Nremt Aemt Level Quiz: Oxygen Therapy And Ventilatory Support

What this quiz covers

This quiz focuses on Oxygen Therapy And Ventilatory Support, giving you a quick way to practice the rules, question types, and explanations that matter most for Nremt Aemt Level.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

Question 1

1. The patient's skin color improves from cyanotic to pink.
2. The pulse oximeter reading increases from 85% to 95%.
3. The abdomen remains flat and soft during ventilation.
4. There is visible and equal bilateral chest rise and fall with each breath. (correct answer)

Explanation: The most direct, immediate, and reliable sign of effective ventilation is observing the chest rise and fall equally with each breath. This confirms that air is entering the lungs. Changes in skin color (A) and pulse oximetry (B) are indicators of oxygenation, which can lag behind ventilation and be affected by other factors like poor perfusion. A flat abdomen (C) indicates you are avoiding gastric insufflation, which is part of good technique, but it does not confirm that air is effectively entering the lungs.

Question 2

1. Carbon monoxide has a higher affinity for hemoglobin than oxygen. (correct answer)
2. The pulse oximeter is likely inaccurate due to peripheral vasoconstriction.
3. The patient will likely develop non-cardiogenic pulmonary edema.
4. High-flow oxygen helps to prevent swelling in the upper airway.

Explanation: When you encounter a fire rescue patient with signs of smoke inhalation (hoarse voice, soot around mouth, singed nasal hairs), you must immediately consider carbon monoxide poisoning, even with normal vital signs and pulse oximetry readings. Carbon monoxide (CO) binds to hemoglobin with an affinity approximately 200-250 times greater than oxygen. This creates carboxyhemoglobin (COHb), which cannot carry oxygen effectively. The critical issue is that standard pulse oximeters cannot distinguish between oxyhemoglobin and carboxyhemoglobin—both appear as "saturated" hemoglobin, giving falsely reassuring SpO2 readings. High-flow oxygen via non-rebreather mask helps displace CO from hemoglobin and reduces the half-life of carboxyhemoglobin from 4-6 hours to approximately 90 minutes. Answer A correctly identifies this pathophysiology. Answer B incorrectly suggests peripheral vasoconstriction affects pulse oximetry accuracy—while vasoconstriction can make readings difficult to obtain, it wouldn't cause the specific problem described here. Answer C mentions non-cardiogenic pulmonary edema, which can occur in severe smoke inhalation but isn't the primary reason for immediate high-flow oxygen in this scenario. Answer D suggests oxygen prevents airway swelling, but oxygen doesn't have anti-inflammatory properties that would reduce upper airway edema. Remember: In any fire rescue scenario, always assume carbon monoxide exposure regardless of normal pulse oximetry. The combination of high-flow oxygen and transport for definitive CO level measurement (via co-oximetry) is essential. Don't let normal SpO2 readings create false reassurance in smoke inhalation cases.

Question 3

1. Administer high-flow oxygen via a non-rebreather mask at 15 L/min.
2. Initiate continuous positive airway pressure (CPAP) at 5-10 cmH2O. (correct answer)
3. Begin positive pressure ventilation with a bag-valve mask at 12 breaths/min.
4. Establish an IV and prepare to assist with administration of a diuretic.

Explanation: The patient is in acute cardiogenic pulmonary edema, evidenced by the CHF history, tripod positioning, bilateral rales, and hypertension. CPAP is the most appropriate initial intervention as it increases intrathoracic pressure, which helps to push fluid out of the alveoli, decreases preload and afterload, and reduces the work of breathing. A non-rebreather mask will increase FiO2 but will not provide the positive pressure needed to address the pulmonary edema. BVM is not indicated as the patient is still conscious and has an adequate respiratory drive. IV access is important but is not the first priority over correcting the severe hypoxia and respiratory distress.

Question 4

1. Deliver each breath over 1 second, providing a rate of 20-22 breaths per minute.
2. Ventilate forcefully to overcome airway resistance, ensuring a rate of 8-10 breaths per minute.
3. Squeeze the bag until the chest visibly rises, delivering one breath every 6 seconds. (correct answer)
4. Provide rapid, shallow breaths at a rate of 15-18 per minute until spontaneous respirations return.

