Burns and Smoke Inhalation: Respiratory Care Guide

Burns and smoke inhalation are serious emergencies that can quickly affect the airway, lungs, circulation, and overall oxygen delivery. Although burns are often thought of as skin injuries, severe burns can produce major systemic changes that place the patient at risk for shock, infection, respiratory failure, and acute respiratory distress syndrome.

Smoke inhalation adds another layer of danger because it can cause airway swelling, bronchospasm, secretion buildup, and toxic gas poisoning.

Early recognition, airway protection, oxygen therapy, and careful respiratory management are essential for improving patient outcomes.

What Are Burns and Smoke Inhalation?

Burns are injuries caused by heat, flame, chemicals, electricity, radiation, or other sources that damage the skin and underlying tissues. The severity of a burn depends on several factors, including the depth of tissue destruction, the percentage of total body surface area affected, the patient’s age, the presence of other injuries, and whether smoke inhalation occurred.

Smoke inhalation refers to injury caused by breathing in hot gases, smoke particles, toxic chemicals, or poisonous gases during a fire. It is especially common in enclosed-space fires, where oxygen levels may be reduced and toxic gases can accumulate. Smoke inhalation can damage the upper airway, lower airway, and lung tissue. It can also interfere with oxygen transport at the cellular level, especially when carbon monoxide or cyanide exposure is present.

Together, burns and smoke inhalation create a high-risk trauma scenario. The patient may look stable at first but deteriorate rapidly as airway swelling worsens, secretions accumulate, oxygen delivery falls, or shock develops.

Why Burns Are a Respiratory Emergency

Burn patients should be approached as trauma patients first. This means the initial focus is on airway, breathing, circulation, disability, and exposure. From a respiratory care standpoint, the most urgent concern is whether the airway is open and likely to remain open.

Severe burns can affect breathing in several ways. Facial and neck burns can cause progressive upper airway edema. Smoke inhalation can damage the tracheobronchial tree, leading to inflammation, bronchospasm, mucus production, and airway obstruction. Circumferential chest burns can restrict chest wall expansion, making ventilation more difficult. Large burns can also trigger systemic inflammation, capillary leak, pulmonary edema, and acute respiratory distress syndrome.

This is why burn patients require frequent reassessment. A patient who is speaking clearly shortly after injury may develop serious airway narrowing later. Waiting until airway obstruction becomes obvious can make intubation much more difficult and dangerous.

Causes of Burn Injuries

Burns may occur from several different mechanisms. Flame burns are among the most common in serious burn injuries and are often associated with smoke inhalation. Scald burns occur when hot liquids or steam damage the skin. Chemical burns result from contact with acids, alkalis, or other corrosive substances. Electrical burns may cause deep tissue damage, cardiac arrhythmias, and muscle injury even when the skin injury appears limited.

Inhalation injuries usually occur when a patient breathes in smoke, superheated gases, or toxic combustion products. Enclosed-space fires are especially dangerous because the patient may be exposed to concentrated smoke, carbon monoxide, cyanide, and low oxygen levels.

Burn Severity

Burn severity is usually determined by the extent of the burn, the depth of the burn, and the presence of complications such as inhalation injury.

The extent of a burn is commonly estimated by calculating the percentage of total body surface area involved. In adults, the rule of nines is often used as a quick estimate. The head accounts for about 9%, each arm 9%, each leg 18%, the anterior torso 18%, and the posterior torso 18%. This estimate is important because it helps guide early fluid resuscitation.

Burn depth describes how deeply the tissue has been damaged. A superficial burn involves only the outer layer of skin. A partial-thickness burn extends into the dermis and is often painful. A full-thickness burn destroys the epidermis and dermis and may extend into subcutaneous tissue. Deeper burns may involve fascia, muscle, or bone.

Note: Severe burns are not limited to local tissue destruction. They can produce fluid shifts, shock, metabolic stress, immune dysfunction, infection, and respiratory complications.

Burn Depth Classifications

Burns may be described as first-degree, second-degree, third-degree, or fourth-degree injuries.

• First-degree burns are superficial and involve only the epidermis. These burns usually cause redness, pain, and mild swelling.
• Second-degree burns involve the epidermis and part of the dermis. They are usually very painful and may produce blisters, swelling, and moist skin.
• Third-degree burns destroy the epidermis and dermis. Because nerve endings may be damaged, the burned area may be painless. The skin may appear dry, leathery, white, brown, or charred.
• Fourth-degree burns extend through the skin into deeper tissues, such as fascia, muscle, tendon, or bone. These injuries are severe and often require extensive surgical treatment.

Note: Although burn depth is not strictly a respiratory issue, it helps determine the seriousness of the injury, the need for surgery, the risk of infection, and the overall prognosis.

