JBUR-4582; No. of Pages 7 burns xxx (2015) xxx–xxx
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/burns
Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study Ning Fang-Gang a,b, Chang Yang a,b, Qiu Yu-Xuan a,b, Rong Yan-Hua a, Du Wei-Li a, Wang Cheng a, Wen Chun-Quan a, Zhang Guo-An a,* a b
Department of Burns, Beijing Jishuitan Hospital, No. 31 Xinjiekou East District, Beijing 100035, China Peking University Health Science Center, Xueyuan Rd. Haidian District, Beijing 100083, China
article info
abstract
Article history:
Background and objectives: Laryngeal morphologic changes are important in risk assessment
Accepted 2 February 2015
of upper airway obstruction (UAO) after inhalation injury. This retrospective study evaluates the clinical application of laryngeal burn classification system.
Keywords:
Materials and methods: Clinical data from January 1999 to June 2013 were analyzed retro-
Inhalation injury
spectively. The following data collected: age, gender, total burned surface area (TBSA), third-
Laryngeal morphologic changes
degree burn surface area, co-morbid injuries and complications, proportion of patients with
Laryngeal burns
tracheotomy, interval between tracheotomy and injury, incidence and mortality of UAO,
Upper airway obstruction
and reasons for death. Results: Four hundred and forty-three patients were included; 405 patients underwent multiple fibro-laryngoscopic observation, of which I, II and III types of laryngeal burns were present in 49.9, 38.0, and 12.1% patients, respectively. Laryngeal burn severity was related to TBSA and third-degree burn surface area. Overall tracheotomy rate (n = 443) was 37.02%. The mean interval between tracheotomy and injury was 10.0 12.17 h. Over 75% patients underwent tracheotomy within 12 h. Compared with moderate inhalation burn group, the severe inhalation burn group showed a significantly higher tracheotomy rate within 12 h and a significantly shorter interval between tracheotomy and injury. Patient mortality was significantly related to the severity of inhalation injury. Conclusion: The classification system of the morphologic laryngeal changes in laryngeal burn patients could effectively evaluate the UAO risk, enable earlier prophylactic tracheotomy after UAO onset, reduce surgical difficulties and risks, decrease clinical pressure of doctors, and prevent UAO. Laryngeal burn severity was related to TBSA and mortality and may be an important severity and prognosis indicator of inhalation injury. # 2015 Published by Elsevier Ltd and ISBI.
* Corresponding author. Tel.: +86 10 58516361. E-mail address: [email protected] (Z. Guo-An). http://dx.doi.org/10.1016/j.burns.2015.02.003 0305-4179/# 2015 Published by Elsevier Ltd and ISBI.
Please cite this article in press as: Fang-Gang N, et al. Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study. Burns (2015), http://dx.doi.org/10.1016/j.burns.2015.02.003
JBUR-4582; No. of Pages 7
2
burns xxx (2015) xxx–xxx
1.
