Clinical standards for the diagnosis and management of asthma in low- and middle-income countries

BACKGROUND: The aim of these clinical standards is to aid the diagnosis and management of asthma in low-resource settings in low- and middle-income countries (LMICs).METHODS: A panel of 52 experts in the field of asthma in LMICs participated in a two-stage Delphi process to establish and reach a consensus on the clinical standards.RESULTS: Eighteen clinical standards were defined: Standard 1, Every individual with symptoms and signs compatible with asthma should undergo a clinical assessment; Standard 2, In individuals (>6 years) with a clinical assessment supportive of a diagnosis of asthma, a hand-held spirometry measurement should be used to confirm variable expiratory airflow limitation by demonstrating an acute response to a bronchodilator; Standard 3, Pre- and post-bronchodilator spirometry should be performed in individuals (>6 years) to support diagnosis before treatment is commenced if there is diagnostic uncertainty; Standard 4, Individuals with an acute exacerbation of asthma and clinical signs of hypoxaemia or increased work of breathing should be given supplementary oxygen to maintain saturation at 94-98%; Standard 5, Inhaled short-acting beta-2 agonists (SABAs) should be used as an emergency reliever in individuals with asthma via an appropriate spacer device for metered-dose inhalers; Standard 6, Short-course oral corticosteroids should be administered in appropriate doses to individuals having moderate to severe acute asthma exacerbations (minimum 3-5 days); Standard 7, Individuals having a severe asthma exacerbation should receive emergency care, including oxygen therapy, systemic corticosteroids, inhaled bronchodilators (e.g., salbutamol with or without ipratropium bromide) and a single dose of intravenous magnesium sulphate should be considered; Standard 8, All individuals with asthma should receive education about asthma and a personalised action plan; Standard 9, Inhaled medications (excluding dry-powder devices) should be administered via an appropriate spacer device in both adults and children. Children aged 0-3 years will require the spacer to be coupled to a face mask; Standard 10, Children aged <5 years with asthma should receive a SABA as-needed at step 1 and an inhaled corticosteroid (ICS) to cover periods of wheezing due to respiratory viral infections, and SABA as-needed and daily ICS from step 2 upwards; Standard 11, Children aged 6-11 years with asthma should receive an ICS taken whenever an inhaled SABA is used; Standard 12, All adolescents aged 12-18 years and adults with asthma should receive a combination inhaler (ICS and rapid onset of action long-acting beta-agonist [LABA] such as budesonide-formoterol), where available, to be used either as-needed (for mild asthma) or as both maintenance and reliever therapy, for moderate to severe asthma; Standard 13, Inhaled SABA alone for the management of patients aged >12 years is not recommended as it is associated with increased risk of morbidity and mortality. It should only be used where there is no access to ICS.The following standards (14-18) are for settings where there is no access to inhaled medicines. Standard 14, Patients without access to corticosteroids should be provided with a single short course of emergency oral prednisolone; Standard 15, Oral SABA for symptomatic relief should be used only if no inhaled SABA is available. Adjust to the individual's lowest beneficial dose to minimise adverse effects; Standard 16, Oral leukotriene receptor antagonists (LTRA) can be used as a preventive medication and is preferable to the use of long-term oral systemic corticosteroids; Standard 17, In exceptional circumstances, when there is a high risk of mortality from exacerbations, low-dose oral prednisolone daily or on alternate days may be considered on a case-by-case basis; Standard 18. Oral theophylline should be restricted for use in situations where it is the only bronchodilator treatment option available.CONCLUSION: These first consensus-based clinical standards for asthma management in LMICs are intended to help clinicians provide the most effective care for people in resource-limited settings.

A worldwide charter for all children with asthma

Childhood asthma is a huge global health burden. The spectrum of disease, diagnosis, and management vary depending on where children live in the world and how their community can care for them. Global improvement in diagnosis and management has been unsatisfactory, despite ever more evidence-based guidelines. Guidelines alone are insufficient and need supplementing by government support, changes in policy, access to diagnosis and effective therapy for all children, with research to improve implementation. We propose a worldwide charter for all children with asthma, a roadmap to better education and training which can be adapted for local use. It includes access to effective basic asthma medications. It is not about new expensive medications and biologics as much can be achieved without these. If implemented carefully, the overall cost of care is likely to fall and the global future health and life chance of children with asthma will greatly improve. The key to success will be community involvement together with the local and national development of asthma champions. We call on governments, institutions, and healthcare services to support its implementation.

