[Predictive factors associated with severity of asthma exacerbations]

Several factors have been accused for asthma exacerbations, however, very few studies have evaluated whether different factors predict severity of asthma exacerbation. We aimed to determine the predictive factors for severity of asthma exacerbation. Retrospective analysis of data on 93 patients visited our emergency-department because of asthma exacerbation was reviewed. Hospitalization in intensive care unit and/or intubation because of asthma was accepted as the criteria for severe exacerbation. Logistic regression analysis estimated the strength of association of each variable, potentially related to severe asthmatic exacerbation, with severe/very severe as compared to mild/moderate asthmatic exacerbation. Independent variables included in the analysis were age, sex, smoking history, inhaler steroid using, compliance with medication, chronic asthma severity, presence of additional atopic diseases, prick test positivity, provocative factors, number of short-acting beta(2)-agonist using, number of visits to emergency department for asthma over one year period, previous severe exacerbation, pulmonary functions, and blood eosinophil count. 20 were severe/very severe and 73 mild/moderate asthmatic exacerbation. Frequent using of short-acting beta(2)-agonist (OR= 1.5, 95% CI= 1.08-5.3, p= 0.003), noncompliance with medication (OR= 3.6, 95% CI= 1.3-9.9, p= 0.013), previous severe asthmatic exacerbation (OR= 3.8, 95% CI= 1.48-10.01, p= 0.005) and recent admission to hospital (OR= 2.9, 95% CI= 1.07-8.09, p= 0.037) were found to be predictive factors for severe asthmatic exacerbation. Different predictive factors, in particular frequent using of short-acting beta(2)-agonist and noncompliance with medication may be associated with severe asthma exacerbations compared to milder exacerbations. This suggests different mechanisms are responsible for severity of asthma exacerbation.

Abnormalities of the bronchial arteries in asthma

STUDY OBJECTIVES

The bronchial arteries supply systemic blood to the airways, tracheobronchial lymph nodes, and nerves. Their structure has not been studied in patients with asthma.

DESIGN

Case-control study of pathologic changes of bronchial arteries in asthma.

PARTICIPANTS AND METHODS

Postmortem lungs were examined from three case groups: (1) fatal asthma (n = 12), death due to asthma; (2) nonfatal asthma (n = 12), asthmatic and death due to nonrespiratory causes; and (3) nonasthmatic control subjects (n = 12), no history of asthma and death due to nonrespiratory causes. In bronchial arteries with outer diameters of 0.1 to 1.0 mm, the areas of lumen, intima, and media were measured and compared between case groups.

RESULTS

There were no significant differences in artery size (outer diameter) or in medial area between the three groups. In the two asthma groups, the intimal area was increased (p < 0.05), with a corresponding decrease in luminal area compared with the control group. There was a significant effect of gender, age, and smoking on intimal area. In the asthma cases, the area of bronchial artery intima was related to duration of asthma (p < 0.05), and this increase was associated with smooth muscle proliferation, reduplication, and calcification of the elastica, but not with inflammatory cell infiltration.

CONCLUSIONS

While the pathophysiologic significance of these changes is uncertain, the relation to duration of asthma, age, and smoking suggests a secondary response to chronic airway disease.

Airway proteoglycans are differentially altered in fatal asthma

It has been suggested that airway remodelling is responsible for the persistent airway obstruction and decline in lung function observed in some asthmatic patients. The small airways are thought to contribute significantly to this functional impairment. Proteoglycans (PGs) are important components of the extracellular matrix (ECM) in the lungs. Besides controlling biophysical properties of the ECM, they play important roles in the regulation of some cytokines. Increased subepithelial PG deposition in the airways of mild asthmatics has been reported. However, there are no data on the PG content in small airways in asthma. This study has compared the content and distribution of PGs in large and small airways of patients who died of asthma with those in control lungs. Immunohistochemistry and image analysis were used to determine the content of lumican, decorin, biglycan, and versican in large (internal perimeter >6 mm) and small (internal perimeter < or =6 mm) airways of 18 patients who had died of asthma (A) and ten controls (C). The results were expressed as PG area (microm2)/epithelial basement membrane length (microm). The main differences between asthmatics and controls were observed in the small airways. There was a significant decrease in decorin and lumican contents in the external area of small airways in asthmatics (decorin: A = 1.05 +/- 0.27 microm, C = 3.97 +/- 1.17 microm, p = 0.042; lumican: A = 1.97 +/- 0.37 microm, C = 5.66 +/- 0.99 microm, p = 0.002). A significant increase in versican content in the internal area of small and large airways in asthmatics was also observed (small: A = 7.48 +/- 0.84 microm, C = 5.16 +/- 0.61 microm, p = 0.045; large: A = 18.38 +/- 1.94 microm, C = 11.90 +/- 2.86 microm, p = 0.028). The results show that PGs are differentially expressed in the airways of fatal asthma and may contribute to airway remodelling. These data reinforce the importance of the small airways in airway remodelling in asthma.