Systemic Effects of Severe Burns

Major burns can affect nearly every organ system. One of the earliest problems is increased capillary permeability. Fluid and protein move from the intravascular space into the interstitial space, which can lead to hypovolemia, hemoconcentration, tissue edema, and shock.

Burn shock is a life-threatening condition that can occur early after severe injury. It is caused by fluid loss, inflammation, vasodilation, and reduced circulating blood volume. If untreated, it may progress to organ failure.

Severe burns also increase metabolic demand. The patient may develop increased oxygen consumption, increased carbon dioxide production, fever, muscle breakdown, and a catabolic state. This creates added stress on the lungs and ventilatory system. Patients may require higher minute ventilation to clear carbon dioxide and maintain acid-base balance.

Note: The immune system is also impaired after major burns. This increases the risk of infection, including wound infection, pneumonia, sepsis, and ventilator-associated pneumonia.

Smoke Inhalation Injury

Smoke inhalation injury can involve three main problems: thermal injury to the upper airway, chemical injury to the lower airway and lungs, and systemic poisoning from toxic gases.

Thermal injury usually affects the upper airway because the mouth, nose, and upper airway absorb much of the heat before it reaches the lower respiratory tract. This can cause swelling of the lips, tongue, pharynx, larynx, and upper trachea. The danger is that edema may progress over time and eventually obstruct the airway.

Chemical injury occurs when smoke particles and toxic substances damage the tracheobronchial tree and lung tissue. This can lead to inflammation, bronchospasm, sloughing of airway tissue, mucus plugging, atelectasis, impaired gas exchange, and pneumonia.

Note: Toxic gas exposure occurs when the patient inhales carbon monoxide, cyanide, or other poisonous gases produced during combustion. These gases can impair oxygen delivery and cellular oxygen use, even when the patient’s PaO₂ appears normal.

Signs of Inhalation Injury

Clinicians should suspect inhalation injury when a burn patient has signs involving the face, airway, or respiratory system. Common findings include facial burns, neck burns, singed nasal hairs, soot around the mouth or nose, soot in the sputum, hoarseness, cough, stridor, dyspnea, wheezing, altered mental status, and worsening oxygenation.

A history of being trapped in an enclosed-space fire is especially concerning. Even if the patient initially appears stable, inhalation injury may worsen over several hours.

Stridor is a particularly serious finding because it suggests upper airway narrowing. In a burn patient, progressive stridor should be treated as an airway emergency. Increasing oxygen alone does not fix the mechanical problem of airway obstruction.

Airway Management in Burn Patients

The first priority in a burn and smoke inhalation patient is airway protection. Early intubation may be necessary when there are signs of upper airway burns, facial burns, neck burns, progressive edema, stridor, altered mental status, worsening gas exchange, or expected clinical deterioration.

Early intubation is safer than waiting until the airway becomes severely swollen. Once edema progresses, visualization of the vocal cords may become difficult or impossible. Emergency airway rescue may then require advanced techniques such as supraglottic airways or surgical airway access.

Endotracheal intubation also allows the clinician to provide high-concentration oxygen, support ventilation, protect the airway, perform suctioning, and use bronchoscopy when needed. It is especially important when the patient has carbon monoxide poisoning, respiratory failure, or severe inhalation injury.

After intubation, the tube must be secured carefully. Facial burns, edema, and damaged skin can make tube stabilization difficult. Accidental extubation is dangerous because reintubation may be much harder after swelling develops.

Oxygen Therapy

High-concentration oxygen should be administered immediately when smoke inhalation, carbon monoxide poisoning, cyanide poisoning, shock, trauma, or acute cardiopulmonary compromise is suspected. In many cases, the initial FiO₂ should be as high as possible.

This is especially important in carbon monoxide poisoning. Carbon monoxide binds to hemoglobin with a much greater affinity than oxygen. This reduces the blood’s oxygen-carrying capacity and prevents oxygen from being released normally to the tissues. High FiO₂ helps displace carbon monoxide from hemoglobin and improves oxygen delivery.

Hyperbaric oxygen therapy may be considered when carboxyhemoglobin levels are significantly elevated, especially when neurologic or cardiac impairment is present. Hyperbaric oxygen can reduce the half-life of carbon monoxide more quickly than normobaric oxygen.

Carbon Monoxide Poisoning

Carbon monoxide poisoning is one of the most important complications of smoke inhalation. It should be suspected in patients rescued from fires, especially enclosed-space fires.

Carbon monoxide binds to hemoglobin to form carboxyhemoglobin. This reduces the amount of hemoglobin available to carry oxygen. It also shifts the oxyhemoglobin dissociation curve to the left, making it harder for oxygen to unload at the tissue level.

