22 Airway, Respiration & Ventilation Practice Questions & Answers

1. 1. What is the normal end-tidal CO2 (EtCO2) range in an adult with adequate alveolar ventilation?

   • A.35-45 mmHg✓ Answer
   • B.25-35 mmHg
   • C.45-55 mmHg
   • D.20-30 mmHg

   Normal alveolar ventilation keeps arterial PaCO2 near 40 mmHg, and exhaled gas sampled at end-expiration closely tracks that value, so a normal EtCO2 is 35-45 mmHg. Values below 35 suggest hyperventilation or low perfusion, and values above 45 indicate hypoventilation with CO2 retention.

   Source: Standard capnography reference range (EtCO2 35-45 mmHg), paramedic-level capnography curriculum; NREMT Paramedic Test Plan (July 1, 2024), Airway/Respiration/Ventilation — AssessmentReport a problem with this question

2. 2. During capnography monitoring of a dyspneic patient, the waveform shows a slanted, 'shark fin' upstroke without a flat alveolar plateau. What does this morphology indicate?

   • A.Pulmonary edema flooding the alveoli
   • B.Hyperventilation lowering arterial CO2
   • C.Esophageal placement of the airway tube
   • D.Bronchospasm delaying expiratory airflow✓ Answer

   In bronchospasm (asthma or COPD), narrowed lower airways empty at different rates, so exhaled CO2 rises gradually instead of abruptly, slurring the upstroke and plateau into a shark-fin shape. Esophageal intubation produces a flat or absent waveform, and hyperventilation lowers the plateau height without distorting its shape.

   Source: Waveform capnography interpretation — obstructive 'shark fin' morphology; National EMS Education Standards (Paramedic), capnography; NREMT Test Plan July 2024, ARV — AssessmentReport a problem with this question

3. 3. An intubated patient's EtCO2 suddenly falls from 38 mmHg to near zero with loss of the waveform. What is the most likely cause?

   • A.Return of spontaneous circulation
   • B.Displacement of the tube from the trachea✓ Answer
   • C.Improvement of pulmonary perfusion
   • D.Worsening of the patient's bronchospasm

   A sudden loss of the CO2 waveform means exhaled gas is no longer passing through the tube, which occurs when the tube dislodges into the esophagus or hypopharynx — the 'D' in the DOPE mnemonic. ROSC and improved perfusion raise EtCO2, and bronchospasm distorts the waveform shape rather than abolishing it.

   Source: DOPE mnemonic (Displacement, Obstruction, Pneumothorax, Equipment); AHA ACLS airway monitoring — abrupt EtCO2 loss indicates tube displacementReport a problem with this question

4. 4. During CPR on an intubated patient, EtCO2 has been 12 mmHg and abruptly rises to 42 mmHg with a sustained waveform. What does this change most likely indicate?

   • A.Excessive ventilation by the rescuer
   • B.Dislodgement of the tube into the esophagus
   • C.Return of spontaneous circulation (ROSC)✓ Answer
   • D.Fatigue of the chest compressor

   During arrest, EtCO2 is limited by the low pulmonary blood flow generated by compressions; when the heart restarts, cardiac output surges and delivers accumulated CO2 to the lungs, producing an abrupt sustained rise toward normal values. Compressor fatigue and esophageal displacement would lower or abolish the reading, and hyperventilation also lowers EtCO2.

   Source: AHA 2020 ACLS Guidelines — abrupt sustained increase in EtCO2 (typically to ≥40 mmHg) during CPR is an indicator of ROSCReport a problem with this question

5. 5. A patient on a transport ventilator has an EtCO2 of 55 mmHg with a normal plateau waveform and stable oxygen saturation. What adjustment is most appropriate?

   • A.Decrease the delivered tidal volume
   • B.Increase the ventilator's respiratory rate✓ Answer
   • C.Increase the PEEP setting by 5 cm H2O
   • D.Increase the FiO2 to 100 percent

   An EtCO2 of 55 mmHg reflects hypoventilation with respiratory acidosis, and CO2 elimination depends on minute ventilation (rate x tidal volume), so increasing the rate (or tidal volume) is the correction. FiO2 and PEEP address oxygenation, not CO2 clearance, and decreasing tidal volume would worsen the hypercapnia.

   Source: Minute ventilation = rate x tidal volume governs CO2 elimination; paramedic transport-ventilator management (respiratory acidosis → increase minute ventilation)Report a problem with this question

6. 6. A suspected opioid overdose patient breathes 6 times per minute with shallow effort. On a nonrebreather at 15 L/min, SpO2 continues to fall. What is the most appropriate next step?

