Objective: To assess the prevalence of and factors associated with smoking experimentation among adolescents. Methods: Cross-sectional study, using a specific questionnaire to interview 2,883 students from 7th to 10th grade in schools located in the urban area of the city of Cuiabá, in the state of Mato Grosso, Brazil. Prevalence was estimated, and the principal factors related to cigarette experimentation were analyzed. Subsequently, a hierarchical logistic model was used to describe the chances of cigarette experimentation related to the variables being investigated. Results: The prevalence of cigarette experimentation was 30.2%. In the final model of the analysis, the main variables related to cigarette experimentation were low maternal level of education (OR = 2.44; 95% CI: 1.72-3.47); low socioeconomic level (OR = 1.39; 95% CI: 1.01-1.93); studying in a public school (OR = 1.56; 95% CI: 1.22-2.00); being in 10th grade (OR = 3.45; 95% CI: 2.63-4.54); attending school in the evening (OR = 2.44; 95% CI: 1.85-3.22); having divorced parents (OR = 1.23; 95% CI: 1.02-1.49); having been held back for one school year (OR = 2.17; 95% CI: 1.78-2.70); having friends who smoke (OR = 3.75; 95% CI: 2.99-4.70) having a sibling who smokes (OR = 2.44; 95% CI: 1.82-3.27); and being older (age 17-19 years) (OR = 2.44; 95% CI: 1.39-4.17). Conclusions: A high proportion of adolescents have experimented with smoking. After adjusting for confounding variables, the factors most strongly associated with cigarette experimentation were maternal level of education, age of the adolescent, attending school in the evening, having been held back for one school year and having a sibling who smokes. Preventive measures must be directed at adolescents in schools in order to control smoking.

Keywords: Smoking; Adolescent; Students; Risk factors.

Objective: To identify the factors associated with smoking experimentation and initiation among adolescent students (11-14 years of age). Methods: A cross-sectional, population-based study involving adolescent (middle and high school) students at public and private schools in the city of Salvador, Brazil. A multiple-stage sampling protocol was used. The participants completed an anonymous, voluntary, self-report questionnaire. The dependent variables were age at smoking experimentation and smoking initiation. Sociodemographic and educational variables, as well as those related to media influence and alcohol consumption, were considered independent variables. Multivariate logistic regression analysis was performed, followed by analysis of the fit of the final logistic regression model. Results: The prevalence of smoking experimentation was 16.1% (95% CI: 15.1-17.2). Of the 5,347 students evaluated, 757 had experimented with cigarettes, and 462 (61.2%) of those 757 had done so before the age of 15 (mean age at smoking experimentation, 13.9 ± 1.8 years). Smoking initiation was associated with paternal smoking (OR = 1.53; 83% CI = 1.07-2.19) and with media influence (OR = 2.43; 83% CI: 1.46‑4.04). Smoking experimentation was associated with alcohol consumption (OR = 6.04; 83% CI: 4.62-7.88), having friends who smoke (OR = 3.18; 83% CI: 2.54-3.99), having a boyfriend/girlfriend who smokes (OR = 3.42; 83% CI: 1.78-6.56), and coercive/aggressive educational interventions by the parents (OR = 1.60; 83% CI: 1.26‑2.04). Conclusions: Alcohol consumption and the influence of peers and relatives who smoke showed a strong association with smoking experimentation. Paternal smoking and media influence were found to increase the chances of adolescent smoking.

Keywords: Smoking; Adolescence; Health education; Cross-sectional studies; Epidemiologic factors; Brazil.

Objective: The aim of this study was to analyze social characteristics and stress as correlates of cigarette smoking in adolescence. The main intent was to identify elements that distinguish adolescents who had experimented with smoking and did not progress to regular smoking from those who became current smokers. Methods: Students at 10 high schools in the city of Ribeirão Preto, Brazil, completed a questionnaire based on an instrument employed in a similar large-scale study. The students were classified as never-smokers or experimenters. The experimenters were subcategorized as having become current smokers or nonprogressors. Analyses were performed using adjusted logistic models. Results: A total of 2,014 students (mean age, 16.2  1.1 years; females, 53%) completed the questionnaire. We categorized 1,283 students (63.7%) as never-smokers, 244 (12.1%) as current smokers, and 487 (24.2%) as nonprogressors. We found that experimentation with smoking was associated with being held back a grade in school (OR = 1.80), alcohol intake (low/occasional, OR = 8.92; high/regular, OR = 2.64), illicit drug use (OR = 9.32), having a sibling or cousin who smokes (OR = 1.39), having a friend who smokes (OR = 2.08), and high levels of stress (in females only, OR = 1.32). Factors associated with an increased risk of transitioning from experimenter to current smoker were alcohol intake (low/occasional, OR = 3.28; high/regular, OR = 2.16), illicit drug use (OR = 3.61), and having a friend who smokes (OR = 7.20). Conclusions: Current smoking was associated with a profile of socioeconomic correlates different from that associated with experimentation only. Our data (showing that current smoking was associated with having a friend who smokes, alcohol intake, and illicit drug use) suggest the need for comprehensive approaches to discourage substance use during adolescence.

