Emergency and Critical Care for Respiratory Therapists

Emergency and critical care focus on the rapid assessment, stabilization, and management of patients with life-threatening illness or injury. In respiratory care, this often involves patients with acute respiratory failure, shock, trauma, cardiac arrest, severe asthma, COPD exacerbation, pulmonary edema, airway obstruction, or other serious cardiopulmonary problems.

Respiratory therapists play an important role in these settings because they help manage oxygenation, ventilation, airway protection, mechanical ventilation, and patient monitoring.

Success in emergency and critical care depends on quick thinking, strong assessment skills, and the ability to act before a patient deteriorates further.

What Is Emergency and Critical Care?

Emergency and critical care refers to the care provided to patients who are unstable, severely ill, or at risk of rapid deterioration. Emergency care usually begins when a patient presents with an urgent problem, such as severe shortness of breath, chest trauma, cardiac arrest, airway obstruction, or altered mental status. Critical care often continues after the patient has been stabilized but still requires close monitoring, advanced support, and ongoing treatment in an intensive care setting.

In respiratory therapy, emergency and critical care are closely connected because many emergencies involve the airway, breathing, circulation, or gas exchange. A patient may need oxygen therapy, bag-mask ventilation, suctioning, intubation, noninvasive ventilation, invasive mechanical ventilation, bronchodilator therapy, arterial blood gas analysis, capnography, or ventilator troubleshooting.

The main goals are to maintain a patent airway, support breathing, improve oxygen delivery, remove carbon dioxide, reduce the work of breathing, and prevent further harm. These goals must often be achieved quickly while the care team is still gathering information.

The Role of the Respiratory Therapist

Respiratory therapists are essential members of the emergency and critical care team. They may work in the emergency department, intensive care unit, neonatal intensive care unit, pediatric intensive care unit, transport team, operating room, or rapid response team.

Their responsibilities may include:

• Assessing breathing patterns, breath sounds, oxygen saturation, and signs of respiratory distress
• Administering oxygen and aerosolized medications
• Assisting with airway management and intubation
• Providing manual ventilation with a bag-mask device
• Initiating noninvasive or invasive mechanical ventilation
• Monitoring ventilator settings, waveforms, pressures, and alarms
• Drawing or interpreting arterial blood gases
• Measuring end-tidal carbon dioxide
• Assisting during cardiac arrest, trauma, or rapid response events
• Recognizing ventilator emergencies and responding quickly

Note: In these settings, the respiratory therapist must be able to separate urgent findings from less urgent information. A stable patient may allow time for a full history and detailed review of records. An unstable patient requires immediate attention to airway, breathing, circulation, oxygenation, and ventilation.

Respiratory Failure

One of the most important concepts in emergency and critical care is respiratory failure. Respiratory failure occurs when the respiratory system cannot maintain adequate oxygen delivery to tissues, remove carbon dioxide effectively, or both.

Respiratory failure is commonly divided into two major types: hypoxemic respiratory failure and hypercapnic respiratory failure.

Hypoxemic Respiratory Failure

Hypoxemic respiratory failure, also called type I respiratory failure, occurs when oxygen levels in the blood are too low. This is often reflected by a low PaO₂ on an arterial blood gas or a low SpO₂ on pulse oximetry.

Common causes include:

• Pneumonia
• Pulmonary edema
• Acute respiratory distress syndrome
• Pulmonary embolism
• Atelectasis
• Aspiration
• Severe asthma
• Interstitial lung disease
• Inhalation injury
• Shock with poor oxygen delivery

Note: In hypoxemic respiratory failure, the patient may have severe dyspnea, tachypnea, cyanosis, confusion, restlessness, accessory muscle use, or falling oxygen saturation. The main goal is to improve oxygenation through supplemental oxygen, positive airway pressure, PEEP, or mechanical ventilation when needed.

Hypercapnic Respiratory Failure

Hypercapnic respiratory failure, also called type II respiratory failure, occurs when the body cannot remove carbon dioxide effectively. This causes the PaCO₂ to rise and may lead to respiratory acidosis.

Common causes include:

• COPD exacerbation
• Severe asthma
• Drug overdose
• Neuromuscular disease
• Guillain-Barré syndrome
• Myasthenia gravis
• Spinal cord injury
• Obesity hypoventilation syndrome
• Chest wall disorders
• Severe respiratory muscle fatigue

Note: In hypercapnic respiratory failure, the patient may show signs of poor ventilation, such as drowsiness, confusion, headache, shallow breathing, reduced tidal volume, or worsening acidosis. Treatment focuses on improving alveolar ventilation and reducing the work of breathing. This may require noninvasive ventilation or invasive mechanical ventilation.

Recognizing an Unstable Patient

Emergency and critical care require the ability to recognize instability quickly. A patient can deteriorate even when only a few signs are present. The respiratory therapist should look for patterns rather than relying on one number.

