Smoke inhalation injury refers to the chemical and thermal injury of the respiratory tract, as well as systemic toxicity, arising from inhalation of various irritants found in smoke. Either occupational or accidental exposure (fires, blast injuries, excessive steam, etc.) may be responsible for this type of injury. Symptoms range from mild bronchial irritation to life-threatening hypoxia and respiratory insufficiency. A thorough clinical assessment is the most important step in the diagnostic workup, followed by laboratory and imaging studies.
Presentation
Smoke inhalation injury is roughly defined as the injury of the bronchial tree and the respiratory system developing as a result of inhalation of particulate matter (soot) and chemical or thermal irritants found in smoke and accounts for up to 10,000 deaths every year in the United States [1]. Some of the most important compounds responsible for this type of injury are carbon monoxide (CO), hydrogen cyanide (HCN), free oxygen radicals (reactive oxygen species, or ROS), sulfur dioxide (SO2), benzene and other aromatic hydrocarbons, as well as ammonia (NH3) [2] [3] [4]. Despite their increasing concentrations in the industrial setting and markedly higher occupational exposure, inhalation of smoke during fires is the predominant mode of smoke related injury, as extensive nasopharyngeal irritation promotes breathing through the mouth and subsequent introduction of large amounts of smoke directly into the bronchial tree [1]. The clinical presentation depends on the amount of smoke inhaled, the concentration of gasses found in the smoke, and the ability of the individual's respiratory tract to cope with chemical and thermal injury [1] [2]. In most cases, mucosal edema and irritation eventually result in stridor, hoarseness, dyspnea, hypoxia, and tachypnea, whereas accompanying burns on the face and surrounding area is quite common [1] [3]. The presence of soot in the nasopharynx and sputum has also been documented as an important finding [3]. Loss of consciousness and respiratory insufficiency are signs of life-threatening smoke inhalation injury, in which case rapid therapeutic measures (mainly in the form of cessation of exposure to smoke) are mandatory [3] [4] [5].
Entire Body System
-
Congestive Heart Failure
If positive, the pattern may be mixed, show an alveolar infiltrate, an interstitial infiltrate, or congestive heart failure. Infiltrates are more common in the upper lung fields. [ahcmedia.com]
Respiratoric
-
Cough
[…] with corrosives Soot on lips Burns of the mucosa Mucosal oedema Pharynx Inhalation of superheated smoke or steam Carbonised material in the pharynx Pharyngeal oedema Difficulty swallowing Larynx Inhalation of superheated smoke or steam Hoarse voice Cough [derangedphysiology.com]
The most common symptom was cough, 46.7% and 73.3% in fire smoke and chronic cough group, respectively ( Table 2 ). [jtd.amegroups.com]
However, patients who have a cough with wheezing (bronchospasm), indicating that the bronchial airways are narrowed or blocked, may be given a bronchodilator to relax the muscles and increase ventilation. [medical-dictionary.thefreedictionary.com]
Your recognised location is United States (US) Chronic cough in a child This article is freely available only to users in the UK. [evidence.nhs.uk]
Increased mucus production causes coughing. [work4youlaw.com]
-
Hoarseness
No statistically significant correlation was found between intubation and any of the classic symptoms of smoke inhalation: stridor, hoarseness, drooling, and dysphagia (all p 1.0). [ncbi.nlm.nih.gov]
Clinical features of airway burns include soot in the airway, stridor, hoarseness, singed nose hair, and mucosal ulceration Historically, survivors of explosions and fires in enclosed spaces are more likely to have suffered airway burns Consequences of [derangedphysiology.com]
In most cases, mucosal edema and irritation eventually result in stridor, hoarseness, dyspnea, hypoxia, and tachypnea, whereas accompanying burns on the face and surrounding area is quite common. [symptoma.com]
Hoarseness: This may be a sign that fluids are collecting in the upper airway causing a blockage. The victim’s upper airways or vocal cords may also become affected by the smoke causing him or her to become hoarse. [work4youlaw.com]
Tissue irritation of the throat and lungs may appear as noisy breathing, coughing, hoarseness, black or gray spittle, and fluid in the lungs. Asphyxiation is apparent from shortness of breath and blue-gray or cherry-red skin color. [medical-dictionary.thefreedictionary.com]
-
Stridor