   • A.Apply CPAP starting at 5 cm H2O
   • B.Give naloxone and wait for it to take effect
   • C.Increase the flow rate to the nonrebreather
   • D.Begin bag-valve-mask assisted ventilations✓ Answer

   Falling SpO2 despite high-flow oxygen signals a ventilation failure, not an oxygenation problem — the patient is not moving enough air, so oxygen delivery devices cannot help and ventilations must be assisted with a BVM. CPAP requires adequate spontaneous breathing, and naloxone is given while ventilating, never instead of ventilating.

   Source: Oxygenation vs ventilation failure distinction; AHA opioid-associated emergency guidance — support ventilation first, titrate naloxone to respirationsReport a problem with this question

7. 7. A patient breathes 40 times per minute with very shallow breaths and a rising EtCO2. Why does this pattern cause CO2 retention?

   • A.The rapid rate causes air trapping and breath-stacking
   • B.The alveoli overdistend and stop diffusing gas
   • C.The fast rate increases metabolic CO2 production
   • D.Each shallow breath mostly moves dead-space air✓ Answer

   Alveolar ventilation equals rate times (tidal volume minus dead space); when tidal volume barely exceeds the roughly 150 mL of anatomic dead space, most of each breath never reaches the alveoli, so CO2 accumulates despite the fast rate. A high rate alone cannot compensate for tidal volumes near dead-space size.

   Source: Alveolar ventilation = rate x (tidal volume − dead space); respiratory physiology, paramedic-level pathophysiology (National EMS Education Standards)Report a problem with this question

8. 8. A severe asthmatic who had loud diffuse wheezing 10 minutes ago now has a nearly silent chest and is becoming drowsy. What does this change signify?

   • A.Bronchospasm has resolved and airflow is improving
   • B.Airflow is now too poor to generate any wheezing✓ Answer
   • C.The obstruction has migrated to the upper airway
   • D.Secretions have cleared from the lower airways

   Wheezing requires air movement through narrowed airways; a 'silent chest' with deteriorating mental status means obstruction is now so severe that almost no air moves, which is a sign of imminent respiratory arrest, not improvement. True improvement would show better mentation, easier breathing, and rising SpO2 alongside diminishing wheezes.

   Source: Silent chest in status asthmaticus = imminent respiratory arrest; paramedic respiratory emergencies curriculum (National EMS Education Standards)Report a problem with this question

9. 9. An unresponsive intoxicated patient snores with each breath but gags when an oral airway is attempted. Which airway device is most appropriate?

   • A.An endotracheal tube (ETT)
   • B.A supraglottic airway device (SGA)
   • C.A nasopharyngeal airway (NPA)✓ Answer
   • D.An oropharyngeal airway (OPA)

   The NPA is tolerated by patients with an intact gag reflex because it does not stimulate the posterior pharynx the way an OPA does, and airway management follows the principle of using the least invasive adjunct that maintains patency. The OPA is contraindicated with a gag reflex, and an SGA or ETT is not yet indicated in a patient protecting his airway reflexes.

   Source: NPA indicated with intact gag reflex; OPA contraindicated with gag reflex — National EMS Education Standards, basic airway adjuncts; least-invasive-first escalation principleReport a problem with this question

10. 10. How is an oropharyngeal airway (OPA) correctly sized before insertion?

    • A.From the center of the lips to the thyroid cartilage
    • B.From the corner of the mouth to the cricoid cartilage
    • C.From the tip of the nose to the earlobe
    • D.From the corner of the mouth to the angle of the jaw✓ Answer

    An OPA is sized from the corner of the mouth to the angle of the jaw (or earlobe) so its tip rests just above the epiglottis, holding the tongue off the posterior pharynx. A tube that is too short fails to displace the tongue, while one that is too long can push the epiglottis over the glottic opening; nose-to-earlobe is the sizing landmark for an NPA, not an OPA.

    Source: OPA sizing landmark (corner of mouth to angle of jaw/earlobe) — National EMS Education Standards, airway adjunctsReport a problem with this question

11. 11. At what rate should a paramedic ventilate an apneic adult who has a strong palpable pulse?

    • A.One breath every 10 seconds
    • B.Two breaths every 5 seconds
    • C.One breath every 3 seconds
    • D.One breath every 6 seconds✓ Answer

    Current resuscitation guidelines set adult rescue breathing at 1 breath every 6 seconds (about 10 breaths per minute) because faster rates raise intrathoracic pressure, reduce venous return and cardiac preload, and promote gastric insufflation. Slower rates risk hypoventilation, and rates near 20 per minute constitute harmful hyperventilation.

    Source: AHA 2020 Guidelines for CPR and ECC — adult rescue breathing: 1 breath every 6 seconds (10/min)Report a problem with this question

12. 12. While ventilating an apneic adult with a BVM, you hear gurgling over the epigastrium and see the abdomen rising. What should you do?

