Inhalation Injury Flashcards
Describe inhalation injury
A nonspecific term for damage to the respiratory tract or lung tissue from heat, smoke or chemical irritants that were carried into the airway during inspiration
Describe a burn injury
Traumatic injury to tissues caused by thermal or other acute exposures to heat, electrical discharge, friction, chemicals or radiation
What factors should be considered when dealing with inhalation injuries?
Duration of exposure
Chemical composition of the smoke
Size of particles in smoke
Temperature of the gas inhaled
Age
PMH
Size and depth of body surface burns
What are the two kinds of smoke?
Pyrolysis = smoldering, low oxygen
Combustion = burning with visible flame, adequate oxygen
What are the two most common gasses inhaled in smoke?
Carbon monoxide
Hydrogen cyanide
What is the main concern with severe burn injuries?
Loss of protective barrier between the patient and the outside world
What is the common rule for estimating the percentage of BSA that has been burned?
Rule of 9s
On an adult, describe the percentage of the body associated with the head, torso, arms and legs
Head = 9
Arm = 9 each
Torso = 36 (front is 18, back is 18)
Legs = 18 each
On a child, describe the percentage of the body associated with the head, torso, arms, and legs
Head = 21
Arms = 9 each
Torso = 36 ( 18 for front, 18 for back)
Legs = 12 each
What populations are most at risk from dying as a result of severe burns?
Elderly
Infants
Which layer of skin do first degree burns involve?
Only the epidermal layer
Describe how 1st degree burns present
Do not blister
Painful, dry and red
Blanch with pressure
What is the recovery time for 1st degree burns?
Pain usually subsides in 2-3 days
Usually healed in about 6 days
Epidermis peels away without scarring
What layers of skin do partial thickness burns involve?
Epidermis and part of dermis
How are partial thickness burns classified?
Superficial or deep
What is another term for partial thickness burn?
Second degree burn
Describe how superficial partial thickness burns present
Painful
Red
Weeping
Blanch with pressure
Blister within 24 hours
What is the recovery time for superficial partial thickness burns?
Generally heal in 7-21 days
What layers of the skin do deep partial thickness burns involve?
Epidermis and dermis
Damage hair follicles and glandular tissue
What do deep partial thickness burns look like?
Painful only to pressure
Mottled coloration, patchy, cheesy white to red
Will cause scarring
How long do deep partial thickness burns take to heal?
Greater than 21 days, frequently require surgical intervention
What layers of the skin are affected by full thickness burns?
All layers of the dermis
Often damage subcutaneous tissue
What do full thickness burns look like?
Waxy white or leathery gray
Burn eschar (burned skin) present and variously colored
Describe the texture of a full thickness burn
Surface is dry
Inelastic
Does not blanch to pressure
Describe the healing time associated with full thickness burns
Burn will probably never heal on its own, will require surgery
What protects the lower respiratory tract from the heat carried by inhaled gases?
Ability of upper respiratory tract to absorb heat
Reflex laryngospasm
Glottic closure
How might a patient with a thermal injury to their respiratory tract present?
Pharyngeal edema
Stridor
Hoarseness
Painful swallowing
What can thermal injuries to the upper airway cause?
Blistering
Mucosal edema
Vascular congestion
Epithelial sloughing
Accumulation of thick secretions
Why is steam inhalation particularly dangerous?
Can carry 500x more heat than dry gas
Inhalation of steam usually results in severe damage to all levels of the respiratory tract
What can thermal injuries to the distal airways cause?
Mucosal edema
Vascular congestion
Epithelial sloughing
Cryptogenic organizing PNA
Atelectasis
Pulmonary edema
Describe how an airway presents in the early stage post smoke inhalation
Tracheobronchial tree becomes inflamed
Bronchospasm
Excess bronchial secretions
Why are secretions difficult for smoke inhalation victims to clear?
Irritants and toxins in the smoke inhibit the movement of the cilia preventing mucus clearance
What must be taken into consideration if a patient has burns around the neck and face?
That swelling from the injury may put pressure on the airway
Burn victims can often enter a state of hypovolemic shock. Explain how this happens
Fluid loss through burned skin
Inflammatory mediators provoke vascular permeability so fluid enters the interstitial/third space
What could cause cardiogenic shock in burn victims?
Hypovolemia
Hypoxia
Increased SVR + PVR
Carbon monoxide poisoning
What are the risks associated with circumferential burns?