Important warning signs include:

• Severe shortness of breath
• Rapid or very slow respiratory rate
• Accessory muscle use
• Nasal flaring
• Cyanosis
• Altered mental status
• Inability to speak in full sentences
• Weak cough
• Inability to protect the airway
• Falling SpO₂ despite oxygen therapy
• Rising PaCO₂
• Worsening acidosis
• Hypotension
• Tachycardia or bradycardia
• Unequal or absent breath sounds
• Sudden increase in airway pressure during mechanical ventilation

Note: Numbers matter, but the clinical picture matters more. A patient with a PaO₂ less than 60 mm Hg or a PaCO₂ greater than 50 mm Hg may meet common criteria for respiratory failure. However, treatment decisions should also consider the patient’s appearance, mental status, work of breathing, vital signs, and overall trend.

Initial Assessment in Emergency Care

The first step in emergency care is a focused assessment. The respiratory therapist should quickly evaluate the patient’s airway, breathing, circulation, oxygenation, ventilation, and level of consciousness.

Airway

The airway must be checked first. A patient cannot oxygenate or ventilate effectively if the airway is blocked or unprotected. Signs of airway problems include snoring respirations, gurgling, stridor, choking, facial trauma, swelling, vomitus, blood, secretions, or a decreased level of consciousness.

An airway emergency may require repositioning, suctioning, insertion of an airway adjunct, manual ventilation, or intubation.

Breathing

Breathing assessment includes respiratory rate, depth, pattern, chest rise, breath sounds, oxygen saturation, and work of breathing. The therapist should look for signs of fatigue or impending respiratory failure, such as shallow breathing, paradoxical chest movement, reduced air entry, or decreasing responsiveness.

Circulation

Circulation includes pulse, blood pressure, skin color, capillary refill, temperature, and signs of shock. Poor circulation can worsen oxygen delivery even if the lungs are functioning. For example, a trauma patient with severe blood loss may have poor tissue oxygenation because cardiac output and hemoglobin levels are reduced.

Mental Status

Mental status is a major sign of oxygenation and ventilation adequacy. Agitation, confusion, lethargy, or sudden drowsiness may indicate hypoxemia, hypercapnia, shock, or neurologic injury. A declining mental status can also mean the patient may no longer be able to protect the airway.

Oxygen Therapy in Emergency Care

Oxygen therapy is one of the most common respiratory interventions in emergency care. The device selected depends on the severity of hypoxemia, the patient’s breathing pattern, and the need for precise oxygen delivery.

Common oxygen devices include:

• Nasal cannula
• Simple mask
• Venturi mask
• Nonrebreathing mask
• High-flow nasal cannula
• Bag-mask device
• Noninvasive ventilation
• Mechanical ventilator

In severe emergencies, high-concentration oxygen is often used initially while the team stabilizes the patient. A nonrebreathing mask may be used for severe hypoxemia, trauma, carbon monoxide exposure, or shock.

If the patient is not breathing adequately, oxygen alone is not enough. Ventilation must also be supported with a bag-mask device, noninvasive ventilation, or intubation and mechanical ventilation.

Airway Management

Airway management is a major part of emergency and critical care. The respiratory therapist may assist with or perform tasks that help establish and maintain a patent airway.

Airway interventions may include:

• Head tilt and chin lift
• Jaw thrust
• Oropharyngeal airway
• Nasopharyngeal airway
• Suctioning
• Bag-mask ventilation
• Endotracheal intubation assistance
• Tracheostomy care
• Artificial airway confirmation
• Securing the airway
• Monitoring cuff pressure

Patients may need advanced airway management if they have respiratory arrest, severe respiratory failure, airway obstruction, trauma, aspiration risk, decreased consciousness, or inability to protect the airway.

After intubation, tube placement must be confirmed. This may include auscultation, chest rise, end-tidal carbon dioxide detection, capnography, and chest radiography. Breath sounds that are absent on the left but present on the right may suggest right mainstem bronchial intubation. Sudden deterioration after intubation requires immediate reassessment of tube position, patency, ventilation, and lung status.

Noninvasive Ventilation

Noninvasive ventilation provides ventilatory support without an artificial airway. It is commonly delivered through a tight-fitting mask and may include CPAP, BiPAP, or pressure support with PEEP.

NIV can be useful for selected patients with:

• COPD exacerbation
• Cardiogenic pulmonary edema
• Mild to moderate hypercapnic respiratory failure
• Increased work of breathing
• Some cases of hypoxemic respiratory failure

The best candidates are awake, cooperative, hemodynamically stable, and able to protect their airway. They should have manageable secretions and a good mask fit.

NIV may reduce work of breathing, improve tidal volume, decrease PaCO₂, improve pH, and improve oxygenation. However, the patient must be monitored closely. Worsening mental status, vomiting, inability to tolerate the mask, severe hypoxemia, hypotension, or failure to improve may require intubation and invasive mechanical ventilation.

Invasive Mechanical Ventilation

Invasive mechanical ventilation is used when a patient cannot maintain adequate oxygenation or ventilation without an artificial airway. It may be needed during severe respiratory failure, cardiac arrest, trauma, shock, surgery, neuromuscular failure, or altered mental status.