Identifying pneumococci in parapneumonic pleural effusion: Is there a role for culture-independent methods?

OBJECTIVE

To evaluate culture-independent procedures (immunochromatography and quantitative polymerase chain reaction [qPCR]) in the detection and susceptibility of Streptococcus pneumoniae directly from culture-negative pleural fluid (PF) in children.

METHOD

Detection of S. pneumoniae in PF of children with parapneumonic effusion and/or empyema by using two culture-independent methods: an immunochromatographic membrane test (IMT) which identifies the pneumococcal C antigen, and a real-time PCR test to detect pneumococcal genes lytA and pbp2b, a marker of susceptibility of β-lactam agents, in PF samples.

RESULTS

We tested 36 PF specimens and recorded the previous use of antimicrobials. In the final analysis, 34 samples were included. IMT and qPCR presented positive results in 23 (67.6%) and 24 (70.6%) of the samples, respectively, showing a moderate agreement (k = 0.518) between the two methods. From the 36 children included, 34 (94.4%) had antibiotic data available by the time when PFs were collected. Thirty-four (100%) children had been given treatment before PF sampling, with 33 (97%) receiving β-lactam antibiotics administered empirically. Of the 24 lytA real-time positive samples, 21 (87.5%) were also positive for pbp2b, a marker of β-lactam susceptibility.

CONCLUSION

The reduced sensitivity of culture for pneumococcal detection can be improved through the addition of IMT and qPCR analysis. The utility of qPCR combining detection of lytA and a marker of β-lactam susceptibility should be explored further.

Health-related quality of life in post-infectious bronchiolitis obliterans: agreement between children and their proxy

OBJECTIVE

To assess the level of agreement in health-related quality of life between children with Post-infectious Bronchiolitis Obliterans and their parent (so-called proxy).

METHODS

Participants aged between 8and 17 years who had been previously diagnosed with Post-infectious Bronchiolitis Obliterans were regularly followed up at a pediatric pulmonology outpatient clinic. Parents or legal guardians (caregivers) of these patients were also recruited for the study. A validated and age-appropriate version of the Pediatric Quality of Life Inventory 4.0 was used for the assessment of health-related quality of life. Caregivers completed the corresponding proxy versions of the questionnaire. The correlation between self and proxy reports of health-related quality of life was determined by intra-class correlation coefficient and dependent t-tests.

RESULTS

The majority of participants were males (79.4%), and the average age was 11.8 years. Intra-class correlations between each of the Pediatric Quality of Life Inventory 4.0 domains and the total score were all lower than 0.6, with a range between 0.267 (poor) and 0.530 (fair). When the means of each domain and the total score of the questionnaires were compared, caregivers were observed to have a significantly lower health-related quality of life score than children, with the exception of the social domain in which the difference was not significant. However, the differences in score exceeded the critical threshold difference of four points in all other domains.

CONCLUSION

Proxies of children and adolescents with Post-infectious Bronchiolitis Obliterans appear to consistently perceive their children as having lower health-related quality of life than how the patients perceive themselves.

Postinfectious bronchiolitis obliterans in children: the South American contribution

Postinfectious bronchiolitis obliterans (PIBO) is an infrequent chronic lung that causes irreversible obstruction and, or, obliteration of the smaller airways. This review particularly focuses on more than 30 studies from South America.

CONCLUSION

The initial PIBO event occurs in the early years of life and is strongly associated with adenovirus infection and the need for mechanical ventilator support. Treatment requires a multidisciplinary strategy. Multicentre studies are needed to determine progression, optimal management and long-term follow-up.

