm recognition and ECG interpretation

An unresponsive patient has no palpable pulse. The monitor shows a regular narrow-complex rhythm at 76/min. Which action is most appropriate?

  1. PEA; give epinephrine and CPR Correct answer.
  2. Ventricular fibrillation; defibrillate
  3. Sinus rhythm; continue monitoring
  4. Asystole; begin CPR

Explanation

Organized electrical activity on the monitor without a palpable pulse defines pulseless electrical activity. Treatment is high-quality CPR, epinephrine, and identification of reversible causes such as hypovolemia or hypoxia. Defibrillation does not apply because the rhythm is organized.

Question 8Rhythm recognition and ECG interpretation

A febrile, dehydrated patient has a regular rhythm at 128/min with an upright P wave before each QRS. What is the most appropriate management?

  1. Adenosine 6 mg IV push
  2. Immediate synchronized cardioversion
  3. Treat the underlying cause Correct answer.
  4. Atropine 1 mg IV push

Explanation

This is sinus tachycardia, a compensatory response to fever and hypovolemia. Management focuses on correcting the underlying cause, such as giving fluids and treating the fever, rather than on rate control or cardioversion.

Question 9Rhythm recognition and ECG interpretation

The rhythm strip shows progressive lengthening of the PR interval over several beats until one P wave is not followed by a QRS, after which the cycle repeats. Which rhythm is this?

  1. First-degree AV block
  2. Second-degree AV block, type I Correct answer.
  3. Third-degree AV block
  4. Second-degree AV block, type II

Explanation

Progressively lengthening PR intervals followed by a dropped QRS in repeating groups is the hallmark of type I second-degree AV block (Wenckebach). The block is usually at the AV node and often responds to atropine if the patient is symptomatic.

Question 10Rhythm recognition and ECG interpretation

An ECG shows a constant PR interval of 0.16 second with an occasional P wave not followed by a QRS, and the QRS complexes are wide. Which statement about this rhythm is correct?

  1. Sinus arrest with a ventricular escape rhythm
  2. Type II block that may progress to complete block Correct answer.
  3. Complete AV block because some P waves are blocked
  4. Type I block that usually responds to atropine

Explanation

A constant PR interval in conducted beats with sudden dropped QRS complexes defines type II second-degree AV block. The block is usually infranodal, which explains the wide QRS and the high risk of progression to complete heart block, often requiring pacing.

Question 11Rhythm recognition and ECG interpretation

P waves occur regularly at 88/min and QRS complexes occur regularly at 32/min, with no relationship between them; the QRS complexes are wide. What is the rhythm?

  1. Second-degree AV block, type II
  2. Sinus bradycardia with first-degree block
  3. Third-degree (complete) AV block Correct answer.
  4. Junctional rhythm with premature ventricular complexes

Explanation

Independent, faster atrial activity with a slow, unrelated ventricular rhythm indicates complete AV dissociation, the defining feature of third-degree AV block. The wide QRS suggests a ventricular escape focus below the AV node. Patients are often symptomatic and may need transcutaneous pacing.

Question 12Rhythm recognition and ECG interpretation

A narrow-complex tachycardia at 150/min shows sawtooth atrial waves between QRS complexes at a rate of about 300/min. What is the rhythm?

  1. AV reentrant tachycardia with 2:1 block
  2. Atrial fibrillation
  3. Atrial flutter with 2:1 block Correct answer.
  4. Sinus tachycardia

Explanation

Organized sawtooth atrial activity near 300/min with a ventricular response of 150/min indicates atrial flutter with 2:1 AV conduction. The regular atrial waves distinguish flutter from the disorganized atrial activity of fibrillation.

Question 13Rhythm recognition and ECG interpretation

Which rhythm is characterized by an irregularly irregular ventricular response with no discrete P waves?

  1. Multifocal atrial tachycardia
  2. Sinus arrhythmia
  3. Atrial fibrillation Correct answer.
  4. Atrial flutter

Explanation

Atrial fibrillation produces chaotic atrial activity without organized P waves and an irregularly irregular ventricular response. Unstable patients with this rhythm are treated with synchronized cardioversion.