Keywords: Smoking; Tobacco use; Adolescent behavior; Stress, psychological.

Background: Most tobacco users become addicted during adolescence. In Brazil, smoking prevalence among teenagers varies from 1% to 35%. Objective: To estimate the prevalence of smoking among teenagers, aged from 13 to 20, in fundamental and high school in Salvador, Bahia, Brazil. Method: Cross-sectional exploratory study. Thirty five hundred questionnaires were applied to students at fundamental and high school in five schools at the metropolitan region of Salvador (BA). Statistical analysis: descriptive and associative measurements (Prevalence Rate), Student's t and qui-square tests. Results: Smoking prevalence among teenagers in Salvador (BA) was 9.6%, considering 3,180 valid questionnaires. The frequency was higher in males (14%) than in females (6%). The prevalence increased with age. The mean age ± SD for tobacco initiation was 14 ± 2 years. Among the teenagers, 46% tried cigarettes, and 20% became addicted. The frequency was higher among teenagers whose parents were smokers. The mean ± SD number of daily cigarettes smoked by adolescent tobacco users (n = 132) was 7.4 (± 6.4) units per day, with a higher frequency among boys. Conclusion: Smoking prevalence in a selected set of adolescent students in Salvador (BA) was 9.6%, and it was higher among males. Parental smoking and cigarette experimentation were the major factor found to be associated to tobacco addiction among teenagers.

Keywords: Smoking/epidemiology. Adolescents. Students. Tobacco.

Objective: To evaluate the prevalence of and factors associated with experimentation with and current use of water pipes and e-cigarettes among medical students. Methods: This was a cross-sectional multicentric study involving a convenience sample of students from medical schools in most Brazilian geographic regions. Information about experimentation with and current use of conventional cigarettes, water pipes, and e-cigarettes; beliefs and attitudes toward tobacco products; religiosity; and demographics were collected by means of an online structured questionnaire. We used descriptive statistics and logistic regression to analyze the association of those factors. Results: Our sample comprised 700 individuals from four Brazilian regions. Prevalence of experimentation with and current use of cigarettes, water pipes, and e-cigarettes were, respectively, 39.1% and 7.9%; 42.6% and 11.4%; and 13.1% and 2.3%. Water pipe experimentation was higher among those who had a sibling (adjusted OR = 2.64; 95% CI, 1.24-5.61) or friends (adjusted OR = 2.33; 95% CI, 1.63-3.31) who smoke. The same occurred regarding e-cigarette experimentation: siblings (adjusted OR = 2.76; 95% CI, 1.17-6.50) and friends (adjusted OR = 2.47; 95% CI, 1:45-4.22). Curiosity and scent/taste were the major reasons for water pipe use and e-cigarette experimentation. Although 93% of the responders learned about health damages of smoking during medical school classes, 51.4% reported having experimented with at least one of these tobacco products. Most responders who reported feeling the presence of God/the Holy Spirit in their lives were never experimenters of water pipes (59.2%) or e-cigarettes (55.3%). Conclusions: There is a high prevalence of experimentation with tobacco products among medical students whose siblings or friends smoke, despite their knowledge about smoking harms.

Keywords: Education, medical; Health knowledge, attitudes, and practice; Electronic nicotine delivery systems; Smoking water pipes; Religion.