A key exam and clinical point is that PaO₂ may appear normal in carbon monoxide poisoning. PaO₂ measures dissolved oxygen in plasma, not the oxygen bound to hemoglobin. Therefore, a patient can have a normal PaO₂ while still having dangerously impaired oxygen delivery.

Pulse oximetry can also be misleading. Standard pulse oximeters may not distinguish oxyhemoglobin from carboxyhemoglobin. As a result, SpO₂ may appear normal or falsely high. This is why suspected carbon monoxide poisoning requires arterial blood gas analysis with co-oximetry.

Signs and symptoms may include headache, anxiety, confusion, tachycardia, tachypnea, dyspnea, hypertension, arrhythmias, seizures, coma, and death. Severe cases may progress to hypotension, bradycardia, pulmonary edema, respiratory failure, and cardiac arrest.

Cyanide Toxicity

Cyanide poisoning may occur when materials such as plastics, synthetic fabrics, foam, rubber, and other nitrogen-containing substances burn. Cyanide interferes with cellular oxygen use by blocking normal aerobic metabolism. This means oxygen may be present in the blood, but the cells cannot use it properly.

Signs and symptoms may include headache, confusion, agitation, seizures, coma, chest tightness, nausea, vomiting, dilated pupils, dyspnea, tachypnea, hyperpnea, hypertension early in the course, and hypotension later. Severe cyanide toxicity can lead to cardiovascular collapse and death.

An elevated lactate level is an important clue. A lactate level of 8 mmol/L or higher in the setting of smoke inhalation may suggest cyanide toxicity because it reflects tissue hypoxia and anaerobic metabolism.

Note: Treatment should not be delayed when cyanide poisoning is strongly suspected. Hydroxocobalamin is commonly used because it binds cyanide and helps form cyanocobalamin, which can be eliminated from the body.

Diagnostic Evaluation

The initial evaluation of a burn and smoke inhalation patient should include a rapid trauma assessment, airway assessment, respiratory assessment, neurologic evaluation, and laboratory testing.

Important tests may include arterial blood gas analysis, co-oximetry, complete blood count, electrolytes, lactate, coagulation studies, and carboxyhemoglobin measurement. A chest x-ray is often obtained, but clinicians must remember that early chest imaging may be normal even when inhalation injury is present.

Co-oximetry is essential when carbon monoxide poisoning is suspected. A standard blood gas analyzer may calculate oxygen saturation incorrectly, while co-oximetry directly measures abnormal hemoglobin forms such as carboxyhemoglobin and methemoglobin.

The Glasgow Coma Scale may be useful when the patient is unresponsive or has altered mental status. Electrical burns may require cardiac monitoring, a 12-lead ECG, and cardiac biomarkers because of the risk of arrhythmias and myocardial injury.

Role of Bronchoscopy

Flexible bronchoscopy is useful in both the diagnosis and treatment of inhalation injury. It allows direct visualization of the tracheobronchial tree. Clinicians can inspect for soot, erythema, edema, ulceration, mucosal sloughing, carbonaceous debris, bleeding, and airway obstruction.

Bronchoscopy may be especially useful when inhalation injury is suspected but chest x-ray findings are normal. It can help confirm the presence and extent of airway damage.

Bronchoscopy also has therapeutic value. It can remove thick secretions, mucus plugs, carbonaceous debris, necrotic tissue, and disrupted mucosa. This can improve ventilation, reduce airway obstruction, improve secretion clearance, and help prevent atelectasis or pneumonia.

However, bronchoscopy can worsen hypoxemia or cause complications in unstable patients. The patient’s oxygenation, ventilation, hemodynamic status, and ability to tolerate the procedure must be considered.

Secretion Management

Secretion management is a major part of respiratory care in smoke inhalation injury. Damaged airway tissue, inflammation, mucus production, debris, and impaired mucociliary transport can lead to thick, tenacious secretions.

These secretions may obstruct the endotracheal tube, block airways, worsen ventilation-perfusion mismatch, and contribute to atelectasis or infection. The respiratory therapist must monitor breath sounds, airway pressures, secretion characteristics, oxygenation, and ventilation.

Key interventions include active humidification, careful suctioning, bronchodilator therapy when bronchospasm is present, airway clearance techniques, and bronchoscopic airway toilet when routine suctioning is not enough.

Intubated burn patients should generally receive active humidification rather than relying only on a heat and moisture exchanger. This helps reduce the risk of thick secretions and tube obstruction, especially when secretions are heavy or the patient has airway burns.

