Basic Life Support (BLS) interview questions

What a strong answer covers

• Explain the 'Scene Safety' principle, identifying potential hazards (e.g., traffic, fire, aggressive individuals).
• Detail how to assess the patient's responsiveness (tap and shout) and check for normal breathing (look, listen, feel for no more than 10 seconds).
• Describe the process of activating EMS (calling 911/local emergency number) and, if available, retrieving an AED, including delegating tasks if bystanders are present.

Where people lose the point

• ×Failing to prioritize scene safety before approaching the patient.
• ×Spending too much time assessing the patient or checking for breathing (exceeding 10 seconds).
• ×Forgetting to activate EMS or delegate this critical task immediately.

What a strong answer covers

• State the correct compression-to-breath ratio for single-rescuer adult CPR (30 compressions to 2 breaths).
• Describe the correct compression depth (at least 2 inches / 5 cm, no more than 2.4 inches / 6 cm).
• Explain the correct compression rate (100-120 compressions per minute).
• Emphasize the importance of full chest recoil and minimizing interruptions.

Where people lose the point

• ×Incorrectly stating the compression-to-breath ratio.
• ×Failing to mention full chest recoil or minimizing interruptions as critical components.
• ×Providing an incorrect range for compression depth or rate.

What a strong answer covers

• Explain to power on the AED and follow its voice/visual prompts while CPR continues.
• Describe how to prepare the patient's chest (expose, dry) and correctly apply the adult AED pads (upper right chest, lower left side).
• Detail the process of allowing the AED to analyze the rhythm (no one touching the patient) and delivering a shock if advised (loudly announce 'CLEAR!').
• State the immediate resumption of CPR (starting with compressions) for 2 minutes after a shock or no-shock advised.

Where people lose the point

• ×Stopping CPR for an extended period to apply the AED or during analysis.
• ×Forgetting to announce 'CLEAR!' before delivering a shock.
• ×Incorrect pad placement or failing to ensure the chest is dry.

What a strong answer covers

• Recognize the signs of severe airway obstruction (universal choking sign, inability to speak/breathe).
• Describe how to perform abdominal thrusts (Heimlich maneuver): stand behind, wrap arms, fist above navel, grasp fist, deliver quick upward thrusts.
• Explain to continue thrusts until the object is expelled or the person becomes unconscious.
• Mention calling EMS if not already done, especially if the person becomes unconscious.

Where people lose the point

• ×Hesitating or failing to act immediately for a conscious choking victim.
• ×Performing chest compressions instead of abdominal thrusts for a conscious victim.
• ×Incorrect hand placement for abdominal thrusts (e.g., too high on the chest).

What a strong answer covers

• Explain the compression technique for infants: two fingers (single rescuer) or two thumbs (two rescuers) on the breastbone, just below the nipple line.
• State the correct compression depth for infants: approximately 1.5 inches (4 cm).
• Mention that the compression rate (100-120 per minute) and full chest recoil remain the same.
• Briefly note the compression-to-breath ratio (30:2 for single, 15:2 for two rescuers) is also different for two-rescuer infant/child CPR.

Where people lose the point

• ×Using the same hand placement or technique as for an adult.
• ×Incorrectly stating the compression depth for an infant.
• ×Forgetting to emphasize the importance of full chest recoil for infants.

What a strong answer covers

• Describe the Head-Tilt/Chin-Lift maneuver: one hand on forehead, fingers of other hand under chin, tilt head back, lift chin.
• Explain that Head-Tilt/Chin-Lift is the preferred method for most non-trauma patients.
• Describe the Jaw-Thrust maneuver: grasping angles of lower jaw, lifting with both hands, displacing mandible forward.
• Explain that Jaw-Thrust is used when a head, neck, or spinal injury is suspected to minimize cervical spine movement.

Where people lose the point

• ×Confusing when to use each maneuver, especially using Head-Tilt/Chin-Lift with suspected trauma.
• ×Incorrectly describing the steps for either maneuver.
• ×Failing to explain the rationale behind using Jaw-Thrust for suspected trauma.

What a strong answer covers

• Gently lower the patient to the ground and immediately begin CPR, starting with chest compressions.
• Explain that before delivering rescue breaths, look inside the mouth for the object; if seen and easily removable, sweep it out.
• Emphasize never performing a blind finger sweep.
• State to continue CPR until EMS arrives or the object is dislodged and the patient recovers.

Where people lose the point

• ×Attempting more abdominal thrusts on an unconscious patient.
• ×Performing a blind finger sweep, potentially pushing the object further down.
• ×Failing to immediately initiate CPR, starting with compressions.