Question 14Rhythm recognition and ECG interpretation

A regular rhythm at 48/min has a narrow QRS and absent P waves. Which rhythm is most likely?

  1. Idioventricular rhythm
  2. Sinus bradycardia
  3. Third-degree AV block
  4. Junctional rhythm Correct answer.

Explanation

The AV junction typically fires at 40 to 60/min and conducts with a narrow QRS when it serves as the escape pacemaker. P waves are absent, inverted, or retrograde because atrial activation occurs abnormally. A ventricular escape rhythm would be slower and wide.

Question 15Rhythm recognition and ECG interpretation

Which of these describes the rhythm that takes over when both the sinus node and the AV junction fail to pace the heart?

  1. A narrow-complex rhythm at 40 to 60 beats/min
  2. A regular narrow-complex rhythm at 60 to 100 beats/min
  3. A wide-complex rhythm at 20 to 40 beats/min Correct answer.
  4. A wide-complex irregular rhythm at 150 to 250 beats/min

Explanation

When higher pacemakers fail, ventricular pacemakers generate a wide-complex escape rhythm at roughly 20 to 40/min. The slow rate and wide QRS reflect conduction through ventricular myocardium rather than the His-Purkinje system. Such a patient is usually symptomatic and may require pacing.

Question 16Rhythm recognition and ECG interpretation

A patient has a polymorphic wide-complex tachycardia with QRS complexes that twist around the baseline, and an earlier ECG showed a QT interval of 0.62 second. Which treatment is specifically indicated?

  1. Adenosine 6 mg rapid IV push
  2. Sodium bicarbonate 1 mEq/kg IV
  3. Synchronized cardioversion at 100 J
  4. IV magnesium sulfate Correct answer.

Explanation

Polymorphic ventricular tachycardia with a prolonged QT interval is torsades de pointes, and intravenous magnesium is the specific treatment. Any contributing cause of QT prolongation, such as hypokalemia or a culprit drug, should be corrected at the same time.

Question 17Rhythm recognition and ECG interpretation

A patient with a regular narrow-complex tachycardia at 190/min is hypotensive, diaphoretic, and complaining of chest pain. Which intervention is indicated?

  1. Synchronized cardioversion at 50 to 100 J Correct answer.
  2. Adenosine 12 mg IV push
  3. Transcutaneous pacing at 80/min
  4. Immediate unsynchronized defibrillation at 200 J

Explanation

A tachyarrhythmia with hypotension, ischemic chest pain, or altered mental status is unstable and requires immediate synchronized cardioversion. For a regular narrow-complex tachycardia the initial energy is typically 50 to 100 J. Unsynchronized shocks are reserved for VF and pulseless VT.

Question 18Rhythm recognition and ECG interpretation

For a stable patient with a regular narrow-complex SVT, what is the recommended first dose of adenosine?

  1. 12 mg rapid IV push
  2. 0.5 mg/kg IV infusion over 10 minutes
  3. 6 mg rapid IV push Correct answer.
  4. 1 mg slow IV push over 5 minutes

Explanation

The ACLS dose of adenosine is 6 mg given as a rapid IV push with a rapid saline flush, followed by a second dose of 12 mg if the rhythm does not convert. Rapid administration is essential because adenosine is metabolized within seconds.

Question 19Rhythm recognition and ECG interpretation

A 12-lead ECG shows peaked, narrow-based T waves, a widened QRS, and flattened P waves. Which electrolyte abnormality is most likely?

  1. Hypocalcemia
  2. Hypernatremia
  3. Hyperkalemia Correct answer.
  4. Hypokalemia

Explanation

Peaked T waves progressing to QRS widening and loss of P waves is the classic sequence of hyperkalemia, which can deteriorate into a sine-wave pattern and cardiac arrest. Treatment includes intravenous calcium to stabilize the myocardium plus measures to shift and remove potassium.