The ventilator performs part or all of the patient’s work of breathing. It can deliver a set tidal volume or pressure, control oxygen concentration, provide PEEP, and support ventilation until the underlying problem improves.

Initial ventilator settings may include:

• Mode
• FiO₂
• Tidal volume or pressure level
• Respiratory rate
• PEEP
• Inspiratory time
• Flow
• Trigger sensitivity
• Alarms
• Humidification

After the ventilator is started, the patient must be reassessed. The therapist should evaluate chest rise, breath sounds, oxygen saturation, end-tidal carbon dioxide, airway pressures, ventilator graphics, patient comfort, blood pressure, and arterial blood gases.

Mechanical ventilation is not a cure by itself. It supports gas exchange and reduces respiratory muscle workload while clinicians treat the cause of the problem, such as pneumonia, pulmonary edema, asthma, COPD exacerbation, trauma, sepsis, or neuromuscular weakness.

Ventilator Monitoring

Critical care ventilators provide important information about the patient’s respiratory status and the interaction between the patient and ventilator.

Key parameters include:

• Peak inspiratory pressure
• Plateau pressure
• Mean airway pressure
• PEEP
• Tidal volume
• Minute ventilation
• Respiratory rate
• Compliance
• Airway resistance
• Auto-PEEP
• End-tidal carbon dioxide
• Flow, pressure, and volume waveforms

Note: Ventilator graphics can help identify problems such as air trapping, patient-ventilator asynchrony, leaks, secretions, increased airway resistance, reduced compliance, or inadequate flow. A sudden change in pressure or volume should never be ignored. It may reflect a serious problem with the patient, the ventilator circuit, or the artificial airway.

Emergency Ventilator Problems

A mechanically ventilated patient can deteriorate quickly. Respiratory therapists must recognize and respond to ventilator emergencies.

A sudden increase in peak inspiratory pressure may be caused by:

• Secretions
• Bronchospasm
• Kinked tubing
• Biting on the tube
• Mucus plugging
• Pneumothorax
• Pulmonary edema
• Worsening compliance
• Right mainstem intubation
• Patient coughing or fighting the ventilator

A sudden drop in pressure may be caused by:

• Circuit disconnect
• Leak
• Cuff rupture
• Extubation
• Loose connection
• Ventilator malfunction

When a ventilated patient suddenly worsens, the therapist should quickly assess the patient and equipment. If needed, the patient should be disconnected from the ventilator and manually ventilated with 100% oxygen using a bag-mask device or resuscitation bag attached to the artificial airway. This helps determine whether the problem is related to the ventilator or the patient.

A classic emergency is tension pneumothorax. Signs may include sudden increased airway pressure, falling oxygen saturation, hypotension, absent breath sounds on one side, tracheal deviation, and hyperresonance. This requires immediate recognition and preparation for emergency decompression and chest tube placement.

Capnography and Emergency Monitoring

Capnography measures exhaled carbon dioxide and displays a waveform. It is especially useful in emergency and critical care because it provides continuous information about ventilation, airway placement, and perfusion.

Capnography may be used to:

• Confirm endotracheal tube placement
• Monitor ventilation during mechanical ventilation
• Assess CPR quality
• Detect return of spontaneous circulation
• Identify hypoventilation or hyperventilation
• Detect accidental extubation
• Monitor transport patients
• Evaluate sudden changes in respiratory status

Note: A sudden loss of end-tidal carbon dioxide may indicate disconnection, extubation, airway obstruction, cardiac arrest, or equipment failure. A sudden increase may indicate hypoventilation, increased metabolism, or return of circulation during resuscitation.

Arterial Blood Gases in Critical Care

Arterial blood gas analysis is an important tool in emergency and critical care. It provides information about oxygenation, ventilation, and acid-base balance.

Important ABG values include:

• pH
• PaCO₂
• HCO₃⁻
• PaO₂
• SaO₂
• Base excess

A low PaO₂ suggests poor oxygenation. A high PaCO₂ suggests inadequate ventilation. A low pH indicates acidemia, while a high pH indicates alkalemia. In emergency care, ABGs help guide oxygen therapy, ventilator changes, and treatment decisions.

For example, a COPD patient with a high PaCO₂ and low pH may need noninvasive ventilation if alert and cooperative. A patient with severe acidosis, altered mental status, and respiratory fatigue may require intubation and invasive mechanical ventilation.

Shock and Oxygen Delivery

Emergency and critical care are not limited to the lungs. Oxygen delivery depends on the lungs, hemoglobin, cardiac output, blood pressure, and tissue perfusion. A patient may have a normal PaO₂ but still have poor tissue oxygen delivery if circulation or hemoglobin is inadequate.

Shock occurs when tissues do not receive enough oxygenated blood to meet metabolic needs. Causes include blood loss, sepsis, cardiac failure, anaphylaxis, and obstruction to blood flow.