Inflammatory cell mapping of the respiratory tract in fatal asthma

BACKGROUND

The site and distribution of inflammation in the airways of asthmatic patients has been largely investigated. Inflammatory cells are distributed in both large and small airways in asthma. It has been demonstrated that distal lung inflammation in asthma may significantly contribute to the pathophysiology of the disease. The upper airways have also been implicated in the overall asthmatic inflammation. Although it is now accepted that lung inflammation is not restricted to the intrapulmonary airways in asthma, little is known about cell distribution in the other lung compartments and their relation to the intrapulmonary airways.

OBJECTIVE

We aimed to map the inflammatory process in fatal asthma (FA), from the upper airways to the lung parenchyma.

METHODS

Eosinophil, neutrophil, mast cell and lymphocyte content were determined in nasal mucosa, the trachea, intrapulmonary airways and parenchyma (peribronchiolar and distal) of 20 patients with FA and 10 controls.

RESULTS

Eosinophil content was higher in all studied areas in FA compared with controls (P<0.02). Mast cell content was higher in the outer area of larger airways, small membranous bronchioles and in peribronchiolar parenchyma of FA compared with controls (P<0.04). CD3+, CD4+and CD20+cells showed increased content in FA intrapulmonary airways compared with controls (P<0.05). There was a positive correlation between CD4+cell content in nasal mucosa and larger airways in asthmatics. Increased neutrophil content was observed only in peribronchiolar parenchyma of FA (P=0.028).

CONCLUSION

Eosinophils present a widespread distribution within the respiratory tract in FA, from the nasal mucosa to the distal lung. The outer wall of small membranous bronchioles is the main site of inflammatory changes in FA. There is a localized distribution of alveolar inflammation at the peribronchiolar region for mast cells and neutrophils. Our findings provide further evidence of the importance of the lung periphery in the pathophysiology of FA.

[Revision of the 3rd Consensus Conference in Intensive Care and Emergency Medicine in 1988: management of acute asthmatic crisis in adults and chidren (excluding infants)]

Experts designated by the "référentiels" committee of the SRLF analyzed the numerous articles published after the French consensus conference on the severe acute asthma of 1988. From their work, a revision of this consensus conference has been performed. The pediatric specificity has been added in this revision. There is no severity score able to predict the severity of acute asthma on admission. In every case, the nebulization of beta-2 agonists represents the priority treatment. The nebulization of anticholinergic associated with the beta-2 agonists induces a moderate additional effect. In the absence of response to nebulizations, the usefulness of the beta-2 agonists associated intravenous. Administration is not demonstrated. Corticosteroids should be administered using a 1 to 2 mg per kg dosage, but their efficacy is delayed. In adult patients, aminophylline should not be prescribe, but it is still used by some pediatricians. Other associated treatments (adrenaline, magnesium sulfate, helium-oxygen mixture) did not demonstrate their efficacy as adjunctive therapies. The therapeutic response should be evaluated using the peak flow determination.

[Pathomorphological alterations in the hypothalamo-hypophyseal-adrenal system in bronchial asthma patients died in status asthmaticus]

Morphologic changes in the paraventricular nucleus (PVN) of the hypothalamus, in hypophyseal frontal lobe and adrenal cortex are adaptive and reactive changes. In status asthmaticus, there is a high hormonal activity manifesting morphologically with hypertrophic neurosecretory granules.

Respiratory effects of halothane in a patient with refractory status asthmaticus

We describe the case of a 36 year old patient who was admitted to the intensive care unit (ICU) for an acute asthma attack that failed to respond to conventional treatment and required mechanical ventilation. The patient's condition improved after halothane was administered; treatment with this inhalational anaesthetic lasted 7 h, and the beneficial effect was obtained by employing concentrations between 0.5 and 2%. Under constant mechanical ventilator settings, a highly significant linear correlation between peak airway pressure and arterial pCO(2)(r: 0.98 P<0.001) was observed. The decrease in p(a)CO(2)induced by halothane may be explained by the diminished dead space that results from the drop in peak airway pressure. Arterial hypotension, which improved with inotropic agents, was the only complication that seemed related to the inhaled anaesthetic. The patient was extubated 24 h after her arrival to the ICU and discharged 72 h later. A causal relationship between the administration of halothane and clinical improvement is suggested.

