Thermal and Inhalation Thermal and Inhalation InjuryInjury

Chapter 39Chapter 39Written by : Melissa Dearing – LSC-KingwoodWritten by : Melissa Dearing – LSC-Kingwood

EpidemiologyEpidemiology

In the U.S.In the U.S. Results in 60,000 hospitalizations Results in 60,000 hospitalizations

annuallyannually 6000 deaths annually6000 deaths annually Mortality the highest inMortality the highest in

Young childrenYoung children elderlyelderly

EpidemiologyEpidemiology

In pediatric thermal injuries:In pediatric thermal injuries:Less than 5% are the result of Less than 5% are the result of

chemical or electrical burnschemical or electrical burns

10-15% result from flame burns10-15% result from flame burns When associated with smoke When associated with smoke

inhalation are the most deadlyinhalation are the most deadly

Scalding burns account for 75-Scalding burns account for 75-

80%80%

PreventionPrevention

Smoke detectors that workSmoke detectors that work

Keep matches out of reachKeep matches out of reach

Lower the temp on hot water heatersLower the temp on hot water heaters

Cover electrical outletsCover electrical outlets

Buy flame resistant children’s Buy flame resistant children’s

clothingclothing

Use fire-safe cigarettesUse fire-safe cigarettes

Mortality RateMortality Rate

Highest when:Highest when:

Burn exceeds 30% body surface Burn exceeds 30% body surface

area.area.

See figure 39-1See figure 39-1

Associated with smoke inhalationAssociated with smoke inhalation

Child younger than 4 years oldChild younger than 4 years old

PathophysiologyPathophysiology

Disruption of the protection Disruption of the protection provided by skin:provided by skin:

Protects body from infection and injuryProtects body from infection and injury Prevents fluid lossPrevents fluid loss Regulates body tempRegulates body temp Provides sensory input from Provides sensory input from

environmentenvironment

PathophysiologyPathophysiology

Composed of 2 layersComposed of 2 layers Epidermis – thin outer layerEpidermis – thin outer layer Dermis – deeper, thick inner layerDermis – deeper, thick inner layer

Dermis contains:Dermis contains: Hair folliclesHair follicles Sweat glandsSweat glands Sebaceous glandsSebaceous glands Sensory fibers for touch, pain, pressure and Sensory fibers for touch, pain, pressure and

temptemp Beneath the dermisBeneath the dermis

Subcutaneous tissue composed of Subcutaneous tissue composed of connective tissue and fatconnective tissue and fat

Classification of BurnClassification of Burn

11stst Degree Degree Superficial Superficial Involves only the dermisInvolves only the dermis Skin is redSkin is red No blistersNo blisters Painful and sensitive to touchPainful and sensitive to touch

Classification of BurnClassification of Burn

22ndnd Degree Degree Involve the epidermis and part of Involve the epidermis and part of

the dermisthe dermis Very painful due to nerve endings Very painful due to nerve endings

that survive the insultthat survive the insult Blistering is commonBlistering is common Healing occurs quicklyHealing occurs quickly

Classification of BurnClassification of Burn

33rdrd Degree Degree ““Full thickness” burnsFull thickness” burns Involve injury and necrosis below Involve injury and necrosis below

the hair follicles thru the entire the hair follicles thru the entire thickness of skin and into thickness of skin and into subcutaneous tissuesubcutaneous tissue

Area swells slowly and appears Area swells slowly and appears blanchedblanched

Sensory nerves are destroyed Sensory nerves are destroyed causing local anesthesiacausing local anesthesia

ManagementManagement

11stst degree usually heals by itself degree usually heals by itself 22ndnd and 3 and 3rdrd degree may require degree may require

grafting, excision and grafting, excision and antimicrobial therapy such as antimicrobial therapy such as Silva dineSilva dine

ManagementManagement

Important to initiate accurate Important to initiate accurate fluid resuscitation ASAPfluid resuscitation ASAP Careful: overaggressive fluid Careful: overaggressive fluid

resuscitation may result in high resuscitation may result in high extravascular hydrostatic pressure, extravascular hydrostatic pressure, pulmonary edema and soft tissue pulmonary edema and soft tissue swellingswelling