Signs of shock may include:

• Hypotension
• Tachycardia
• Cool or clammy skin
• Altered mental status
• Weak pulses
• Low urine output
• Lactic acidosis
• Rapid breathing

Note: Respiratory therapists help manage shock by supporting oxygenation, ventilation, airway protection, and mechanical ventilation when needed. In trauma or severe blood loss, oxygen therapy is important, but fluid resuscitation, blood replacement, hemorrhage control, and restoration of circulation are also essential.

Cardiac Arrest and Resuscitation

Cardiac arrest is one of the most serious emergencies. During cardiac arrest, circulation stops or becomes ineffective, which prevents oxygen delivery to the brain and vital organs.

Respiratory therapists may assist by:

• Providing bag-mask ventilation
• Managing the airway
• Confirming endotracheal tube placement
• Monitoring end-tidal carbon dioxide
• Adjusting oxygen delivery
• Supporting mechanical ventilation after return of circulation
• Helping assess ventilation effectiveness

Note: During resuscitation, ventilation must be adequate but not excessive. Hyperventilation can increase intrathoracic pressure, reduce venous return, and worsen circulation. Capnography can help monitor ventilation and may provide information about CPR quality and return of spontaneous circulation.

Asthma and COPD Exacerbations

Asthma and COPD exacerbations are common emergency respiratory conditions. Both can cause increased airway resistance, air trapping, increased work of breathing, and ventilatory failure.

Asthma

Severe asthma may present with wheezing, chest tightness, tachypnea, accessory muscle use, low peak flow, hypoxemia, and anxiety. A silent chest, altered mental status, or rising PaCO₂ is especially concerning because it may indicate severe obstruction and respiratory muscle fatigue.

Treatment may include oxygen, inhaled bronchodilators, corticosteroids, magnesium sulfate in selected cases, noninvasive ventilation, or intubation if the patient deteriorates.

COPD

A COPD exacerbation may present with increased dyspnea, wheezing, sputum production, hypoxemia, hypercapnia, and respiratory acidosis. NIV is often useful when the patient is alert and able to cooperate. It can reduce work of breathing, improve ventilation, and decrease the need for intubation in selected patients.

However, COPD patients must be monitored carefully. Worsening acidosis, declining mental status, inability to clear secretions, or hemodynamic instability may require invasive ventilation.

Pulmonary Edema and Heart Failure

Cardiogenic pulmonary edema occurs when fluid backs up into the lungs due to left-sided heart dysfunction. The patient may present with severe shortness of breath, crackles, frothy sputum, hypoxemia, anxiety, hypertension or hypotension, and increased work of breathing.

Respiratory care may include oxygen therapy, CPAP or BiPAP, intubation if needed, and close monitoring of oxygenation and ventilation. Positive pressure can help improve oxygenation and reduce the work of breathing. It may also reduce venous return and left ventricular workload in some patients, which can be helpful in cardiogenic pulmonary edema.

Trauma and Emergency Respiratory Care

Trauma patients often require rapid respiratory assessment. Chest trauma, head injury, spinal cord injury, burns, smoke inhalation, drowning, and massive blood loss can all lead to respiratory failure.

The respiratory therapist may need to support oxygenation, assist with intubation, provide manual ventilation, manage mechanical ventilation, monitor ABGs, and help detect complications such as pneumothorax or pulmonary contusion.

In trauma, oxygenation may be impaired by airway obstruction, lung injury, blood loss, shock, or reduced consciousness. A patient with severe hemorrhage may have poor tissue oxygen delivery even when oxygen is being administered, because there may not be enough circulating blood or hemoglobin to carry oxygen effectively.

Carbon Monoxide Poisoning

Carbon monoxide poisoning is an important emergency because pulse oximetry and PaO₂ can be misleading. Carbon monoxide binds to hemoglobin with high affinity and reduces the blood’s ability to carry and release oxygen.

A patient may have a normal or high PaO₂ while still having severe tissue hypoxia. Signs may include headache, dizziness, confusion, nausea, vomiting, loss of consciousness, and cherry-red skin in some cases.

Treatment includes high-concentration oxygen to help displace carbon monoxide from hemoglobin. Severe cases may require hyperbaric oxygen therapy depending on the patient’s condition and facility protocols.

Transport and Disaster Readiness

Emergency and critical care may continue during patient transport. Transporting a critically ill patient requires preparation because monitoring and support may be harder outside the ICU or emergency department.

Before transport, the team should check:

• Oxygen supply
• Airway equipment
• Bag-mask device
• Transport ventilator
• Battery power
• Suction equipment
• Monitoring devices
• Medications
• IV access
• Emergency backup equipment

Respiratory therapists may also be involved in disaster response. Disasters may include chemical exposures, infectious outbreaks, fires, explosions, mass trauma events, or environmental emergencies.

In these situations, therapists may help with triage, oxygen therapy, airway management, mechanical ventilation, infection control, and protection of healthcare workers.

Liberation From Mechanical Ventilation

Critical care does not end when the patient is stabilized. Many patients require ongoing support until the underlying disease improves. Once the patient is ready, the team begins the process of reducing and discontinuing ventilatory support.