Eosinophils are a major source of nitric oxide-derived oxidants in severe asthma: characterization of pathways available to eosinophils for generating reactive nitrogen species

Eosinophil recruitment and enhanced production of NO are characteristic features of asthma. However, neither the ability of eosinophils to generate NO-derived oxidants nor their role in nitration of targets during asthma is established. Using gas chromatography-mass spectrometry we demonstrate a 10-fold increase in 3-nitrotyrosine (NO(2)Y) content, a global marker of protein modification by reactive nitrogen species, in proteins recovered from bronchoalveolar lavage of severe asthmatic patients (480 +/- 198 micromol/mol tyrosine; n = 11) compared with nonasthmatic subjects (52.5 +/- 40.7 micromol/mol tyrosine; n = 12). Parallel gas chromatography-mass spectrometry analyses of bronchoalveolar lavage proteins for 3-bromotyrosine (BrY) and 3-chlorotyrosine (ClY), selective markers of eosinophil peroxidase (EPO)- and myeloperoxidase-catalyzed oxidation, respectively, demonstrated a dramatic preferential formation of BrY in asthmatic (1093 +/- 457 micromol BrY/mol tyrosine; 161 +/- 88 micromol ClY/mol tyrosine; n = 11 each) compared with nonasthmatic subjects (13 +/- 14.5 micromol BrY/mol tyrosine; 65 +/- 69 micromol ClY/mol tyrosine; n = 12 each). Bronchial tissue from individuals who died of asthma demonstrated the most intense anti-NO(2)Y immunostaining in epitopes that colocalized with eosinophils. Although eosinophils from normal subjects failed to generate detectable levels of NO, NO(2-), NO(3-), or NO(2)Y, tyrosine nitration was promoted by eosinophils activated either in the presence of physiological levels of NO(2-) or an exogenous NO source. At low, but not high (e.g., >2 microM/min), rates of NO flux, EPO inhibitors and catalase markedly attenuated aromatic nitration. These results identify eosinophils as a major source of oxidants during asthma. They also demonstrate that eosinophils use distinct mechanisms for generating NO-derived oxidants and identify EPO as an enzymatic source of nitrating intermediates in eosinophils.

Clinical features and outcome of management of severe acute asthma (status asthmaticus) in the intensive care unit of a tertiary medical center

AIM OF THE STUDY

The recognition and management of severe acute asthma have attracted considerable attention since the seventies because of the morbidity and mortality that may accompany the condition. Recognition and appropriate management of severe acute asthma is essential. Admission to intensive care, intubation and ventilation risks versus benefit have been argued. We highlight these controversies by documenting our experience and comparing it to others in the literature

METHODOLOGY

We prospectively document our experience over a two-year period in the management of severe asthma in the intensive Care Unit (ICU). Patients were established asthmatics, who came in severe exacerbation. Attention was paid to the duration of onset of acute attack, time to presentation, spirometric and blood gas data, the type of treatment given, factors responsible for complications and mortality were identified. The findings in this study were compared with those in similar studies in the literature.

RESULTS

A total of 30 patients were studied. Twenty-one patients were ventilated and 9 were not. 82% had a history of asthma longer than 5 years. The duration of symptoms before admission to ICU was very short (one day or less in 57%). Hypercapnia was significantly higher in intubated patients. The duration of stay in ICU and hospital was longer for intubated patients (P<0.02). Complications were higher in intubated patients.

CONCLUSION

ICU care provides an excellent setting for management of acute severe asthma. The reported high morbidity and mortality in ICU can be improved. Without ICU care the mortality and morbidity increases,so physicians should not hesitate to admit asthmatics early to ICU.

[Management of severe acute asthma in children in pediatric urgent and intensive care units]

Mortality in cases of severe asthma attacks in children is evaluated at 1%. During initial medical care, repeated evaluation of clinical and para-clinical severity criteria constitutes the main therapeutic guide. Emergency care treatment is based mainly on oxygen therapy, bronchodilatory therapy by discontinuous inhalation, and general corticotherapy. Intravenous theophylline treatment is controversial. The response after a few hours should allow a decision to be made [1] to follow up with outpatient treatment (rapid marked improvement), [2] to continue the hospital treatment (stabilization), or [3] to transfer to intensive care (worsening, exhaustion). In the intensive care unit, the treatment is based on continuous intravenous administration of beta 2 mimetics in addition to the above therapies. The objective is to avoid resorting to assisted ventilation. When this proves necessary, it must not be detrimental; controlled alveolar hypoventilation allows dynamic hyper-inflation linked to ventilation to be reduced. Prevention of relapse is indispensable. This requires hospitalization in a specialized care unit after discharge from intensive care.

