Acute inhalation injury

Mechanistic Understanding of Lung Inflammation: Recent Advances and Emerging Techniques

Acute respiratory distress syndrome (ARDS) is a life-threatening lung injury characterized by an acute inflammatory response in the lung parenchyma. Hence, it is considered as the most appropriate clinical syndrome to study pathogenic mechanisms of lung inflammation. ARDS is associated with increased morbidity and mortality in the intensive care unit (ICU), while no effective pharmacological treatment exists. It is very important therefore to fully characterize the underlying pathobiology and the related mechanisms, in order to develop novel therapeutic approaches. In vivo and in vitro models are important pre-clinical tools in biological and medical research in the mechanistic and pathological understanding of the majority of diseases. In this review, we will present data from selected experimental models of lung injury/acute lung inflammation, which have been based on clinical disorders that can lead to the development of ARDS and related inflammatory lung processes in humans, including ventilation-induced lung injury (VILI), sepsis, ischemia/reperfusion, smoke, acid aspiration, radiation, transfusion-related acute lung injury (TRALI), influenza, Streptococcus (S.) pneumoniae and coronaviruses infection. Data from the corresponding clinical conditions will also be presented. The mechanisms related to lung inflammation that will be covered are oxidative stress, neutrophil extracellular traps, mitogen-activated protein kinase (MAPK) pathways, surfactant, and water and ion channels. Finally, we will present a brief overview of emerging techniques in the field of omics research that have been applied to ARDS research, encompassing genomics, transcriptomics, proteomics, and metabolomics, which may recognize factors to help stratify ICU patients at risk, predict their prognosis, and possibly, serve as more specific therapeutic targets.

Preclinical and clinical studies of smoke-inhalation-induced acute lung injury: update on both pathogenesis and innovative therapy

Smoke-inhalation-induced acute lung injury (SI-ALI) is a leading cause of morbidity and mortality in victims of fire tragedies. SI-ALI contributes to an estimated 30% of burn-caused patient deaths, and recently, more attention has been paid to the specific interventions for this devastating respiratory illness. In the last decade, much progress has been made in the understanding of SI-ALI patho-mechanisms and in the development of new therapeutic strategies in both preclinical and clinical studies. This article reviews the recent progress in the treatment of SI-ALI, based on pathophysiology, thermal damage, airway obstruction, the nuclear-factor kappa-B signaling pathway, and oxidative stress. Preclinical therapeutic strategies include use of mesenchymal stem cells, hydrogen sulfide, peroxynitrite decomposition catalysts, and proton-pump inhibitors. Clinical interventions include high-frequency percussive ventilation, perfluorohexane, inhaled anticoagulants, and nebulized epinephrine. The animal model, dose, clinical application, and pharmacology of these medications are summarized. Future directions and further needs for developing innovative therapies are discussed.

A Comparative Study of Respiratory Quality of Life among Firefighters, Traffic Police and Other Occupations in Malaysia

BACKGROUND

Despite its excellent psychometric properties, St George's Respiratory Questionnaire (SGRQ) has not been previously used in measuring respiratory quality of life (RQoL) among traffic police and firefighters who are at risk of poor respiratory health by virtue of their occupations.

OBJECTIVE

To assess and compare the RQoL of the occupationally exposed (firefighters and traffic police) and the occupationally unexposed populations in Penang, Malaysia.

METHODS

We recruited male traffic police and firefighters from 5 districts of Penang by convenient sampling during June to September 2018. Participants completed the SGRQ. Scores (symptoms, activity, impacts, total) were derived using a scoring calculator. Higher scores indicate poorer RQoL. Univariate and multivariate linear regression models were fitted to explore the relationship of the independent predictive factors with participants' RQoL.

RESULTS

We recruited 706 participants---211 firefighters, 198 traffic police, and 297 from general population. Smokers had significantly higher scores than non-smokers in all SGRQ domains. Regardless of smoking status, the "occupationally exposed group" had higher symptoms score than the "occupationally unexposed group," who had higher activity and impact scores. Smoking status, comorbidity status and monthly income were significant independent predictors of SGRQ total score.