Clinical features of airway burns include soot in the airway, stridor, hoarseness, singed nose hair, and mucosal ulceration Historically, survivors of explosions and fires in enclosed spaces are more likely to have suffered airway burns Consequences of [derangedphysiology.com]
No statistically significant correlation was found between intubation and any of the classic symptoms of smoke inhalation: stridor, hoarseness, drooling, and dysphagia (all p 1.0). [ncbi.nlm.nih.gov]
In most cases, mucosal edema and irritation eventually result in stridor, hoarseness, dyspnea, hypoxia, and tachypnea, whereas accompanying burns on the face and surrounding area is quite common. [symptoma.com]
Steroids are not recommended in the treatment of inhalation injury but may have a role in preventing post-extubation stridor caused by laryngeal oedema, although there have been no specific studies in burn patients. [academic.oup.com]
The same study suggested that stridor, hoarseness, drooling, and dysphagia are not predictive of the need for intubation. [clinicaladvisor.com]
-
Dyspnea
In most cases, mucosal edema and irritation eventually result in stridor, hoarseness, dyspnea, hypoxia, and tachypnea, whereas accompanying burns on the face and surrounding area is quite common. [symptoma.com]
In some cases, there is a lower respiratory tract injury that results in wheezing, coughing, rhonchi, and dyspnea, among other symptoms. [pulgininorton.com]
Chemical pneumonitis, asphyxiation, and physical trauma to the respiratory passages may occur. observations Characteristics include irritation of the upper respiratory tract, singed nasal hairs, dyspnea, hypoxia, dusty gray sputum, rhonchi, rales, restlessness [medical-dictionary.thefreedictionary.com]
In a fire environment, victims typically breathe through their mouths as a result of nasopharyngeal edema and dyspnea. [clinicaladvisor.com]
[…] inhalation effects if exposed to fire in a confined space assess for airway injury and respiratory compromise — features of airway burns — upper airways: singed nasal airs, facial burns, soot in nose and pharynx, stridor, hoarseness — lower airways: wheeze, dyspnea [lifeinthefastlane.com]
-
Rales
Chemical pneumonitis, asphyxiation, and physical trauma to the respiratory passages may occur. observations Characteristics include irritation of the upper respiratory tract, singed nasal hairs, dyspnea, hypoxia, dusty gray sputum, rhonchi, rales, restlessness [medical-dictionary.thefreedictionary.com]
Note rhonchi, rales, wheeze and use of accessory muscles of respiration. Facial burns show nearness to the fire. Other burns demonstrate an inability to escape. [patient.info]
Hypoxia, rales and rhonchi occur only in those with the most severe injuries. 1 An admission chest X-ray is also a poor predictor, but is important for the baseline of evaluations. 6, 24 Figure 1 An algorithm to manage the patients at risk for inhalation [dovepress.com]
Gastrointestinal
-
Choking
The survivors from fire accidents may inhale toxic combustion products generated by fires and present with symptoms that resemble asthma, such as severe cough, sputum, choking sensation, and wheezing ( 2 - 4 ). [jtd.amegroups.com]
If the patient has respiratory distress or mental status changes, they may also be intubated to enable the staff to help with breathing, to suction mucus, and keep the patient from choking on secretions. [emedicinehealth.com]
-
Gagging
If the patient has an alteration of consciousness or loss of the gag reflex, intubation is indicated for airway protection and to provide 100% oxygen. A pediatric flexible fiberoptic bronchoscope requires a 4-mm tube orifice to pass. [ahcmedia.com]
Cardiovascular
-
Chest Pain
Primary endpoints were death, chest pain, and adverse changes in cardiopulmonary hemodynamics (arrhythmia, arterial blood pressure, electrocardiographic [ST segment] changes, and peak inspiratory pressure). [ncbi.nlm.nih.gov]
But they often include Coughing and phlegm A scratchy throat Irritated sinuses Shortness of breath Chest pain or tightness Headaches Stinging eyes A runny nose If you have a chronic heart or lung problem, an inhalation injury can make it worse. [medlineplus.gov]
Indications for treatment with methylene blue as follows: Alteration in mental status Acidosis Electrocardiographic (ECG) changes Ischemic chest pain Methemoglobin levels lower than 30% may not require treatment, depending on the patient's cardiorespiratory [emedicine.medscape.com]
-
Cyanosis
Note whether there is cyanosis. Note whether the chest wall moves normally and symmetrically. Assess the airway but, if there is any risk of cervical spine trauma, be careful with the neck. Note respiratory rate. Listen to the chest. [patient.info]