Contribution of 92 kDa gelatinase/type IV collagenase in bronchial inflammation during status asthmaticus

In order to assess inflammatory features related to severe asthma as compared with mild asthma, we investigated the secretion of 92 kDa gelatinase matrix metalloproteinase (MMP-9) in bronchial lavages of six patients undergoing mechanical ventilation (MV) for status asthmaticus (SA) and in six patients with mild asthma. Ten healthy nonventilated patients and four patients under MV without preexisting respiratory disease were also investigated. Patients with SA were characterized by prominent neutrophilic inflammation (82 +/- 4% versus 10% in mild asthma). On the basis of enzymatic and immunological analysis, results showed an acute 10- to 160-fold increase of 92 kDa gelatinase (MMP-9) concentration in epithelial lining fluid (ELF) from patients with SA, together with activated forms (46 and 26 kDa) of stromelysin-1 matrix metalloproteinase (MMP-3) and detectable concentration of free metallogelatinolytic activity (1-5 micrograms gelatin hydrolyzed/48 h/ml ELF). Concomitant elevated level of tissue inhibitor of metalloproteinase-1 (TIMP-1) was shown only in patients with SA, thus counterbalancing, at least partially, excess of activated 92 kDa gelatinase. Acutely enhanced albumin levels were only observed in patients with SA; in addition, 92 kDa gelatinase and albumin levels were significantly and positively correlated (r = 0.96, p < 0.0001), suggesting that 92 kDa gelatinase may account for increased bronchial permeability in patients with SA. Several arguments support that 92 kDa gelatinase during SA originates both from numerous activated chemoattracted neutrophils and from activated bronchial epithelial cells in response to in situ lung injury. The fact that no relevant change in ELF, albumin, MMP-9, MMP-3, TIMP-1, or laminin degradation products was observed during mild asthma, strongly supports that the mechanism of airway inflammation in SA is quite distinct from that observed in mild asthma.

Balance between proinflammatory cytokines and their inhibitors in bronchial lavage from patients with status asthmaticus

Status asthmaticus (SA) is an acute respiratory failure combining an acute bronchospastic reaction with a severe airway inflammation. We previously reported an important influx of neutrophils and an increased secretion of interleukin-8 (IL-8) in patients with SA. The aim of this prospective study was to evaluate in bronchial lavage (BL) of patients with SA (n = 9) under mechanical ventilation (MV) the concentrations of cytokines and related mediators which have the ability to modulate inflammation, either proinflammatory (interleukin-1beta [IL-1beta], IL-6, tumor necrosis factor-alpha [TNF-alpha]), or anti-inflammatory mediators (IL-10, transforming growth factor-beta1 [TGF-beta1]), interleukin-1 receptor antagonist [IL-1Ra], soluble TNF receptor I and II [sTNFRI and II]). To determine the relative importance of both pro- and anti-inflammatory mediators, the net inflammatory activity was analyzed by the capacity of BL fluids (BLF) to increase intercellular adhesion molecule-1 (ICAM-1) expression in the human lung A549 epithelial cell line. These data were compared with those obtained from patients who required MV without respiratory disease (V, n = 4), controlled asthma (A, n = 11), and nonsmoking healthy volunteers (C, n = 8). Levels of IL-1, IL-6, TNF-alpha, and of the active form of TGF-beta1 were significantly higher in SA compared with the other groups. The concentrations of IL-1Ra, IL-10, the latent form of TGF-beta1, and of the sTNFRI and II were not significantly different between SA and V, albeit higher in SA than in A and C. The ratio between IL-1Ra and IL-1beta was significantly higher in patients with SA compared with the other groups, whereas there was no difference for the ratio between both types of sTNFR and TNF-alpha. Despite a marked increase of anti-inflammatory mediators in BL from patients with SA, the net inflammatory activity was found to be proinflammatory and mainly due to the presence of bioactive IL-1beta (79% inhibition of ICAM-1 expression with anti-IL-1beta antibodies) and to a lesser extent TNF-alpha (32% inhibition with anti-TNF-alpha antibodies).

Impaired perception of dyspnea in patients with severe asthma. Relation to sputum eosinophils

Poor dyspnea perception might be a risk factor for developing asthma exacerbations. We investigated whether severe asthmatics with recurrent exacerbations (brittle asthma) have different dyspnea perception and sputum cells compared with equally severe, but stable asthmatics, or patients with mild steroid-naive asthma. Fifteen brittle asthmatics (13 female, median age 28 yr [range, 20 to 47 yr]), 15 matched severe-stable asthmatics (14 female, median age 26 yr [range, 17 to 52 yr]), and 11 mild asthmatics (8 female, median age 25 yr [range, 19 to 43 yr]) underwent inhalation tests with methacholine (MCh), and hypertonic saline combined with sputum induction. Dyspnea was assessed by Borg and Visual Analogue Scale (VAS), plotted against the percent fall in FEV1, and expressed as the slope of the regression line (Slope-Borg and Slope-VAS). The brittle and stable asthmatics had poorer perception than patients with mild asthma (Slope-Borg [p = 0.036], Slope-VAS [p < 0.001] for MCh). In patients with brittle asthma the perception was less as compared with severe-stable asthma (Slope-Borg for MCh: p = 0.05). In the severe asthmatics there was an inverse correlation between sputum eosinophilia and Slope-Borg and Slope-VAS (R = -0.55, p = 0. 002 and R = -0.37, p = 0.049), whereas this correlation was a positive one in the mild asthmatics (R = 0.79, p = 0.012 and R = 0. 67, p = 0.05). In conclusion, patients with severe asthma, particularly those with recurrent exacerbations, have blunted perception of dyspnea, which is related to the degree of sputum eosinophilia. This suggests that increased sputum eosinophilia is an indicator of clinical instabililty, and that eosinophilic airways inflammation might affect dyspnea perception in severe asthma.

