Smoke inhalation: diagnosis and treatment

Acute clinical manifestations in toxic smoke inhalation victims: systematic review of observational studies

Abstract Introduction: Lung injuries from toxic smoke inhalation are the main causes of death in fire victims; however, information regarding the acute effects on the respiratory system after smoke inhalation and its constituents in closed environments are still scarce in literature. Objective: To investigate the acute clinical manifestations observed in victims of smoke inhalation during enclosed-space fires by means of systematic review. Methods: A systematic search was conducted in the following databases: MEDLINE (via PubMed), Lilacs, Scopus and Web of Science. There were no appliedrestrictions in terms of thepublication date. In addition, a manual search was performed on the references of published studies. Observational studies assessing the prevalence of acute clinical manifestations in victims of toxic smoke inhalation in closed environments were included. Results: Of the 4,603 articles identified, eight were included, comprising a total of 233 patients. The signs and symptoms were identified and ranked according to frequency. Dyspnea (58.80%, six studies), carbonaceous sputum (54.51%, four studies), hoarseness (39.91%, three studies), wheezing (34.33%, five studies) and sore throat (33.90%, two studies) were the most frequent acute clinical manifestations of smoke inhalation. Besides these, chest pain and pulmonary edema were observed, respectively in 13.30%, 5.15% of the studies. Conclusion: The results suggest that dyspnea, carbonaceous sputum, hoarseness, wheezing and sore throat were the most frequent acute clinical manifestations in victims of smoke inhalation. Further studies of a higher level of evidence and greater methodological rigor are required.

Smoking and haptoglobin phenotype modulate serum ferritin and haptoglobin levels in Parkinson disease

The phenotype Hp 2-1 of haptoglobin has been previously associated with increased risk of Parkinson disease (PD) and with serum iron abnormalities in PD patients. Tobacco smoking has been consistently observed in epidemiology studies to be inversely related to PD risk, with mechanisms that remain uncertain. We recently observed that the protective effect of smoking on PD risk is stronger among subjects of haptoglobin Hp 2-2 and Hp 1-1 phenotypes, and weaker among subjects of haptoglobin Hp 2-1 phenotype. In this PD case-control study, we investigated whether tobacco smoking was associated with changes in serum haptoglobin and ferritin concentration that depended on haptoglobin phenotype among 106 PD patients and 238 controls without PD or other neurodegenerative disorders. Serum ferritin concentration, serum haptoglobin concentration, haptoglobin phenotype, and smoking data information of cases and controls were obtained. Differences in haptoglobin and ferritin concentration by smoking status and pack-years of smoking were calculated as well as regression between pack-years and haptoglobin and ferritin concentration, and the effect of haptoglobin phenotype on these parameters. Tobacco smoking was associated with an elevation in serum haptoglobin concentration, especially among healthy controls of haptoglobin Hp 2-2 phenotype, and with an elevation in ferritin concentration especially among PD patients of haptoglobin Hp 2-1 phenotype. These findings suggest that an elevation in haptoglobin concentration, preferentially among subjects of haptoglobin Hp 2-2 phenotype, could be a contributing factor to the protective effect of smoking on PD risk.

Effects of cigarette smoke, cessation and switching to a candidate modified risk tobacco product on the liver in Apoe -/- mice--a systems toxicology analysis