Risk factors for need of mechanical ventilation in children with influenza A(H1N1)pdm09

OBJECTIVE

The pandemic caused by influenza A(H1N1)pdm09 virus peaked between July and August of 2009 in southern Brazil, with the highest incidence in children and young adults. In the post-pandemic period, there was an increase in the incidence of cases during the winter months of 2011 and 2012 in Brazil, similar to seasonal influenza virus. Since infections due to pandemic influenza are still occurring, the present study aimed to investigate the risk factors for worse outcome in children.

METHODS

A retrospective cohort study was performed by reviewing the charts of hospitalized patients younger than 14 years with reverse transcription-polymerase chain reaction (RT-PCR) positive for influenza A(H1N1)pdm09 during the first pandemic wave in six Brazilian tertiary centers. Need for mechanical ventilation was defined as the severity of outcome; age, chronic diseases, bacterial and viral co-detection, chest radiograph findings, and use of oseltamivir were possible predictors.

RESULTS

In the present study, 120 patients were included. In a multivariate analysis, chronic diseases (prevalence ratio: 2.613, 95% CI: 1.267-5.386) and viral co-detection (prevalence ratio: 2.43, 95% CI: 1.203-4.905) were statistically associated with worse outcome (p<0.05).

CONCLUSIONS

The presence of chronic diseases as predictors reinforces previous finding. Furthermore, viral co-detection was found to be a risk factor. Further studies are necessary to confirm this association.

A randomized, double-blind, placebo-controlled trial of cyproheptadine for appetite stimulation in cystic fibrosis

OBJECTIVE

To determine whether the administration of cyproheptadine was able to induce weight gain in patients with cystic fibrosis.

METHODS

We performed a double-blind, placebo-controlled trial in two centers in Brazil. Twenty-five patients with cystic fibrosis between 5 and 18 years completed the study. Patients were randomized into two groups, to receive either cyproheptadine 4 mg three times per day for 12 weeks or placebo. All data were collected at the beginning and at the end of the study period and included weight, height and spirometry.

RESULTS

Average weight gain was 0.67 kg in the placebo group and 1.61 kg in the cyproheptadine group (p = 0.036). Body mass index (BMI) decreased 0.07 kg/m(2); in the placebo group and increased 0.46 kg/m(2); in the intervention group (p = 0.027). The change in BMI for age (z score) was -0.19 in the placebo group and +0.20 in the cyproheptadine group (p = 0.003). BMI z score decreased 0.19 in the placebo group and increased 0.2 in the cyproheptadine group (p = 0.003). Changes in pulmonary function were not statistically different.

CONCLUSION

Use of cyproheptadine in cystic fibrosis patients was well tolerated, showing a significant weight gain and a significant increase in BMI after 12 weeks. A clinically relevant effect size for weight/age (z score) and body mass index for age (z score) was found. Such findings suggest that the prescription of cyproheptadine can be an alternative approach for patients who need nutritional support for a short period of time.

Post infectious bronchiolitis obliterans in children

Bronchiolitis Obliterans (BO) is an infrequent chronic and obstructive lung disease secondary to an insult to the terminal airway and its surroundings. In children, the most common presentation is the post-infectious variant, closely related to a severe viral infection in the first three years of life. However, the increase in the number of lung and bone-marrow transplants has also been followed by an increase in post-transplant BO. Post-transplant BO is progressive while post-infectious BO does not seem to be, but both forms share some common pathways that result in a characteristic histopathology of bronchiolar obliteration. This review covers up-to-date evidence on epidemiology, diagnosis, treatment and prognosis of post-infectious bronchiolitis obliterans, including areas of controversy that need to be addressed in future studies.

Performance of the ISAAC questionnaire to establish the prevalence of asthma in adolescents: a population-based study

BACKGROUND

The epidemiology of asthma has been investigated with questionnaires, such as the International Study of Asthma and Allergies in Childhood protocol.

AIM

To investigate the performance of the questions of the International Study of Asthma and Allergies in Childhood questionnaire to diagnose asthma in adolescents.

METHODS

This is a population-based cross-sectional study of adolescents in the Syndrome of Obesity and Risk Factors for Cardiovascular Disease study. The validity of the asthma symptoms of the International Study of Asthma and Allergies in Childhood protocol was assessed by calculating sensitivity, specificity, positive and negative posttest probabilities, and Youden's Index, taking as a gold standard the history of a medical diagnosis of asthma. Risk ratios (RRs) and 95% confidence intervals (CIs), adjusting for sex and age, were calculated using Cox regression model.