Mechanical Ventilation

Burn and smoke inhalation patients who require mechanical ventilation should be managed with lung-protective principles. The goal is to support gas exchange while minimizing ventilator-induced lung injury.

Tidal volume is commonly set based on predicted body weight, often in the range of 4 to 8 mL/kg. Plateau pressure should be monitored and kept as low as possible, often below 28 to 30 cm H₂O, unless reduced chest wall compliance makes interpretation more difficult. Driving pressure should also be limited when possible.

PEEP is used to improve oxygenation, recruit alveoli, and prevent derecruitment. Patients without ARDS may need modest PEEP, while patients with ARDS require management according to ARDS protocols.

Because burn patients may have increased metabolic demand and increased carbon dioxide production, minute ventilation needs may be higher than expected. When possible, increasing respiratory rate is preferred over increasing tidal volume, since large tidal volumes can worsen lung injury.

Permissive hypercapnia may be acceptable in some cases if it helps prevent excessive airway pressures and lung injury. However, this must be balanced with the patient’s neurologic status, hemodynamics, and overall acid-base condition.

ARDS and Pulmonary Complications

Severe burns and inhalation injury can lead to acute respiratory distress syndrome. ARDS occurs when widespread inflammation damages the alveolar-capillary membrane, causing fluid leakage into the lungs, decreased compliance, impaired oxygenation, and diffuse pulmonary infiltrates.

Burn patients are also at risk for atelectasis, pneumonia, bronchospasm, pulmonary edema, mucus plugging, and ventilator-associated pneumonia. These complications may develop over time, even if the initial chest x-ray is normal.

Prevention and management include lung-protective ventilation, appropriate PEEP, secretion clearance, humidification, early recognition of infection, careful fluid management, and ventilator-associated pneumonia prevention strategies.

Fluid Resuscitation and Respiratory Effects

Fluid resuscitation is essential in major burns because of capillary leak and intravascular volume loss. Large volumes of fluid may be needed during the first 24 hours after injury. However, fluid management must be carefully monitored because both under-resuscitation and over-resuscitation can cause harm.

Inadequate fluid replacement can worsen shock and organ perfusion. Excessive fluid administration may contribute to edema, including airway edema and pulmonary edema. Respiratory therapists should understand the fluid plan because changes in fluid status can affect oxygenation, compliance, airway swelling, and ventilator requirements.

Note: Urine output is commonly monitored to assess resuscitation adequacy. In many cases, a target of about 1 mL/kg/hr may be used, although goals can vary based on clinical circumstances.

Circumferential Chest Burns

Circumferential full-thickness burns of the chest can restrict chest wall movement. As the burned tissue becomes stiff and inelastic, the patient may have difficulty expanding the chest during inspiration. This can reduce tidal volume, increase work of breathing, and worsen ventilation.

In mechanically ventilated patients, circumferential chest burns may cause high airway pressures and poor chest rise. If ventilation is compromised, escharotomy may be needed. Escharotomy involves cutting through the burned tissue to relieve restriction and allow better chest expansion.

Note: This is an important respiratory consideration because the problem is not always in the lungs themselves. Sometimes ventilation is impaired because the chest wall cannot expand properly.

Post-Extubation Airway Obstruction

Burn and smoke inhalation patients are at risk for post-extubation airway obstruction. Edema, airway injury, inflammation, and healing tissue can narrow the upper airway after the tube is removed.

Mild post-extubation stridor may be treated with measures such as humidified oxygen and racemic epinephrine. However, worsening stridor, anxiety, severe hypoxemia, altered mental status, or signs of respiratory failure require immediate airway intervention.

Note: A key clinical principle is that airway obstruction should not be managed with diagnostic delays. If the patient is deteriorating after extubation, reintubation may be the safest and most appropriate action.

Noninvasive Ventilation and Heliox

Noninvasive ventilation may be considered only in selected burn patients with mild to moderate respiratory distress who do not have major inhalation injury, facial burns, airway edema, altered mental status, or high aspiration risk. It is generally not appropriate when airway protection is needed or when the face is burned and a mask seal is difficult.

Heliox may be considered in some cases of upper airway narrowing because its lower density can reduce turbulent airflow and decrease work of breathing. However, heliox is not a substitute for intubation when airway obstruction is severe or worsening.

Infection and Sepsis

Infection is a major cause of morbidity and mortality in burn patients who survive the initial injury. The skin normally acts as a barrier against pathogens, and severe burns disrupt that barrier. Inhalation injury also damages airway defenses, making pneumonia more likely.

Burn patients may undergo repeated procedures, grafting, wound care, and prolonged mechanical ventilation, all of which increase infection risk. Pneumonia and sepsis can worsen oxygenation, prolong ventilator dependence, and increase mortality.