Introduction
Inhalation injury remains a major contributor to mortality, the risk of which is comparable to infection and shock. Severe burns with large surface area are frequently combined with inhalation injury [1–3]. Inhalation injury may cause upper airway obstruction (UAO), and a combination of UAO and pulmonary interstitial edema may lead to acute respiratory distress syndrome (ARDS). UAO occurs in 20–33% of hospitalized patients with inhalation injury [4]. Because of the location and structure of the larynx in the upper airway, laryngeal injury is an important cause of UAO. Moreover, the larynx has significant heat-retention ability [5–7], which means that the larynx can take in more heat than the trachea in the event of an inhalation injury. This may in turn cause more serious injuries in the larynx than in other areas. The larynx is the narrowest part of the upper airway, which increases the risk of UAO in the larynx than in other parts of the airway. Pathological changes of the upper airway were primarily characterized by edema, and tissues in the upper glottis were most often involved in edema of the airway. Edema occurring in three areas (aryepiglottic fold, arytenoid juga, and interstitial arytenoidal cartilage) have been frequently observed using a fibro-laryngoscope and was confirmed to be the cause of airway obstruction [8]. In addition, progression from moderate laryngeal edema to complete airway obstruction may occur in a very short time [4]. For patients with a larger burn area, fluid resuscitation would also accelerate the development of laryngeal edema. Therefore, changes in the larynx are reflective of the severity of inhalation injury and related to the severity of burns. One of the most effective treatments for patients at risk of UAO is to provide an artificial airway opening (tracheotomy) without delay. This method has been widely used in patients at risk of airway obstruction. Artificial airway opening methods include tracheal intubation and tracheotomy, and in China, tracheotomy is the most commonly used method. Tracheotomy relieves the airway obstruction by reducing laryngeal edema and easing discharge of sputum and other secretions. This will ensure that the airway is unobstructed during the subsequent surgery. However, tracheotomy in inhalation injury increases the burden of health care practitioners, adds to the suffering of the patients, increases the risk of infection and pneumonia, and may even result in cervical scar. The decision to perform a tracheotomy is made for patients with inhalation injury with manifestations of respiratory failure and UAO, which include severe hypoxemia, dyspnea, and moist rales all over the lungs. However, it is even more difficult to accurately evaluate the risk of UAO and make a clinical decision for patients without respiratory failure and UAO manifestations. Facial and cervical edema develops rapidly within 72 h, and this may result in surgical complications. A relatively more accurate risk assessment of the upper airway is needed to help doctors make treatment decisions on whether to take prophylactic tracheotomy before the onset of UAO. This may significantly reduce the difficulties and risks associated with the surgery. Morphologic laryngeal changes are important in the risk assessment of UAO after inhalation injury. Zhang et al.
successfully developed a risk assessment for UAO, based on multiple fibro-laryngoscopic observations of 164 inhalation injury patients from 1993 to 1998 [9], to help doctors make a judgment on performing a prophylactic tracheotomy [11,12]. The burn center of Beijing Jishuitan Hospital now covers 20 million residents of Beijing and adjacent provinces. We evaluated the risk of UAO in patients with inhalation injury using a fibro-laryngoscope based on the risk assessment proposed by Zhang et al. [9]. Prophylactic tracheotomy was performed in patients with confirmed UAO risk. In this retrospective study, we analyzed the clinical data of 14 years (January 1999–June 2013).
2.
Patients and methods
2.1.
Patients
All patients who presented with inhalation injury with laryngeal burns between January 2009 and June 2013 were included in the study, which included a total of 443 patients; 405 of these patients underwent multiple fibro-laryngoscopic observations every 6–12 h until the risk of UAO was excluded. If the risk of obstruction persisted, the decision of tracheotomy was made. Other patients with manifestations of respiratory failure and UAO that included severe hypoxemia, dyspnea, and moist rales over the lungs received immediate tracheotomy without fibro-laryngoscopic observations.
2.2. Morphologic laryngeal changes in patients with laryngeal burns Based on the clinical symptoms and fibro-laryngoscopic observations of inhalation injury patients who presented with laryngeal burns, the burns were classified into three types (Fig. 1) [10,11]: 1. I type (mild): Patients with mild laryngeal discomfort and pharyngalgia. Fibro-laryngoscopic observations showed laryngeal congestion and hyperemia within 12 h after the burn. Mild edema and pink areas with small blisters were distributed occasionally in the mucosa. The function of the larynx was still good. 2. II type (moderate): Patients showed discomfort while swallowing, and cough was observed. Fibro-laryngoscopic observations suggested laryngeal mucosa with diffused congestion, punctate hemorrhages, edema, and blister formation. The color of the mucosa was between pink and white, with blisters of different sizes. Edema was also observed in the submucosal laryngeal tissues. Laryngeal movement was restricted. 3. III type (severe): Patients showed choking, hoarseness, severe cough, salivation, tachypnea, stridor and difficulty breathing when lying down. Fibro-laryngoscopic observations showed pale or yellow-white laryngeal mucosa with edema. Enhanced secretion and blackening of the mucosa were observed. Edema in mucosal and submucosal tissues developed rapidly over time, with occasional blisters and extensive secretion or formation of a layer of
Please cite this article in press as: Fang-Gang N, et al. Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study. Burns (2015), http://dx.doi.org/10.1016/j.burns.2015.02.003
JBUR-4582; No. of Pages 7 burns xxx (2015) xxx–xxx
3
Fig. 1 – Fibro-laryngoscopic observations of laryngeal burns. (A) Laryngeal mucosal congestion, I type; (B) blister formation in the larynx, II type; (C) laryngeal edema, II type; (D) epiglottis stiffness, III type.
pseudo-membrane. Laryngeal tissues were stiff, with anatomic signs unclear. The glottis was swollen like a ball.