On extremities = impaired circulation and tissue necrosis
On chest and abdomen = reduced chest wall compliance and increased WOB
Describe what happens to the upper airways during the intermediate stage after inhalation injury?
Upper airway injuries usually improve
What happens to the lower airways in the intermediate stage after inhalation injury?
Deteriorate
Increased mucus production
Mucociliary transport continues to decrease
Mucosa of tracheobronchial tree becomes necrotic and sloughs off
The continued compromise of the mucociliary transport and the sloughing of the tracheobronchial mucosa leads to what?
Mucus plugging and atelectasis
Why are inhalation injury victims at high risk for developing bronchitis and pneumonia?
Mucus accumulation due to compromised mucociliary transport results in bacterial colonization
Why are burns to the chest wall particularly concerning from a respiratory perspectiv
Inhibit deep breathing and coughing
What are the late stage problems associated with smoke inhalation?
Infections on body surface
Pneumonia
PE
Restrictive and obstructive lung disorders
What can infections on the body surface of burn victims lead to?
Systemic inflammatory response syndrome (SIRS)
What is the primary cause of death in burn patients during the late stage?
Sepsis induced SIRS
Why do burn victims have an increased risk for a pulmonary embolism?
They are immobilized and at risk for deep venous thrombosis and hypercoagulability
Why is carbon monoxide such a problem?
CO has an affinity for hemoglobin that is 210x greater than for oxygen
Hemoglobin will load CO instead of oxygen causing hypoxia
Why is it difficult to detect CO poisoning?
If using a pulse oximeter, the device will register a high SpO2 but it will not be able to discern between hgb loaded with oxygen and hgb load with CO
How will a patient with mild CO poisoning present?
Mild headache
Cherry red skin (possibly)
How will a patient with moderate CO poisoning present?
Throbbing headache
Nausea, vomitting
Impaired judgement
How will a patient with severe CO poisoning present?
Syncope
Increased HR and RR
Coma
Convulsions
Cheyne stokes
What is the risk associated with inhaled cyanide?
Will prevent the body from being able to use oxygen to produce ATP resulting in anaerobic metabolism which increases the bodys pH
SpO2 and PaO2 will look normal, but body will be unable to use oxygen
Describe how a victim caught in a fire could suffer from a triple threat of hypoxia
Hypoxic hypoxia = fire uses all available oxygen
Histotoxic hypoxia = carbon monoxide poisoning prevents oxygen loading
Histotoxic hypoxia = cyanide prevents the body from using oxygen
When evaluating a patient and you suspect smoke inhalation, what signs would you look for?
Singed nasal hair
Soot it nares
Soot in upper airway
Oral and laryngeal edema
Cyanosis
A patient who is suspected to have inhaled smoke is coughing. Describe what kind of sputum would confirm the suspicions of smoke inhalation
Carbonaceous sputum
How do you confirm a diagnosis of smoke inhalation?
Patient history
Visual inspection of airway
Bronchoscopy
What would the PFT of smoke inhalation patient look like?
Decreased flows
Decreased volumes
Decreased capacities
Describe how a CXR would look for a smoke inhalation patient in the early, middle and late stages
Early = normal
Intermediate = pulmonary edema or ARDS
Late = patchy of segmental infiltrates
What carboxyhemoglobin level would indicate carbon monoxide poisoning?
COHb> 20%
What carboxyhemoglobin level would indicate severe carbon monoxide poisoning?
Approaching 40%
A COHb if >50% may have what effects?
Lasting damage to the nervous system
Why should the airway of smoke inhalation victims be checked frequently?
Development of
Upper airway edema
Blisters
Thick secretions
Stridor
When intubating patients, what size tube should be favored and why?
8.0-8.5
Allows for bronchoscopy for diagnostics and interventions
What strategies should be employed to prevent infection in burn victims?
Reverse isolation precautions
Positive pressure rooms
Air filtration
Wound coverings
What are options for treating CO poisoning?
Hyperbaric oxygen if patient is stable
High flow nasal cannula
If face is burned, NIV can be difficult
How is cyanide poisoning treated?
Cyanokit aka hydroxocobalamin IV
What medications are given via aerosol to smoke inhalation victims?
Heparin every 4 hours
20% NAC
What does heparin do for smoke inhalation victims?
Reduces the formation of heparin casts in the airways
Scavenge for reactive oxygen species
What does NAC do for smoke inhalation victims?
Mucolytic
Prevent cast formation
Scavenge for reactive oxygen species
How are secretions in burn victims managed?
Bronchoscopy to provide suction
Intrapulmonary percussive ventilation