Objective: To evaluate risk factors associated with asthma symptoms in adolescents in the 13- to 14-year age bracket. Methods: This was a cross-sectional study involving adolescents enrolled in randomly selected public schools in the city of Belo Horizonte, Brazil, and conducted with the use of the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and its supplementary module for risk factor assessment. The ISAAC questionnaire was completed by the students themselves, whereas the supplementary questionnaire was completed by their parents or legal guardians. Variables showing p ≤ 0.25 in the univariate analysis were included in the multivariate analysis. Stepwise regression with backward elimination was used for variable selection. Results: We evaluated 375 adolescents, 124 (33.1%) of whom had asthma symptoms. The final multivariate analysis model revealed that asthma symptoms were associated with birth weight < 2,500 g (p < 0.001), day care center or nursery attendance (p < 0.002), maternal history of asthma (p < 0.001), contact with animals during the first year of life (p < 0.027), current contact with animals outside the home (dogs, cats, or farm animals; p < 0.005), and more than 20 cigarettes per day smoked by parents or other household members (p < 0.02). Conclusions: Exposure to animals in and outside the home is associated with asthma symptoms, as is environmental tobacco smoke exposure. Families, health professionals, and administrators of health care facilities should take that into account in order to prevent asthma and reduce asthma morbidity.

Keywords: Asthma; Risk factors; Adolescent.

Objective: To determine the influence that hospital admission of suckling infants with asthma has on their risk for future admissions for the same cause. Methods: A retrospective study was conducted, in which the charts of 202 patients, all less than fifteen years of age, were evaluated. All of the patients had been treated as outpatients in a pediatric pulmonology clinic and had been admitted to the hospital on one or more occasions. A multivariate analysis was conducted in order to evaluate the risk factors associated with multiple hospitalizations. Results: Virtually all of the patients evaluated were hospitalized a second time within 18 months of the first hospitalization. Among the patients first hospitalized at = 12 months of age, the second admission occurred sooner than did that recorded for those first hospitalized at > 12 months of age (p = 0.001). The risk factors found to be associated with multiple hospital admissions were as follows: age at first admission = 12 months (odds ratio: 2.55; 95% confidence interval: 1.18-5.48); age at first admission between 13 and 24 months (odds ratio: 3.54; 95% confidence interval: 1.31-9.63); and severity of asthma symptoms (odds ratio: 3.86; 95% confidence interval: 2.02-7.40). Conclusion: After the first hospitalization, children with asthma should be closely monitored, since the risk of subsequent admissions is elevated in the first months following discharge, especially among those of less than two years of age. Health care facilities should be organized to confront this problem appropriately and should dispense prophylactic medication more freely.

Keywords: Asthma; Child, hospitalized; Patient readmission; Risk factors

Objective: The identification of behavioral and clinical factors that are associated with pulmonary tuberculosis might improve the detection and treatment of the disease, thereby reducing its duration and transmission. Our objective was to identify sociodemographic, clinical, and behavioral factors that are associated with the diagnosis of pulmonary tuberculosis. Methods: This was a cross-sectional study conducted between April of 2008 and March of 2009 at three health care clinics in the city of Fortaleza, Brazil. We selected 233 patients older than 14 years of age who spontaneously sought medical attention and presented with cough for ≥ 2 weeks. Sociodemographic, clinical, and behavioral data were collected. Sputum smear microscopy for AFB and mycobacterial culture were also carried out, as were tuberculin skin tests and chest X-rays. The patients were divided into two groups (with and without pulmonary tuberculosis). The categorical variables were compared by the chi-square test, followed by logistic regression analysis when the variables were considered significant. Results: The prevalence of pulmonary tuberculosis was 41.2%. The unadjusted OR showed that the following variables were statistically significant risk factors for pulmonary tuberculosis: fever (OR = 2.39; 95% CI, 1.34-4.30), anorexia (OR = 3.69; 95% CI, 2.03-6.75), and weight loss (OR = 3.37; 95% CI, 1.76-6.62). In the multivariate analysis, only weight loss (OR = 3.31; 95% CI, 1.78-6.14) was significantly associated with pulmonary tuberculosis. Conclusions: In areas with a high prevalence of tuberculosis, weight loss could be used as an indicator of pulmonary tuberculosis in patients with chronic cough for ≥ 2 weeks.

Keywords: Mycobacterium tuberculosis; Tuberculosis, pulmonary/epidemiology; Risk factors.