RESULTS

In total, 575 adolescents were investigated. Overall, 28.7% reported a lifetime medical diagnosis of asthma, and 40.0% reported at least one episode of wheezing. Ever wheezing had the highest sensitivity (80.6%) for the diagnosis of asthma, compared with the other ISAAC questions. Adolescents who reported ever wheezing were about 8 times more likely (adjusted RR: 8.3; 95% CI: 4.9-14.2) to have ever had asthma, independent of age and sex. Symptoms within the last 12 months (wheezing, cough without cold or respiratory infection, sleep disturbed due to wheezing, wheezing due to exercise, speech limited due to wheezing) had specificity of 92.0% or higher. Dry cough at night without cold or respiratory infection was the strongest independent predictor of asthma (adjusted RR: 8.8; 95% CI: 6.1-12.7).

CONCLUSIONS

Ever wheezing is the most sensitive indicator of the diagnosis of asthma but falsely identifies a portion of adolescents as asthmatic. Symptoms of asthma in the last 12 months, such as cough without cold or respiratory infection, are rarely positive in the absence of a lifetime asthma diagnosis. The combination of ever wheezing for screening and the presence of other symptoms within the past 12 months to confirm the diagnosis could be an effective strategy to identify the prevalence of asthma in communities.

Post-infectious bronchiolitis obliterans: can CT scan findings at early age anticipate lung function?

BACKGROUND

The image findings of post-infectious bronchiolitis obliterans (PIBO) have been described, however, we do not know if such findings can predict lung function (LF) deterioration with increasing patient age.

AIM

To assess whether computed tomography (CT) abnormalities detected at an early stage of the disease can anticipate abnormal LF a decade later in children with PIBO.

METHODS

We compared CT scans of 21 children with PIBO, done within their first 3 years of life, and their actual LF. To evaluate CT scans we used a modified Bhalla score and, for LF, FEV1 as percentage of predicted values. We calculated prevalence ratios (PRs) by comparing the proportion of patients with worst CT score and worst LF, with the proportion of those with best CT score and worst LF.

RESULTS

PR was 1.17 (CI 1.02; 1.34, P = 0.02).

CONCLUSIONS

The CT finding early in the life of children with PIBO, when assessed by the Bhalla, score seem to anticipate future LF status.

Acute lower respiratory illness in under-five children in Rio Grande, Rio Grande do Sul State, Brazil: prevalence and risk factors

This study aimed to determine the prevalence of acute lower respiratory illness and to identify associated factors among children less than five years of age in the city of Rio Grande, southern Brazil. Using a cross-sectional survey, a standardized household questionnaire was applied to mothers or guardians. Information was collected on household conditions, socioeconomic status, and parental smoking. Prenatal care attendance, nutritional status, breastfeeding pattern, and use of health services for the children were also investigated. Data analysis was based on prevalence ratios and logistic regression, using a conceptual framework. Among 771 children studied, 23.9% presented acute lower respiratory illness. The main risk factors were previous episodes of acute lower respiratory infection or wheezing, crowding, maternal schooling less than five years, monthly family income less than US$ 200, four or more people per room, asthma in family members, and maternal smoking. Mothers 30 years or older were identified as a protective factor. These results can help define specific measures to reduce morbidity and mortality due to acute lower respiratory illness in this setting.

The effect of adenotonsillectomy on oxygen saturation in children with sleep breathing disorders

OBJECTIVE

To evaluate the effect of adenotonsillectomy on the oxygen saturation measures by nocturnal pulse oximetry in children with sleep breathing disorders (SBD).

METHODS

A non-controlled clinical trial was performed. Thirty-one children with suspected SBD and a clinical indication for adenotonsillectomy were recruited. All of them underwent overnight oxygen saturation monitoring before and after surgery.