Urine output is a good indicator Urine output is a good indicator of hydrationof hydration

Inhalation InjuryInhalation Injury

Mortality from smoke injury Mortality from smoke injury alone is 0-11%alone is 0-11%

Mortality from smoke injury and Mortality from smoke injury and burns is 30-90%burns is 30-90%

Smoke inhalation that results in Smoke inhalation that results in pneumonia has a mortality rate pneumonia has a mortality rate of 60%of 60%

Physiologic Consequences Physiologic Consequences of Inhalation Injuryof Inhalation Injury

Box 39-1Box 39-1

Upper Airway InjuryUpper Airway Injury

Results in obstruction from:Results in obstruction from: EdemaEdema HemorrhageHemorrhage Ulceration of mucosaUlceration of mucosa

Mild pharyngeal edema can lead Mild pharyngeal edema can lead to complete upper airway to complete upper airway obstruction and asphyxia in only a obstruction and asphyxia in only a few hoursfew hours

Inflammation can be the result of Inflammation can be the result of ammonia, hydrogen chloride and ammonia, hydrogen chloride and chemical irritants found in smokechemical irritants found in smoke

Lung Parenchyma InjuryLung Parenchyma Injury

Only steam is capable of Only steam is capable of overwhelming the upper airway overwhelming the upper airway defenses and transmitting heat defenses and transmitting heat to the subglottic airwaysto the subglottic airways

Direct cellular injury results in Direct cellular injury results in inflammatory responseinflammatory response Leads to bronchoconstrictionLeads to bronchoconstriction Increase in tracheobronchial blood Increase in tracheobronchial blood

flow with edemaflow with edema Leukocyte infiltrationLeukocyte infiltration

Lung Parenchyma InjuryLung Parenchyma Injury

Sloughing of necrotic tissue Sloughing of necrotic tissue plugs up the airways plugs up the airways

Can cause partial or complete airway Can cause partial or complete airway obstructionobstruction

Can be fatalCan be fatal

Lung Parenchyma InjuryLung Parenchyma Injury

Pulmonary parenchyma shows:Pulmonary parenchyma shows: Varying degrees of congestionVarying degrees of congestion Interstitial and alveolar edemaInterstitial and alveolar edema Hyaline membranesHyaline membranes Dense atelectasisDense atelectasis

Lung Parenchyma InjuryLung Parenchyma Injury

Systemic effects:Systemic effects: Increase in RAWIncrease in RAW V/Q mismatchV/Q mismatch Increase in oxygen consumptionIncrease in oxygen consumption Decrease in complianceDecrease in compliance Decrease in oxygenationDecrease in oxygenation Decreased surfactant productionDecreased surfactant production

Carbon Monoxide Carbon Monoxide PoisoningPoisoning

Smoke inhalation from all types Smoke inhalation from all types of fires result in significant CO of fires result in significant CO exposure.exposure.

Pulse oximeter do not reflect the Pulse oximeter do not reflect the true oxygen saturation in the true oxygen saturation in the presence of COHB.presence of COHB.

Symptoms- Table 39-1Symptoms- Table 39-1

Clinical ManifestationsClinical Manifestations

Smoke inhalation injury more Smoke inhalation injury more likely in individuals with:likely in individuals with:

History of burn injury in an enclosed History of burn injury in an enclosed spacespace

Appearance of facial burnsAppearance of facial burns Singed nose and facial hairSinged nose and facial hair Erythema of the oropharynx Erythema of the oropharynx Carbonaceous sputumCarbonaceous sputum Debris around the nose, mouth and Debris around the nose, mouth and

pharynxpharynx

BronchoscopyBronchoscopy

Gold standard for diagnosis of Gold standard for diagnosis of inhalation injuryinhalation injury

Provides direct visualization of Provides direct visualization of airwayairway

SootSoot CharringCharring Mucosal erythemaMucosal erythema UlcerationUlceration HemorrhageHemorrhage EdemaEdema inflammationinflammation