Readiness for weaning may include:

• Improved cause of respiratory failure
• Adequate oxygenation
• Hemodynamic stability
• Acceptable mental status
• Manageable secretions
• Effective cough
• Adequate respiratory muscle strength
• Acceptable acid-base status

Note: The respiratory therapist may assist with spontaneous breathing trials, ventilator adjustments, secretion management, airway assessment, and extubation planning. After extubation, the patient must be monitored for airway obstruction, respiratory distress, secretion retention, hypoxemia, or fatigue.

Emergency and Critical Care Practice Questions

1. What is emergency and critical care in respiratory therapy?
Emergency and critical care in respiratory therapy involves the rapid assessment, stabilization, and treatment of patients with life-threatening cardiopulmonary problems, especially those affecting oxygenation, ventilation, airway protection, and respiratory failure.

2. What is the main priority in emergency respiratory care?
The main priority is to quickly assess and support the patient’s airway, breathing, circulation, oxygenation, and ventilation to prevent further deterioration.

3. How does Egan define respiratory failure?
Respiratory failure is the inability to maintain normal oxygen delivery to the tissues or normal carbon dioxide removal from the tissues.

4. What are the two major types of respiratory failure?
The two major types are type I hypoxemic respiratory failure and type II hypercapnic respiratory failure.

5. What is type I respiratory failure?
Type I respiratory failure is hypoxemic respiratory failure, which occurs when oxygenation is inadequate and PaO₂ or SpO₂ is low.

6. What is type II respiratory failure?
Type II respiratory failure is hypercapnic respiratory failure, which occurs when ventilation is inadequate and PaCO₂ rises, often causing respiratory acidosis.

7. What PaO₂ value is commonly associated with acute respiratory failure?
A PaO₂ less than 60 mm Hg is commonly associated with acute respiratory failure in otherwise healthy individuals at sea level.

8. What PaCO₂ value is commonly associated with acute respiratory failure?
A PaCO₂ greater than 50 mm Hg is commonly associated with acute respiratory failure, especially when accompanied by respiratory acidosis.

9. Why should treatment decisions not be based on numbers alone?
Treatment decisions should not be based on numbers alone because the patient’s overall clinical condition, work of breathing, mental status, vital signs, and trend are often more important than a single value.

10. What are common signs of impending respiratory failure?
Common signs include severe dyspnea, tachypnea, accessory muscle use, falling SpO₂, rising PaCO₂, worsening acidosis, altered mental status, weak cough, and respiratory muscle fatigue.

11. What is the purpose of ventilatory support?
The purpose of ventilatory support is to improve oxygenation, improve alveolar ventilation, increase lung volume, reduce work of breathing, and support the patient until the underlying problem improves.

12. What is noninvasive ventilation?
Noninvasive ventilation is ventilatory support delivered without an artificial airway, usually through a mask using CPAP, BiPAP, or pressure support with PEEP.

13. Which patients are often good candidates for noninvasive ventilation?
Good candidates are usually awake, alert, cooperative, hemodynamically stable, able to protect their airway, and able to tolerate the mask.

14. What are two common conditions where noninvasive ventilation may be useful?
Noninvasive ventilation may be useful in acute COPD exacerbation and cardiogenic pulmonary edema.

15. When should noninvasive ventilation be avoided or discontinued?
Noninvasive ventilation should be avoided or discontinued if the patient has worsening mental status, inability to protect the airway, severe hypoxemia, vomiting, poor mask tolerance, hemodynamic instability, or failure to improve.

16. What is invasive mechanical ventilation?
Invasive mechanical ventilation is ventilatory support delivered through an artificial airway, such as an endotracheal tube or tracheostomy tube.

17. What is the primary purpose of a mechanical ventilator?
The primary purpose of a mechanical ventilator is to perform part or all of the patient’s work of breathing while supporting oxygenation and ventilation.

18. What ventilator setting controls the oxygen concentration delivered to the patient?
FiO₂ controls the oxygen concentration delivered to the patient.

19. What does PEEP help improve during mechanical ventilation?
PEEP helps improve oxygenation by keeping alveoli open at the end of exhalation and reducing alveolar collapse.

20. Why is patient reassessment important after starting mechanical ventilation?
Patient reassessment is important because ventilator settings must be adjusted based on oxygenation, ventilation, airway pressures, patient comfort, blood pressure, ABGs, and overall response.

21. What is capnography?
Capnography is the continuous measurement and waveform display of exhaled carbon dioxide during ventilation.

22. Why is capnography useful in emergency care?
Capnography is useful for confirming endotracheal tube placement, monitoring ventilation, detecting accidental extubation, assessing CPR quality, and identifying sudden changes in respiratory status.

23. What does a sudden loss of end-tidal carbon dioxide suggest?
A sudden loss of end-tidal carbon dioxide may suggest disconnection, accidental extubation, airway obstruction, cardiac arrest, or equipment failure.

24. What are arterial blood gases used to assess in critical care?
Arterial blood gases are used to assess oxygenation, ventilation, and acid-base balance.

25. What ABG finding suggests inadequate ventilation?
An elevated PaCO₂ suggests inadequate ventilation, especially when accompanied by a low pH and respiratory acidosis.