RESULTS

Twenty-seven patients completed the study. The mean age was 5.2+/-1.8 years. Eighteen (66.7%) were male. The most prevalent symptoms were: snoring (100%), respiratory pauses (96.8%), nocturnal mouth breathing (96.8%), restless sleep (80%) and drooling (74.1%). Twenty-three children (85.2%) presented grade 3 or 4 tonsillar hyperplasia. There was a significant improvement in the postoperative oxygen desaturation index (ODI) (0.65; 0.5-1.3) compared with the preoperative index (1.63; 1.1-2.4) (p<0.001).

CONCLUSION

Adenotonsillectomy improved the oxygen saturation measures by nocturnal pulse oximetry in children with sleep breathing disorders.

Changes in the prevalence of asthma and allergic diseases among Brazilian schoolchildren (13-14 years old): comparison between ISAAC Phases One and Three

The present study is aimed to describe the changes in the prevalence of symptoms of asthma, rhinitis and eczema among Brazilian adolescents (AD, 13-14 years old) between Phases 1 and 3 of the International Study of Asthma and Allergies in Childhood (ISAAC). The prevalence of self-reported symptoms of asthma, rhinitis and eczema in AD from five Brazilian cities (Curitiba, Porto Alegre, Recife, Salvador and São Paulo), obtained during ISAAC Phase 1 (n = 15 419) and Phase 3 (n = 15 684), was compared to determine the trend of prevalence in a 7-year interval. There was a trend to reduction in the current prevalence of wheezing and increasing of nocturnal cough when averaging figures from the five cities. The prevalence of wheezing in the last 12 months was 27.7 vs. 19.9% (p < 0.01); asthma ever 14.9 vs. 14.7% (p > 0.05); severe episode of wheezing 5.2 vs. 5.2%; nocturnal cough 32.6 vs. 34.9% (p < 0.01); exercise wheezing 23.6 vs. 23.0% (p > 0.05) and awake with wheezing 11.8 vs. 11.2% (p > 0.05). Similar things were observed with the prevalence of current symptoms of rhinitis and eczema. In Brazil, there was a small but significant mean decrease in the prevalence of two asthma-related symptoms, wheezing and nocturnal cough, though this trend was not consistent in the surveyed cities. The prevalence of asthma symptoms in Brazil, despite its mean trend to a decrease, is still one of the highest in Latin America.

Prevalence of symptoms of asthma, rhinitis, and atopic eczema in Brazilian adolescents related to exposure to gaseous air pollutants and socioeconomic status

OBJECTIVES

To evaluate the relationship between exposure to gaseous air pollutants (ozone [O3], carbon monoxide [CO], nitrogen dioxide [NO2], and sulfur dioxide [SO2]) socioeconomic status and the prevalence of symptoms of asthma, rhinitis and atopic eczema in adolescents.

SUBJECTS AND METHODS

A sample of 16 209 adolescents from São Paulo West (SPW), São Paulo South (SPS), Santo André (SA), Curitiba (CR), and Porto Alegre (PoA) were enrolled. Data on air pollutants and socioeconomic status were compared to prevalence of symptoms with the Spearman correlation coefficient.

RESULTS

Socioeconomic status was quite similar in all cities. The levels of O3 in SPW, SPS, and SA, and of CO in SA were higher than the acceptable ones. In relation to O3 and CO exposures, adolescents from SPW and SA had a significant risk of current wheezing, whereas living in SPW was associated with a high risk of rhinoconjunctivitis, eczema, and flexural eczema and living in CR to rhinitis. Exposure to NO2 was associated with a high risk of current wheezing in SPW and SA, and of severe asthma in SPW and PoA. Exposure to SO2 was associated with a high risk of current wheezing in SPW and SA, severe asthma in SPW and PoA, and nighttime cough, eczema, flexural eczema and severe eczema in SPW. Living in SPW, CR, or PoA was associated with a high risk of rhinitis, rhinoconjunctivitis, and severe rhinitis.

CONCLUSIONS

Although we did not detect a characteristic pattern for all symptoms evaluated or a specific air pollutant, our data suggest a relationship between higher exposure to photochemical pollutants and high prevalence or risk of symptoms of asthma, rhinitis, and atopic eczema.