Prophylactic antibiotics are generally not recommended simply because a burn or inhalation injury occurred. Antibiotics should be used when infection is suspected or confirmed. Respiratory therapists help by monitoring sputum, breath sounds, oxygenation trends, ventilator changes, fever, and signs of worsening pulmonary status.

Key Respiratory Care Priorities

The respiratory therapist has several important responsibilities in burns and smoke inhalation. These include assessing airway patency, identifying signs of inhalation injury, administering high-concentration oxygen, recommending co-oximetry when carbon monoxide poisoning is suspected, assisting with intubation, managing mechanical ventilation, optimizing humidification, clearing secretions, monitoring for ARDS, and helping prevent ventilator-associated pneumonia.

The therapist must also recognize when pulse oximetry is unreliable. In suspected carbon monoxide poisoning, a normal SpO₂ should not reassure the clinician. Co-oximetry is needed to measure carboxyhemoglobin and guide treatment.

Note: Frequent reassessment is essential. Burn patients can deteriorate quickly, and respiratory problems may become more obvious hours after the initial injury.

Exam Tips for Burns and Smoke Inhalation

For exam purposes, burns plus smoke inhalation should immediately suggest a high-risk airway and oxygenation emergency. The first priority is airway protection. Facial burns, soot, singed nasal hairs, hoarseness, stridor, altered mental status, and worsening oxygenation should point toward early intubation.

If carbon monoxide poisoning is suspected, recommend high-concentration oxygen and co-oximetry. Do not rely on standard pulse oximetry alone. Remember that PaO₂ may be normal because it measures dissolved oxygen, not oxygen bound to hemoglobin.

Bronchoscopy may be appropriate when direct visualization of the airway is needed, especially after smoke exposure in an enclosed fire. It may also help remove secretions or mucus plugs.

Note: If a post-extubation burn patient develops worsening stridor and severe hypoxemia, the best action is usually reintubation, not simply increasing oxygen or waiting for more tests.

Burns and Smoke Inhalation Practice Questions

1. What is the first priority when assessing a patient with burns and smoke inhalation?
The first priority is assessing and protecting the airway.

2. Why should burn patients be approached as trauma patients first?
Because burns may be associated with airway injury, respiratory compromise, shock, toxic gas exposure, and other traumatic injuries that require immediate assessment.

3. What makes smoke inhalation especially dangerous in burn patients?
Smoke inhalation can cause airway edema, bronchospasm, secretion buildup, lung injury, carbon monoxide poisoning, and cyanide toxicity.

4. Why is early intubation often recommended for patients with facial burns and smoke inhalation?
Early intubation is recommended because airway edema can progress rapidly and make later intubation difficult or impossible.

5. What clinical signs suggest a high risk of inhalation injury?
Facial burns, neck burns, singed nasal hairs, soot around the mouth or nose, sooty sputum, hoarseness, cough, stridor, dyspnea, and altered mental status suggest inhalation injury.

6. Why can a chest x-ray appear normal early after smoke inhalation?
Early imaging may appear normal because airway inflammation, atelectasis, pulmonary edema, and infection may develop later.

7. What is the Rule of Nines used for in burn assessment?
The Rule of Nines is used to estimate the percentage of total body surface area affected by burns.

8. Why is estimating total body surface area important in burn care?
It helps guide fluid resuscitation and provides information about burn severity.

9. What percentage is assigned to each arm in the adult Rule of Nines?
Each arm is assigned 9% of total body surface area.

10. What percentage is assigned to each leg in the adult Rule of Nines?
Each leg is assigned 18% of total body surface area.

11. What percentage is assigned to the anterior torso in the adult Rule of Nines?
The anterior torso is assigned 18% of total body surface area.

12. What percentage is assigned to the posterior torso in the adult Rule of Nines?
The posterior torso is assigned 18% of total body surface area.

13. What is a first-degree burn?
A first-degree burn is a superficial burn that involves only the epidermis.

14. What is a second-degree burn?
A second-degree burn involves the epidermis and part of the dermis and is usually very painful.

15. What is a third-degree burn?
A third-degree burn destroys the epidermis and dermis and may cause little or no pain because nerve endings are damaged.

16. What is a fourth-degree burn?
A fourth-degree burn extends into deeper tissues such as fascia, muscle, tendon, or bone.

17. Why may a full-thickness burn be painless?
A full-thickness burn may be painless because nerve endings in the burned area have been destroyed.

18. What is burn shock?
Burn shock is a life-threatening condition caused by fluid loss, increased capillary permeability, inflammation, vasodilation, and reduced circulating blood volume.