CONCLUSION

In comparison with the general population, firefighters and traffic police reported poorer RQoL; smoking further deteriorated their respiratory health. There is a need to strengthen preventive health measures against occupational disease and smoking cessation among firefighters and traffic police.

Acute respiratory distress syndrome and chemical burns after exposure to chlorine-containing bleach: a case report

Chlorine-containing bleach can cause acute respiratory distress syndrome (ARDS) and chemical burns. However, simultaneous occurrence of the two conditions caused by this agent is very rare. We describe the case of a 74-year-old female who presented with shortness of breath and hemoptysis following accidental exposure to chlorine-containing bleach. She had second- to third-degree chemical burns on both buttocks and thighs, and received mechanical ventilation because of the development of ARDS. Mechanical ventilation was discontinued on day 6 of hospitalization because of the rapid improvement of hypoxemia, and the patient was transferred to another hospital for further management of the chemical burns on day 18.

Laryngeal Trauma Following an Inhalation Injury: A Review and Case Report

The primary concern when managing a patient with inhalation injury is security of the airway. Airflow may be impeded by both edema of the upper airway and reduction of oxygen delivery to the lower respiratory tract. Although there has been much discussion regarding management of the latter, the focus of this article is the management of the former. This review aimed to determine the optimum management in burn victims with upper airway inhalation injury as an attempt to prevent laryngeal trauma leading to long-term voice disorders and upper airway dyspnea. We describe the case of a 57-year-old woman with significant inhalation injury and discuss the natural progression of her injuries and the laryngeal controversies surrounding her care. We conclude with advice on the optimal management of this condition based on our experience, combined with current best evidence.

Acute and subacute chemical-induced lung injuries: HRCT findings

Lung injury caused by chemicals includes bronchitis, bronchiolitis, chemical pneumonitis, pulmonary edema, acute respiratory distress syndrome, organizing pneumonia, hypersensitivity pneumonitis, acute eosinophilic pneumonia, and sarcoid-like granulomatous lung disease. Each chemical induces variable pathophysiology and the situation resembles to the drug induced lung disease. The HRCT features are variable and nonspecific, however HRCT may be useful in the evaluation of the lung injuries and so we should know about HRCT features of lung parenchymal abnormalities caused by chemicals.

Pulmonary function decline in firefighters and non-firefighters in South Korea

Objectives

The purpose of this study was to evaluate and compare changes to pulmonary function among firefighters and non-firefighters who were exposed to harmful substances in their work environments.

Methods

Firefighters (n = 322) and non-firefighters (n = 107) in Daegu who received a pulmonary function test in 2008 and 2011 as well as a regular health examination were included. Repeated measures ANOVA was performed to evaluate the pulmonary function of the two groups over the three-year period.

Results

After adjusting for age, height, body mass index, duration of exposure, physical activity, and smoking, which were statistically different between the two groups and known risk factors of pulmonary function, the forced expiratory volume in one s FEV₁, forced vital capacity FVC, and FEV₁/FVC% over the 3 year period were significantly lower among firefighters compared with non-firefighters.

Conclusions

Evaluating the working environment of firefighters is difficult; however, our study revealed that pulmonary function declined in firefighters. Thus, more effort should be made to prevent and manage respiratory diseases early by preforming strict and consistent pulmonary function tests in firefighters.

Inhaled anticoagulation regimens for the treatment of smoke inhalation-associated acute lung injury: a systematic review

OBJECTIVE

Inhaled anticoagulation regimens are increasingly being used to manage smoke inhalation-associated acute lung injury. We systematically reviewed published and unpublished preclinical and clinical trial data to elucidate the effects of these regimens on lung injury severity, airway obstruction, ventilation, oxygenation, pulmonary infections, bleeding complications, and survival.

DATA SOURCES

PubMed, Scopus, EMBASE, and Web of Science were searched to identify relevant published studies. Relevant unpublished studies were identified by searching the Australian and New Zealand Clinical Trials Registry, World Health Organization International Clinical Trials Registry Platform, Cochrane Library, ClinicalTrials.gov, MINDCULL.com, Current Controlled Trials, and Google.