What a strong answer covers

• State the correct compression-to-breath ratio for two-rescuer child CPR (15 compressions to 2 breaths).
• Explain that rescuers should switch roles approximately every 2 minutes (or 5 cycles of 15:2) to prevent fatigue.
• Describe how to switch roles efficiently with minimal interruption to compressions (e.g., the compressor calls for the switch, the ventilating rescuer takes over compressions immediately after the last breath).
• Mention that the compression depth for a child is about 2 inches (5 cm) and the rate is 100-120 per minute.

Where people lose the point

• ×Using the adult 30:2 ratio for two-rescuer child CPR.
• ×Allowing significant interruptions during the switch between rescuers.
• ×Failing to mention the importance of switching roles to prevent fatigue.

What a strong answer covers

• Define agonal gasps as infrequent, noisy gasps that may sound like snorting, gurgling, or labored breathing.
• Explain that agonal gasps are not normal breathing and are a sign of cardiac arrest.
• State that a rescuer should interpret agonal gasps as an indication to immediately begin CPR.
• Emphasize that these gasps are a reflex and do not provide effective oxygenation.

Where people lose the point

• ×Mistaking agonal gasps for normal breathing and delaying CPR.
• ×Failing to recognize agonal gasps as a critical sign of cardiac arrest.
• ×Not understanding that agonal gasps are ineffective for oxygenation.

What a strong answer covers

• Hairy Chest: Explain that excessive hair can prevent pads from sticking; if possible, quickly shave the area or use a second set of pads to rip off hair.
• Transdermal Medication Patch: Describe removing the patch and wiping the area clean before applying AED pads.
• Implanted Pacemaker/Defibrillator: Explain to avoid placing AED pads directly over the implanted device; place pads at least 1 inch (2.5 cm) away from the device.
• Emphasize that these considerations should not delay defibrillation significantly.

Where people lose the point

• ×Delaying AED use excessively due to these considerations.
• ×Applying pads directly over a medication patch or implanted device.
• ×Failing to address the issue of a hairy chest, leading to poor pad contact.

What a strong answer covers

• Explain that each breath should last about 1 second and cause the chest to visibly rise.
• Describe the technique: pinch the nose, make a complete seal over the mouth, deliver breath.
• State that if the chest does not rise with the first breath, reposition the airway (head-tilt/chin-lift) and try again before the second breath.
• Emphasize avoiding over-ventilation (giving too much air or breathing too forcefully), which can lead to gastric inflation.

Where people lose the point

• ×Delivering breaths too quickly or too forcefully (over-ventilation).
• ×Failing to ensure a proper seal or pinch the nose, leading to air leakage.
• ×Not repositioning the airway if the first breath is ineffective.

What a strong answer covers

• Support the infant's head and neck, placing them face down on your forearm.
• Deliver 5 firm back blows between the shoulder blades with the heel of your hand.
• Turn the infant face up on your other forearm, supporting the head, and deliver 5 rapid chest thrusts using two fingers on the breastbone, just below the nipple line.
• Alternate between 5 back blows and 5 chest thrusts until the object is expelled or the infant becomes unconscious.

Where people lose the point

• ×Using abdominal thrusts (Heimlich) on an infant.
• ×Failing to adequately support the infant's head and neck.
• ×Not alternating between back blows and chest thrusts, or performing an incorrect number of each.

What a strong answer covers

• Explain that CPR should continue until EMS personnel arrive and take over.
• State that CPR can be stopped if an AED becomes available and is ready for use.
• Mention stopping if the patient shows obvious signs of life (e.g., starts breathing normally, moves).
• Include stopping if the rescuer becomes too exhausted to continue effectively or the scene becomes unsafe.

Where people lose the point

• ×Stopping CPR prematurely without a valid reason (e.g., after a few minutes without signs of life).
• ×Continuing CPR when the scene becomes unsafe for the rescuer.
• ×Failing to recognize that an AED's arrival is a reason to pause and use it, not necessarily stop CPR entirely.

What a strong answer covers

• Adults: Depth at least 2 inches (5 cm), no more than 2.4 inches (6 cm); Rate 100-120 compressions/minute.
• Children: Depth about 2 inches (5 cm); Rate 100-120 compressions/minute.
• Infants: Depth about 1.5 inches (4 cm); Rate 100-120 compressions/minute.
• Emphasize that the rate is consistent across all age groups, but depth varies.

Where people lose the point

• ×Confusing the depth requirements between age groups.
• ×Stating an incorrect rate for any age group.
• ×Failing to mention the 'no more than 2.4 inches' for adults.

What a strong answer covers

• Place the patient in the recovery position (on their side) if they are breathing normally and are unresponsive but have a pulse, to maintain an open airway and prevent aspiration.
• Monitor the patient closely for any changes in their condition (breathing, responsiveness).
• Keep the patient warm and comfortable.
• Stay with the patient and continue to reassure them until EMS arrives and takes over care.

Where people lose the point

• ×Leaving the patient unattended after resuscitation.
• ×Placing a patient who is not breathing normally into the recovery position.
• ×Failing to continue monitoring the patient's condition.