19. How do severe burns affect capillary permeability?
Severe burns increase capillary permeability, allowing fluid and protein to shift from the bloodstream into the interstitial space.

20. What respiratory problem can occur when circumferential chest burns restrict chest expansion?
Circumferential chest burns can reduce chest wall compliance and impair ventilation.

21. What procedure may be needed if circumferential chest burns prevent effective ventilation?
An escharotomy may be needed to relieve restriction and allow better chest expansion.

22. What are the three major concerns during respiratory assessment of a burn patient?
The major concerns are external burn extent and depth, lung tissue involvement, and toxic gas exposure.

23. Why should patients from enclosed-space fires be considered high risk?
Enclosed-space fires increase the risk of smoke inhalation, carbon monoxide poisoning, cyanide toxicity, and oxygen deprivation.

24. What toxic gases are commonly associated with smoke inhalation?
Carbon monoxide and cyanide are commonly associated with smoke inhalation.

25. Why is high-concentration oxygen given initially to smoke inhalation patients?
High-concentration oxygen is given to improve oxygen delivery and help displace carbon monoxide from hemoglobin.

26. Why can standard pulse oximetry be misleading in carbon monoxide poisoning?
Standard pulse oximetry may falsely appear normal because it may not distinguish oxyhemoglobin from carboxyhemoglobin.

27. What test is needed to measure carboxyhemoglobin levels?
Co-oximetry is needed to measure carboxyhemoglobin levels.

28. Why can PaO₂ appear normal in carbon monoxide poisoning?
PaO₂ measures oxygen dissolved in plasma, not oxygen bound to hemoglobin.

29. What does carbon monoxide do to hemoglobin?
Carbon monoxide binds to hemoglobin and forms carboxyhemoglobin, reducing the blood’s ability to carry oxygen.

30. How does carbon monoxide affect oxygen unloading to tissues?
Carbon monoxide shifts the oxyhemoglobin dissociation curve to the left, making it harder for oxygen to unload at the tissue level.

31. At what carboxyhemoglobin level do patients often become symptomatic?
Patients often become symptomatic when carboxyhemoglobin levels exceed 15%.

32. What carboxyhemoglobin level may be lethal?
Carboxyhemoglobin levels above 50% may be lethal.

33. What are early signs of carbon monoxide or cyanide poisoning?
Early signs may include anxiety, tachycardia, arrhythmias, tachypnea, hypertension, headache, confusion, and dyspnea.

34. What severe findings may occur with advanced toxic gas poisoning?
Severe poisoning may cause hypotension, bradycardia, seizures, decreased consciousness, pulmonary edema, respiratory failure, coma, or death.

35. Why does carbon monoxide poisoning not always cause cyanosis?
Carbon monoxide poisoning may not cause cyanosis because oxygenation impairment occurs at the hemoglobin and tissue-delivery level rather than always producing visible bluish discoloration.

36. Why should carbon monoxide poisoning be suspected in a patient rescued from a house fire?
House fires, especially enclosed-space fires, commonly expose patients to carbon monoxide from incomplete combustion.

37. What is the recommended evaluation for a suspected smoke inhalation patient with facial burns and unconsciousness?
An arterial blood gas sample analyzed with co-oximetry is recommended.

38. Why is a standard blood gas analyzer alone insufficient in suspected carbon monoxide poisoning?
A standard blood gas analyzer may calculate oxygen saturation falsely and may not directly measure carboxyhemoglobin.

39. What is cyanide’s main effect on the body?
Cyanide interferes with cellular oxygen use by disrupting aerobic metabolism.

40. When should cyanide poisoning be suspected in a smoke inhalation patient?
It should be suspected after smoke exposure from burning plastics, synthetic materials, or other toxic combustion products, especially with severe lactic acidosis.

41. What lactate level may suggest cyanide toxicity in smoke inhalation?
A lactate level of 8 mmol/L or higher may suggest cyanide toxicity.

42. What medication is commonly used to treat suspected cyanide poisoning?
Hydroxocobalamin, also known as Cyanokit, is commonly used.

43. Why should treatment for suspected cyanide poisoning not be delayed?
Cyanide toxicity can rapidly impair cellular oxygen use and lead to cardiovascular collapse and death.

44. What is the purpose of hyperbaric oxygen therapy in carbon monoxide poisoning?
Hyperbaric oxygen helps displace carbon monoxide from hemoglobin more rapidly and improves oxygen delivery to tissues.

45. When may hyperbaric oxygen therapy be recommended?
It may be recommended when carboxyhemoglobin is greater than 25% with neurologic or cardiac impairment, if available.

46. Why is high FiO₂ recommended initially for patients with pulmonary burns or smoke inhalation?
High FiO₂ is recommended because carbon monoxide poisoning may be present and rapid oxygen delivery is critical.