STUDY SELECTION

Inclusion criteria were any preclinical or clinical study in which 1) animals or subjects experienced smoke inhalation exposure, 2) they were treated with nebulized or aerosolized anticoagulation regimens, including heparin, heparinoids, antithrombins, or fibrinolytics (e.g., tissue plasminogen activator), 3) a control and/or sham group was described for preclinical studies, and 4) a concurrent or historical control group described for clinical studies. Exclusion criteria were 1) the absence of a group treated with a nebulized or aerosolized anticoagulation regimen, 2) the absence of a control or sham group, and 3) case reports.

DATA EXTRACTION

Ninety-nine potentially relevant references were identified. Twenty-seven references met inclusion criteria including 19 preclinical references reporting 18 studies and eight clinical references reporting five clinical studies.

DATA SYNTHESIS

A systematic review of the literature is provided. Both clinical and methodological diversity precluded combining these studies in a meta-analysis.

CONCLUSIONS

The high mortality associated with smoke inhalation-associated acute lung injury results from airway damage, mucosal dysfunction, neutrophil infiltration, airway coagulopathy with cast formation, ventilation-perfusion mismatching with shunt, and barotrauma. Inhaled anticoagulation regimens in both preclinical and clinical studies improve survival and decrease morbidity without altering systemic markers of clotting and anticoagulation. In some preclinical and clinical studies, inhaled anticoagulants were associated with a favorable effect on survival. This approach appears sufficiently promising to merit a well-designed prospective study to validate its use in patients with severe smoke inhalation-associated acute lung injury requiring mechanical ventilation.

Admission chest CT complements fiberoptic bronchoscopy in prediction of adverse outcomes in thermally injured patients

In burned patients, inhalation injury can result in progressive pulmonary dysfunction, infection, and death. Although bronchoscopy is the standard for diagnosis, it only assesses the proximal airway and does not provide a comprehensive analysis of pulmonary insult. Chest radiographs have not been proven helpful in diagnosis of inhalation injury. Our hypothesis is that a CT scan alone or in conjunction with bronchoscopy can be used as a prognostic tool for critically ill burn patients, especially those with inhalation injury. The authors performed a retrospective study of all patients admitted to the U.S. Army Institute of Surgical Research Burn Center between 2002 and 2008 with chest CT within 24 hours of admission. They divided subjects into two groups, those with evidence of inhalation injury on bronchoscopy and those without. They used a radiologist's score to assess the degree of damage to the pulmonary parenchyma. The primary endpoint was a composite of pneumonia, acute lung injury/acute respiratory distress syndrome, and death. The inhalation injury group consisted of 25 patients and the noninhalation injury group of 19 patients. Groups were not different in age, TBSA burned, and percentage full-thickness burn. By multiple logistic regression, detection of inhalation injury on bronchoscopy was associated with an 8.3-fold increase in the composite endpoint. The combination of inhalation injury on bronchoscopy and a high radiologist's score was associated with a 12.7-fold increase in the incidence of the composite endpoint. Admission CT assists in predicting future lung dysfunction in burn patients.

Early single-shot intravenous steroids do not affect pulmonary complications and mortality in burned or scalded patients

BACKGROUND AND OBJECTIVES

Inhalation injury, especially in combination with cutaneous burns, is the major cause of morbidity and mortality in patients admitted to burn care centers. Either with or without the presence of a cutaneous burn, inhalation injury contributes to high risk for developing severe pulmonary complications. Steroids may reduce a prolonged and destructive inflammatory response to toxic or allergic substances. The objective of this study was to evaluate the effect of early single-shot intravenous steroids on pulmonary complications and mortality in burned or scalded patients with or without inhalation injury.

METHODS

Retrospective analysis of a prospective single center database of patients registered between 1989 and 2011 who were admitted to the intensive care unit of our burn care center after burn or scald injury. Uni-variate statistical analysis was performed comparing two groups (steroid treated vs. non steroid treated patients) with regard to clinical outcome. Main parameters were sepsis, mortality and pulmonary complications such as pneumonia, ALI and ARDS. Multi-variate analysis was used by logistic regression with mortality and pulmonary complications as the dependent variables to identify independent risk factors after burn or scald injuries.