Question 20Rhythm recognition and ECG interpretation

A patient with chest pain has 3 mm of ST elevation in leads V2 through V4 with reciprocal ST depression in leads II, III, and aVF. What is the interpretation and priority?

  1. Pericarditis; start anti-inflammatory therapy
  2. Stable angina; give nitroglycerin and discharge
  3. Anterior STEMI; activate emergency reperfusion Correct answer.
  4. NSTEMI; await serial troponins before reperfusion decisions

Explanation

ST elevation in contiguous precordial leads with reciprocal depression in inferior leads indicates an acute anterior myocardial infarction. The priority is emergent reperfusion, either primary PCI or fibrinolysis when PCI is not available in time.

Question 21Rhythm recognition and ECG interpretation

Which finding on the ECG most strongly supports ventricular tachycardia rather than SVT with aberrant conduction?

  1. A regular rhythm
  2. AV dissociation Correct answer.
  3. A wide QRS complex
  4. A rate above 150/min

Explanation

AV dissociation, fusion or capture beats, extreme axis deviation, and precordial concordance favor a ventricular origin. Wide QRS, fast rates, and regularity occur in both ventricular tachycardia and SVT with aberrancy, so they do not discriminate. In doubt, a regular wide-complex tachycardia is treated as VT.

Question 22Rhythm recognition and ECG interpretation

A patient with atrial fibrillation has a single wide QRS complex that follows a short R-R interval occurring after a long R-R interval. Which phenomenon explains this?

  1. Premature ventricular complex
  2. Wenckebach periodicity
  3. Torsades de pointes
  4. Ashman phenomenon Correct answer.

Explanation

Ashman phenomenon is rate-related aberrant conduction: a long cycle lengthens refractoriness, and the following short cycle delivers an impulse while part of the conduction system is still refractory. The beat is supraventricular despite its wide appearance, and it is common in atrial fibrillation.

Question 23Rhythm recognition and ECG interpretation

An ECG shows an irregular rhythm at 130/min with at least three different P-wave morphologies and varying PR intervals. Which rhythm is this?

  1. Multifocal atrial tachycardia Correct answer.
  2. Atrial flutter
  3. Wandering atrial pacemaker
  4. Atrial fibrillation

Explanation

Three or more distinct P-wave morphologies with an irregular ventricular response and a rate above 100/min define multifocal atrial tachycardia. It usually occurs in patients with severe pulmonary disease and is treated by correcting the underlying illness rather than by cardioversion.

Question 24Rhythm recognition and ECG interpretation

A patient who is awake and talking has a monitor tracing that looks like chaotic ventricular fibrillation. What is the best next step?

  1. Give epinephrine 1 mg IV
  2. Check the patient and leads Correct answer.
  3. Defibrillate immediately at 200 J
  4. Start chest compressions

Explanation

Monitor tracings must always be correlated with the patient; a conscious, talking patient cannot be in ventricular fibrillation, so artifact from movement or a loose lead is the likely cause. Checking the patient and the leads prevents an unnecessary and dangerous shock.

Question 25Rhythm recognition and ECG interpretation

A 2:1 AV block is present. Which finding favors second-degree AV block type II over type I?

  1. The PR interval of conducted beats is longer than 0.20 second
  2. The PR interval is constant and the QRS is wide Correct answer.
  3. The ventricular rhythm is regular
  4. The atrial rate is faster than the ventricular rate

Explanation

In type II block the PR interval of conducted beats stays constant and the block is typically infranodal, producing a wide QRS. Type I block usually shows PR lengthening before a dropped beat and a narrow QRS. Atrial-to-ventricular rate differences and regularity are seen with both types.

Question 26Rhythm recognition and ECG interpretation

Which rhythms are appropriately treated with immediate defibrillation during cardiac arrest?