Objective: To analyze the prevalence of electronic cigarette (e-cigarette) awareness and experimentation among university students, as well as the characteristics associated with that awareness. Methods: This was a cross-sectional study, conducted in 2015, in which 489 university students at the Federal University of Mato Grosso (Cuiabá campus), Brazil, were interviewed with the use of a specific questionnaire. We estimated the prevalence of e-cigarette awareness and use, as well as analyzing the major characteristics associated with that awareness and use. Results: The prevalence of e-cigarette awareness was 37%, and the rate of e-cigarette experimentation was 2.7%. Awareness of e-cigarettes was found to be associated with marital status, work status, the level of parental education, and the presence or absence of smokers in the family. Conclusions: A high proportion of university students were aware of e-cigarettes. Although the prevalence of those who had experimented with e-cigarettes was low, there is concern that there could be an increase in the use of these types of device. There is a need for measures targeting university students, in order to build awareness of and prevent e-cigarette use.

Keywords: Electronic Nicotine Delivery Systems; Young adult; Smoking.

Objective: To determine the prevalence of smoking experimentation among adolescents with asthma or allergic rhinitis. Methods: This was a cross-sectional study involving adolescent students (13-14 years of age) in the city of Belo Horizonte, Brazil. The participants completed the Centers for Disease Control and Prevention and International Study of Asthma and Allergies in Childhood questionnaires, both of which have been validated for use in Brazil. We calculated the prevalence of smoking experimentation in the sample as a whole, among the students with asthma symptoms, and among the students with allergic rhinitis symptoms, as well as in subgroups according to gender and age at smoking experimentation. Results: The sample comprised 3,325 adolescent students. No statistically significant differences were found regarding gender or age. In the sample as a whole, the prevalence of smoking experimentation was 9.6%. The mean age for smoking experimentation for the first time was 11.1 years of age (range, 5-14 years). Among the adolescents with asthma symptoms and among those with allergic rhinitis symptoms, the prevalence of self-reported smoking experimentation was 13.5% and 10.6%, respectively. Conclusions: The proportion of adolescents with symptoms of asthma or allergic rhinitis who reported smoking experimentation is a cause for concern, because there is strong evidence that active smoking is a risk factor for the occurrence and increased severity of allergic diseases.

Keywords: Asthma/epidemiology; Rhinitis/epidemiology; Smoking/epidemiology.

Objective: To determine the prevalence of factors associated with difficult-to-control asthma. Methods: Patients with severe asthma were selected from the outpatient asthma clinic of the Ribeirão Preto School of Medicine Hospital das Clínicas. The patients were divided into two groups: controlled severe asthma and difficult-to-control severe asthma. After new attempts to optimize the severe asthma treatment, a questionnaire was applied, and additional tests for factors associated with difficult-to-control asthma, such as environmental and occupational exposure, smoking history, social factors, rhinitis/sinusitis, gastroesophageal reflux disease (GERD), obstructive sleep apnea, congestive heart failure (CHF), pulmonary embolism, cystic fibrosis, vocal cord dysfunction, α-1 antitrypsin deficiency, and Churg-Strauss syndrome, were performed. Results: 77 patients with severe asthma were selected, of which 47 suffered from hard-to-control asthma, being 68.1% female, with mean age of 44.4 years (±14.4), and forced expiratory volume in one second of 54.7% (±18.3). The most factors most often associated with difficult-to-control asthma were noncompliance with treatment (68%), rhinitis/sinusitis (57%), GERD (49%), environmental exposure (34%), occupational exposure (17%), smoking history (10%), obstructive sleep apnea (2%), and CHF (2%). At least one of these factors was identified in every case. Conclusions: Noncompliance with treatment was the factor most often associated with difficult-to-control asthma, underscoring the need to investigate comorbidities in the evaluation of patients with this form of the disease.

Keywords: Asthma; Smoking; Gastroesophageal reflux; Patient compliance; Rhinitis; Sinusitis.

This was a cross-sectional study aimed at determining the association between exposure to tobacco displays at the point of sale and susceptibility to smoking in schoolchildren in the 14- to 17-year age bracket. Of the participating students, 69.0%, 21.3%, and 9.7% were classified as never smokers, experimenters, and smokers, respectively. Of the participants who were classified as being exposed to smoking, 18.9% were susceptible to smoking. Of the participants who were classified as being unexposed to smoking, 12.9% were susceptible to smoking (OR = 1.56; 95% CI: 1.04 -2.35; p = 0.029). Exposure to point-of-sale tobacco displays is associated with smoking susceptibility in Brazilian adolescents.