RESULTS

A total of 1637 patients with complete data were included in the present analysis. 199 (12.2%) received single-shot intravenous steroids during the prehospital phase of care. In 133 (66.8%) of these patients, inhalation injury was diagnosed via bronchoscopy. Steroid treated patients had sustained a significantly higher severity of burn than non-steroid treated patients (Abbreviated Burn Severity Index 7.1±3 vs. 6.0±2.9; p<0.001). In a multivariate analysis using a logistic regression model early intravenous steroid treatment had no significant effect on pulmonary complications and mortality.

CONCLUSIONS

In our single center cohort of burned and scalded patients single-shot intravenous steroids during the pre-hospital phase of care was not associated with pulmonary complications or mortality.

Isolated inhalational injury: Clinical course and outcomes in a multidisciplinary intensive care unit

Background and Aims:

Although smoke inhalation is well known to cause acute lung injury, there are few reports in literature that study the evolution, clinical course and outcomes of isolated inhalational lung injury in a modern intensive care setting. A major fire disaster provided us the opportunity to study victims of isolated inhalational injury admitted to our Multidisciplinary Intensive Care Unit (MICU).

Materials and Methods:

We studied the clinical course, ICU and hospital outcomes of 13 victims of a fire disaster who required mechanical ventilation for isolated inhalational lung injury. All patients were followed up at regular intervals, and their functional status was assessed at 8 months after hospital discharge.

Results:

The Lung Injury Scores (LIS) worsened to reach a nadir on Day 3 of injury. There was a significant correlation between the LIS on Day 3 and duration of mechanical ventilation (r = 0.8; P = 0.003), ICU (r = 0.8; P = 0.002) and hospital (r = 0.6; P = 0.02) days. Late-onset airway complications were encountered in four patients. Three of them required long-term artificial airways – two with a tracheostomy while the third patient required surgical insertion of a “T” tube. Persistent problems with phonation occurred in two patients. At 8 months postdischarge, all patients were independent with activities of daily living; all were back to work, except for two who continued to need artificial airways.

Conclusions:

Inhalational lung injury progresses over the first few days and is worst after 72 h. Late-onset airway complications may manifest after several weeks and require repeated intervention.

EAACI consensus statement for investigation of work-related asthma in non-specialized centres

Work-related asthma (WRA) is a relevant problem in several countries, is cause of disability and socioeconomic consequences for both the patient and the society and is probably still underdiagnosed. A correct diagnosis is extremely important to reduce or limit the consequences of the disease. This consensus document was prepared by a EAACI Task Force consisting of an expert panel of allergologists, pneumologists and occupational physicians from different European countries. This document is not intended to address in detail the full diagnostic work-up of WRA, nor to be a formal evidence-based guideline. It is written to provide an operative protocol to allergologists and physicians dealing with asthma useful for identifying the subjects suspected of having WRA to address them to in-depth investigations in a specialized centre. No evidence-based system could be used because of the low grade of evidence of published studies in this area, and instead, 'key messages' or 'suggestions' are provided based on consensus of the expert panel members.

Toxic inhalational exposures

Respirable toxicants are a spectrum of irritant and nonirritant gases, vapors, fumes, and airborne particles that can be entrained into the body through the respiratory tract, resulting in exposures that cause pulmonary injury and/or systemic disease. Sources of respirable toxicants include structural fires, industrial accidents, domestic mishaps, and intentional releases of injurious agents on the battleground (warfare) or in civilian settings (acts of terrorism). Acute toxic inhalational exposures may result in respiratory failure, multisystem organ dysfunction, and death. Management of victims includes assessment and protection of the airway, monitoring and treatment of systemic toxicity, and delivery of exposure-specific and nonspecific therapies that improve outcomes. Treatments may include antidotes, hyperbaric oxygen, and other nonspecific life-supporting interventions.