Explanation: The correct ventilation rate for an apneic adult is one breath every 6 seconds, which equates to 10 breaths per minute. Each breath should be delivered smoothly over 1 second, with just enough volume to produce visible chest rise. Ventilating too quickly (A, D) or too forcefully (B) significantly increases the risk of gastric insufflation, which can lead to vomiting, aspiration, and decreased lung compliance. It also increases intrathoracic pressure, which can impede venous return and decrease cardiac output.

Question 5

1. Increase the nasal cannula flow rate to 8 L/min to maximize FiO2.
2. Transition the patient to a non-rebreather mask at 15 L/min. (correct answer)
3. Initiate CPAP to help recruit collapsed alveoli in the affected lobe.
4. Begin assisting her ventilations with a bag-valve mask.

Explanation: The patient remains hypoxic despite receiving the maximum effective flow rate for a nasal cannula (typically 6 L/min). The next step is to increase the fraction of inspired oxygen (FiO2) by switching to a non-rebreather (NRB) mask at a flow rate high enough to keep the reservoir bag inflated (12-15 L/min). Increasing the nasal cannula flow above 6 L/min provides minimal increase in FiO2 and causes patient discomfort. CPAP is not indicated as the primary issue is hypoxia, not ventilatory failure from a condition like CHF or COPD exacerbation. BVM is inappropriate as the patient is alert and maintaining her own airway and respiratory effort.

Question 6

1. Insert a nasogastric tube to decompress the stomach.
2. Increase the ventilation rate to compensate for decreased lung volume.
3. Apply firm manual pressure to the epigastrium to expel the air.
4. Reposition the patient's head and neck to ensure an open airway. (correct answer)

Explanation: When managing airway complications during BVM ventilation, your first priority is always ensuring effective ventilation through a patent airway. The scenario describes gastric insufflation - air entering the stomach instead of (or in addition to) the lungs, causing abdominal distension and rigidity. While your partner sees chest rise, this doesn't guarantee optimal ventilation if airway positioning is compromised. The correct answer is D because improper head and neck positioning is the most common cause of gastric insufflation during BVM ventilation. When the airway isn't optimally aligned, higher pressures are needed to achieve chest rise, inadvertently forcing air into the esophagus and stomach. Repositioning to achieve proper head-tilt, chin-lift or jaw-thrust immediately addresses the root cause and often resolves the problem. Option A is invasive and not an immediate first-line intervention - you'd attempt repositioning first before considering nasogastric decompression. Option B would worsen the problem by increasing the pressure and volume of air entering the stomach, potentially causing vomiting or aspiration. Option C is dangerous and contraindicated - applying epigastric pressure during active ventilation can cause regurgitation and aspiration, creating a life-threatening airway emergency. Remember this sequence for gastric insufflation: reposition first, reassess ventilation effectiveness, then consider advanced interventions if repositioning fails. The key concept is that most BVM complications stem from airway positioning issues, making repositioning your immediate go-to intervention before attempting more complex solutions.

Question 7

1. It delivers a higher concentration of oxygen than the non-rebreather mask.
2. It directly reverses the bronchoconstriction causing the asthma attack.
3. It forces bronchodilator medication deeper into the lung tissue.
4. It reduces the work of breathing and helps to stent open constricted airways. (correct answer)

Explanation: When treating respiratory emergencies, understanding the specific mechanisms of different interventions helps you choose the most appropriate therapy. CPAP (Continuous Positive Airway Pressure) provides unique benefits beyond simple oxygen delivery. CPAP works by delivering constant positive pressure throughout the respiratory cycle, which serves two critical functions in asthma management. First, it reduces the work of breathing by providing pressure support during inspiration, making it easier for the patient to draw air into their lungs. Second, the positive pressure acts as a "pneumatic splint" that helps keep airways open that would otherwise collapse or remain constricted due to bronchospasm and inflammation. This is why option D is correct. Option A is incorrect because both CPAP and non-rebreather masks can deliver high oxygen concentrations (near 100%). The primary benefit of CPAP isn't the oxygen percentage but the pressure delivery. Option B misunderstands CPAP's mechanism—it doesn't directly reverse bronchoconstriction like bronchodilator medications do. Instead, it mechanically supports breathing despite the constriction. Option C confuses CPAP with nebulized medication delivery; while some CPAP systems can deliver medications, this isn't the primary therapeutic benefit in acute asthma. For NREMT questions about respiratory interventions, focus on understanding the specific mechanism of action rather than just memorizing protocols. CPAP questions often test whether you understand that positive pressure provides mechanical support for breathing, not just oxygen delivery or medication administration.