ManagementManagement

Oxygen TherapyOxygen Therapy Airway MaintenanceAirway Maintenance Bronchial Hygiene TherapyBronchial Hygiene Therapy Pharmacologic ManagementPharmacologic Management Mechanical VentilationMechanical Ventilation

ConventionalConventional High frequencyHigh frequency

ManagementManagement

Oxygen TherapyOxygen Therapy Initially give 100%Initially give 100%

Wean by blood gas valuesWean by blood gas values

Analyze COHB with co-oxAnalyze COHB with co-ox

ManagementManagement

Airway maintenanceAirway maintenance Intubation by most skilled clinicianIntubation by most skilled clinician

Nasal intubation is easier for securing Nasal intubation is easier for securing

a tube to a burned facea tube to a burned face

Burns to the neck can cause tightening Burns to the neck can cause tightening

of the tissue causing restriction to the of the tissue causing restriction to the

airwayairway Escharotomies to reduce the pressure Escharotomies to reduce the pressure

exerted to the areaexerted to the area

ManagementManagement

Bronchial Hygiene TherapyBronchial Hygiene Therapy Retained secretions can be life threateningRetained secretions can be life threatening

Early ambulationEarly ambulation

Therapeutic coughingTherapeutic coughing

Chest PTChest PT

Airway suctioningAirway suctioning

Therapeutic bronchoscopyTherapeutic bronchoscopy

Pharmacologic agents for retained Pharmacologic agents for retained

secretionssecretions

ManagementManagement

Pharmacological ManagementPharmacological Management Inhalation injury creates intense Inhalation injury creates intense

bronchospasm and wheezingbronchospasm and wheezing Manage with B2 – agonistsManage with B2 – agonists

Racemic epinephrine to promote Racemic epinephrine to promote

vasoconstriction (trx edema), bronchodilation, vasoconstriction (trx edema), bronchodilation,

and breaking up of secretionsand breaking up of secretions

Mucomyst to break down mucus in the airwayMucomyst to break down mucus in the airway

Heparin/mucomyst nebulizer may reduce pts Heparin/mucomyst nebulizer may reduce pts

mortalitymortality

ManagementManagement

Mechanical VentilationMechanical Ventilation For resp failure associated with For resp failure associated with

inhalation injuryinhalation injury

Pts with this type of injury are at Pts with this type of injury are at

increased risk of ventilator associated increased risk of ventilator associated

injuryinjury

ManagementManagement

Conventional Mechanical Conventional Mechanical

VentilationVentilation Start with Vt of 12-15 ml/kgStart with Vt of 12-15 ml/kg

Better outcomes with non conventional Better outcomes with non conventional

modes of ventilation such as:modes of ventilation such as: Pressure limited ventilationPressure limited ventilation

Reduced rate of death with this type of Reduced rate of death with this type of

injury injury

High Frequency High Frequency VentilationVentilation

Provides o2 at lower Provides o2 at lower concentrations and adequate concentrations and adequate ventilation at reduced airway ventilation at reduced airway pressures.pressures.

Reduces barotraumaReduces barotrauma Less incidence of pneumoniaLess incidence of pneumonia Improved PaO2/FiO2 ratioImproved PaO2/FiO2 ratio

ComplicationsComplications

Most common complications are Most common complications are infection and resp failureinfection and resp failure

Barotrauma due to MVBarotrauma due to MV Late complications due to Late complications due to

inflammatory responses of the inflammatory responses of the bodybody

BronchiectasisBronchiectasis Bronchial stenosisBronchial stenosis ETT cuffs erosionETT cuffs erosion

Long Term OutcomesLong Term Outcomes

Most patients have normal lung Most patients have normal lung parenchyma return within 5 parenchyma return within 5 monthsmonths

Children heal slowlyChildren heal slowly PFT changes for up to 8 yearsPFT changes for up to 8 years Altered lung mechanicsAltered lung mechanics Impaired gas exchangeImpaired gas exchange Chest wall scarringChest wall scarring Weak resp musclesWeak resp muscles Some children never regain normal lung Some children never regain normal lung

functionfunction