    • A.Squeeze the bag harder to overcome resistance
    • B.Slow the rate and deliver each breath over 1 second✓ Answer
    • C.Apply firm cricoid pressure and bag faster
    • D.Speed up ventilations to replace lost volume

    Gastric insufflation occurs when breaths are delivered too fast or too forcefully, driving air past the esophageal opening pressure into the stomach; the fix is a slower rate with each breath given over about 1 second at roughly 500-600 mL, just enough to produce visible chest rise. A distended stomach elevates the diaphragm and raises the risk of vomiting and aspiration, so bagging harder or faster worsens the problem.

    Source: AHA BLS/ACLS ventilation technique — ~500-600 mL over 1 second, avoid rapid/forceful breaths to prevent gastric insufflationReport a problem with this question

13. 13. In rapid sequence intubation (RSI), what is the correct order of drug administration?

    • A.Give the paralytic alone and sedate after intubation
    • B.Give the paralytic agent, then the induction agent
    • C.Give the induction agent, then the paralytic agent✓ Answer
    • D.Give both agents only after the first laryngoscopy

    The induction agent (such as etomidate or ketamine) must be on board before the paralytic (such as succinylcholine or rocuronium), because paralyzing a conscious patient leaves them awake, terrified, and unable to move or breathe. Sedation must also be continued after the tube is placed, since paralytics wear off at different rates than sedatives.

    Source: RSI pharmacology sequence — sedative/induction before neuromuscular blockade; paramedic advanced airway curriculum (NAEMSP / National EMS Education Standards)Report a problem with this question

14. 14. In which of these patients is succinylcholine contraindicated for RSI?

    • A.A patient on dialysis who missed two sessions✓ Answer
    • B.A patient in severe asthmatic bronchospasm
    • C.A patient burned one hour before your arrival
    • D.A patient with an isolated closed head injury

    Succinylcholine depolarizes muscle membranes and releases potassium into the serum, so it is contraindicated in patients with existing or suspected hyperkalemia — such as renal failure patients who have missed dialysis — as well as burns or crush injuries more than about 24 hours old. A burn only one hour old has not yet upregulated the receptors that cause the exaggerated potassium release, so fresh burns are not a contraindication.

    Source: Succinylcholine contraindications — hyperkalemia, burns/crush injury >24 h old (depolarizing NMB pharmacology; succinylcholine prescribing information)Report a problem with this question

15. 15. A paramedic has attempted laryngoscopy for 30 seconds without passing the tube, and the patient's SpO2 is beginning to fall. What should be done next?

    • A.Advance the tube blindly toward the glottic opening
    • B.Stop and reoxygenate the patient with a BVM✓ Answer
    • C.Continue the attempt until the cords are visualized
    • D.Convert immediately to a surgical cricothyrotomy

    Laryngoscopy attempts should be limited to about 30 seconds because the patient receives no ventilation during the attempt and desaturates quickly; the correct response to a failed attempt is to abort, reoxygenate with a BVM, and optimize conditions before trying again or moving to a rescue device. A surgical airway is reserved for can't-intubate-can't-ventilate situations, and blind advancement risks esophageal placement and trauma.

    Source: Laryngoscopy attempt limit ~30 seconds with reoxygenation between attempts — paramedic advanced airway curriculum; failed-airway algorithm (NAEMSP)Report a problem with this question

16. 16. Immediately after intubation, breath sounds are present on the right but absent on the left, and the abdomen is quiet. What is the appropriate action?

    • A.Withdraw the tube slightly while auscultating the left✓ Answer
    • B.Remove the tube entirely and reintubate from the start
    • C.Decompress the left chest with a large-bore needle
    • D.Advance the tube another 2 cm and then reassess

    Unilateral right-sided breath sounds after intubation classically indicate the tube has advanced into the right mainstem bronchus, because the right bronchus branches at a shallower angle; pulling the tube back slightly until breath sounds become bilateral corrects it without losing the airway. Advancing deepens the malposition, and complete removal sacrifices a tube that is in the trachea and needs only repositioning.

    Source: Right mainstem intubation — absent left breath sounds, corrected by slight tube withdrawal; advanced airway placement confirmation curriculumReport a problem with this question

17. 17. A patient with massive facial trauma cannot be intubated after multiple optimized attempts, a supraglottic airway will not seat, and BVM ventilation moves no air. What is indicated?

    • A.Continue forceful two-person BVM ventilation
    • B.Insert a different supraglottic airway model
    • C.Perform a surgical cricothyrotomy without delay✓ Answer
    • D.Attempt laryngoscopy one additional time

    This is a can't-intubate-can't-ventilate (CICV) failed airway, the specific indication for surgical cricothyrotomy: every less invasive option has failed and the patient will die of hypoxia within minutes without an airway below the obstruction. Repeating failed maneuvers consumes the small oxygen reserve the patient has left.