Structural alterations and inflammation of bronchi in asthma

The structural and inflammatory changes occurring in the bronchi of asthmatics have been examined in specimens from subjects dying in status asthmaticus and from bronchial biopsies of subjects with mild asthma. Histological changes in the bronchi of asthmatics include shedding and damage of the airway surface epithelium and thickening of the reticular basement membrane. Exposure of an asthmatic subject to an allergen results in an immediate allergic response characterised by mast cell degranulation. This may be followed by a late-phase response involving eosinophil degranulation and differentiation of a myofibroblast phenotype which may be the precursor of increased amounts of bronchial smooth muscle present in chronic severe asthma. These changes are accompanied by vasodilatation, vascular congestion and consequent oedema, and result in thickening of the airway wall and reduction of the airway lumen. Mucus secretion further increases airflow resistance and, in conjunction with an inflammatory exudate, forms tenacious airway plugs which are characteristic of severe life-threatening attacks.

Bronchial neutrophilia in patients with noninfectious status asthmaticus

Cellular events that occur in status asthmaticus (SA) remain poorly investigated. Autopsy studies frequently emphasized about the presence of eosinophils in bronchial airway wall, whereas recent studies reported increased number of neutrophils in patients dying of sudden-onset fatal asthma. Mucus plugs occluding the bronchial lumen are almost constant features during SA. Bronchial lavage (BL) may be useful to remove mucus plugs in cases of atelectasis and/or refractory SA. We investigated the contribution of different cell types and cellular mediators (neutrophil elastase, eosinophil cationic protein [ECP], histamine, interleukin-8 [IL-8]) to the pathogenesis of SA. We studied 16 BL from eight patients undergoing mechanical ventilation (MV) for SA (time interval from onset of MV = Day 0 to Day 11), four BL from patients undergoing MV without preexisting respiratory disease (V), 11 BL from patients with stable asthma (A) and eight BL from healthy controls (C). SA exhibited higher number and percentage of neutrophils (81.5 +/- 4.5%) than V (44.3 +/- 12.2) (p < 0.05), A (6.9 +/- 2.7) and C (9.5 +/- 3.8) (p < 0.0001), and higher number of eosinophils than V, A, and C (p < 0.01). Neutrophil elastase, ECP, and IL-8 levels were dramatically increased in SA. Histamine was higher in SA than in C and V (p < 0.05). Bronchial neutrophilia was not related to concomitant bacterial infection as bacteriological cultures were positive in only three BL. Eosinophils, mast cells and histamine were higher in BL performed within the first 48 h of MV (p < 0.05) than in BL performed later on. Our results indicate that bronchial inflammation in SA differs from bronchial inflammation in mild asthma. Persistent bronchial neutrophilia is associated with increased eosinophils and mast cells in the early phase of SA. Neutrophils may result in tissue damage and participate to the shedding of the epithelium in SA.

Acute severe asthma: pathophysiology and pathobiology of gas exchange abnormalities

Acute severe asthma, or "status asthmaticus", is a devastating clinical condition ultimately resulting in life-threatening hypoxaemia. The pivotal intrapulmonary mechanism of this condition is profound ventilation/perfusion (V'A/Q') mismatch, characterized by a predominant bimodal blood flow pattern reflecting a marked deterioration (increase) of the dispersion of pulmonary blood flow. This V'A/Q' profile is consistent with the presence of numerous alveolar units with low V'A/Q' ratios, in which ventilation is markedly reduced, although never abolished, but perfusion is maintained. Further V'A/Q' worsening whilst breathing 100% O2 suggests the presence of an underlying vigorous hypoxic vascular response. Of equal importance, gas exchange disturbances are poorly related to the severity of reduced maximal airflow rates. Inhaled platelet-activating factor (PAF), both in normal individuals and asthmatic patients, results in moderate-to-severe disturbance of V'A/Q' status, a finding that is probably related to altered microvascular permeability within the airway wall. Salbutamol, but not ipratropium bromide, prevented all PAF-induced systemic and lung function abnormalities, possibly because venoconstriction in the bronchial circulation was antagonized. Taken together, these findings support the hypothesis that platelet-activating factor may play a critical role in the pathobiology of severe acute exacerbations of asthma.

