inhalation injury n.
Download
Skip this Video
Download Presentation
Inhalation Injury

Loading in 2 Seconds...

play fullscreen
1 / 51

Inhalation Injury - PowerPoint PPT Presentation


  • 177 Views
  • Uploaded on

Inhalation Injury. Arek Wiktor M.D. Burn Fellow University of Colorado Hospital. Outline. Background Smoke Pathophysiology Diagnosis Treatment Specific Lethal Compounds. http://spanishlakefd.com/firealarms/. Learning Objectives. Describe the pathophysiology of inhalation injury

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Inhalation Injury' - lani-atkinson


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
inhalation injury

Inhalation Injury

Arek Wiktor M.D.

Burn Fellow

University of Colorado Hospital

outline
Outline
  • Background
  • Smoke
  • Pathophysiology
  • Diagnosis
  • Treatment
  • Specific Lethal Compounds

http://spanishlakefd.com/firealarms/

learning objectives
Learning Objectives
  • Describe the pathophysiology of inhalation injury
  • How is inhalation injury diagnosed?
  • What adjunctive measures are used to treat inhalation injury?
  • What is the treatment for carbon monoxide and cyanide poisoning?
a sunday afternoon stroll thru the fire
A Sunday afternoon stroll thru the fire…

http://www.aeromedix.com/product-exec/parent_id/1/category_id/12/product_id/1074/nm/Safe_Escape_Smoke_Hood

epidemiology
Epidemiology
  • 15-30% of burn admissions have inhalation injury
  • Independent predictor of mortality, ↑ by 20%
  • Increases pneumonia risk
  • Leading diagnosis of those hospitalized and treated on 9/11, World Trade Center attack
anatomic classification
Anatomic Classification
  • Upper airway
  • Lower airway
  • Systemic toxicity

http://www.monroecc.edu/depts/pstc/backup/parasan4.htm

smoke
SMOKE
  • Variable, changes with time burning
  • Toxic gases and low ambient oxygen
  • Ingredients:

Aldehydes (formaldehyde, acrolein), ammonia, hydrogen sulfide, sulfur dioxide, hydrogen chloride, hydrogen fluoride, phosgene, nitrogen dioxide, organic nitriles

  • Particulate matter

Prien et al. Burns 1988; 14:451-460

pathophysiology
Pathophysiology
  • Cilia loss, respiratory epithelial sloughing
  • Neutrophilic infiltration
  • Atelectasis, occlusion by debris/edema
  • Pseudomembranes
  • Bacterial colonization at 72 hrs

Hubbard et al. J Trauma 1991; 31:1477-1486

secondary lung injury
Secondary Lung Injury
  • Unilateral smoke inhalation damages contralateral lung
  • Immune response, increased permeability
  • Oxygen-derived free radicals
  • NO mediated damage (chemotactic factor neuts)
  • Eiscosanoids (TXA2→TXB2)
  • Reduced phagocytosis in macrophages
systemic effects
Systemic Effects
  • Larger fluid resuscitation (2→5cc/kg/%)
  • Additive effect to burns
  • 12% pts inhalation injury alone require intubation*
  • 62% pts burn + inhalation injury intubated*

Clark et al. J Burn Care Rehabilitation, 1990; 11:121-134

diagnosis
Diagnosis
  • Clinical findings:
    • Facial burns (96%)
    • Wheezing (47%)
    • Carbonaceous sputum (39%)
    • Rales (35%)
    • Dyspnea (27%)
    • Hoarsness (26%)
    • Tachypnea (26%)
    • Cough (26%)
    • Cough and hypersecretion (26%)

DiVincenti et al. Journal of Trauma, 1971; 11:109-117

tools for diagnosis
Tools for Diagnosis
  • Bronchoscopy
  • Pulmonary function testing
  • Xenon133 lung scan
grades of inhalation injury
Grades of Inhalation Injury

Endorf and Gamelli. Journal of Burn Care and Research. 2007; 28:80-83

treatments
Treatments
  • Airway Control
  • Chest physiotherapy
  • Suctioning
  • Therapeutic bronchoscopy
  • Ventilatory strategies
  • Pharmacologic adjuncts
treatment
Treatment

Control the Airway!!!