47. Why should airway status be monitored continuously after smoke inhalation?
Airway edema may progress over time and eventually cause serious obstruction.

48. What does hoarseness suggest in a burn patient?
Hoarseness may suggest upper airway irritation, edema, or injury from smoke inhalation.

49. What does stridor suggest in a burn and smoke inhalation patient?
Stridor suggests upper airway narrowing and possible impending airway obstruction.

50. Why should clinicians avoid waiting for obvious radiographic changes before treating suspected inhalation injury?
Radiographic findings may be normal early, while airway swelling and respiratory compromise can still progress.

51. What is the diagnostic role of flexible bronchoscopy in smoke inhalation injury?
Flexible bronchoscopy allows direct visualization of the tracheobronchial tree to assess airway burns, soot, edema, inflammation, debris, and obstruction.

52. What is the therapeutic role of bronchoscopy in smoke inhalation patients?
Bronchoscopy can help remove secretions, mucus plugs, carbonaceous debris, disrupted mucosa, and necrotic tissue from the airway.

53. Why may repeated bronchoscopies be needed after inhalation injury?
Repeated bronchoscopies may be needed because thick secretions, debris, and necrotic tissue can recur after the initial airway cleaning.

54. What type of airway secretions are common after smoke inhalation?
Thick, tenacious secretions are common after smoke inhalation.

55. Why do secretions accumulate after inhalation injury?
Secretions accumulate because of increased mucus production, toxic debris, necrotic cells, inflammatory fluid, and impaired mucociliary clearance.

56. How can damaged tracheobronchial epithelium worsen respiratory status?
Damaged epithelium can impair mucus clearance, promote mucus plugging, cause atelectasis, and increase the risk of infection.

57. What are key secretion management strategies in smoke inhalation injury?
Key strategies include active humidification, careful suctioning, airway clearance, and bronchoscopic airway toilet when needed.

58. Why is active humidification important for intubated burn patients?
Active humidification helps prevent drying of secretions, mucus plugging, and endotracheal tube obstruction.

59. Why is an HME often avoided in intubated burn patients with inhalation injury?
An HME may be less effective when secretions are heavy and may increase the risk of tube obstruction.

60. What ventilator strategy is recommended for smoke inhalation and pulmonary burns?
A lung-protective ventilation strategy is recommended.

61. What tidal volume range is generally recommended for ventilated burn patients?
A tidal volume of about 4 to 8 mL/kg predicted body weight is generally recommended.

62. Why should tidal volume be based on predicted body weight?
Predicted body weight better reflects lung size and helps reduce the risk of ventilator-induced lung injury.

63. What plateau pressure goal is commonly recommended during lung-protective ventilation?
Plateau pressure should generally be kept below about 28 to 30 cm H₂O, unless chest wall compliance is decreased.

64. What is the recommended driving pressure goal in lung-protective ventilation?
Driving pressure should generally be kept at 15 cm H₂O or less when possible.

65. What PEEP range may be used initially when ARDS is not present?
PEEP is commonly set around 5 to 10 cm H₂O when ARDS is not present.

66. What should be done if ARDS develops in a burn patient?
The patient should be managed according to standard ARDS ventilator protocols.

67. Why can burn patients require increased minute ventilation?
Burn patients may have increased metabolic demand, increased oxygen consumption, and increased carbon dioxide production.

68. How should minute ventilation usually be increased in a lung-protective strategy?
Minute ventilation is usually increased by raising the respiratory rate rather than using large tidal volumes.

69. Why may mild to moderate respiratory acidosis be accepted in ventilated burn patients?
Mild to moderate respiratory acidosis may be accepted to avoid excessive tidal volumes and high airway pressures.

70. What pulmonary complications can occur after severe burns or smoke inhalation?
Complications include ARDS, atelectasis, pneumonia, pulmonary edema, bronchospasm, mucus plugging, and respiratory failure.

71. Why is pneumonia common after severe burns and inhalation injury?
Pneumonia is common because airway defenses are damaged, secretions accumulate, and the immune response is impaired.

72. Why are prophylactic antibiotics generally not recommended for burns and smoke inhalation?
Prophylactic antibiotics are not recommended because antibiotics should be reserved for suspected or confirmed infection.

73. What medication may be used for bronchospasm after smoke inhalation?
Aerosolized bronchodilators may be used to treat bronchospasm.

74. What medications may be used to help manage airway casts and secretions in inhalation injury?
N-acetylcysteine and aerosolized heparin may be used in some cases to help manage thick secretions and airway casts.