Assessment of airway inflammation in children with acute asthma using induced sputum

The aims of this study were: to assess the safety of a sputum induction method using inhaled normal saline in children with acute asthma; and to investigate changes in sputum cell counts between acute exacerbations of asthma and its resolution. Ultrasonically nebulized normal saline was used to induce sputum from children (n = 8) presenting with acute asthma within 1 h of arrival and again at least 14 days later, after resolution of the exacerbation. Children received pretreatment with bronchodilator, and peak expiratory flow (PEF) was monitored throughout the procedure. Samples were analysed for total cell count, differential cell counts, and for eosinophils and neutrophils using specific immunochemical stains. Sputum induction was performed without adverse effect in each child with acute asthma. The mean fall in PEF from baseline during sputum induction was 5.3% during the acute attack and 3.4% at resolution. A shorter nebulization time was required to induce sputum in acute asthma than at follow-up (7.8 vs 13.9 min; p = 0.04). During acute asthma, there was an intense cellular infiltrate (mean total cell count 34 x 10(6) cells.mL-1), which resolved after recovery (1.9 x 10(6) cells.mL-1) (p = 0.04). The infiltrate was heterogenous, comprising eosinophils (6.7 x 10(6) cells.mL-1), neutrophils (5.4 x 10(6) cells.mL-1) and mast cells (0.47 x 10(6) cells.mL-1). Resolution of the exacerbation was accompanied by a significant fall in eosinophils and neutrophils (p < or = 0.04). Normal saline induction of sputum can be used to assess airway inflammation in acute asthma. Children with acute asthma have intense airway inflammation that is heterogeneous and involves neutrophils, eosinophils and mast cells.

Classification of severe asthma exacerbations: a proposal

The intensity of asthma exacerbations may vary from mild to severe. Many studies have demonstrated that the speed at which severe asthma exacerbation (SAE) develops varies among patients. In some asthmatics, the exacerbation comes on very quickly, whereas in others there is a progressive deterioration of clinical, functional and blood gas parameters. Sudden SAE are characterised by their explosive presentation and quick recovery. This evolution contrasts with that of patients with a slow onset SAE, who often need prolonged hospitalization. Absence of secretions suctioned from the airways during mechanical ventilation has been reported in sudden SAE, whereas large amounts of viscid mucus are found in patients with the slow onset SAE. The lungs of patients who died during a sudden onset SAE often show empty airways and a predominant neutrophilic infiltration in the bronchial epithelium, in contrast to the presence of abundant eosinophils in patients who died during a slow onset SAE. Sudden onset SAE may occur as sporadic cases or in outbreaks. Sporadic cases may result from the ingestion of nonsteroidal anti-inflammatory drugs (NSAID) in patients with intolerance to these products, massive exposure to common allergens and ingestion of foods containing sulphites. Asthma outbreaks have been described in many cities. In contrast to sudden onset SAE, slow onset SAE is characterized by a progressive deterioration, accompanied by an increase in the use of bronchodilators. Lack of appropriate monitoring of function by peak expiratory flow (PEF) recording, failure of patients to recognize worsening symptoms and underusage of inhaled and oral steroid treatment have been repeatedly identified as factors which are likely to be associated with slow onset SAE. The contribution of psychosocial problems, depression, denial of asthma severity and nonadherence with the treatment should not be overlooked in patients with slow onset SAE. Classification of severe asthma exacerbations into two types (sudden onset and slow onset) could help to reveal the aetiology of the attack and may also be relevant to the management of the patient.

Myofibroblast and elastic and collagen fiber hyperplasia in the bronchial mucosa: a possible basis for the progressive irreversibility of airway obstruction in chronic asthma

Considering the role proposed for myofibroblasts in inflammatory and hyperelastotic lung diseases, the possibility arises that these cells are involved in bronchial pathology, including asthma. To address this issue, we have analyzed by light microscopy, histochemistry and immunohistochemistry the structure of extra- and intra-pulmonary bronchi of patient died of asthma. We have demonstrated hyperplasia of connective tissue cells and fibers in the mucosa, all around the lumen of extra- and intra-pulmonary bronchi. The cells were thin and elongated, labeled by anti-actin and anti-vimentin antibodies and interspersed with many elastic and collagen fibers, therefore they were interpreted as myofibroblasts. These findings may explain the rigidity of the bronchial wall in patients with asthma, which causes the progressively more limited resolution of airway obstruction upon pharmacological treatment and the gross anatomical finding of bronchial stiffness at inspection of the lungs. The possibility should also be considered that myofibroblasts and elastic--not collagen--fibers have contributed to bronchial hyperreactivity at an early stage of the disease.

