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Inhalation injury from heat, smoke, or chemical irritants

Ronald P Mlcak, PhD, MBA, RRT, FAARC
Section Editors
Eileen M Bulger, MD, FACS
Marc G Jeschke, MD, PhD
Jess Mandel, MD
Deputy Editors
Kathryn A Collins, MD, PhD, FACS
Geraldine Finlay, MD


Inhalation injury is a nonspecific term that refers to damage to the respiratory tract or lung tissue from heat, smoke, or chemical irritants carried into the airway during inspiration [1]. The term is often used synonymously with smoke inhalation injury. Inhalation injury resulting from fire remains one of the leading causes of death [2]. The pathophysiology, clinical features, diagnosis, initial management, subsequent management, and special considerations of inhalation injury are reviewed here. The emergency care of thermal burns is discussed separately. (See "Emergency care of moderate and severe thermal burns in adults" and "Emergency care of moderate and severe thermal burns in children".)


Annually in the United States, an estimated 372,900 fires in residential buildings result in an average of 2530 deaths, 13,125 injuries, and $7 billion (USD) in property loss [3]. Pulmonary complications following burns and inhalation injury are responsible for up to 77 percent of the deaths, among which the majority are due to carbon monoxide poisoning [4,5]. Inhalation injury is common following burn injury and increases in incidence with the size of the burn injury and age of the patient [6,7]. In addition, inhalation injury has been shown to be an independent predictor of mortality in burn patients [8].


Inhalation injury can affect the airways as well as result in systemic toxicity [9]. The location and severity of injury depends on several factors, including the ignition source, the size and diameter of the particles in the smoke, the duration of the exposure, and the solubility of the gases [10,11]. Direct toxin damage is caused by the lower molecular weight constituents of smoke because of their pH, ability to form free radicals, and ability to reach the distal airways and alveoli [12-15]. Based upon the primary localization of the insult, inhalation injury is classified into injuries of the upper airway, the tracheobronchial system, or the lung parenchyma [9,16].

Upper airway injury — The leading injury in the upper airway (above the vocal cords) is thermal injury due to the efficient heat exchange in the oro- and nasopharynx. The immediate injury results in erythema, ulcerations, and edema. In combined burn and inhalation injury, aggressive fluid administration required to treat burn shock promotes early edema formation [17]. In addition, burns to the face and neck may cause anatomic distortion or external compression of the upper airway, complicating airway management [18]. In addition to the acute inflammation, damage of ciliary function impairs physiological clearance processes of the airway, leading to an increased risk of bacterial infection for several weeks. Furthermore, the increased production of thick secretions can cause distal airway obstruction, atelectasis, and impaired gas exchange [11,18,19].

Tracheobronchial injury — With the exception of inhalation of steam, injury to the tracheobronchial tree (figure 1) is usually caused by chemicals in smoke. However, toxic inhalation of noxious gases (eg, chlorine), liquids (eg, acid), and direct airway fire (eg, intraoperative) can also be associated with a similar process. Clinical symptoms include persistent coughing and wheezing, soot-containing airway secretions (ie, melanoptysis), increased work of breathing resulting in hypoventilation, erythema, hyperemia, and increased pulmonary shunting from lobar collapse or atelectasis [11,18].