(Table 2) Table 2 Clinical Manifestations of Carbon Monoxide Poisoning General Signs of Inhalational Injury Burns of the neck and face Singed nasal hair Soot-laden oral and nasal secretions Cough, hoarseness, dysphonia, and stridor Tachypnea, cyanosis [clinicaladvisor.com]
The skin should be checked for cyanosis, cherry red color, or brownish tinge. The inhaled toxin may lead to necrosis, ulcers, or frank burns on exposed skin. Bullae formation on dependent parts is particularly common in carbon monoxide poisoning. [ahcmedia.com]
-
Tachycardia
Tachycardia, increased cardiac output, arrhythmias, and cardiac ischemia may also be evident. Retinal hemorrhages and cherry-red skin color, the “classic” manifestations of carbon monoxide poisoning, are relatively uncommon. [clinicaladvisor.com]
[…] icteric sclera, neck supple, no lymphadenopathy, no mass/carotid bruit, unable to assess oral cavity due to presence of endotracheal tube, dry and mild swollen lips Cardiovascular : S1/S2 with regular rate and rhythm, no murmurs/rubs/gallops, sinus tachycardia [ispub.com]
In small doses, headache, confusion, anxiety, dizziness, nausea, palpitations, tachycardia, tachypnea, and combativeness all may be found. [ahcmedia.com]
Face, Head & Neck
-
Facial Burn
Intubation was positively correlated with physical examination findings of soot in the oral cavity (p 0.001), facial burns (p 0.025), and body burns (p 0.025). [ncbi.nlm.nih.gov]
"Acute management of the upper airway in facial burns and smoke inhalation." Archives of Surgery 111.7 (1976): 744-749. Gaissert, Henning A., Robert H. Lofgren, and Hermes C. Grillo. "Upper airway compromise after inhalation injury. [derangedphysiology.com]
Furthermore, findings such as facial burns, soot in the nasopharynx and sputum, as well as voice changes are highly indicative signs of smoke inhalation injury, which is why the role of a proper physical exam must not be overlooked. [symptoma.com]
Facial burns show nearness to the fire. Other burns demonstrate an inability to escape. Investigations [ 10 ] A baseline CXR may be useful for comparison if pulmonary oedema ensues. [patient.info]
Neurologic
-
Irritability
Smoke inhalation injury refers to the chemical and thermal injury of the respiratory tract, as well as systemic toxicity, arising from inhalation of various irritants found in smoke. [symptoma.com]
Smoke is heterogeneous and unique to each fire; it comprises particulates, respiratory irritants and systemic toxins as well as heat, all contributing to the pathological insult. [ncbi.nlm.nih.gov]
It is more common for smoke to cause mild throat irritation, which is not a sign of a significant burn to the airway. [uhs.berkeley.edu]
-
Confusion
As many patients develop altered consciousness and confusion, a heterogeneous anamnesis (friends, relatives, or coworkers who were exposed together with the patient) can be of great help in identifying the circumstances that preceded the development of [symptoma.com]
Smoke inhalation can cause a host of other injuries, including: Difficulty breathing Coughing Nose or throat irritation Nausea Headaches Fainting Confusion Seizures Coma Corneal and other eye damage If negligence played any kind of role in a fire, the [winstonbriggslaw.com]
Changes in mental status: The presence of chemicals and low levels of oxygen can cause symptoms such as dizziness, confusion, seizures or even lack of consciousness and fainting. [work4youlaw.com]
Dyspnoea, decreased level of consciousness, or confusion Hypoxaemia (low pulse oximetry saturation or arterial oxygen tension) or increased carbon monoxide levels ( 2%) Pathophysiologic consequences of airway burns Mechanisms organised by pathophysiological [derangedphysiology.com]
More significant exposures are associated with confusion, loss of consciousness, and possible death. Tachycardia, increased cardiac output, arrhythmias, and cardiac ischemia may also be evident. [clinicaladvisor.com]
-
Altered Mental Status
Pulmonary injury should be considered in any patient with history of burn in a closed space, loss of consciousness, or altered mental status. [totalburncare.com]
Carboxyhemoglobin and methemoglobin levels : This level should be obtained in all smoke inhalation victims with respiratory distress, altered mental status, low blood pressure, seizures, fainting, and blood pH changes. [webmd.com]
mental status to hypotension, arrhythmia, and cardiovascular collapse followed by shock. [emedicine.medscape.com]