Question 8

1. Titrate the oxygen concentration to maintain the SpO2 between 94% and 99%. (correct answer)
2. Continue 100% oxygen to maximize cerebral oxygen delivery and prevent secondary injury.
3. Wean oxygen completely as soon as possible to prevent oxygen toxicity.
4. Switch to a nasal cannula to reduce the risk of barotrauma from the BVM.

Explanation: Post-cardiac arrest care has evolved significantly based on evidence showing that both hypoxia and hyperoxia can worsen neurological outcomes. The key principle is optimizing oxygenation without causing harm from excess oxygen. Answer A is correct because current AHA guidelines specifically recommend titrating oxygen to maintain SpO2 between 94-99% once ROSC is achieved. This range ensures adequate tissue oxygenation while avoiding hyperoxia, which can increase reactive oxygen species and worsen reperfusion injury to the brain and other organs. Answer B represents outdated thinking. While maximizing oxygen delivery sounds logical, research has shown that 100% oxygen after ROSC can actually cause secondary injury through oxidative stress. The "more is better" approach to oxygen has been replaced by targeted therapy. Answer C goes too far in the opposite direction. While you want to avoid hyperoxia, completely weaning oxygen risks hypoxia, which is equally dangerous for a post-arrest patient. The goal is controlled optimization, not elimination. Answer D misses the point entirely. The issue isn't the delivery method or barotrauma risk—it's the oxygen concentration. A nasal cannula would likely provide inadequate ventilatory support for a post-arrest patient who may not have fully recovered spontaneous breathing patterns. Remember this pattern: Post-ROSC care questions often test whether you know current evidence-based practices versus older "maximum intervention" approaches. Look for answers that balance avoiding both hypoxia AND hyperoxia—the sweet spot is typically SpO2 94-99%.

Question 9

1. Decrease the oxygen flow rate to 1 L/min to reduce the drying effect.
2. Switch to a simple face mask, which provides more natural humidity.
3. Attach a sterile water humidifier bottle to the oxygen regulator. (correct answer)
4. Advise the patient that this is an unavoidable side effect of oxygen therapy.

Explanation: For patients requiring low to moderate flow oxygen for an extended period, the dry, unhumidified medical oxygen can cause discomfort, dryness, and nosebleeds. Attaching a simple humidifier bottle to the oxygen source adds moisture to the inspired gas, significantly improving patient comfort and tolerance without changing the prescribed oxygen flow. Decreasing the flow rate (A) would be clinically inappropriate as it could lead to hypoxia. A simple face mask (B) does not provide more humidity. Advising the patient to tolerate it (D) is poor patient care when a simple solution exists.

Question 10

1. Decreased cardiac preload from increased intrathoracic pressure. (correct answer)
2. Resolution of anxiety as his breathing improved.
3. Vasodilation caused by improved oxygenation of the tissues.
4. A secondary cardiac event such as a myocardial infarction.

Explanation: When treating respiratory emergencies with CPAP, you need to understand how positive pressure ventilation affects cardiovascular hemodynamics, not just respiratory function. CPAP works by maintaining continuous positive airway pressure throughout the breathing cycle, which increases intrathoracic pressure. This elevated pressure compresses the vena cava and reduces venous return to the right ventricle, effectively decreasing cardiac preload (the amount of blood filling the heart before contraction). With less preload, stroke volume decreases according to the Frank-Starling mechanism, leading to reduced cardiac output and lower blood pressure. Answer A correctly identifies this physiological mechanism. Answer B incorrectly suggests anxiety resolution caused the pressure drop. While anxiety can elevate blood pressure, a 60 mmHg systolic decrease is far too dramatic to attribute solely to psychological factors. Answer C proposes vasodilation from improved oxygenation, but better tissue oxygenation doesn't typically cause significant vasodilation that would drop pressure this substantially. Answer D suggests a secondary cardiac event like MI, but the patient's improved respiratory status and stable clinical picture make this unlikely - plus, you'd expect additional concerning signs beyond just hypotension. The key learning point: CPAP's cardiovascular effects are predictable and common. While CPAP effectively treats pulmonary edema by reducing preload (which actually helps the failing heart), it can also cause hypotension through the same mechanism. Always monitor blood pressure closely during CPAP treatment, especially in patients who aren't severely hypertensive to begin with.

Question 11

1. Successful reversal of bronchospasm and patient improvement.
2. An allergic reaction to the nebulized medication.
3. Progression to respiratory failure requiring immediate ventilation. (correct answer)
4. The patient is calming down and her respiratory effort is normalizing.