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Literature review current through: Oct 2017. | This topic last updated: Feb 02, 2017.
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  1. Woodson CL. Diagnosis and treatment of inhalation injury. In: Total Burn Care, 4 ed, Herndon DN (Ed), 2009.
  2. emedicine.medscape.com/article/771194-overview (Accessed on November 23, 2015).
  3. www.cdc.gov/HomeandRecreationalSafety/Fire-Prevention/index.html (Accessed on October 09, 2015).
  4. Ryan CM, Schoenfeld DA, Thorpe WP, et al. Objective estimates of the probability of death from burn injuries. N Engl J Med 1998; 338:362.
  5. Darling GE, Keresteci MA, Ibañez D, et al. Pulmonary complications in inhalation injuries with associated cutaneous burn. J Trauma 1996; 40:83.
  6. Carr JA, Phillips BD, Bowling WM. The utility of bronchoscopy after inhalation injury complicated by pneumonia in burn patients: results from the National Burn Repository. J Burn Care Res 2009; 30:967.
  7. Guo F, Chen XL, Wang YJ, et al. Management of burns of over 80% of total body surface area: a comparative study. Burns 2009; 35:210.
  8. Shirani KZ, Pruitt BA Jr, Mason AD Jr. The influence of inhalation injury and pneumonia on burn mortality. Ann Surg 1987; 205:82.
  9. Woodson LC. Diagnosis and grading of inhalation injury. J Burn Care Res 2009; 30:143.
  10. Traber DL. The pathophysiology of inhalation injury. In: Total Burn Care, 4 ed, Herndon DN (Ed), 2009. p.219.
  11. Rehberg S, Maybauer MO, Enkhbaatar P, et al. Pathophysiology, management and treatment of smoke inhalation injury. Expert Rev Respir Med 2009; 3:283.
  12. Pruitt BA Jr, Cioffi WG, Shimazu T, et al. Evaluation and management of patients with inhalation injury. J Trauma 1990; 30:S63.
  13. Demling RH. Smoke inhalation injury. New Horiz 1993; 1:422.
  14. Herndon DN, Traber DL, Niehaus GD, et al. The pathophysiology of smoke inhalation injury in a sheep model. J Trauma 1984; 24:1044.
  15. Stollery DE, Jones RL, King EG. Deadspace ventilation: a significant factor in respiratory failure after thermal inhalation. Crit Care Med 1987; 15:260.
  16. Traber DL, Enkhbaatar P, Maybauer MO. The pathophysiology of inhalation injury. In: Total Burn Care, 3 ed, Herndon DN (Ed), 2007.
  17. Navar PD, Saffle JR, Warden GD. Effect of inhalation injury on fluid resuscitation requirements after thermal injury. Am J Surg 1985; 150:716.
  18. Demling RH. Smoke inhalation lung injury: an update. Eplasty 2008; 8:e27.
  19. Cox RA, Burke AS, Soejima K, et al. Airway obstruction in sheep with burn and smoke inhalation injuries. Am J Respir Cell Mol Biol 2003; 29:295.
  20. Pérez Fontan JJ. On lung nerves and neurogenic injury. Ann Med 2002; 34:226.
  21. Fontán JJ, Cortright DN, Krause JE, et al. Substance P and neurokinin-1 receptor expression by intrinsic airway neurons in the rat. Am J Physiol Lung Cell Mol Physiol 2000; 278:L344.
  22. Kraneveld AD, Nijkamp FP. Tachykinins and neuro-immune interactions in asthma. Int Immunopharmacol 2001; 1:1629.
  23. Walker PF, Buehner MF, Wood LA, et al. Diagnosis and management of inhalation injury: an updated review. Crit Care 2015; 19:351.
  24. Murakami K, Traber DL. Pathophysiological basis of smoke inhalation injury. News Physiol Sci 2003; 18:125.
  25. Cancio LC, Batchinsky AI, Dubick MA, et al. Inhalation injury: pathophysiology and clinical care proceedings of a symposium conducted at the Trauma Institute of San Antonio, San Antonio, TX, USA on 28 March 2006. Burns 2007; 33:681.
  26. Enkhbaatar P, Herndon DN, Traber DL. Use of nebulized heparin in the treatment of smoke inhalation injury. J Burn Care Res 2009; 30:159.
  27. Herlihy JP, Vermeulen MW, Joseph PM, Hales CA. Impaired alveolar macrophage function in smoke inhalation injury. J Cell Physiol 1995; 163:1.
  28. Nguyen TT, Gilpin DA, Meyer NA, Herndon DN. Current treatment of severely burned patients. Ann Surg 1996; 223:14.