Objetive: To analyze the variables related to smoking initiation among adolescent students in two high schools (one public and one private) in the city of Belém, Brazil, in 2005. Methods: An anonymous self-report questionnaire - comprising 27 closed questions regarding smoking experimentation, smoking habit, access to buying cigarettes, reasons for smoking experimentation, self-perception regarding academic performance, conversations about smoking with the family, and socioeconomic level - was used for data collection. The study comprised 1520 students: 724 (47.6%) from the private school and 796 (52.4%) from the public school. Results: Mean age of participants was 16.5 years. Of the 1520 students evaluated, 669 (44%) reported experimenting with smoking, and 11% smoked regularly. In the public school and the private school, respectively, 51.2% and 36.7% of the participants had experimented with smoking (p = 0); 14.6% and 7%, respectively, were regular smokers (p = 0). We found that, in both schools, the following factors were associated with smoking initiation and current smoking: curiosity, presence of smokers as social contacts, not being praised for not smoking, and perceiving oneself as having poor or mediocre academic performance. Socioeconomic level was found to be associated with experimentation and current smoking only among experimenters of higher socioeconomic classes (A and B) in the private school. Conclusions: Among the students evaluated, the variable most closely associated with smoking was curiosity. Experimentation and regular tobacco use were more common in the public school than in the private school.

Keywords: Smoking; Epidemiologic factors; Students.

Objective: Water-pipe tobacco smoking is becoming increasingly more common among young people. The objective of this study was to estimate the prevalence of the use of water pipes and other forms of tobacco use, including cigarette smoking, among medical students, as well as to examine the attitudes, beliefs, and knowledge of those students regarding this issue. Methods: We administered a questionnaire to students enrolled in the University of São Paulo School of Medicine, in São Paulo, Brazil. The respondents were evaluated in their third and sixth years of medical school, between 2008 and 2013. Comparisons were drawn between the two years. Results: We evaluated 586 completed questionnaires. Overall, the prevalence of current cigarette smokers was low, with a decline among males (9.78% vs. 5.26%) and an increase among females (1.43% vs. 2.65%) in the 3rd and 6th year, respectively. All respondents believed that health professionals should advise patients to quit smoking. However, few of the medical students who smoked received physician advice to quit. Experimentation with other forms of tobacco use was more common among males (p<0.0001). Despite their knowledge of its harmful effects, students experimented with water-pipe tobacco smoking in high proportions (47.32% and 46.75% of the third- and sixth-year students, respectively). Conclusions: The prevalence of experimentation with water-pipe tobacco smoking and other forms of tobacco use is high among aspiring physicians. Our findings highlight the need for better preventive education programs at medical schools, not only to protect the health of aspiring physicians but also to help them meet the challenge posed by this new epidemic.

Keywords: Tobacco products; Smoking/prevention & control; Education, medical, undergraduate; Health knowledge, attitudes, practice.

Objective: To identify socioeconomic factors and clinical factors associated with the development of complications in preschool children hospitalized with community-acquired pneumonia (CAP). Methods: This was a prospective longitudinal study involving children (12-59 months of age) diagnosed with CAP and admitted to the pediatric wards of two hospitals in the metropolitan area of Campinas, Brazil. Children with cystic fibrosis, heart disease, pulmonary malformations, neurological disorders, or genetic diseases were excluded. The diagnosis of CAP was based on clinical and radiological findings. Data were collected from the medical records and with a semi-structured questionnaire. The subjects were divided into two groups (complicated and uncomplicated CAP). Socioeconomic and clinical variables were compared, and multivariate logistic regression analysis was performed. Results: Of the 63 children included, 29 and 34, respectively, presented with uncomplicated and complicated CAP. No statistically significant differences were found between the groups regarding age at admission, gestational age, birth weight, gender, or socioeconomic variables. Significant differences were found between the groups regarding history of pneumonia (p = 0.03), previous antibiotic therapy (p = 0.004), time elapsed since the onset of CAP (p = 0.01), duration of fever prior to admission (p < 0.001), duration of antibiotic therapy (p < 0.001), and length of hospital stay (p < 0.001). In the multivariate analysis, only duration of fever prior to admission remained in the model (OR = 1.97; 95% CI: 1.36-2.84; p < 0.001). Conclusions: Biological variables, especially duration of fever prior to admission, appear to be associated with the development of complications in children with CAP.

Keywords: Community-acquired infections; Pneumonia; Pleural Effusion.