26. What ABG finding suggests poor oxygenation?
A low PaO₂ suggests poor oxygenation and may indicate hypoxemic respiratory failure.

27. What is the first major assessment priority in an emergency?
The first major priority is to assess the airway because oxygenation and ventilation cannot occur effectively if the airway is blocked or unprotected.

28. What signs may indicate an airway obstruction?
Signs may include stridor, gurgling, snoring respirations, choking, poor air movement, cyanosis, accessory muscle use, and inability to speak.

29. Why is altered mental status concerning in emergency respiratory care?
Altered mental status may indicate hypoxemia, hypercapnia, shock, neurologic injury, or loss of the patient’s ability to protect the airway.

30. What is the purpose of manual ventilation with 100% oxygen?
Manual ventilation with 100% oxygen supports oxygenation and ventilation while clinicians assess the airway, troubleshoot equipment, or prepare for intubation.

31. Why might a patient need intubation during an emergency?
A patient may need intubation due to respiratory arrest, severe respiratory failure, airway obstruction, aspiration risk, decreased consciousness, or inability to protect the airway.

32. What should be confirmed after endotracheal intubation?
Endotracheal tube placement should be confirmed using chest rise, breath sounds, end-tidal carbon dioxide detection, capnography, and chest radiography when appropriate.

33. What may absent breath sounds on the left after intubation suggest?
Absent breath sounds on the left with breath sounds present on the right may suggest right mainstem bronchial intubation.

34. What is a key sign that a tracheostomy tube may be obstructed?
A key sign is the inability to pass a suction catheter through the tracheostomy tube, especially when the patient is in respiratory distress.

35. What should the respiratory therapist do when a ventilated patient suddenly deteriorates?
The therapist should quickly assess the patient and equipment, check for obstruction or disconnection, and manually ventilate with 100% oxygen if needed.

36. What may cause a sudden increase in peak inspiratory pressure?
A sudden increase in peak inspiratory pressure may be caused by secretions, bronchospasm, a kinked circuit, biting on the tube, mucus plugging, pneumothorax, or worsening lung compliance.

37. What may cause a sudden decrease in airway pressure during mechanical ventilation?
A sudden decrease in airway pressure may be caused by a circuit disconnect, leak, cuff rupture, accidental extubation, loose connection, or ventilator malfunction.

38. What findings may suggest tension pneumothorax in a ventilated patient?
Findings may include rising airway pressure, falling SpO₂, hypotension, absent breath sounds on one side, hyperresonance, and tracheal deviation.

39. Why is tension pneumothorax considered an emergency?
Tension pneumothorax is an emergency because trapped air under pressure can collapse the lung, shift mediastinal structures, reduce venous return, and cause cardiovascular collapse.

40. What should be prepared for a suspected tension pneumothorax?
Emergency decompression and chest tube placement should be prepared while oxygenation and ventilation are supported.

41. What is cardiogenic pulmonary edema?
Cardiogenic pulmonary edema is fluid accumulation in the lungs caused by left-sided heart dysfunction or elevated pulmonary vascular pressures.

42. How can positive pressure help in cardiogenic pulmonary edema?
Positive pressure can improve oxygenation, reduce work of breathing, recruit alveoli, and may help reduce venous return and left ventricular workload.

43. What are common signs of cardiogenic pulmonary edema?
Common signs include severe dyspnea, crackles, frothy sputum, hypoxemia, anxiety, tachypnea, and increased work of breathing.

44. Why is COPD exacerbation a common emergency respiratory condition?
COPD exacerbation can cause increased airway resistance, air trapping, hypercapnia, respiratory acidosis, increased work of breathing, and possible ventilatory failure.

45. What makes noninvasive ventilation useful in some COPD exacerbations?
Noninvasive ventilation can improve tidal volume, reduce PaCO₂, improve pH, decrease work of breathing, and reduce the need for intubation in selected patients.

46. What signs suggest a COPD patient may need invasive ventilation instead of NIV?
Signs include worsening acidosis, declining mental status, inability to clear secretions, severe hypoxemia, hemodynamic instability, or failure to improve with NIV.

47. Why is severe asthma dangerous in emergency care?
Severe asthma can cause intense bronchospasm, air trapping, increased work of breathing, hypoxemia, hypercapnia, and respiratory muscle fatigue.

48. What does a silent chest suggest in a patient with severe asthma?
A silent chest may suggest very poor air movement and severe airway obstruction, which can indicate impending respiratory failure.

49. What respiratory treatments may be used for a severe asthma exacerbation?
Treatment may include oxygen therapy, inhaled bronchodilators, corticosteroids, magnesium sulfate in selected cases, noninvasive ventilation, or intubation if deterioration occurs.

50. Why is continuous reassessment important during an emergency?
Continuous reassessment is important because patient status can change rapidly, and early recognition of worsening oxygenation, ventilation, circulation, or mental status can prevent further harm.

51. What is shock?
Shock is a life-threatening condition in which tissues do not receive enough oxygenated blood to meet metabolic needs.