  • ≥ 40% burn
  • Transport

http://www.burnsurgery.com/Betaweb/Modules/initial/bsinitialsec2.htm

ventilator strategies
Ventilator Strategies
  • Airway pressure release ventilation (APRV)
  • Intrapulmonary percussive ventilation (IPV)
  • High-frequency percussive ventilation (HFPV)
  • High frequency oscillatory ventilation (HFOV)
slide21
Single center, prospective randomized trial 2006-2009
  • 387 pts screened
  • 31 pts HFPV, 31 pts LTV (ARDSnet)

Chung et al. CCM; 2010: 38(10) 1970-1977

results
Results
  • No significant difference in mortality or ventilator free days
  • Significant difference in “Rescue Therapy”
results1
Results
  • No significant difference in mortality or ventilator free days
  • Significant difference in “Rescue Therapy”
p f ratio vs ventilator mode
P/F ratio vs Ventilator Mode

Chung et al. CCM; 2010: 38(10) 1970-1977

study conclusions
Study Conclusions
  • Study stopped for safety concerns in LTV group
  • Gas exchange goals met in all HFPV pts, and not in 1/3 of LTV pts
  • Trend for less barotrauma, less VAP, less sedation

“Strict application of LTV may be suboptimal in the burn population”

pharmacologic intervention
Pharmacologic Intervention

Bartley et al. Drug Design, Development and Therapy. 2008; 2: 9–16.

pharmacologic intervention1
Pharmacologic Intervention

Bartley et al. Drug Design, Development and Therapy. 2008; 2: 9–16.

airway obstructive casts
Airway Obstructive Casts
  • Mucus secretions
  • Denuded airway epithelial cells
  • Inflammatory cells
  • Fibrin
    • -Solidifies airway content
  • Several studies shown reduction in size of casts with fibrinolytic agents (tPA)
casts
Casts

Enkhbaatar et al., 2007

theory behind inhaled heparin
Theory Behind Inhaled Heparin
  • Animals with Burn + ARDS have decreased levels of antithrombin in plasma and BAL specimens
  • Heparin potentiates antithrombin by 2000x
  • Prevention of fibrin deposition in lungs
  • Heparin inhibits antihrombin’s anti-inflammatory effect - ? systemic rhAT ?
shriners protocol since 1990 560 patients treated
Shriners Protocol Since 1990 (560+ patients treated)

Mlcak RP et al. Burns, 2007;33:2-13

evidence pro
Evidence (Pro)
  • Desai et al. 1998
    • Pediatric burns (90 pts total)
    • 1985-1989 (43) vs 1990-1994 (47pts)
    • ↓ reintubation, atelectasis, and mortality
  • Miller et al. 2009
    • 30 patients over 5 years, retrospective review
    • Tx 10,000 units heparin, 20% NA, 0.5 ml AS q4 hrs
    • Survival benefit, improved LIS scores, compliance
    • Number needed to treat 2.73
evidence con
Evidence (Con)
  • Holt et al. 2008
    • Retrospective review 1999-2005, 150 pts total
    • Burn size, LOS, time on vent, mortality SAME
    • Only 68% pts had bronchoscopy,
    • Attending discretion which treatment to use
carbon monoxide co
Carbon Monoxide (CO)
  • CO from incomplete combustion
  • CO + Hb → COHb (affinity 200-250x)
  • LEFT shift of oxy-Hb curve (Haldane effect)
  • CO binding to intracellular cytochromes and metalloproteins (myoglobin)
  • “Two compartment” pharmacokinetics
      • Animal experiment 64% COHb transfusion
co toxicity symptoms
CO Toxicity Symptoms
  • “Cherry-red lips, cyanosis, retinal hemorrhage”- rare
  • CNS and Cardiovascular
    • ↑ RR, ↑HR, dysrhythmias, MI, ↓BP, coma, seizures
  • Delayed neuropsychiatric syndrome (3-240d)
    • Cognitive/personality changes/parkinsonianism
    • Spontaneous resolution
signs and symptoms
Signs and Symptoms