Update on the critical care management of severe burns

Care of the severely injured patient with burn requires correct diagnosis, appropriately tailored resuscitation, and definitive surgical management to reduce morbidity and mortality. Currently, mortality rates related to severe burn injuries continue to steadily decline due to the standardization of a multidisciplinary approach instituted at tertiary health care centers. Prompt and accurate diagnoses of burn wounds utilizing Lund-Browder diagrams allow for appropriate operative and nonoperative management. Coupled with diagnostic improvements, advances in resuscitation strategies involving rates, volumes, and fluid types have yielded demonstrable benefits related to all aspects of burn care. More recently, identification of comorbid conditions such as inhalation injury and malnutrition have produced appropriate protocols that aid the healing process in severely injured patients with burn. As more patients survive larger burn injuries, the early diagnosis and successful treatment of secondary and tertiary complications are becoming commonplace. While advances in this area are exciting, much work to elucidate immune pathways, diagnostic tests, and effective treatment regimens still remain. This review will provide an update on the critical care management of severe burns, touching on accurate diagnosis, resuscitation, and acute management of this difficult patient population.

[Acute interstitial pneumonia: diagnostic approach and management]

Acute interstitial pneumonia (AIP) encompasses a spectrum of pulmonary disorders characterized by involvement of the lung interstitium and distal airways (bronchioles and alveoli). The onset of respiratory symptoms is acute, most often within two weeks. Most AIP take place de novo, but sometimes represent an acute exacerbation of chronic lung disease. The clinical presentation of AIP comprises rapidly progressive dyspnoea, associated sometimes with cough, fever, myalgia and asthenia. Chest radiography shows diffuse pulmonary opacities. The associated hypoxemia may be severe enough to cause acute respiratory failure. Underlying aetiologies are numerous and variable, particularly in relation to the underlying immune status of the host. Various histopathological entities may be responsible for AIP although diffuse alveolar damage is the predominant pattern. The diagnostic approach to a patient presenting with AIP is to try to determine the most likely underlying histopathological pattern and to search for a precise aetiology. It relies mainly on a meticulous clinical evaluation and accurate biological investigation, essentially guided by the results of bronchoalveolar lavage performed in an area identified by abnormalities on high resolution computed tomography of the lungs. Initial therapeutic management includes symptomatic measures, broad-spectrum antibiotic treatment adapted to the clinical context, frequently combined with systemic corticosteroid therapy.

Acute inhalation injury

Inhaled substances may cause injury in pulmonary epithelium at various levels of respiratory tract, leading from simple symptoms to severe disease. Acute inhalation injury (AII) is not uncommon condition. There are certain high risk groups but AII may occur at various places including home or workplace. Environmental exposure is also possible. In addition to individual susceptibility, the characteristics of inhaled substances such as water solubility, size of substances and chemical properties may affect disease severity as well as its location. Although AII cases may recover in a few days but AII may cause long-term complications, even death. We aimed to discuss the effects of short-term exposures (minutes to hours) to toxic substances on the lungs.

Bilateral pneumothorax following acute inhalation injury

INTRODUCTION

Inhalation injury can be thermal and/or chemical. We report bilateral pneumothorax following acute inhalation injury.

CASE REPORT

A male worker in an upholstery factory was confined in the tanning machine for 15 min. The device was used to contain sodium sulfate, sulfur dioxide, and sulfuric acid. On admission, he was confused with Glasgow coma scale score as 9. His vital signs were as follows: blood pressure, 80/58 mmHg; pulse rate, 114 bpm; respiratory rate, 30 bpm; temperature, 37.1 degrees C; and oxygen saturation, 48%. He was intubated. Physical examination disclosed extensive subcutaneous emphysema on the neck and pinkish foamy discharge from the mouth. Chest X-ray showed bilateral pneumothoraces and pneumomediastinum that warranted bilateral tube thoracostomy. Bronchoscopy demonstrated web-shaped hyperemic areas on the upper airway mucosa with aphtous lesions in the base. Extensive hemorrhage and edema were evident around epiglottis. The patient was admitted to the intensive care unit and mechanically ventilated. He was discharged without any sequelae on day 8.