    Source: Failed-airway algorithm — surgical cricothyrotomy for can't-intubate-can't-ventilate (NAEMSP / difficult airway consensus; paramedic scope of practice)Report a problem with this question

18. 18. Which method is the most reliable for continuous confirmation that an endotracheal tube remains in the trachea during transport?

    • A.Auscultation of bilateral breath sounds
    • B.Condensation misting inside the tube lumen
    • C.Visible rise and fall of the chest wall
    • D.Continuous waveform capnography monitoring✓ Answer

    Continuous waveform capnography is the gold standard because a sustained CO2 waveform can only come from gas exchanged in the lungs, and it instantly reveals dislodgement in a moving ambulance where auscultation is unreliable. Chest rise, breath sounds, and tube misting can all be falsely reassuring — misting in particular occurs even with esophageal placement.

    Source: AHA 2020 ACLS — continuous waveform capnography recommended as the most reliable method to confirm and monitor ET tube placementReport a problem with this question

19. 19. Which of these patients is NOT an appropriate candidate for CPAP?

    • A.A CHF patient with crackles and a BP of 168/94
    • B.An asthma patient with wheezes and a BP of 142/88
    • C.A COPD patient speaking in short phrases
    • D.A pulmonary edema patient responsive only to pain✓ Answer

    CPAP requires a patient who is awake enough to protect the airway, breathe spontaneously, and tolerate the mask; a patient responsive only to painful stimuli cannot protect against aspiration and needs assisted ventilation instead. Other contraindications include apnea, vomiting, hypotension (SBP typically below 90), and significant facial trauma — while hypertensive CHF with crackles is CPAP's classic indication.

    Source: CPAP contraindications — altered mental status/inability to protect airway, apnea, vomiting, hypotension (SBP <90), facial trauma; prehospital CPAP protocols (National Model EMS Clinical Guidelines)Report a problem with this question

20. 20. An intubated head-injury patient develops a unilaterally dilated pupil and extensor posturing. What EtCO2 target should guide ventilation?

    • A.40-45 mmHg
    • B.30-35 mmHg✓ Answer
    • C.50-55 mmHg
    • D.20-25 mmHg

    Signs of herniation justify mild, controlled hyperventilation to an EtCO2 of about 30-35 mmHg, because lowering CO2 constricts cerebral vessels and temporarily reduces intracranial pressure. Aggressive hyperventilation to 20-25 mmHg causes cerebral vasoconstriction severe enough to produce ischemia, and normal-to-high targets fail to counter the herniation; routine hyperventilation without herniation signs is harmful.

    Source: Brain Trauma Foundation prehospital TBI guidelines — hyperventilation only for signs of herniation, target EtCO2 ~30-35 mmHg; avoid routine or aggressive hyperventilationReport a problem with this question

21. 21. Compared with an adult's airway, which statement about a young child's airway is correct?

    • A.The narrowest point lies at the glottic opening
    • B.The larynx sits lower and more posterior in the neck
    • C.The tongue takes up proportionally less of the mouth
    • D.The narrowest point lies at the cricoid cartilage✓ Answer

    In young children the funnel-shaped airway is narrowest at the cricoid cartilage below the vocal cords, whereas the adult airway is narrowest at the glottic opening — which is why a tube can pass the cords in a child yet meet resistance below them. Children also have a proportionally larger tongue, a higher and more anterior larynx, and a large occiput that flexes the neck when supine.

    Source: Pediatric airway anatomy — narrowest at cricoid cartilage (vs glottis in adults), larger tongue, higher/more anterior larynx, large occiput; PALS / paramedic pediatric airway curriculumReport a problem with this question

22. 22. During transport of a ventilated patient, the ventilator's low-pressure alarm sounds and the SpO2 begins to fall. What is the most likely cause?

    • A.A leak or disconnection in the breathing circuit✓ Answer
    • B.Bronchospasm raising the airway resistance
    • C.A mucus plug obstructing the tube lumen
    • D.A tension pneumothorax compressing one lung

    A low-pressure alarm means the ventilator cannot build the expected circuit pressure, which happens when gas escapes through a leak, a deflated cuff, or a disconnected circuit — so the immediate action is to trace the circuit from patient to machine. Mucus plugs, bronchospasm, and tension pneumothorax all increase resistance or reduce compliance and therefore trigger the high-pressure alarm instead.

    Source: Transport ventilator alarm troubleshooting — low-pressure alarm = leak/disconnection; high-pressure alarm = obstruction, bronchospasm, pneumothorax (paramedic ventilator management curriculum)Report a problem with this question

Practice questions modeled on the NREMT paramedic examination specifications and the National EMS Education Standards. Drug doses, device settings, and other figures that national guidelines revise are deliberately not tested — always follow your medical director, current guidelines, and local protocols. Not medical advice, and not affiliated with or endorsed by the National Registry of Emergency Medical Technicians (NREMT) or NHTSA. Study the official materials at nremt.org. Official NREMT →