Carboxyhemoglobin and methemoglobin levels: These levels should be measured in all smoke inhalation victims with respiratory distress, altered mental status, low blood pressure, seizures, fainting, and blood pH changes. [emedicinehealth.com]
Ethanol levels should be determined, particularly if the patient has any altered mental status. Likewise, toxicology screens may be appropriate for some patients. Cyanide levels often are unavailable or greatly delayed. [ahcmedia.com]
-
Dizziness
Common side effects of carbon monoxide poisoning include: Dizziness Headaches Nausea Vomiting Carbon Monoxide is especially dangerous because it can not be smelled (odorless) or seen (colorless). [skylawgroup.com]
Changes in mental status: The presence of chemicals and low levels of oxygen can cause symptoms such as dizziness, confusion, seizures or even lack of consciousness and fainting. [work4youlaw.com]
[…] respiratory distress Nausea and vomiting Neurologic findings, including loss of consciousness Carboxyhemoglobin 10% within the first hour Clinical Manifestations of Carbon Monoxide Poisoning With mild exposure, neurologic symptoms include headache, dizziness [clinicaladvisor.com]
In small doses, headache, confusion, anxiety, dizziness, nausea, palpitations, tachycardia, tachypnea, and combativeness all may be found. [ahcmedia.com]
-
Personality Change
Within 1 month, he developed neuropsychiatric problems including toxic encephalopathy, cognitive disorder, depression symptoms and personality change. [ncbi.nlm.nih.gov]
Within 1 month, he developed neuropsychiatric problems including toxic encephalopathy, cognitive disorder, depression symptoms and personality change. [casereports.bmj.com]
Workup
The need for rapid treatment necessitates a prompt clinical workup by the physician, but in order to gain sufficient evidence for a presumptive diagnosis, a detailed patient history, and a thorough physical examination must be performed. As many patients develop altered consciousness and confusion, a heterogeneous anamnesis (friends, relatives, or coworkers who were exposed together with the patient) can be of great help in identifying the circumstances that preceded the development of symptoms [4]. Furthermore, findings such as facial burns, soot in the nasopharynx and sputum, as well as voice changes are highly indicative signs of smoke inhalation injury, which is why the role of a proper physical exam must not be overlooked [1]. As soon as clinical suspicion is raised, both laboratory and imaging studies should be performed [3] [6]. A complete blood count (CBC), pulse oximetry, and arterial blood gas (ABG) analysis are vital for evaluating the status of tissue perfusion and oxygen content, whereas computed tomography (CT) of the thorax is the recommended imaging modality [1] [3] [4] [5]. Pulmonary function testing (spirometry), electrocardiography (ECG), and measurements of carboxyhemoglobin are also a part of the initial workup, but in order to make a definite diagnosis and establish the severity of smoke inhalation injury, fiberoptic bronchoscopy (FOP), although being an invasive procedure, is the gold standard [2] [6].
X-Ray
-
Atelectasis
Although he survived the acute stages following injury, his pulmonary function subsequently deteriorated with a damaged trachea and bronchi, repeated attacks of pneumonia, atelectasis, pneumothorax and lung fibrosis, leading to death with hypercapnia [ncbi.nlm.nih.gov]
Subglottic stenosis, bronchiectasis, pulmonary oedema and atelectasis can occur. [patient.info]
Chronic bronchitis, bronchiolitis obliterans, bronchial stenosis, lung fibrosis, bronchiectasis and atelectasis have been reported to be resulted from exposure to fire smoke and subsequent inflammatory consequences ( 16 ). [jtd.amegroups.com]
There is limited evidence in victims of smoke inhalation that these techniques limit atelectasis and barotrauma, 16–18 but it is a common sense strategy to avoid ventilator-induced lung injury in these at-risk patients A regimen of aerosolized heparin [academic.oup.com]
The use of percutaneous cupping and postural drainage seem reasonable to clear airways of cellular debris and soot, thereby preventing atelectasis and obstruction. [emedicine.medscape.com]
-
Pulmonary Infiltrate
On ICU day 5, she was weaned from vasopressor support, her chest x-ray showed decreasing bilateral pulmonary infiltrates, and she had a decreased FiO2 requirement with increasing PaO2/FiO2 ratio of 210. [ispub.com]
Although some authors reported that bronchial wall thickening was sometimes found on initial chest radiographs, patients with inhalation injuries often have a normal chest radiograph at initial stages. 38 In contrast, the presence of pulmonary infiltrates [dovepress.com]