[A clinical and morphological study of status asthmaticus]

Clinical and morphologic studies were carried out in 230 patients suffering a grave course of an exacerbation of infectious bronchial asthma. A protracted attack of the condition was detected in 70 patients, in 80 patients status asthmaticus, Stages I-II was found, 50 patients suffered a Stage III status asthmaticus, and 30 patients were hospitalized in the terminal state and died within 12 hours since admission. The circulatory, metabolic, immunologic homeostasis parameters were studied, morphologic, examination of pulmonary, tracheal, cardiac, cerebral, splenic and hepatic tissue was carried out in 30 patients who died at the height of the status asthmaticus. The authors have analyzed the contribution of the homeostasis parameters to the formation of the critical state in status asthmaticus and the relationships of these parameters between each other and with the condition severity. The severity of the patients' condition was found closely related to the degree of respiratory, circulatory, and metabolic disturbances. Respiratory failure and circulatory disorders were the principal clinical manifestations of status asthmaticus, though the disorders of the metabolic and immunologic homeostasis also much contributed to the formation of a critical condition due to status asthmaticus. Characteristic histomorphologic changes of the viscera, detected at autopsy, were the morphologic equivalent of these clinical symptoms. The findings regarding status asthmaticus as a critical state that is characterized by the development of multiorgan insufficiency involving the formation of incompetence of natural detoxication routes.

[Coma polyneuropathy after cardiopulmonary resuscitation]

A 60 year old female patient developed an acute polyneuropathy a few days after a successful cardiopulmonary reanimation followed by coma for several days. Recovery was good as demonstrated at one year follow-up. Residual damage consisted in very mild myoclonic jerks (abortive Lance-Adams syndrome).

T lymphocytes and activated eosinophils in airway mucosa in fatal asthma and cystic fibrosis

With the use of monoclonal antibodies (mAb) and immunohistology, the numbers of phenotypically distinct cells infiltrating lung tissue from 15 postmortem (PM) cases of fatal asthma were quantified and compared with 6 cases of cystic fibrosis (CF) (three postmortem, three transplant) and 10 nonasthmatic cases of sudden death matched for age and sex. Tissue eosinophilia was significantly greater (p less than 0.001) in the fatal asthma group than in the CF or sudden death controls. In asthma, approximately 40% of the eosinophilic infiltrate was EG2 positive (an indication of eosinophil activation and secretion of eosinophil cationic protein). The numbers of eosinophils and EG2 positive cells were significantly elevated in the subjects with acute severe asthma who had had a duration of terminal illness exceeding, as compared with less than, 24 h (p less than 0.05). When compared with the sudden death controls, there were increases in the numbers of Dako L C positive cells (i.e., CD45 positive "total leukocytes") in both fatal asthma and CF (p less than 0.01 and 0.05, respectively). The mean number of MT-1 positive (T) cells in the asthma and CF groups was approximately twice that of the control (p less than 0.05 and 0.01, respectively). The mean number of MB2 positive (B) cells was similar for both the asthma and sudden death control groups but was significantly increased in CF (p less than 0.05). The average T:B cell ratios were 6:1, 1:1, and 2:1 in the fatal asthma, CF, and control groups, respectively. The results support a role for the T lymphocyte in the pathogenesis of fatal asthma and CF.(ABSTRACT TRUNCATED AT 250 WORDS)

Marked goblet cell hyperplasia with mucus accumulation in the airways of patients who died of severe acute asthma attack

To examine the changes in airways in bronchial asthma (BA) during an asthma attack causing death, we performed morphometric analysis of autopsied lungs from three outpatients who died of severe acute asthma attacks (group A) and compared these to five patients who died of non-status asthmaticus (group B). Controls (group NL) were four patients who died of diseases other than respiratory disorders. Area proportions of bronchial glands to bronchial wall (gland [percent]) and of goblet cells to total epithelial layer (goblet [percent]) and the intraluminal amount of mucus in the airways (MOR) were measured in a paraffin section. There were no significant differences in age, sex, smoking history, duration of BA history, and dosage of glucocorticoids received between groups A and B. Although both groups A and B showed significantly larger values of gland (percent) in the central airways and of inflammatory cell numbers in the airway walls than did group NL, no significant differences were observed between groups A and B. In contrast, markedly significant increases in goblet (percent) and in MOR were observed in group A compared to groups B and NL. These increases in group A were more dominant in the peripheral airway: 30-fold and threefold increases of group B in goblet (percent) and MOR, respectively. Furthermore, MOR significantly correlated with goblet (percent) in the peripheral airways (p less than 0.05). These findings suggest that a marked increase in goblet cells of the airways is a feature characteristic of patients with BA who die of a severe acute attack.