  1. Sinus bradycardia and junctional rhythm
  2. Asystole and PEA
  3. Pulseless VT and VF Correct answer.
  4. Atrial fibrillation and atrial flutter

Explanation

Ventricular fibrillation and pulseless ventricular tachycardia are shockable arrest rhythms because an unsynchronized shock can terminate the disorganized or rapid ventricular activity. Asystole and pulseless electrical activity are nonshockable and are managed with CPR and medications.

Question 27Rhythm recognition and ECG interpretation

A 6-second ECG strip contains 9 QRS complexes. What is the approximate ventricular rate?

  1. 90/min Correct answer.
  2. 150/min
  3. 108/min
  4. 54/min

Explanation

To estimate rate from a 6-second strip, count the number of QRS complexes and multiply by 10. Nine complexes in 6 seconds gives approximately 90 beats per minute.

Question 28Rhythm recognition and ECG interpretation

An ECG shows an irregular rhythm with an upright P wave before every QRS and a constant PR interval. The R-R interval lengthens during inspiration and shortens during expiration. Which rhythm is this?

  1. Second-degree AV block type I
  2. Multifocal atrial tachycardia
  3. Sinus arrhythmia Correct answer.
  4. Atrial fibrillation

Explanation

Sinus arrhythmia is a phasic variation in sinus rate, usually with respiration, while every P wave still conducts with a constant PR interval. The presence of consistent P waves distinguishes it from atrial fibrillation and multifocal atrial tachycardia.

Question 29Rhythm recognition and ECG interpretation

A 12-lead ECG shows a QRS duration of 0.14 second with an rsR' pattern in V1 and a broad, slurred S wave in leads I and V6. Which conduction abnormality does this represent?

  1. Right bundle branch block Correct answer.
  2. First-degree AV block
  3. Left anterior fascicular block
  4. Left bundle branch block

Explanation

Right bundle branch block delays right ventricular activation, producing a widened QRS with an rsR' pattern in V1 and a broad S wave in lateral leads such as I and V6. These features separate it from left bundle branch block and from blocks that do not widen the QRS.

Question 30Rhythm recognition and ECG interpretation

A rhythm strip shows a normal narrow QRS complex followed by a wide, premature QRS complex, and this alternating pattern repeats continuously. What is the best description?

  1. Ventricular bigeminy Correct answer.
  2. Ventricular couplet
  3. Atrial bigeminy
  4. Ventricular trigeminy

Explanation

Ventricular bigeminy describes an alternating pattern in which every other beat is a premature ventricular complex. The wide, premature QRS without a preceding P wave identifies the ectopic beat as ventricular.

Question 31Rhythm recognition and ECG interpretation

The monitor shows a flat line in one lead. What is the most appropriate next step to confirm asystole?

  1. Give atropine 1 mg IV
  2. Start synchronized cardioversion
  3. Deliver an unsynchronized shock immediately
  4. Check leads, gain, and another lead Correct answer.

Explanation

Asystole should be confirmed in more than one lead and by checking for technical causes such as loose leads or low gain. Fine ventricular fibrillation can mimic a flat line, so verifying the tracing prevents inappropriate treatment.

Question 32Rhythm recognition and ECG interpretation

A patient is unresponsive with no palpable pulse. The monitor shows an organized narrow-complex rhythm at 80/min. What is the rhythm diagnosis?

  1. Asystole
  2. Pulseless electrical activity Correct answer.
  3. Ventricular fibrillation
  4. Pulseless ventricular tachycardia

Explanation

Pulseless electrical activity is organized electrical activity on the monitor without a palpable pulse. The organized narrow complexes rule out ventricular fibrillation, asystole, and pulseless ventricular tachycardia.

Question 33Rhythm recognition and ECG interpretation

A paced rhythm shows regular pacing spikes, but many spikes are not followed by a QRS complex. What is the most likely pacemaker problem?

  1. Oversensing
  2. Pacemaker-mediated tachycardia
  3. Failure to sense
  4. Failure to capture Correct answer.

Explanation

Capture occurs when a pacing spike successfully depolarizes the myocardium and produces a QRS complex. Failure to capture is present when pacing spikes occur without a following QRS, indicating that the stimulus is not producing ventricular activation.