2.3.
Treatment of patients with laryngeal burns
1. I type (mild): Treatment was aimed at protecting the laryngeal mucosa and relieving clinical symptoms to promote the recovery of laryngeal burns. Sedative, salbutamol and inhaled corticosteroids were administrated to prevent laryngospasm and inflammation, if necessary. 2. II type (moderate): The therapy goals of treating edematous type included preventing laryngeal obstruction, postponing development of laryngeal injury, and promoting recovery and healing of laryngeal injury. These methods were intended to protect the laryngeal mucosa, alleviate congestion, exudation and edema, and reduce the development of blisters and the incidence of laryngeal obstruction. Fibrolaryngoscopic observation was conducted to monitor the patient. Once a laryngeal obstruction was inevitable, immediate tracheotomy was undertaken. 3. III type (severe): Tracheotomy was undertaken immediately once diagnosed in order to avoid death due to asphyxiation resulting from laryngeal obstruction. Other treatments, including aerosol inhalation, should also be administered to prevent or reduce the occurrence of co-morbid injuries and complications.
2.4.
The clinical condition of tracheotomy
The decision of tracheotomy was based on the results of fibrolaryngoscopic observations. Tracheotomy was performed once blisters in the laryngeal pharynx exceeded the glottis or burn area was >33%. Movement of the epiglottis was restricted. Over half of the glottis remained covered even while breathing or speaking. The opening and closing of the vocal cords were restricted with an open angle
Available online at www.sciencedirect.com
ScienceDirect journal homepage: www.elsevier.com/locate/burns
Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study Ning Fang-Gang a,b, Chang Yang a,b, Qiu Yu-Xuan a,b, Rong Yan-Hua a, Du Wei-Li a, Wang Cheng a, Wen Chun-Quan a, Zhang Guo-An a,* a b
Department of Burns, Beijing Jishuitan Hospital, No. 31 Xinjiekou East District, Beijing 100035, China Peking University Health Science Center, Xueyuan Rd. Haidian District, Beijing 100083, China
article info
abstract
Article history:
Background and objectives: Laryngeal morphologic changes are important in risk assessment
Accepted 2 February 2015
of upper airway obstruction (UAO) after inhalation injury. This retrospective study evaluates the clinical application of laryngeal burn classification system.
Keywords:
Materials and methods: Clinical data from January 1999 to June 2013 were analyzed retro-
Inhalation injury
spectively. The following data collected: age, gender, total burned surface area (TBSA), third-
Laryngeal morphologic changes
degree burn surface area, co-morbid injuries and complications, proportion of patients with
Laryngeal burns
tracheotomy, interval between tracheotomy and injury, incidence and mortality of UAO,
Upper airway obstruction
and reasons for death. Results: Four hundred and forty-three patients were included; 405 patients underwent multiple fibro-laryngoscopic observation, of which I, II and III types of laryngeal burns were present in 49.9, 38.0, and 12.1% patients, respectively. Laryngeal burn severity was related to TBSA and third-degree burn surface area. Overall tracheotomy rate (n = 443) was 37.02%. The mean interval between tracheotomy and injury was 10.0 12.17 h. Over 75% patients underwent tracheotomy within 12 h. Compared with moderate inhalation burn group, the severe inhalation burn group showed a significantly higher tracheotomy rate within 12 h and a significantly shorter interval between tracheotomy and injury. Patient mortality was significantly related to the severity of inhalation injury. Conclusion: The classification system of the morphologic laryngeal changes in laryngeal burn patients could effectively evaluate the UAO risk, enable earlier prophylactic tracheotomy after UAO onset, reduce surgical difficulties and risks, decrease clinical pressure of doctors, and prevent UAO. Laryngeal burn severity was related to TBSA and mortality and may be an important severity and prognosis indicator of inhalation injury. # 2015 Published by Elsevier Ltd and ISBI.