  29. Al Ashry HS, Mansour G, Kalil AC, et al. Incidence of ventilator associated pneumonia in burn patients with inhalation injury treated with high frequency percussive ventilation versus volume control ventilation: A systematic review. Burns 2016; 42:1193.
  30. Centers for Disease Control and Prevention (CDC). Carbon monoxide--related deaths--United States, 1999-2004. MMWR Morb Mortal Wkly Rep 2007; 56:1309.
  31. Weaver LK. Carbon monoxide poisoning. Crit Care Clin 1999; 15:297.
  32. Prien T, Traber DL. Toxic smoke compounds and inhalation injury--a review. Burns Incl Therm Inj 1988; 14:451.
  33. Endorf FW, Gamelli RL. Inhalation injury, pulmonary perturbations, and fluid resuscitation. J Burn Care Res 2007; 28:80.
  34. Palmieri TL. Inhalation injury: research progress and needs. J Burn Care Res 2007; 28:549.
  35. Dries DJ, Endorf FW. Inhalation injury: epidemiology, pathology, treatment strategies. Scand J Trauma Resusc Emerg Med 2013; 21:31.
  36. Lee MJ, O'Connell DJ. The plain chest radiograph after acute smoke inhalation. Clin Radiol 1988; 39:33.
  37. Masanès MJ, Legendre C, Lioret N, et al. Using bronchoscopy and biopsy to diagnose early inhalation injury. Macroscopic and histologic findings. Chest 1995; 107:1365.
  38. Yamamura H, Kaga S, Kaneda K, Mizobata Y. Chest computed tomography performed on admission helps predict the severity of smoke-inhalation injury. Crit Care 2013; 17:R95.
  39. Yamamura H, Morioka T, Hagawa N, et al. Computed tomographic assessment of airflow obstruction in smoke inhalation injury: Relationship with the development of pneumonia and injury severity. Burns 2015; 41:1428.
  40. Cox RA, Jacob S, Andersen CR, et al. Integrity of airway epithelium in pediatric burn autopsies: Association with age and extent of burn injury. Burns 2015; 41:1435.
  41. Fang-Gang N, Yang C, Yu-Xuan Q, et al. Laryngeal morphologic changes and epidemiology in patients with inhalation injury: a retrospective study. Burns 2015; 41:1340.
  42. Albright JM, Davis CS, Bird MD, et al. The acute pulmonary inflammatory response to the graded severity of smoke inhalation injury. Crit Care Med 2012; 40:1113.
  43. Hassan Z, Wong JK, Bush J, et al. Assessing the severity of inhalation injuries in adults. Burns 2010; 36:212.
  44. Oh JS, Chung KK, Allen A, et al. Admission chest CT complements fiberoptic bronchoscopy in prediction of adverse outcomes in thermally injured patients. J Burn Care Res 2012; 33:532.
  45. www.ameriburn.org/BurnCenterReferralCriteria.pdf (Accessed on November 23, 2015).
  46. Weiss SM, Lakshminarayan S. Acute inhalation injury. Clin Chest Med 1994; 15:103.
  47. Principals of Critical Care, Hall JB, Schmidt GA, Wood LD (Eds), McGraw-Hill, 1992.
  48. Principles of Critical Care, Hall JB, Schmidt GA, Wood LD (Eds), McGraw-Hill, New York 1992.
  49. Rue LW 3rd, Cioffi WG, Mason AD Jr, et al. The risk of pneumonia in thermally injured patients requiring ventilatory support. J Burn Care Rehabil 1995; 16:262.
  50. https://evidencebasedpractice.osumc.edu/Documents/Guidelines/ABLSProviderManual_20101018.pdf (Accessed on March 03, 2016).
  51. Airway Management and Smoke Inhalation. In: ABLS Provider Manual, 2007. p.25.
  52. Cochran A. Inhalation injury and endotracheal intubation. J Burn Care Res 2009; 30:190.
  53. Heimbach DM, Waeckerle JF. Inhalation injuries. Ann Emerg Med 1988; 17:1316.
  54. Cancio LC, Chávez S, Alvarado-Ortega M, et al. Predicting increased fluid requirements during the resuscitation of thermally injured patients. J Trauma 2004; 56:404.
  55. Textbook of Critical Care, 3rd ed, Ayres SM, Grenvik A, Holbrook PR, Shoemaker WC (Eds), WB Saunders, 1995.
  56. Robinson NB, Hudson LD, Riem M, et al. Steroid therapy following isolated smoke inhalation injury. J Trauma 1982; 22:876.
  57. Mlcak RP. Respiratory Care. In: Total Burn Care, 4 ed, Herndon DN (Ed), 2009.
  58. Carr JA, Crowley N. Prophylactic sequential bronchoscopy after inhalation injury: results from a three-year prospective randomized trial. Eur J Trauma Emerg Surg 2013; 39:177.