Question 34Rhythm recognition and ECG interpretation

A rhythm strip shows a pause in the sinus rhythm. The pause duration is exactly equal to two normal P-P intervals. Which phenomenon does this most suggest?

  1. Premature atrial complex
  2. Sinoatrial exit block Correct answer.
  3. Junctional escape beat
  4. Sinus arrest

Explanation

In sinoatrial exit block, the sinus node continues to fire but the impulse fails to exit the node, so the pause is a multiple of the normal P-P interval. Sinus arrest produces a pause that is not an exact multiple because the sinus node itself fails to fire.

Question 35High-quality BLS and airway management

What is the recommended chest compression rate for an adult in cardiac arrest?

  1. 100 to 120 per minute Correct answer.
  2. 80 to 100 per minute
  3. At least 140 per minute
  4. 60 to 80 per minute

Explanation

High-quality CPR for adults uses a compression rate of 100 to 120 per minute. Rates above 120 tend to reduce compression depth, and rates below 100 reduce cardiac output.

Question 36High-quality BLS and airway management

How deep should chest compressions be in an adult in cardiac arrest?

  1. At least 3 inches (7.5 cm)
  2. Exactly 1.5 inches (4 cm)
  3. About 1 inch (2.5 cm)
  4. At least 2 inches (5 cm) Correct answer.

Explanation

Adult compressions should be at least 2 inches (5 cm) deep while avoiding excessive depth beyond about 2.4 inches (6 cm). Shallow compressions generate inadequate forward flow.

Question 37High-quality BLS and airway management

What compression-to-ventilation ratio is used by a single rescuer for an adult in cardiac arrest without an advanced airway?

  1. 50:2
  2. 15:2
  3. 5:1
  4. 30:2 Correct answer.

Explanation

For an adult without an advanced airway, CPR uses 30 compressions to 2 ventilations. The same 30:2 ratio applies when two rescuers are present before an advanced airway is placed.

Question 38High-quality BLS and airway management

Complete chest recoil during compressions is important mainly because it:

  1. allows blood to refill the heart Correct answer.
  2. keeps the AED algorithm accurate
  3. prevents gastric inflation
  4. reduces the risk of rib fractures

Explanation

Full recoil lets the chest wall return to its resting position so intrathoracic pressure falls and the heart can refill. Leaning on the chest between compressions reduces filling and lowers cardiac output.

Question 39High-quality BLS and airway management

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

  1. Over the xiphoid process
  2. On the upper third of the sternum
  3. On the lower half of the sternum Correct answer.
  4. Over the left fifth rib

Explanation

The heel of one hand goes on the lower half of the sternum with the second hand on top. Placement over the xiphoid or the ribs increases injury risk and reduces compression effectiveness.

Question 40High-quality BLS and airway management

When checking the pulse and rhythm during resuscitation, the check should take no more than:

  1. 5 seconds
  2. 30 seconds
  3. 20 seconds
  4. 10 seconds Correct answer.

Explanation

Pulse and rhythm checks should be completed within 10 seconds to limit interruptions in compressions. Prolonged checks reduce coronary and cerebral perfusion pressure.

Question 41High-quality BLS and airway management

An oropharyngeal airway is correctly sized by measuring from the:

  1. tip of the nose to the earlobe
  2. corner of the mouth to the angle of the jaw Correct answer.
  3. chin to the sternal notch
  4. corner of the mouth to the clavicle

Explanation

A correctly sized OPA reaches from the corner of the mouth to the angle of the mandible. An improperly sized device can obstruct the airway or fail to hold the tongue forward.

Question 42High-quality BLS and airway management

How often should the rescuer performing chest compressions be changed?

  1. Every 5 minutes
  2. Only when the compressor reports fatigue
  3. About every 2 minutes Correct answer.
  4. Every 30 seconds

Explanation

Compressors should rotate approximately every 2 minutes, ideally during a rhythm check, because compression quality declines with fatigue. Waiting for the rescuer to report fatigue usually means shallow compressions have already occurred.