* Corresponding author. Tel.: +86 10 58516361. E-mail address: [email protected] (Z. Guo-An). http://dx.doi.org/10.1016/j.burns.2015.02.003 0305-4179/# 2015 Published by Elsevier Ltd and ISBI.
Please cite this article in press as: Fang-Gang N, et al. Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study. Burns (2015), http://dx.doi.org/10.1016/j.burns.2015.02.003
JBUR-4582; No. of Pages 7
2
burns xxx (2015) xxx–xxx
1.
Introduction
Inhalation injury remains a major contributor to mortality, the risk of which is comparable to infection and shock. Severe burns with large surface area are frequently combined with inhalation injury [1–3]. Inhalation injury may cause upper airway obstruction (UAO), and a combination of UAO and pulmonary interstitial edema may lead to acute respiratory distress syndrome (ARDS). UAO occurs in 20–33% of hospitalized patients with inhalation injury [4]. Because of the location and structure of the larynx in the upper airway, laryngeal injury is an important cause of UAO. Moreover, the larynx has significant heat-retention ability [5–7], which means that the larynx can take in more heat than the trachea in the event of an inhalation injury. This may in turn cause more serious injuries in the larynx than in other areas. The larynx is the narrowest part of the upper airway, which increases the risk of UAO in the larynx than in other parts of the airway. Pathological changes of the upper airway were primarily characterized by edema, and tissues in the upper glottis were most often involved in edema of the airway. Edema occurring in three areas (aryepiglottic fold, arytenoid juga, and interstitial arytenoidal cartilage) have been frequently observed using a fibro-laryngoscope and was confirmed to be the cause of airway obstruction [8]. In addition, progression from moderate laryngeal edema to complete airway obstruction may occur in a very short time [4]. For patients with a larger burn area, fluid resuscitation would also accelerate the development of laryngeal edema. Therefore, changes in the larynx are reflective of the severity of inhalation injury and related to the severity of burns. One of the most effective treatments for patients at risk of UAO is to provide an artificial airway opening (tracheotomy) without delay. This method has been widely used in patients at risk of airway obstruction. Artificial airway opening methods include tracheal intubation and tracheotomy, and in China, tracheotomy is the most commonly used method. Tracheotomy relieves the airway obstruction by reducing laryngeal edema and easing discharge of sputum and other secretions. This will ensure that the airway is unobstructed during the subsequent surgery. However, tracheotomy in inhalation injury increases the burden of health care practitioners, adds to the suffering of the patients, increases the risk of infection and pneumonia, and may even result in cervical scar. The decision to perform a tracheotomy is made for patients with inhalation injury with manifestations of respiratory failure and UAO, which include severe hypoxemia, dyspnea, and moist rales all over the lungs. However, it is even more difficult to accurately evaluate the risk of UAO and make a clinical decision for patients without respiratory failure and UAO manifestations. Facial and cervical edema develops rapidly within 72 h, and this may result in surgical complications. A relatively more accurate risk assessment of the upper airway is needed to help doctors make treatment decisions on whether to take prophylactic tracheotomy before the onset of UAO. This may significantly reduce the difficulties and risks associated with the surgery. Morphologic laryngeal changes are important in the risk assessment of UAO after inhalation injury. Zhang et al.
successfully developed a risk assessment for UAO, based on multiple fibro-laryngoscopic observations of 164 inhalation injury patients from 1993 to 1998 [9], to help doctors make a judgment on performing a prophylactic tracheotomy [11,12]. The burn center of Beijing Jishuitan Hospital now covers 20 million residents of Beijing and adjacent provinces. We evaluated the risk of UAO in patients with inhalation injury using a fibro-laryngoscope based on the risk assessment proposed by Zhang et al. [9]. Prophylactic tracheotomy was performed in patients with confirmed UAO risk. In this retrospective study, we analyzed the clinical data of 14 years (January 1999–June 2013).