Weaver LK. N Engl J Med 2009;360:1217-25.

co toxicity diagnosis
CO Toxicity Diagnosis
  • Pulse oximetry false HIGH SpO2
  • Need cooximetry direct measurement of COHb
    • Older ABG analyzers (estimate off dissolved PO2)
  • MRI – lesions globus pallidus/basal ganglia/deep white matter
co toxicity diagnosis1
CO Toxicity Diagnosis
  • Pulse oximetry false HIGH SpO2
  • Need cooximetry direct measurement of COHb
    • Older ABG analyzers (estimate off dissolved PO2)
  • MRI – lesions globus pallidus/basal ganglia/deep white matter
co toxicity treatment
CO Toxicity Treatment
  • OXYGEN
  • Half-life COHb (min)
  • Carbogen – normobaric, normocapnic, hyperventilation (4.5-4.8% CO2)
  • Hyperbaric oxygen???
cyanide cn
Cyanide (CN)
  • Combustion of synthetics (plastics, foam, varnish, paints, wool, silk)
  • Binds to cytochrome c oxidase – dose dependent
  • Uncouple mitochondria
  • Aerobic → anaerobic = Lactic acid
  • Half-life 1-3 hours
cn toxicity symptoms
CN Toxicity Symptoms
  • Dyspnea
  • Tachypnea
  • Vomiting
  • Bradycardia
  • Hypotension
  • Giddiness/Coma/Siezures
  • Death

* The smell of bitter almonds on the breath suggests exposure (cannot be detected by 60% of the population)

cn toxicity diagnosis
CN Toxicity Diagnosis
  • No rapid assay
  • High lactate (>10mmol/L) (s/s, 87%/94%)
  • Metabolic acidosis
  • Elevated mixed venous saturation (<10% a-v) difference
  • High index of suspicion

** Also get: COHb and Methemoglobin levels

cn treatment
CN Treatment

Cyanokit (Hydroxocobalamin)

  • 70mg/kg dose (5g vials)
  • Combines with cyanide to from cyanocobalamin (Vit B12)
  • Red membranes/urine
  • Hypertension, Anaphylaxis
  • 5% increase COHb, interfere with HD LFTs/Cr/Fe levels
slide46
Cyanide Antidote Kit (CAK)

Amyl nitrite pearls, sodium nitrite, and sodium thiosulfate

  • Amyl nitrate and sodium nitrate induce methemoglobin
  • Methemoglobin+cyanide→releases cyanide from CC
  • Sodium thiosulfate enhances cyandide→thiocynate→renal excretion
  • Avoid nitrate portion in pts with inhalation injury (COHb >10%)
  • Vasodilation and hypotension
acquired methemolgobinemia
Acquired Methemolgobinemia
  • NO2, NO, benzene gases → oxidation of iron
  • Fe2+ → Fe3+
  • Shift curve to LEFT
  • Blood “Chocolate brown color”
  • Normal PaO2, pulse ox >85%
  • Tx: Methylene blue (1-2 mg/kg Q 30-60min)
final thoughts
Final Thoughts
  • Inhalation injury is bad
  • Support the airway
  • Frequent bronchoscopy and monitoring
  • Different ventilatory strategies
  • Adjunctive measures need further investigation
the toilet snorkel
The Toilet Snorkel

http://www.icbe.org/2006/01/18/the-toilet-snorkel/

learning objectives1
Learning Objectives
  • Describe the pathophysiology of inhalation injury
  • How is inhalation injury diagnosed?
  • What adjunctive measures are used to treat inhalation injury?
  • What is the treatment for carbon monoxide and cyanide poisoning?