Asthma in urban setting: a southern American perspective

To manage asthma in urban setting of developing countries is a challenge to the health system of developing countries. To reduce asthma morbidity (hospital admissions and emergency visits) is the main goal to be reached. It is necessary to adapt international guidelines considering the local constraints. The provision of free medication is mandatory. Education of parents and patients must be a priority of asthma programs.

Inhaled corticosteroid treatment and growth of asthmatic children seen at outpatient clinics

OBJECTIVE

To ascertain the effect of inhaled corticosteroid use on gain in height and weight of asthmatic pediatric outpatients.

METHODS

A one-year prospective cohort study was carried out with 124 asthmatic children aged 3 to 16 years who were prescribed inhaled corticosteroids for at least 12 months, evaluating z-scores for height/age, weight/age, body mass index and parental target height for current age. Exclusion criteria were: birth weight less than 2,500 g, malnutrition, chronic diseases and systemic corticoid use for more than 7 consecutive days.

RESULTS

The mean +/- standard deviation for z-scores for initial and final height/age were 0.06+/-1.2 and 0.01+/-1.2 (95%CI 0.05-0.11), respectively; for initial and final weight/age z-scores they were 0.6+/-1.5 and 0.5+/-1.5 (95%CI 1.84-6.6), respectively. These figures did not differ significantly (p = 0.199 and p = 0.808). There was also no loss in stature when children were stratified into well and poorly controlled asthma or into pubescent and non-pubescent groups.

CONCLUSIONS

In comparison with the NCHS (National Center for Health Statistics) growth curves, there was no compromise to the height or body weight of children/adolescents using inhaled corticosteroids for more than 1 year at the doses recommended for asthma prevention.

The burden of pneumonia in children in Latin America

Under-five mortality varies widely between countries, ranging from four to over 300 deaths/1000 live births. The World Summit for Children established the aim of a two-thirds reduction in worldwide child mortality by 2015. Progress toward this goal during 1990-2000 was variable between world regions. In 2000, 70% of the 1.89 million deaths of children under the age of 5 years due to acute respiratory infections occurred in developing countries. Among Latin American countries, Chile and Uruguay had the lowest percentage of deaths (5-10%), while Bolivia, Peru and Guyana had the highest (15-20%). Mortality rates due to lower respiratory infections have declined in most countries, increased in some and remained unacceptably high in others. To reach the 2015 goal of reducing mortality in the under-fives, effective interventions, such as breastfeeding and complementary feeding, Haemophilus influenzae type B vaccine, zinc supplementation and the use of antibiotics to treat pneumonia need to be implemented in all Latin American countries.

[Interobserver agreement in the radiological diagnosis of lower respiratory tract infections in children]

OBJECTIVE

To evaluate the inter-observer agreement of radiological diagnosis of lower respiratory tract infections in children.

METHODS

Chest X-rays from 60 children younger than 5 years of age were evaluated by three physicians: a pediatric radiologist (PR), a pediatric pulmonologist (PP) and an experienced emergency pediatrician (EP). All children had sought an emergency room due to acute respiratory infections with apparent lower respiratory tract involvement. Observers were blinded to the original diagnostic conclusions, but clinical and laboratory data from the initial medical evaluation were provided with each film. Variables were grouped into five categories: a) film quality; b) site of abnormality; c) radiological patterns; d) other radiographic images; e) diagnosis. Inter-observer agreement was assessed using Kappa statistics, accepting prevalence-bias-adjusted values (PABAK). compare the prevalence of breastfeeding and exclusive breastfeeding during the first six months of life among pacifier and non-pacifier users.

RESULTS

Kappa values for each of the three observer pairs (RP vs. PP, RP vs. EP, and PP vs. PE) were 0.41, 0.43, and 0.39, respectively. The overall inter-observer agreement was moderate (0.41). Agreement on other variables was as follows: regular for "film quality" (0.30); moderate for "site of abnormality" (0.48); fair for "radiological patterns" (0.29); moderate for "other radiographic images" (0,43); and moderate for "diagnosis" (0.33). The overall intra-observer agreement was "moderate" (0.54), which is below the agreement values reported by other studies on chest X-ray variability.