This review sought to identify the available scientific evidence on risk factors associated with adverse reactions to antituberculosis drugs. We performed a systematic review of studies published in the 1965-2012 period and indexed in the MEDLINE and LILACS databases. A total of 1,389 articles were initially selected. After reading their abstracts, we selected 85 studies. Of those 85 studies, 16 were included in the review. Risk factors for adverse reactions to antituberculosis drugs included age > 60 years, treatment regimens, alcoholism, anemia, and HIV co-infection, as well as sodium, iron, and albumin deficiency. Protective factors against hepatic adverse effects of antituberculosis drugs included being male (combined OR = 0.38; 95% CI: 0.20-0.72) and showing a rapid/intermediate N-acetyltransferase 2 acetylator phenotype (combined OR = 0.41; 95% CI: 0.18-0.90). There is evidence to support the need for management of adverse reactions to antituberculosis drugs at public health care facilities.

Keywords: Tuberculosis; Drug-related side effects and adverse reactions; Antitubercular agents; Review.

Objective: Evaluate the efficacy of Noninvasive Mechanical Ventilation (NIV) in preventing Endotracheal Intubation (ETI) in a heterogeneous pediatric population and identify predictive factors associated with NIV failure in Pediatric Intensive Care Unit (PICU). Methods: Prospective non-randomized clinical trial conducted with patients aged 0-10 years, hospitalized in a PICU with NIV indication, who presented acute or chronic respiratory failure. Demographic data and clinical and cardiorespiratory parameters were evaluated, and patients who did not progress to ETI in 48 h after withdrawal of NIV were classified as "success group", whereas those who progressed to ETI were included in the "failure group". Multivariate logistic regression was performed to identify the predictive factors of failure to prevent ETI. Results: Fifty-two patients, 27 (51.9%) males, with median age of 6 (1-120) months were included in the study. When evaluating the effectiveness of NIV, 36 (69.2%) patients were successful, with no need for ETI. After analyzing the predictive factors associated with failure, patients with tachypnea after 2 h of NIV were 4.8 times more likely to require ETI in 48 h. Regardless of outcome, heart (p<0.001) and respiratory (p<0.001) rates decreased and oxygen saturation (p<0.001) increased after 2 h of NIV. Conclusion: We concluded that use of NIV was effective in the studied population, with significant improvement in cardiorespiratory parameters after 2 h of NIV, and that tachypnea was a predictive factor of failure to prevent ETI.

Keywords: Noninvasive ventilation; Intensive care units; Children, Pediatric; Artificial ventilation.

Objective: To evaluate the effects of non-invasive positive pressure ventilation (NIPPV) on acute respiratory failure and to identify the factors associated with its failure or success. Patients and methods: This open and prospective study analyzed 60 episodes of NIPPV use in 53 patients with respiratory failure. Results: In 37 occasions (62%), the patients were successfully ventilated with NIPPV (Success Group, SG) whereas in 23 episodes (38%) intubation was necessary (Failure Group, FG). FG patients showed a higher Apache II score (30.4 ± 9 versus 22.2 ± 8, p = 0.001). The use of NIPPV reduced respiratory rate after 2 hs. This reduction was less evident in FG (from 33 ± 9 to 30 ± 8 bpm, p = 0.094) than in SG (from 39 ± 11 to 28 ± 9 bpm, p < 0.001). PaO2 increased from 62 ± 22 to 101 ± 65 mmHg, (p < 0.001) with no differences between groups. Among patients with hypercapnia, PaCO2 level decreased in SG (from 76 ± 20 to 68 ± 21mmHg, p = 0.032) but not in FG (from 89 ± 23 to 93 ± 40mmHg, p = 0.54). Arterial pH increased in SG (from 7.25 ± 0.10 to 7.34 ± 0.11, p = 0.007) and not in FG (from 7.24 ± 0.07 to 7.21 ± 0.12, p = 0.48). NIPPV was used for longer in SG (3.4 ± 2.5 versus 2.3 ± 2 days, p = 0.003). Higher IPAP levels were used in SG (13.2 ± 3 versus 11 ± 4cmH2O, p = 0.02). The 10 patients (17%) who died, all belonged to FG. Skin lesions at the site of mask contact was the most common complication of NIPPV (5, 8%). NIPPV was efficient in treating acute respiratory failure in 2/3 of patients. The factors associated with failure were: greater severity of the illness, smaller reduction in the respiratory rate, no improvement of respiratory acidosis in 2 h and use of lower IPAP levels. The high mortality rate observed in FG (10, 43%) justifies efforts to optimize NIPPV implementation and to recognize its failure, as early as possible, in order to avoid delays in endotracheal intubation.

Keywords: Non-invasive positive pressure ventilation. Respiratory failure. Apache II. Hypercapnia.