The liver is one of the most important organs involved in elimination of xenobiotic and potentially toxic substances. Cigarette smoke (CS) contains more than 7000 chemicals, including those that exert biological effects and cause smoking-related diseases. Though CS is not directly hepatotoxic, a growing body of evidence suggests that it may exacerbate pre-existing chronic liver disease. In this study, we integrated toxicological endpoints with molecular measurements and computational analyses to investigate effects of exposures on the livers of Apoe(-/- )mice. Mice were exposed to 3R4F reference CS, to an aerosol from the Tobacco Heating System (THS) 2.2, a candidate modified risk tobacco product (MRTP) or to filtered air (Sham) for up to 8 months. THS2.2 takes advantage of a "heat-not-burn" technology that, by heating tobacco, avoids pyrogenesis and pyrosynthesis. After CS exposure for 2 months, some groups were either switched to the MRTP or filtered air. While no group showed clear signs of hepatotoxicity, integrative analysis of proteomics and transcriptomics data showed a CS-dependent impairment of specific biological networks. These networks included lipid and xenobiotic metabolism and iron homeostasis that likely contributed synergistically to exacerbating oxidative stress. In contrast, most proteomic and transcriptomic changes were lower in mice exposed to THS2.2 and in the cessation and switching groups compared to the CS group. Our findings elucidate the complex biological responses of the liver to CS exposure. Furthermore, they provide evidence that THS2.2 aerosol has reduced biological effects, as compared with CS, on the livers of Apoe(-/- )mice.

Second-hand tobacco smoke and children

Cigarette smoke contains harmful chemicals with hazardous adverse effects on almost every organ in the body of smokers as well as of nonsmokers exposed to environmental tobacco smoke (ETS). There has been increasing interest in the effects of passive smoking on the health of children. In order to detect the magnitude of passive smoking in children, parental questionnaires, measuring nicotine and cotinine body levels, and evaluating expired carbon monoxide (CO) concentrations, have been used. Passive smoking causes respiratory illness, asthma, poor growth, neurological disorders, and coronary heart diseases. Herein, we focused on the deleterious influences of passive smoking on immunity and liver. Besides, its effects on the concentrations of various biomarker levels related to the oxidant/antioxidant status were considered. Understanding these effects may help clinicians to counsel parents on smoking cessation and smoke exposure elimination. It may also help to develop interventions to improve the health of children. This review potentially demonstrated some nutraceuticals with a promising role in the prevention of smoking-related diseases.

Systemic inflammation caused by white smoke inhalation in a combat exercise

BACKGROUND

White smoke inhalation is an uncommon but potentially deadly cause of acute lung injury. No clinical spectrum or treatment protocol have been developed.

METHODS

Twenty patients accidentally been exposed to white smoke during military training were the subjects of this study. We analyzed clinical manifestations, cytokine changes, and treatment outcomes.

RESULTS

All patients initially presented with fever, dry cough, chest tightness, and shortness of breath. Twenty-five percent of these patients had severe acute lung injury requiring artificial ventilation support. Elevation of serum tumor necrosis factor-alpha was observed before treatment with antibiotics and glucocorticoids, but the elevation of transforming growth factor-beta(1) was delayed for 2 to 4 weeks after the accident. All the patients had leukocytosis, which correlated positively to disease severity and negatively to intensive treatments. Ninety-five percent of patients had varying degrees of restrictive ventilation impairment, and 85% of these patients had a significantly reduced diffusion capacity in the lungs. Seventy percent of these patients had transient impairment of liver function, which did not correlate to disease severity. The respiratory sequela of restrictive ventilation impairment developed in the most severely affected patients, whereas other tissue toxicities were mostly transient. Treatment included glucocorticoids, antibiotics, and respiratory therapy. All of the patients survived.

CONCLUSION

A proper ventilation strategy, early pharmacologic therapy including glucocorticoids, and complication prevention may contribute to good treatment outcomes after white smoke inhalation.