52. Why can shock worsen respiratory failure?
Shock can worsen respiratory failure because poor circulation reduces oxygen delivery to tissues, even when oxygen is present in the lungs.

53. What are common signs of shock?
Common signs include hypotension, tachycardia, cool or clammy skin, weak pulses, altered mental status, low urine output, lactic acidosis, and rapid breathing.

54. Why is oxygen delivery not based on PaO₂ alone?
Oxygen delivery is not based on PaO₂ alone because it also depends on hemoglobin level, cardiac output, blood pressure, and tissue perfusion.

55. Why might a trauma patient have poor oxygen delivery despite receiving oxygen?
A trauma patient may have poor oxygen delivery if blood loss reduces circulating volume, hemoglobin concentration, cardiac output, and tissue perfusion.

56. What is the respiratory therapist’s role during cardiac arrest?
The respiratory therapist may assist with bag-mask ventilation, airway management, endotracheal tube confirmation, oxygen delivery, capnography, and ventilatory support after return of circulation.

57. Why should ventilation not be excessive during resuscitation?
Excessive ventilation can increase intrathoracic pressure, reduce venous return, decrease cardiac output, and worsen circulation during resuscitation.

58. How can end-tidal CO₂ monitoring help during CPR?
End-tidal CO₂ monitoring can help assess ventilation, confirm airway placement, evaluate CPR quality, and detect return of spontaneous circulation.

59. What may a sudden increase in end-tidal CO₂ suggest during resuscitation?
A sudden increase in end-tidal CO₂ during resuscitation may suggest improved perfusion or return of spontaneous circulation.

60. What is carbon monoxide poisoning?
Carbon monoxide poisoning occurs when carbon monoxide binds to hemoglobin and reduces the blood’s ability to carry and release oxygen.

61. Why can pulse oximetry be misleading in carbon monoxide poisoning?
Pulse oximetry can be misleading because it may read carboxyhemoglobin as oxyhemoglobin, making oxygen saturation appear normal or falsely reassuring.

62. Why can PaO₂ be normal or high in carbon monoxide poisoning?
PaO₂ can be normal or high because it measures dissolved oxygen in plasma, not the amount of oxygen bound to hemoglobin or delivered to tissues.

63. What treatment is commonly used for carbon monoxide poisoning?
High-concentration oxygen is commonly used to help displace carbon monoxide from hemoglobin and improve oxygen delivery.

64. What is the purpose of a nonrebreathing mask in an emergency?
A nonrebreathing mask delivers a high concentration of oxygen and is often used for severe hypoxemia, trauma, shock, or suspected carbon monoxide exposure.

65. When is a bag-mask device needed?
A bag-mask device is needed when the patient is not breathing adequately, requires assisted ventilation, or needs temporary support during airway management or ventilator troubleshooting.

66. What is the purpose of suctioning in emergency airway care?
Suctioning removes secretions, blood, vomitus, or other material from the airway to help restore airflow and reduce the risk of aspiration or obstruction.

67. What is the purpose of an oropharyngeal airway?
An oropharyngeal airway helps prevent the tongue from obstructing the upper airway in an unconscious patient without a gag reflex.

68. What is the purpose of a nasopharyngeal airway?
A nasopharyngeal airway helps maintain upper airway patency and may be used in some patients who cannot tolerate an oropharyngeal airway.

69. Why is stridor an important emergency finding?
Stridor is important because it may indicate upper airway obstruction, which can rapidly progress to severe respiratory distress or complete airway blockage.

70. What does accessory muscle use indicate?
Accessory muscle use indicates increased work of breathing and may be a sign of respiratory distress or impending respiratory failure.

71. Why is a weak cough concerning in critical care?
A weak cough is concerning because the patient may not be able to clear secretions or protect the airway effectively.

72. Why are manageable secretions important before extubation?
Manageable secretions are important because excessive secretions can cause airway obstruction, aspiration, respiratory distress, or extubation failure.

73. What is a spontaneous breathing trial?
A spontaneous breathing trial is a test used to determine whether a mechanically ventilated patient can breathe with minimal support before extubation.

74. What factors suggest readiness for ventilator weaning?
Readiness factors include improved underlying disease, adequate oxygenation, hemodynamic stability, acceptable mental status, manageable secretions, effective cough, and acceptable acid-base status.

75. What should be monitored after extubation?
After extubation, the patient should be monitored for airway obstruction, respiratory distress, secretion retention, hypoxemia, fatigue, and the need for further ventilatory support.

76. What is the difference between emergency care and critical care?
Emergency care focuses on rapid stabilization during an urgent or life-threatening event, while critical care involves ongoing monitoring and advanced support for patients who remain unstable or severely ill.

77. Why must respiratory therapists act quickly during acute respiratory failure?
Respiratory therapists must act quickly because untreated respiratory failure can lead to severe hypoxemia, hypercapnia, acidosis, cardiac instability, brain injury, or death.

78. What does tachypnea suggest in an emergency assessment?
Tachypnea may suggest respiratory distress, hypoxemia, metabolic acidosis, pain, anxiety, fever, shock, or increasing work of breathing.