2.
Patients and methods
2.1.
Patients
All patients who presented with inhalation injury with laryngeal burns between January 2009 and June 2013 were included in the study, which included a total of 443 patients; 405 of these patients underwent multiple fibro-laryngoscopic observations every 6–12 h until the risk of UAO was excluded. If the risk of obstruction persisted, the decision of tracheotomy was made. Other patients with manifestations of respiratory failure and UAO that included severe hypoxemia, dyspnea, and moist rales over the lungs received immediate tracheotomy without fibro-laryngoscopic observations.
2.2. Morphologic laryngeal changes in patients with laryngeal burns Based on the clinical symptoms and fibro-laryngoscopic observations of inhalation injury patients who presented with laryngeal burns, the burns were classified into three types (Fig. 1) [10,11]: 1. I type (mild): Patients with mild laryngeal discomfort and pharyngalgia. Fibro-laryngoscopic observations showed laryngeal congestion and hyperemia within 12 h after the burn. Mild edema and pink areas with small blisters were distributed occasionally in the mucosa. The function of the larynx was still good. 2. II type (moderate): Patients showed discomfort while swallowing, and cough was observed. Fibro-laryngoscopic observations suggested laryngeal mucosa with diffused congestion, punctate hemorrhages, edema, and blister formation. The color of the mucosa was between pink and white, with blisters of different sizes. Edema was also observed in the submucosal laryngeal tissues. Laryngeal movement was restricted. 3. III type (severe): Patients showed choking, hoarseness, severe cough, salivation, tachypnea, stridor and difficulty breathing when lying down. Fibro-laryngoscopic observations showed pale or yellow-white laryngeal mucosa with edema. Enhanced secretion and blackening of the mucosa were observed. Edema in mucosal and submucosal tissues developed rapidly over time, with occasional blisters and extensive secretion or formation of a layer of
Please cite this article in press as: Fang-Gang N, et al. Laryngeal morphologic changes and epidemiology in patients with inhalation injury: A retrospective study. Burns (2015), http://dx.doi.org/10.1016/j.burns.2015.02.003
JBUR-4582; No. of Pages 7 burns xxx (2015) xxx–xxx
3
Fig. 1 – Fibro-laryngoscopic observations of laryngeal burns. (A) Laryngeal mucosal congestion, I type; (B) blister formation in the larynx, II type; (C) laryngeal edema, II type; (D) epiglottis stiffness, III type.
pseudo-membrane. Laryngeal tissues were stiff, with anatomic signs unclear. The glottis was swollen like a ball.
2.3.
Treatment of patients with laryngeal burns
1. I type (mild): Treatment was aimed at protecting the laryngeal mucosa and relieving clinical symptoms to promote the recovery of laryngeal burns. Sedative, salbutamol and inhaled corticosteroids were administrated to prevent laryngospasm and inflammation, if necessary. 2. II type (moderate): The therapy goals of treating edematous type included preventing laryngeal obstruction, postponing development of laryngeal injury, and promoting recovery and healing of laryngeal injury. These methods were intended to protect the laryngeal mucosa, alleviate congestion, exudation and edema, and reduce the development of blisters and the incidence of laryngeal obstruction. Fibrolaryngoscopic observation was conducted to monitor the patient. Once a laryngeal obstruction was inevitable, immediate tracheotomy was undertaken. 3. III type (severe): Tracheotomy was undertaken immediately once diagnosed in order to avoid death due to asphyxiation resulting from laryngeal obstruction. Other treatments, including aerosol inhalation, should also be administered to prevent or reduce the occurrence of co-morbid injuries and complications.
2.4.
The clinical condition of tracheotomy
The decision of tracheotomy was based on the results of fibrolaryngoscopic observations. Tracheotomy was performed once blisters in the laryngeal pharynx exceeded the glottis or burn area was >33%. Movement of the epiglottis was restricted. Over half of the glottis remained covered even while breathing or speaking. The opening and closing of the vocal cords were restricted with an open angle