CONCLUSION

Exposure to irritant gases such as sulfuric acid and sulfur dioxide can cause severe pulmonary injury leading to pneumothorax and pneumomediastinum.

Swimming pool, respiratory health, and childhood asthma: should we change our beliefs?

Swimming is often recommended as a sport because of its several benefits to health. It is also recommended in asthmatic children as a sport with a lower potential for prompting exercise-induced asthma. However, there is growing interest in the potentially harmful effects of repeated respiratory tract exposure to chlorinated products and the problem of possible swimming-related health hazards is gaining importance at international level. It is already known that acute exposure to chlorine gas as in swimming pool accidents causes lung damage and also that elite swimmers may have increased airway inflammation and bronchial hyperreactivity, probably as a result of repeated exposure to chlorine derivatives. Recently some studies have been conducted to investigate whether repeated exposure to chlorine by-products in recreational swimmers might also lead to lung damage. In addition, some studies have been lately published on the even more debated issue of the possible harmful effects of baby swimming on respiratory health. This article reviews and discusses data from the literature on the effects of chlorine derivatives in different categories of people routinely attending swimming pools. The need for longitudinal studies is emphasized to definitely clarify any role of chlorinated swimming pool attendance in the development of asthma in recreational swimmers.

Acute respiratory distress syndrome from chlorine inhalation during a swimming pool accident: a case report and review of the literature

Chlorine inhalation can result in significant morbidity and mortality. The most common clinical ramification is mucosal irritation. Rarely, depending upon the degree of exposure, patients can develop acute respiratory distress syndrome. Management is usually supportive with an unproven role for inhaled or systemic corticosteroids. A case of a young woman who developed respiratory failure secondary to acute respiratory distress syndrome from accidental exposure to chlorine fumes at a community swimming pool is described. The patient suffered a prolonged hospitalization with the need for mechanical ventilation. Despite limited data to support the decision, the patient was started on treatment with corticosteroids. She recovered completely from her illness and was discharged home without supplemental oxygen. A concise discussion of chlorine inhalation injury and a literature review on the utility of inhaled and/or systemic corticosteroids for this clinical entity is presented.

Lead poisoning due to adulterated marijuana in leipzig

BACKGROUND

Between August and December 2007, a mass poisoning due to adulterated marijuana was uncovered in the area of Leipzig, Germany.

METHODS

Retrospective reports of patients with lead poisoning who were treated at Leipzig University Hospital. Analysis of data from the local health office, where marijuana consumers could have their blood lead concentration determined.

RESULTS

At Leipzig University Hospital, 35 patients (7 female; age 24.2 +/- 4.4 years) had to be treated for lead poisoning (blood lead levels 1063.3 +/- 864.0 microg/L). Five hundred ninety-seven marijuana consumers (439 men, 158 women; age 26.9 +/- 4.8 years) had their blood lead levels measured at the local health office. Among them, 27.3% had lead levels above the HBM-II threshold, 12.2% had concentrations that required monitoring, and 60.5% had levels below the HBM-I threshold.

CONCLUSION

Drug consumption should be considered in otherwise unexplained anemia and abdominal colic. Several hundred people suffered lead poisoning presumably resulting from the desire of drug dealers to maximize profits.

Uncontrolled occupational exposure to 1,1-dichloro-1-Fluoroethane (HCFC-141b) is associated with acute pulmonary toxicity

BACKGROUND

The toxicity of 1,1-dichloro-1-fluoroethane (HCFC-141b), a hydrochlorofluorocarbon (HCFC), is low according to animal studies. However, pulmonary manifestations associated with acute HCFC exposure by inhalation have not been reported as yet in man. We evaluated the pulmonary effects of HCFC-141b inhalation, caused by an accident, in previously healthy individuals.

METHODS

The subjects in this study were 15 workers in whom unpleasant symptoms developed after inhaling HCFC-141b at work. Clinical manifestations, radiologic findings, and changes in pulmonary function and airway hyperresponsiveness (AHR) over time were assessed, and BAL fluid analyses findings for four subjects were compared with those of four healthy volunteers (control subjects).