Question 43High-quality BLS and airway management

An adult in cardiac arrest has an advanced airway in place and compressions are continuous. What ventilation rate should be provided?

  1. 1 breath every 10 seconds
  2. 1 breath every 3 seconds
  3. 1 breath every 6 seconds Correct answer.
  4. 2 breaths after every 30 compressions

Explanation

Once an advanced airway is in place, compressions become continuous and ventilations are given at 1 breath every 6 seconds, or 10 per minute. The 30:2 cycle no longer applies.

Question 44High-quality BLS and airway management

Which approach best improves mask seal and delivered volume during bag-mask ventilation of an adult?

  1. Squeeze the bag with one hand while lifting the chin with the other
  2. Deliver each breath as forcefully as possible
  3. Have a second rescuer squeeze the bag while both hands hold the mask Correct answer.
  4. Use a smaller mask to increase pressure

Explanation

Two rescuers allow one to hold the mask with both hands while the other squeezes the bag, producing a better seal and more reliable tidal volumes. A one-handed technique commonly leaks and delivers inadequate volume.

Question 45High-quality BLS and airway management

Which consequence is most associated with delivering breaths too rapidly during CPR?

  1. Higher end-tidal CO2 values
  2. Reduced venous return and cardiac output Correct answer.
  3. Increased coronary perfusion pressure
  4. Improved cerebral blood flow

Explanation

Rapid or large breaths raise intrathoracic pressure, which reduces venous return and cardiac output, and they increase the risk of gastric inflation. Hyperventilation during CPR is harmful.

Question 46High-quality BLS and airway management

Which method is most reliable for confirming and continuously monitoring tracheal tube placement?

  1. Chest rise alone
  2. Auscultation of the epigastrium
  3. A colorimetric detector only
  4. Continuous waveform capnography Correct answer.

Explanation

Continuous waveform capnography is the most reliable method to confirm and monitor tracheal tube position. It detects both esophageal placement and later dislodgement.

Question 47High-quality BLS and airway management

An adult in cardiac arrest has a confirmed tracheal tube and continuous waveform capnography. End-tidal CO2 stays below 10 mmHg after 2 minutes of compressions. What is the best interpretation?

  1. The tube has migrated into the esophagus
  2. Compression quality is inadequate and ROSC is unlikely Correct answer.
  3. The patient has achieved ROSC
  4. Ventilation is excessive and should be slowed

Explanation

With a confirmed tracheal tube, a persistently low end-tidal CO2 during CPR reflects poor pulmonary blood flow, usually from inadequate compressions. Values below 10 mmHg are associated with a very low likelihood of ROSC.

Question 48High-quality BLS and airway management

When suctioning an adult airway, each suction attempt should be limited to no more than:

  1. 10 seconds Correct answer.
  2. 30 seconds
  3. 60 seconds
  4. 5 seconds

Explanation

Suctioning should be limited to no more than 10 seconds in adults, with oxygen restored between attempts. Prolonged suctioning causes hypoxemia and can provoke vagal bradycardia.

Question 49High-quality BLS and airway management

An adult in cardiac arrest has a suspected cervical spine injury, and the airway must be opened. Which technique is preferred?

  1. Turning the head to one side
  2. Inserting an airway without opening the mouth
  3. Head-tilt chin-lift with maximal neck extension
  4. Jaw thrust without head extension Correct answer.

Explanation

In suspected cervical spine injury, the jaw thrust opens the airway without extending the neck. Head-tilt chin-lift is reserved for patients without suspected spinal injury.

Question 50High-quality BLS and airway management

Which finding is a reason to avoid placing a nasopharyngeal airway?

  1. The cough reflex is absent
  2. Basilar skull fracture is suspected Correct answer.
  3. Copious secretions are present
  4. A gag reflex is present

Explanation

A nasopharyngeal airway should be avoided when midface trauma or a basilar skull fracture is suspected because of the risk of intracranial placement. An oropharyngeal airway is an alternative in an unresponsive patient.