CONCLUSIONS

Inter-observer variability is an intrinsic characteristic of the interpretation of chest X-rays, and the diagnosis of lower respiratory tract infections in children remains a challenge. Most of our results were similar to those previously reported.

[Clinical and transcutaneous oxygen saturation characteristics in hospitalized infants with acute viral bronchiolitis]

OBJECTIVE

To describe the clinical characteristics of infants with acute viral bronchiolitis (AVB) and to assess the influence of oxygen desaturation time (DT) as a prognostic test to estimate the evolution of such patients.

METHODS

We performed a cohort study with 111 hospitalized patients diagnosed with AVB receiving oxygen therapy through nasal prong. The outcomes were: length of admission, length of oxygen therapy and time elapsed to read 95% saturation in room air. A severity score was obtained twice a day based on clinical signs during the time when the patient required oxygen supplementation. After the supply of oxygen was interrupted, the time required for transcutaneous oxygen saturation decreased to 90% and 85%. The Chi2 test or Fisher's exact test were used to compare categorical variables. The t test or Mann-Whitney's test were used for numerical variables. Spearman's correlation was used to evaluate associations in continuous variables with asymmetric distribution.

RESULTS

Most patients (61.3%) were younger than 4 months. Patients with wheezing history (45%) were analyzed separately and had similar results to those of the group with AVB (p< or =0.05). Twenty-six patients (23%) had moderate or severe malnutrition. All patients were using bronchodilators; 20% were using systemic corticosteroids; and 47%, antibiotics. The median time of oxygen therapy required for a reading of 95% oxygen saturation in room air was 83 hours (IQI 55-128). The median of length of admission was 7 days (IQI 5-10.5). Little clinical variability was observed in the period studied. No significant correlations were found between the clinical scores, DT and the outcomes.

CONCLUSION

DT was not useful as an aid to assess AVB patients on oxygen therapy in this study. It is possible that this tool could have been more useful in patients with more clinical variability.

[Respiratory illnesses in children younger than 5 years of age in southern Brazil: the influence of the home environment]

OBJECTIVE

To determine the prevalence of acute lower respiratory tract infections and the risk factors associated with living conditions among children up to 5 years of age in the city of Rio Grande, in the state of Rio Grande do Sul, Brazil.

METHODS

A population-based cross-sectional study was carried out with 775 children. A standardized questionnaire was administered to the mother or other caregiver at the child's home in order to collect information on housing conditions, socioeconomic status, and smoking in the home. Additional variables examined included nutritional status, duration of breast-feeding, prenatal care, and utilization of health care services. Environmental variables were analyzed individually and were also grouped together in an "environmental score" that encompassed 10 variables: type of house construction, type of floor, home heating system, type of stove, dog in the child's room, dog in the house, cat in the child's room, cat in the house, number of people per room, and maternal smoking. The grouped environmental score ranged from 0 (best) to 10 (worst). The analysis included two stages: a bivariate stage, in which the prevalence ratio was calculated for each risk factor, and a multivariate stage, with logistic regression.

RESULTS

The overall prevalence of acute lower respiratory tract infections was 23.9%. The main risk factors identified were: environmental score >/= 3 points, maternal schooling < 5 years, monthly family income < US$ 200, four or more people sharing the child's bedroom, and maternal smoking. Maternal age > or = 30 years was found to protect against the development of respiratory illness.

CONCLUSIONS

Specific programs need to be implemented to control acute respiratory illnesses in the population studied. In future studies with this population, the environmental score that we developed could be used in place of the complete set of environmental variables that we tested. This environmental score should be applied in other contexts so as to determine its external validity.

[Acute disease of the lower airways in children under five years of age: role of domestic environment and maternal cigarette smoking]

OBJECTIVE

To study the prevalence of acute disease of the lower airways and the role of the domestic environment and maternal smoking. Among the recognized risk factors, passive smoking, living in crowded environments and poor housing conditions play a fundamental role in the causal chain of these diseases.