75. Why is ventilator-associated pneumonia prevention important in burn patients?
Burn patients may require prolonged ventilation and have impaired defenses, which increases the risk of ventilator-associated pneumonia.

76. What is the main goal of the resuscitation phase in major burn care?
The main goal is to support vital organ systems, restore circulation, protect the airway, and prevent early death.

77. What are the “four Rs” of major burn management?
The four Rs are resuscitation, resurfacing, rehabilitation, and reconstruction.

78. During which phase of burn care does most early respiratory management occur?
Most early respiratory management occurs during the resuscitation phase.

79. What laboratory tests may be recommended during the initial assessment of a major burn patient?
Recommended tests may include CBC, electrolytes, lactate, arterial blood gas, CO-oximetry, coagulation studies, and carboxyhemoglobin measurement.

80. Why is lactate useful in smoke inhalation assessment?
Lactate helps identify tissue hypoxia and may support suspicion of cyanide poisoning when significantly elevated.

81. Why should the Glasgow Coma Scale be used in an unresponsive burn patient?
It helps assess neurologic status and the severity of altered consciousness.

82. Why are electrical burns associated with cardiac concerns?
Electrical burns can disrupt cardiac conduction and cause arrhythmias or myocardial injury.

83. What tests may be recommended after an electrical burn?
A 12-lead ECG and cardiac biomarkers may be recommended.

84. Why is fluid resuscitation important after major burns?
Fluid resuscitation replaces intravascular volume lost from capillary leak, tissue edema, and burn shock.

85. How much fluid may a 70-kg major burn patient require in the first 24 hours?
A 70-kg patient may require 8 to 10 liters or more during the first 24 hours, depending on burn severity.

86. What urine output goal may be used to monitor burn resuscitation?
A urine output goal of about 1 mL/kg/hr may be used.

87. Why can excessive fluid administration worsen respiratory status?
Excessive fluids can contribute to airway edema, pulmonary edema, impaired oxygenation, and reduced respiratory compliance.

88. Why can under-resuscitation be dangerous in major burns?
Under-resuscitation can worsen shock, tissue hypoperfusion, organ dysfunction, and mortality.

89. Why should burn patients be covered during initial management?
Covering the patient helps reduce heat loss, fluid loss, contamination, and further physiologic stress.

90. Why must pain control be monitored carefully in burn patients?
Pain control is important, but medications such as morphine can cause respiratory depression.

91. When should a smoke inhalation patient be admitted for further care?
Admission may be needed with hypoxemia, carboxyhemoglobin greater than 15%, metabolic acidosis, bronchospasm, or painful and difficult swallowing.

92. What PaO₂ value indicates hypoxemia in the smoke inhalation admission criteria?
A PaO₂ less than 60 torr indicates hypoxemia.

93. Why can facial or neck burns make noninvasive ventilation inappropriate?
Facial or neck burns may prevent a good mask seal and may indicate airway edema that requires airway protection.

94. When may noninvasive ventilation be considered in a burn patient?
It may be considered only in mild to moderate distress without major inhalation injury, facial burns, airway edema, or impaired mental status.

95. Why is tracheotomy considered in some burn patients?
Tracheotomy may be considered if vocal cords are damaged or prolonged ventilation beyond 10 to 12 days is expected.

96. Why is prevention of accidental extubation especially important in burn patients?
Reintubation may be difficult because facial burns, neck burns, and airway edema can worsen after the initial airway is secured.

97. What backup airway methods may be needed for severe airway compromise?
Backup airway methods may include a laryngeal mask airway, cricothyrotomy, or other emergency airway techniques.

98. What can mild post-extubation stridor be treated with?
Mild post-extubation stridor may be treated with humidified oxygen and inhaled racemic epinephrine.

99. What is the best action for worsening stridor with severe hypoxemia after extubation?
The best action is immediate airway intervention, usually reintubation.

100. What is the most important clinical takeaway for burns and smoke inhalation?
The most important takeaway is to protect the airway early, give high-concentration oxygen, evaluate for toxic gas exposure, manage secretions, and monitor closely for rapid deterioration.

Final Thoughts

Burns and smoke inhalation are complex emergencies that require fast, organized respiratory care. The most important priorities are protecting the airway, providing high-concentration oxygen, recognizing carbon monoxide and cyanide poisoning, using co-oximetry when needed, and managing secretions and ventilation carefully.

These patients can worsen even when early chest imaging or pulse oximetry appears reassuring. Facial burns, soot, hoarseness, stridor, altered mental status, and enclosed-space fire exposure should raise concern for serious inhalation injury.

Early airway control, careful monitoring, humidification, bronchoscopic airway clearance, lung-protective ventilation, and infection prevention can significantly affect survival and recovery.