Explanation: This is a classic 'silent chest' presentation, which is an ominous sign. The decrease in wheezing is not due to improvement, but rather due to such severe bronchoconstriction and fatigue that the patient is no longer moving enough air to generate sound. This, combined with the decreased respiratory rate (bradypnea) and altered mental status, indicates profound respiratory muscle fatigue and imminent respiratory arrest. This patient is in respiratory failure and requires immediate positive pressure ventilation with a BVM.

Question 12

1. Development of a tension pneumothorax from barotrauma.
2. Decreased cardiac output due to excessive positive pressure.
3. Gastric distention from ventilating too rapidly and forcefully. (correct answer)
4. Airway obstruction from an improperly sized OPA.

Explanation: Ventilating too rapidly (18/min is too fast for an adult) and likely with too much force causes air to be diverted down the esophagus into the stomach, leading to gastric distention. This distention pushes up on the diaphragm, restricting lung movement and making ventilation more difficult. It also increases the risk of regurgitation and aspiration. While decreased cardiac output (B) is a concern with positive pressure ventilation, the prominent abdominal distention points directly to gastric insufflation as the primary problem. A tension pneumothorax (A) would present with unilateral chest rise and tracheal deviation. An improper OPA (D) would cause an obstruction felt from the beginning.

Question 13

1. Attach the bag-valve device directly to the tracheostomy tube and ventilate. (correct answer)
2. Seal the patient's mouth and nose and continue ventilating with a standard adult mask.
3. Use a pediatric mask to create a seal over the stoma and ventilate through the neck.
4. Remove the tracheostomy tube and attempt to ventilate through the mouth and nose.

Explanation: When you encounter a patient with a tracheostomy who needs ventilation, remember that the tracheostomy creates a direct pathway to the trachea that bypasses the upper airway. This fundamentally changes your ventilation approach. The correct procedure is to attach your bag-valve device directly to the tracheostomy tube and ventilate (Answer A). The tracheostomy tube is specifically designed with standard 15mm connectors that fit directly onto bag-valve devices. This creates the most efficient seal and delivers ventilation directly into the trachea where it needs to go. Since the patient is apneic, this direct connection ensures immediate, effective ventilation. Answer B is incorrect because sealing the mouth and nose while the tracheostomy remains open won't create effective ventilation. Air will escape through the stoma, preventing adequate chest rise and tidal volume delivery. Answer C represents a common misconception. While pediatric masks are sometimes used over stomas in specific situations, when a tracheostomy tube is present and accessible, direct connection is always preferred. Using a mask over the stoma is less reliable and may not create an adequate seal. Answer D is dangerous and incorrect. Never remove a tracheostomy tube in the field unless you're specifically trained in tracheostomy management. The stoma may close rapidly, and the original airway problem that necessitated the tracheostomy likely still exists. Remember this key principle: when a tracheostomy is present, it becomes your primary airway. Always ventilate through the tracheostomy tube directly rather than attempting to use the upper airway.

Question 14

1. One breath every 3-5 seconds, synchronized with chest compressions.
2. One breath every 6 seconds, delivered asynchronously with chest compressions if needed. (correct answer)
3. Two breaths every 10 seconds, pausing chest compressions for ventilation.
4. One breath every 10 seconds, using only enough force to see abdominal rise.

Explanation: Once an advanced airway (such as an SGA or ET tube) is in place, ventilations are delivered at a rate of one breath every 6 seconds (10 breaths per minute) for an adult. If CPR is in progress, these breaths are delivered asynchronously, meaning chest compressions are not paused for ventilation. A rate of one breath every 3-5 seconds is for children or infants. Pausing compressions is only done when using a BVM without an advanced airway. Ventilations should cause chest rise, not abdominal rise.

Question 15

1. A nasal cannula at 2 L/min to avoid suppressing the hypoxic drive.
2. A non-rebreather mask at 15 L/min to correct severe hypoxia. (correct answer)
3. Withhold oxygen therapy and prepare for immediate CPAP application.
4. A Venturi mask set to 28% FiO2 to provide precise oxygen concentration.