METHODS

A cross-sectional study was carried out in a sample of 775 children aged between 0 and 59 months living in Rio Grande, southern Brazil. Trained interviewers applied a standardized questionnaire to the mothers or guardians of these children in their homes and gathered information about maternal characteristics, housing conditions, socio-economic status of the family and smoking habits. Environmental factors were individually studied, and classified according to a score that evaluated the intensity of their association with respiratory diseases. Bivariate analyses were performed, calculating the prevalence ratios for each risk factor, as well as multivariate ones, by means of non-conditional regression analyses.

RESULTS

The main risks identified were: unfavorable environment (P<0.01), less than five years of maternal educational level (P=0.01), monthly family income under US$ 200 (P=0.04), crowded environments (P=0.02), smoking during pregnancy (P=0.03) and present maternal smoking (P=0.01). A thirty-year-old or older mother was identified as offering a protection factor (P=0.05).

CONCLUSIONS

These results indicate the need to improve the income distribution, improve the rates of educational level, and combat the smoking habit, particularly concerning mothers. The programs of control of respiratory diseases must address these critical points that represent an important risk to children's health.

Viral etiology of acute respiratory infections among children in Porto Alegre, RS, Brazil

Although acute respiratory infections (ARIs) are a major cause of child morbidity and mortality in Southern Brazil, little information is available on their seasonality and viral etiology. This study was conducted on children under 5 years of age with ARI to assess viral etiology in the State of Rio Grande do Sul, from 1990 to 1992. A total of 862 nasopharyngeal secretion (NPS) samples were tested using indirect immunofluorescence. The results showed that 316 (36.6%) NPS samples were positive: 26.2% for RSV, 6% for adenovirus, 1.7% for influenza viruses, 1.5% for parainfluenza viruses, and 1.2% for mixed infection. The mean viral prevalence rates in out-patient services, emergency wards, and in-patient hospital wards were 26.7%, 53% and 42.3%, respectively. Respiratory syncytial virus (RSV) and adenovirus accounted for 91.4 % of the viral diagnoses. RSV was more frequent in children under one year of age at the three levels of health care and was prevalent in infants under six months. Adenovirus was the most prevalent pathogen in hospitalized children, in 1992. Influenza A virus showed an increased prevalence with age among out-patient children. This study shows the annual occurrence of viral respiratory infections in the coldest months, with a significant annual variation in the frequency of RSV infection.

[Association between gastroesophageal reflux and dips in the oxygen transcutaneous saturation of the hemoglobin in infants with chronic obstructive ventilatory disease]

OBJECTIVE: To verify the association between oxygen desaturation episodes and the dips in pH in infants with chronic obstructive respiratory symptoms. METHOD: Cross-sectional study with children 24 months old or younger hospitalized for investigation of chronic obstructive respiratory symptoms from 1997 to 1999. The patients underwent esophageal pH monitoring associated with transcutaneous oxygen saturation during the night. The patients were included in the study according to their need to be hospitalized and availability of equipment. The indices used to measure this association were reflux index, total number of refluxes, number of refluxes longer than 5 minutes, Euler index, ZMD index, 24-hour mean pH, and mean pH of desaturation. RESULTS: We studied 44 children. The mean age was 7.5 months, and 20% had desaturation below 93% during pH monitoring. We used the t test to compare the occurrence of desaturation with the pH monitoring parameters. We found higher significance with the reflux index (RI), number of episodes longer than 5 minutes, ZMD index, 24-hour mean pH, and mean pH of desaturation. The bivariate analysis, taking into account possible confounding factors and RI, showed PR equal to 6.61 (IC 95% 1.67 - 26.12) for an RI higher than 4%. CONCLUSION: Oxygen saturation monitoring associated with pH monitoring may be a useful tool to establish an association between GER and respiratory problems in patients with chronic or recurrent wheeze.

Respiratory syncytial virus (RSV) bronchiolitis: comparative study of RSV groups A and B infected children

The grouping characteristics of 29 respiratory syncytial virus (RSV) present in nasopharyngeal cells collected from hospitalized children with bronchiolitis during the 1990 RSV season in Porto Alegre, RS, were analysed. Twenty-two were grouped as belonging to group A and 7 to group B. Cyanosis, oxygen therapy, cough, length of hospitalization and atelectasis were observed to be more frequently found within group B infected children. Other clinical signs and symptoms were similarly found in both groups.