Adrenal atrophy at autopsy in two asthmatic children

In two children dying in status asthmaticus, adrenocortical atrophy was demonstrable at autopsy. Both children had been treated since infancy with pulsed steroidal inhalers, short courses of oral or parenteral steroids, and steroidal skin preparations (for associated eczema). Adrenocortical atrophy has not been described previously in this clinical context. The increasing administration of steroids to asthmatic children may lead to the production of overt--or more frequently, subclinical--atrophy of the adrenal cortices with important consequences to mortality and morbidity.

Inverse correlation of expiratory lung flows and sputum eosinophils in status asthmaticus

Seventy-six consecutive patients admitted to Los Angeles County General Hospital with acute asthma were studied. Blood and sputum smears for cell counts were obtained on all patients within 12 hours of admission. Fifty-one (67%) patients were able or willing to perform spirometry and flow/volume curves in the first 24 hours of hospitalization. The severity of airway obstruction as assessed by forced expiratory volume in one second (FEV1), maximum mid-expiratory flow rate (MMFR), and forced vital capacity (FVC) was compared with blood and sputum eosinophil counts. Although there was no relation between the blood eosinophilia and airway obstruction, an inverse relationship between the number of eosinophils in the sputum and airway flow rates was observed. Higher percentages of sputum eosinophils were associated with diminished flow rates. We believe that sputum eosinophils may be helpful in the initial assessment of severe bronchial asthma.

Characterization of airway mucus from a fatal case of status asthmaticus

We used density gradient methods to analyze mucus recovered from the airways of a patient who died from status asthmaticus. At postmortem the mucus that plugged the length of the bronchial tree could only be removed by cutting with forceps. It was dispersed in cesium bromide (CsBr) and examined in the analytical ultracentrifuge. Surprisingly, no macromolecular component was seen in the buoyant density region typical of mucus glycoprotein (at 1.5 g/ml). The gelatinous material migrated to the region of lowest density, typical of lipids, and thin-layer chromatography indicated that besides neutral lipids, a variety of phospho- and glycolipids (including gangliosides) were present. The residue left after the lipid extraction contained all sugar components of mucus glycoprotein, and alkaline borohydride cleaved oligosaccharides three to 12 sugars long, indicating that the sugars were O-glycosidically linked as in mucus glycoproteins. Prior desulfation of the residue increased the number of oligosaccharides released by borohydride; analysis showed the presence in these of components (glucose, methylmannuronate) not present in epithelial glycoprotein. A trace component of high buoyant density was also present: Glucose was the predominant component in this, but glycoprotein sugars were also present. The above results suggest that in status asthmaticus plugging of the airways with mucus can occur even in the absence of typical epithelial glycoprotein and that lipids play a crucial role in such plugging.

Status asthmaticus, severe acute asthma or severe exacerbation of asthma

"Status Asthmaticus" is an old term which has been defined in many different ways. Two distinctive features are usually used to identify "Status Asthmaticus": severity and lack of response to bronchodilators. However, the latter condition is not always observed and thus the term "Status Asthmaticus" basically implies severity. "Severe acute asthma" is a new term which has replaced "Status Asthmaticus". Nevertheless, a severe attack of asthma may occur suddenly or can take place after days or weeks of a progressive deterioration. A "Status Asthmaticus" can be "acute" or "subacute" according to the rate of deterioration; therefore the term "Severe acute asthma" is misleading. Since the term "Status Asthmaticus" essentially implies severity, severe attacks would be better described as "Severe exacerbation of asthma" (SEA). Classification of the SEA into two types (acute and subacute), could help to reveal the etiology of the attack and might also be relevant to the management of the patient. For instance an acute SEA can be seen in brittle asthma and in patients with aspirin intolerance. On the other hand, patients with the subacute form are refractory to bronchodilators and must be treated with corticosteroids.

Treatment of a patient with chronic bronchial asthma with many bronchoscopies and lavages using acetylcysteine: a case report

This Case Report is that of a young woman followed for 21 years, whose life was saved repeatedly by bronchoscopy and lavage to remove mucous plugs and casts from the tracheobronchial tree. In 1982, after again having a respiratory crisis and not having a bronchoscopy and lavage, she died. The pathology revealed a thickened hyalinized basement membrane and numerous mucous plugs filling the larger bronchi and bronchioles.

Appearance of basophils in the sputum of patients with bronchial asthma

A total of 108 samples of sputum obtained from twenty patients with bronchial asthma were examined for appearance of basophils and eosinophils. Both cell types are present in sputum during an asthmatic attack and disappear at the conclusion of the attack. Their presence correlates with the severity of the disease. It has previously been demonstrated that the blood basophils count falls during attacks of bronchial asthma, and the present study suggests that basophils move from the blood stream into bronchial tissue during the acute phase of an asthmatic attack.