Explanation: This patient is in severe respiratory distress with significant hypoxia (SpO2 84%). The immediate priority is to correct the life-threatening hypoxia. The most effective way to do this is with a non-rebreather mask at 15 L/min. While there is a theoretical concern about suppressing the hypoxic drive in some COPD patients, allowing severe hypoxia to persist is far more dangerous. Starting with low-flow oxygen (A) is inadequate for this level of distress. A Venturi mask (D) is more for stable patients requiring a specific FiO2. Withholding oxygen (C) is inappropriate.

Question 16

1. A nasal cannula at 4 L/min since her SpO2 is above 94%.
2. A simple face mask at 10 L/min to provide moderate oxygen support.
3. No oxygen is required as her SpO2 is within normal limits.
4. A non-rebreather mask at 15 L/min due to the mechanism and signs of shock. (correct answer)

Explanation: When you encounter a trauma patient with mechanism of injury suggesting internal bleeding, oxygen delivery decisions must account for both current oxygenation status and the potential for rapid deterioration due to shock. This patient shows classic signs of compensated shock: tachycardia (HR 130), hypotension (BP 90/60), anxiety, pallor, and left upper quadrant tenderness suggesting possible splenic injury from the high-speed MVC. While her SpO2 of 96% might seem adequate, shock patients require aggressive oxygenation to maximize oxygen delivery to hypoperfused tissues and prepare for potential decompensation. Answer D is correct because a non-rebreather mask at 15 L/min provides the highest concentration of oxygen (up to 95%) for a spontaneously breathing patient. The mechanism of injury combined with shock signs mandates aggressive oxygen therapy regardless of current SpO2 readings. Answer A is wrong because managing by SpO2 alone ignores the shock state—this patient needs maximum oxygenation, not minimal support. Answer B provides inadequate oxygen concentration (35-60%) for a patient showing signs of hemorrhagic shock who may rapidly deteriorate. Answer C dangerously ignores the clinical picture; while her SpO2 appears normal, she's compensating for shock and needs aggressive support before decompensation occurs. Remember: In trauma patients with signs of shock, always provide high-flow, high-concentration oxygen regardless of pulse oximetry readings. SpO2 can remain falsely reassuring during compensated shock, but tissue hypoxia is already occurring at the cellular level.

Question 17

1. Delivering breaths more forcefully to overcome smaller airway resistance.
2. Placing a small towel roll under the infant's shoulders to align the airway. (correct answer)
3. Ventilating at a slower rate of one breath every 8-10 seconds.
4. Hyperextending the neck to ensure the airway is maximally open.

Explanation: Infants have a relatively large occiput (back of the head) which causes the neck to flex when they are laid flat, potentially occluding the airway. Placing a small pad or towel roll under the shoulders helps to align the trachea into a neutral or 'sniffing' position, which is the optimal position for airway patency. Hyperextending the neck (D) can actually collapse the soft tracheal cartilage and obstruct the airway. Ventilations should be delivered gently (not forcefully) and at the appropriate pediatric rate of one breath every 3-5 seconds for an apneic infant with a pulse.

Question 18

1. The patient is becoming fatigued and retaining more CO2.
2. The CPAP is causing hypoventilation and is not effective.
3. The patient's ventilatory status is improving. (correct answer)
4. There is likely a leak in the CPAP mask seal.

Explanation: In a patient with a COPD exacerbation, a high EtCO2 (hypercapnia) indicates inadequate ventilation. The goal of CPAP is to improve alveolar ventilation and help the patient 'blow off' excess CO2. A decrease in the EtCO2 from 65 mmHg to 55 mmHg, coupled with clinical improvement, indicates that the patient is ventilating more effectively and the treatment is working. If the patient were worsening, the EtCO2 would likely increase or stay the same despite treatment. A mask leak would cause the EtCO2 waveform and value to be erratic or lost.

Question 19

1. Apply a non-rebreather mask and transport rapidly.
2. Initiate CPAP to support his weakened respiratory muscles.
3. Provide gentle ventilatory assistance with a bag-valve mask. (correct answer)
4. Withhold all respiratory support in accordance with the DNR.

Explanation: This patient is in respiratory failure, characterized by an altered mental status and inadequate respiratory rate and depth (bradypnea). The definitive treatment is to assist ventilations. A BVM used gently to supplement his own breaths can provide immediate support. An NRB mask is insufficient because the patient is not moving enough air on his own to benefit. CPAP is contraindicated because the patient is lethargic and cannot protect his own airway or maintain the respiratory effort needed to work with the machine. Since the DNR allows for comfort care and non-invasive support, assisting ventilations falls within appropriate treatment to alleviate suffering from air hunger.