RESULTS

(1) Cough, shortness of breath, and malaise developed in most patients, but only two patients complained of a sore throat. (2) A high-resolution CT scan of the chest revealed bilateral diffuse ground-glass opacities that were predominant in upper lung zones. (3) The mean (+/- SD) FVC was 71.4 +/- 18.86% predicted, and the mean FEV(1)/FVC ratio was 92.9 +/- 4.25%. Eleven patients (73%) showed restrictive ventilatory impairments during the initial tests. FVC gradually improved, and the FEV(1)/FVC ratio gradually decreased with time. (4) AHR was observed in four subjects during the initial tests. (5) BAL fluid samples revealed significantly higher neutrophil counts than those in control subjects.

CONCLUSIONS

Overexposure to HCFC-141b was associated with parenchymal lung injury that was characterized by ground-glass opacities, elevated BAL neutrophil counts, and restrictive ventilatory impairment. Restrictive impairments improved with time after exposure.

Isolated smoke inhalation injuries: Acute respiratory dysfunction, clinical outcomes, and short-term evolution of pulmonary functions with the effects of steroids

Relatively few reports exist regarding isolated smoke inhalation injuries in human patients. In this study, we describe the acute manifestations and short-term evolution of respiratory injuries after isolated smoke inhalation in victims of fires. Ninety-six patients admitted as the result of a subway fire were examined for acute respiratory dysfunction with clinical outcomes. Some of the survivors suffering from less severe injuries were evaluated for changes in pulmonary function over time, with the effects of steroid treatment. In 13 patients (14%), immediate respiratory failure resulted from ventilatory insufficiency, which was induced principally by mechanical airway obstruction, and manifested as significantly lowered pH and higher PaCO2 levels than in the patients requiring no mechanical ventilation. Toilet bronchoscopy allowed for early liberation from mechanical ventilation. Along with the death of 4 patients (4%), vocal cord and tracheal stenosis were noted in 5 patients and 1 patient, respectively, among 17 patients for whom endotracheal intubation was required. Pulmonary functions improved significantly after 3 months, with no further changes being observed within the subsequent 3 months. Steroid therapy resulted in no additional improvements in the pulmonary functions of these patients. In patients with isolated smoke inhalation injuries, immediate ventilatory insufficiency resulting from mechanical airway obstruction should be watched for, and managed via toilet bronchoscopy. Vigilance is required to avoid airway complications after endotracheal intubation. The improvement of pulmonary functions progressed primarily within the first 3 months, whereas short-course steroid therapy exerted no influence on the eventual recovery of pulmonary functions in the less severe cases.

The effect of nebulized NaHCO3 treatment on "RADS" due to chlorine gas inhalation

Chlorine is one of the most common substances involved in toxic inhalation. As with all irritant gases, the airway injuries caused by chlorine gas may result in clinical manifestations similar to those of asthma. In this study, we investigated the effect of nebulized sodium bicarbonate (NSB) on the treatment and quality of life (QoL) of victims exposed to chlorine gas. Forty-four consecutive patients with reactive airways dysfunction syndrome (RADS) due to chlorine inhalation (40 females and 4 males, age range 17-56 yr) were included in this study. Patients were placed in control and treatment groups in a sequential odd-even fashion based on their order of presentation. Treatment of all patients included corticosteroids and nebulized short-acting beta2-agonists. Then the control group (n = 22) received nebulized placebo (NP), and the NSB group (n = 22) received NSB treatment (4 cm3 of 4.20% sodium bicarbonate solution). A quality of life (QoL) questionnaire and pulmonary function tests (PFTs) were performed before and after treatments in both groups. The most common symptoms were dyspnea (82%) and chest tightness (82%). Baseline characteristics of both groups were similar. Compared to the placebo group, the NSB group had significantly higher FEV1 values at 120 and 240 min (p < .05). Significantly more improvement in QoL questionnaire scores occurred in the NSB group compared to the NP group (p < .001). Thus, NSB is a clinically useful treatment, as tested by PFTs and QoL questionnaire, for patients with RADS caused by exposure to chlorine gas.