Heavy smoking and liver

Smoking causes a variety of adverse effects on organs that have no direct contact with the smoke itself such as the liver. It induces three major adverse effects on the liver: direct or indirect toxic effects, immunological effects and oncogenic effects. Smoking yields chemical substances with cytotoxic potential which increase necro-inflammation and fibrosis. In addition, smoking increases the production of pro-inflammatory cytokines (IL-1, IL-6 and TNF- alpha) that would be involved in liver cell injury. It contributes to the development of secondary polycythemia and in turn to increased red cell mass and turnover which might be a contributing factor to secondary iron overload disease promoting oxidative stress of hepatocytes. Increased red cell mass and turnover are associated with increased purine catabolism which promotes excessive production of uric acid. Smoking affects both cell-mediated and humoral immune responses by blocking lymphocyte proliferation and inducing apoptosis of lymphocytes. Smoking also increases serum and hepatic iron which induce oxidative stress and lipid peroxidation that lead to activation of stellate cells and development of fibrosis. Smoking yields chemicals with oncogenic potential that increase the risk of hepatocellular carcinoma (HCC) in patients with viral hepatitis and are independent of viral infection as well. Tobacco smoking has been associated with suppression of p53 (tumour suppressor gene). In addition, smoking causes suppression of T-cell responses and is associated with decreased surveillance for tumour cells. Moreover, it has been reported that heavy smoking affects the sustained virological response to interferon (IFN) therapy in hepatitis C patients which can be improved by repeated phlebotomy. Smoker's syndrome is a clinico-pathological condition where patients complain of episodes of facial flushing, warmth of the palms and soles of feet, throbbing headache, fullness in the head, dizziness, lethargy, prickling sensation, pruritus and arthralgia.

Management of burn injuries in the horse

Extensive thermal injuries in horses can be difficult to manage. The large surface of the burn dramatically increases the potential for loss of fluids,electrolytes, and calories. Burns are classified by the depth of injury: first-degree burns involve only the most superficial layers of the epidermis;second-degree burns involve the entire epidermis and can be superficial or deep; third-degree burns are characterized by loss of the epidermal and dermal components; and fourth-degree burns involve all the skin and underlying muscle, bone, and ligaments. Burns cause local and systemic effects. Routine use of systemic antibiotics is not recommended in burn patients. Topical medications should be water based, be easily applied and removed, not interfere with wound healing, and be readily excreted or metabolized. Weight loss of 10% to 15% during the course of illness is indicative of inadequate nutritional intake. Gradually increasing the grain,adding fat in the form of vegetable oil, and offering free-choice alfalfa hay increase caloric intake.

Lesão por inalação de fumaça

A lesão inalatória é hoje a principal causa de morte nos pacientes queimados, motivo pelo qual se justifica o grande número de estudos publicados sobre o assunto. Os mecanismos envolvidos na gênese da lesão inalatória envolvem tanto os fatores de ação local quanto os de ação sistêmica, o que acaba por aumentar muito as repercussões da lesão. Atualmente, buscam-se ferramentas que permitam o diagnóstico cada vez mais precoce da lesão inalatória e ainda estratégias de tratamento que minimizem as conseqüências da lesão já instalada. Esta revisão aborda os mecanismos fisiopatológicos, os métodos diagnósticos e as estratégias de tratamento dos pacientes vítimas de lesão inalatória. Ressalta ainda as perspectivas terapêuticas em desenvolvimento.

Inhalation injury in the burn patient

Patients who survive to hospital admission after bums with inhalation injury face a difficult and potentially prolonged course of treatment in the burn center. Continuing survival and especially functional outcome hinges on the patient's receiving comprehensive, well-coordinated care from an interdisciplinary team of skilled health care providers. The best care plan combines close monitoring of vital organ/tissue perfusion indicators, aggressive management of pulmonary compromise, and scrupulous attention to all details of nursing care. Many patients suffer complications from their injuries or treatment, and not all survive. Those who do may face prolonged and painful therapies on the way to recovery. The expert nurse managing and caring for this unfortunate population faces tremendous clinical challenges but also has the opportunity and satisfaction of helping each patient achieve the best possible outcome.

Alterations in regional ventilation, perfusion, and shunt after smoke inhalation measured by PET

Regional changes in ventilation and perfusion occurring in the early hours after smoke inhalation injury were evaluated through the use of positron emission tomography. Five lambs were imaged before and 1, 2, and 4 h after receiving 100 breaths of cotton smoke. Utilizing a recently developed model of (13)N tracer kinetics (3), we evaluated changes in ventilation, perfusion, shunt, and regional gas content in nondependent, middle, and dependent lung zones. The data demonstrated a progressive development of regional shunt in dependent (dorsal) regions in which perfusion remained the highest throughout the study. These findings, together with decreasing regional ventilation and fractional gas content in the dependent regions, correlated with decreasing arterial Pa(O(2)) values over the course of the study. A negative correlation between regional shunt fraction and regional gas content in dependent and middle regions suggests that shunt was caused by progressive alveolar derecruitment or flooding.