-
Bilateral Pulmonary Infiltrate
On ICU day 5, she was weaned from vasopressor support, her chest x-ray showed decreasing bilateral pulmonary infiltrates, and she had a decreased FiO2 requirement with increasing PaO2/FiO2 ratio of 210. [ispub.com]
Serum
-
Hypercapnia
Although he survived the acute stages following injury, his pulmonary function subsequently deteriorated with a damaged trachea and bronchi, repeated attacks of pneumonia, atelectasis, pneumothorax and lung fibrosis, leading to death with hypercapnia [ncbi.nlm.nih.gov]
Burns 2007 ; 33 : 2 – 13 17 Permissive hypercapnia as a ventilatory strategy in burned children: effect on barotrauma, pneumonia, and mortality. [academic.oup.com]
[…] instituting ventilation a balance has to be struck between providing sufficient oxygenation and causing as little collateral harm as possible. [ 5 ] Lower tidal volumes and plateau pressures with high positive end-expiratory pressure (PEEP) and permissive hypercapnia [patient.info]
Permissive hypercapnia can be used if the targeted pH is above 7.25. [dovepress.com]
Treatment
This case review details the treatment of a 32-year-old woman who was at 36 weeks of gestation on admission to the Evans-Haynes Burn Center. The authors will report her injuries and the course of treatment. [ncbi.nlm.nih.gov]
Prognosis
Moreover, no worldwide consensus criteria exist for its diagnosis, severity grading, and prognosis. Therapeutic approaches are highly variable depending on the country and burn centre or hospital. [ncbi.nlm.nih.gov]
Prognosis Although the outcome depends of the severity of the smoke inhalation and the severity of any accompanying burns or other injuries, with prompt medical treatment, the prognosis for recovery is good. [medical-dictionary.thefreedictionary.com]
Due to its relative rarity, information on prognosis is not abundant. [patient.info]
What is the prognosis for patients managed in the recommended ways? Neurologic Sequelae of Smoke Inhalation Cognitive sequelae have been reported in nearly half of CO poisoning victims six weeks following exposure. [clinicaladvisor.com]
Etiology
Etiology and consequences of respiratory failure in thermally injured patients. Am J Surg 1993;166:592-597. 20. Peters WJ. Inhalation injury caused by the products of combustion. Can Med Assoc J 1981;125:249. 21. Rue LW, Cioffi WG, Mason AD, et al. [ahcmedia.com]
Epidemiology
We aimed to investigate the epidemiology and outcomes of this select patient population. [ncbi.nlm.nih.gov]
الصفحة 441 - Becklake MR: Asbestos-related diseases of the lung and other organs: Their epidemiology and implications for clinical practice. الصفحة 279 - Intravascular activation of complement and acute lung injury. [books.google.com]
In contrast, Akgun & Gorguner (2010) report that acute lung injury due to inhalation of flaming gas seems to be epidemiologically more common among miners, because of the combination of inescapable confinement and limited fresh gas supply. [derangedphysiology.com]
Epidemiology Most burns managed in hospitals are from scalds (54%) and contact burns (23%). [academic.oup.com]
A further 19% were due to a combination of burns and being overcome by gas or smoke. [ 1 ] Epidemiology [ 2, 3 ] A study from North West England found that the overall admission rate to hospital for smoke inhalation or burns was 0.29/1,000 population [patient.info]
Pathophysiology
Treatment strategies should be planned based on these pathophysiological aspects. [ncbi.nlm.nih.gov]
Prevention
Primary prevention is the most important way to reduce the poor outcome from significant exposure. [ncbi.nlm.nih.gov]
How can smoke inhalation be prevented? To prevent fires, make sure that electrical wiring, chimneys, wood stoves, and space heaters are working properly. Use flammable liquids safely and store them in a locked area out of the reach of children. [uhs.berkeley.edu]
References
- Rehberg S, Maybauer MO, Enkhbaatar P, Maybauer DM, Yamamoto Y, Traber DL. Pathophysiology, management and treatment of smoke inhalation injury. Expert Rev Respir Med. 2009;3(3):283-297.
- Langford RM, Armstrong RF. Algorithm for managing injury from smoke inhalation. BMJ. 1989;299(6704):902-905.
- Dries DJ, Endorf FW. Inhalation injury: epidemiology, pathology, treatment strategies. Scand J Trauma Resusc Emerg Med. 2013;21:31.
- Walker PF, Buehner MF, Wood LA, et al. Diagnosis and management of inhalation injury: an updated review. Crit Care. 2015;19:351.
- Gill P, Martin RV. Smoke inhalation injury. BJA Education. 2015;15(3):143–148.
- Demling RH. Smoke Inhalation Lung Injury: An Update. Eplasty. 2008;8:e27.