79. What does bradypnea suggest in an emergency assessment?
Bradypnea may suggest respiratory depression, drug overdose, neurologic impairment, fatigue, or impending respiratory arrest.

80. Why is trend assessment important in critical care?
Trend assessment is important because worsening oxygen saturation, rising PaCO₂, increasing airway pressures, declining mental status, or falling blood pressure may show deterioration before a crisis occurs.

81. What is the purpose of ventilator alarms?
Ventilator alarms alert clinicians to problems such as high pressure, low pressure, apnea, circuit disconnection, low tidal volume, high respiratory rate, or equipment malfunction.

82. Why should ventilator alarms never be ignored?
Ventilator alarms should never be ignored because they may indicate a serious patient problem, airway issue, circuit leak, obstruction, or ventilator malfunction.

83. What can ventilator waveforms help identify?
Ventilator waveforms can help identify air trapping, leaks, patient-ventilator asynchrony, inadequate flow, secretions, bronchospasm, or changes in lung mechanics.

84. What is patient-ventilator asynchrony?
Patient-ventilator asynchrony occurs when the patient’s breathing effort does not match the timing, flow, volume, or pressure delivered by the ventilator.

85. Why is auto-PEEP important in emergency and critical care?
Auto-PEEP is important because trapped air can increase work of breathing, worsen hyperinflation, reduce venous return, lower blood pressure, and make ventilation more difficult.

86. What is the purpose of bronchodilator therapy during an emergency?
Bronchodilator therapy helps relax airway smooth muscle, reduce bronchospasm, improve airflow, decrease work of breathing, and support ventilation.

87. Why are corticosteroids used in some respiratory emergencies?
Corticosteroids are used to reduce airway inflammation, especially during asthma exacerbations and COPD exacerbations.

88. What is pulmonary embolism?
Pulmonary embolism is a blockage in the pulmonary circulation, usually caused by a blood clot, that can impair perfusion, gas exchange, oxygenation, and hemodynamic stability.

89. Why can pulmonary embolism cause hypoxemia?
Pulmonary embolism can cause hypoxemia by creating ventilation-perfusion mismatch, where alveoli may be ventilated but not adequately perfused.

90. What is acute respiratory distress syndrome?
Acute respiratory distress syndrome is a severe form of respiratory failure marked by widespread lung inflammation, reduced lung compliance, severe hypoxemia, and the need for advanced oxygenation support.

91. Why is reduced lung compliance important during mechanical ventilation?
Reduced lung compliance makes the lungs harder to inflate, often increasing airway pressures and raising the risk of ventilator-associated complications.

92. What does increased airway resistance mean?
Increased airway resistance means airflow is obstructed or narrowed, which can occur with bronchospasm, secretions, mucus plugging, airway edema, or a kinked artificial airway.

93. Why is humidification important during invasive mechanical ventilation?
Humidification is important because artificial airways bypass the upper airway’s natural warming and humidifying functions, which can lead to thick secretions and airway obstruction.

94. What is the purpose of checking cuff pressure?
Checking cuff pressure helps maintain an adequate seal for ventilation while reducing the risk of air leaks, aspiration, or tracheal injury from excessive pressure.

95. Why is chest rise assessed during emergency ventilation?
Chest rise helps determine whether air is entering the lungs during manual or mechanical ventilation.

96. What does unequal chest rise suggest?
Unequal chest rise may suggest mainstem intubation, pneumothorax, airway obstruction, atelectasis, trauma, or poor ventilation of one lung.

97. Why is blood pressure monitored closely during positive-pressure ventilation?
Blood pressure is monitored closely because positive-pressure ventilation can increase intrathoracic pressure, reduce venous return, and contribute to hypotension in some patients.

98. What is the goal of treating the underlying cause of respiratory failure?
The goal is to correct the condition that caused the failure, such as pneumonia, pulmonary edema, asthma, COPD exacerbation, shock, trauma, or neuromuscular weakness.

99. Why is teamwork important in emergency and critical care?
Teamwork is important because unstable patients often require coordinated airway management, oxygen therapy, ventilation, medication administration, hemodynamic support, monitoring, and rapid decision-making.

100. What is the overall goal of emergency and critical care respiratory therapy?
The overall goal is to stabilize the patient, protect the airway, support oxygenation and ventilation, reduce work of breathing, monitor for deterioration, and help restore cardiopulmonary stability.

Final Thoughts

Emergency and critical care require fast assessment, sound clinical judgment, and a clear understanding of cardiopulmonary physiology. For respiratory therapists, the main priorities are airway protection, oxygenation, ventilation, monitoring, and rapid response to deterioration.

These patients may have respiratory failure, shock, trauma, cardiac arrest, pulmonary edema, COPD exacerbation, asthma, carbon monoxide poisoning, or ventilator complications.

The respiratory therapist must recognize what is most urgent, provide appropriate support, and continue reassessing the patient’s response. In critical care, small changes can signal serious problems, so careful monitoring and timely intervention are essential for patient safety.