Smoke inhalation injury

Pulmonary injury due to smoke inhalation is a significant cause of death in fire victims. Singed nasal hair and carbonaceous sputum are easily recognized warning signs, but other subtle clues should prompt thorough evaluation and aggressive treatment. Dr Lee-Chiong describes the basic mechanisms of injury and discusses how to assess and manage complications caused by smoke inhalation.

A new biological assay for measuring cyanide in blood

Clinical diagnosis of cyanide poisoning is complicated by the lack of an easy, convenient assay for cyanide concentration in blood. Therapy may be delayed with unconfirmed diagnosis because the conventional antidote to cyanide poisoning exposes patients to substantial risks. We developed a new spectrophotometric assay to measure cyanide by extraction into a sodium hydroxide trap, followed by the addition of exogenous methemoglobin as a colormetric indicator. Samples of blood from 15 healthy subjects and 5 patients who had received prolonged nitroprusside infusions were assayed. To optimize assay characteristics, methemoglobin concentrations, pH, temperature, incubation time, and buffer strengths were varied. Duplicate samples were assayed by using the polarographic method for assay validation. Over a range from 300 ng/mL to 7 microg/mL, the correlation between methods was r = 0.983. Interassay and intraassay variability were 5% and 2%, respectively. Samples drawn from the five patients and tested by using both methods yielded a correlation of r = 0.978. This new assay for cyanide in blood may greatly facilitate the diagnosis and treatment of cyanide ingestion. The use of methemoglobin as the colorimetric indicator in the assay contributes to its low cost and ease of use.

IMPLICATIONS

Cyanide, an important factor in death from burn-related inhalation injury, is difficult and time-consuming to measure. We developed a new, rapid blood test for cyanide using methemoglobin as a colormetric indicator. A rapid, accessible test for cyanide may speed the diagnosis and treatment of cyanide poisoning.

Pre-hospital strategy for therapeutic intervention of fire victims

Fire victims are exposed to the triple threat of thermal injury (skin and lungs), smoke toxicity (toxic or irritant gases and soots) and even trauma whose occurrences are somewhat independent one from the other but whose addition does sharply increase the probability of death of the victims. As the different victims of the same fire may not suffer from the same injuries, this triple threat must be looked for in each fire victim.

Hospital treatment of victims exposed to combustion products

Combustion toxicology is complex so, although victims exposed to combustion products are mainly treated symptomatically, it is important to identify those situations when specific therapeutic measures might be of importance. Victims presenting respiratory symptoms including severe cough, bronchoconstriction, hypoxia and respiratory distress should be given oxygen and ventilatory assistance or support. Furthermore, bronchoconstriction should be treated with bronchodilators (beta-2-adrenoreceptor agonists, theophylline). Corticosteroids should be considered both for inhalation and systemically due to the risk of developing toxic pulmonary oedema that may appear after a symptom-free interval that might last up to 48-72 h. Victims with impaired consciousness should be regarded as being exposed to carbon monoxide and cyanides. Apart from oxygen and optimal symptomatic treatment hyperbaric oxygen therapy should be considered in carbon monoxide poisoning. Certain cyanide antidotes, namely those with low intrinsic toxicity (as sodium thiosulphate, hydroxocobalamin) should be given liberally in these situations. Other specific therapeutic measures that might be considered when appropriate are administration of organophosphate antidotes (atropine, oximes), heavy metal chelators (e.g. dimercaptopropane sulfonate, dimercaptosuccinic acid) and methemoglobinemia antidotes (methylthionine, toluidine blue). Inhalation of hot fumes may cause upper respiratory tract oedema (e.g. laryngeal oedema) necessitating orotracheal intubation and ventilatory support.