  59. Miller AC, Elamin EM, Suffredini AF. Inhaled anticoagulation regimens for the treatment of smoke inhalation-associated acute lung injury: a systematic review. Crit Care Med 2014; 42:413.
  60. Elsharnouby NM, Eid HE, Abou Elezz NF, Aboelatta YA. Heparin/N-acetylcysteine: an adjuvant in the management of burn inhalation injury: a study of different doses. J Crit Care 2014; 29:182.e1.
  61. Desai MH, Mlcak R, Richardson J, et al. Reduction in mortality in pediatric patients with inhalation injury with aerosolized heparin/N-acetylcystine [correction of acetylcystine] therapy. J Burn Care Rehabil 1998; 19:210.
  62. Miller AC, Rivero A, Ziad S, et al. Influence of nebulized unfractionated heparin and N-acetylcysteine in acute lung injury after smoke inhalation injury. J Burn Care Res 2009; 30:249.
  63. Holt J, Saffle JR, Morris SE, Cochran A. Use of inhaled heparin/N-acetylcystine in inhalation injury: does it help? J Burn Care Res 2008; 29:192.
  64. Yip LY, Lim YF, Chan HN. Safety and potential anticoagulant effects of nebulised heparin in burns patients with inhalational injury at Singapore General Hospital Burns Centre. Burns 2011; 37:1154.
  65. Glas GJ, Muller J, Binnekade JM, et al. HEPBURN - investigating the efficacy and safety of nebulized heparin versus placebo in burn patients with inhalation trauma: study protocol for a multi-center randomized controlled trial. Trials 2014; 15:91.
  66. McIntire AM, Harris SA, Whitten JA, et al. Outcomes Following the Use of Nebulized Heparin for Inhalation Injury (HIHI Study). J Burn Care Res 2017; 38:45.
  67. Belenkiy SM, Buel AR, Cannon JW, et al. Acute respiratory distress syndrome in wartime military burns: application of the Berlin criteria. J Trauma Acute Care Surg 2014; 76:821.
  68. Peck MD, Harrington D, Mlcak RP, Cartotto R. Potential studies of mode of ventilation in inhalation injury. J Burn Care Res 2009; 30:181.
  69. Acute Respiratory Distress Syndrome Network, Brower RG, Matthay MA, et al. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. N Engl J Med 2000; 342:1301.
  70. Chung KK, Rhie RY, Lundy JB, et al. A Survey of Mechanical Ventilator Practices Across Burn Centers in North America. J Burn Care Res 2016; 37:e131.
  71. Sousse LE, Herndon DN, Andersen CR, et al. High tidal volume decreases adult respiratory distress syndrome, atelectasis, and ventilator days compared with low tidal volume in pediatric burned patients with inhalation injury. J Am Coll Surg 2015; 220:570.
  72. Cartotto R. Use of high frequency oscillatory ventilation in inhalation injury. J Burn Care Res 2009; 30:178.
  73. Saffle JR, Morris SE, Edelman L. Early tracheostomy does not improve outcome in burn patients. J Burn Care Rehabil 2002; 23:431.
  74. Langford RM, Armstrong RF. Algorithm for managing injury from smoke inhalation. BMJ 1989; 299:902.
  75. Porro LJ, Demling RH, Pierira CT, Herndon DN. Care of the geriatric patient. In: Total Burn Care, 4 ed, Herndon DN (Ed), 2009. p.415.
  76. Kadri SS, Miller AC, Hohmann S, et al. Risk Factors for In-Hospital Mortality in Smoke Inhalation-Associated Acute Lung Injury: Data From 68 United States Hospitals. Chest 2016; 150:1260.
  77. www.ameriburn.org/NBR.php (Accessed on November 23, 2015).
  78. You K, Yang HT, Kym D, et al. Inhalation injury in burn patients: establishing the link between diagnosis and prognosis. Burns 2014; 40:1470.
  79. Bourbeau J, Lacasse Y, Rouleau MY, Boucher S. Combined smoke inhalation and body surface burns injury does not necessarily imply long-term respiratory health consequences. Eur Respir J 1996; 9:1470.
  80. Tasaka S, Kanazawa M, Mori M, et al. Long-term course of bronchiectasis and bronchiolitis obliterans as late complication of smoke inhalation. Respiration 1995; 62:40.
  81. Slutzker AD, Kinn R, Said SI. Bronchiectasis and progressive respiratory failure following smoke inhalation. Chest 1989; 95:1349.
  82. Rosenberg M, Ramirez M, Epperson K, et al. Comparison of long-term quality of life of pediatric burn survivors with and without inhalation injury. Burns 2015; 41:721.