This is a report on a methodological adaptation of the photogrammetric technique, which is used in other medical specialties, for use in analyzing respiratory movements. Photogrammetry and a model of photogrammetry designated biofotogrametria para análise da mecânica respiratória (BAMER, photogrammetric analysis of respiratory mechanics) were tested under previously described pathophysiological conditions: post-exercise dynamic hyperinflation using positive end-expiratory pressure. The BAMER model identified an increase in the thoraco-abdominal area following exercise using positive end-expiratory pressure. These results are comparable to those obtained with more robust systems of respiratory kinematics. The use of photogrammetry has value in many areas, since it produces quantitative data, being particularly relevant in pediatrics, in which monitoring resources are scarce.

Keywords: Biomechanics; Photogrammetry; Respiratory mechanics; Thoracic wall.

Objective: To test the applicability of a geometric model, adapted to the supine position, for the analysis of respiratory mechanics regarding changes in lateral thoracoabdominal areas in children with asthma. Methods: Nineteen children (mean age, 11.26 ± 1.28 years) performed isovolume maneuvers (IVMs) after maximal inspiration, followed by glottal closure and alternation of airflow between the abdominal and thoracic compartments. The maneuvers were recorded in a digital video camera placed perpendicularly to the movement plane, and the images of interest were selected. The geometric model was traced on each image based on surface landmarks of anatomical references. The traced areas were calculated using a computer program, and the results were converted into metric units (cm2) using a surface landmark of a known area. Relative contributions (RCs) of the subcompartments in relation to their original compartments and to the chest wall (CW) were calculated. Results: The model was based on 55 thoracic IVM images and 55 abdominal IVM images. Areas and subareas were compared between the maneuvers. There were significant differences in all subcompartments (p < 0.001). All of the RCs were significantly different for the CW (p < 0.001) but not for the ratios between the subcompartments and their original compartments. Conclusions: This geometric model, applied in children and adapted to the supine position, was effective in profiling changes in the thoracoabdominal silhouette during the IVMs, and the selected subdivisions were useful for the identification of areas contributing the most and the least to CW composition.

Keywords: Photogrammetry; Respiratory mechanics; Image processing, computer-assisted.

Objective: To assess airway hyperresponsiveness to 4.5% hypertonic saline solution in comparison to that obtained through challenge with other bronchoconstriction agents and in relation to patient allergic sensitization. Methods: A cross-sectional, experimental study was conducted, initially involving 85 subjects. After exclusions, the final sample consisted of 62 patients, divided into two groups: a study group of those with asthma (n = 45) and a control group of those with no asthma or allergies (n = 17). Hypertonic saline was nebulized using an ultrasonic nebulizer and administered successively for 0.5, 1, 2, 4 and 8 minutes until a drop in forced expiratory volume in one second of = 15% was achieved in relation to the baseline value. The level of specific immunoglobulin E to Dermatophagoides pteronyssinus level was determined by ImmunoCAP assay and was considered positive when > 0.35 kU/L. Results: In the 36 asthma group subjects presenting a response, the mean drop in forced expiratory volume in one second after hypertonic saline nebulization was 27.4%. None of control group subjects (immunoglobulin E < 0.35 kU/L) presented a positive response to hypertonic saline. The mean forced expiratory volume in one second for control group subjects was 9%. The results of a bronchial provocation test were negative in 9 of the asthma group subjects. The frequency of bronchial provocation test positivity was higher in the subjects presenting elevated levels of specific immunoglobulin E, indicating that there is a relationship between bronchial hyperresponsiveness and the level of specific immunoglobulin E. The sensitivity and specificity of the test were 80% and 92%, respectively. Conclusion: Bronchial provocation with hypertonic saline presents satisfactory sensitivity and specificity. Therefore, in addition to being a low cost procedure that requires very little equipment, it is a useful means of assessing hyperresponsiveness in children and adolescents.

Keywords: Bronchial provocation tests; Bronchial hyperreactivity; Saline solution, hypertonic; Administration, inhalation;

There has been an increase in hospital admissions and mortality rates for asthma in several countries. The objectives of this study were to assess hospital morbidity for asthma in Curitiba and mortality rates for asthma in Curitiba and in the State of Paraná. Hospital admissions for asthma in 1994 and 1995 were analyzed among users of SUS-Sistema Único de Saúde (Public health care system) in Curitiba. The authors verified asthma deaths that occurred from 1984 to 1995 in Curitiba and in the State of Paraná. Specific mortality rates for asthma were obtained through a mortality information system (SIM) of the State and City Departments of Health. Population data were obtained from IPARDES (Institute for Demographic and Statistical Information of the State of Paraná). Hospital admissions for asthma represented 0.8% of total admissions and remained unchanged in 1994 and 1995. Mean mortality rates for asthma was 0.24 ± 0.08/100,000 inhabitants aged 5 to 34 years. In 1989, the mortality rate was greater than the positive standard deviation, but was stable in the remaining years. In Curitiba, the mean mortality rate was 0.39 ± 0.28/100,000. Two peaks occurred in 1984 and 1989, respectively 1.04 and 0.81/100,000. Despite an increase in prevalence of asthma and increasing mortality rates in the past years, Curitiba and the State of Paraná remained with stable rates for ages 5 to 34.

Keywords: Asthma. Mortality rates. Morbidity.

Background: Several factors influence the pulmonary function values considered normal. In children of short stature, there are difficulties in interpreting the pulmonary function. Objective: To assess spirometric values in children and adolescents with short stature and to identify a correction factor to adequately predict the expected values for this population. Method: A prospective selection of 77 patients was made, all with short stature and no respiratory disease. These patients were submitted to spirometry, transcutaneous hemoglobin oxygen saturation, chest perimeter measurement, and immediate hypersensitivity testing. Bone age was assessed by wrist X-rays. The data obtained by spirometry (FVC, FEV1, and FEF25-75%) were compared with those of Polgar and Promadhat (1971), predicted in three ways: a) by actual height; b) by height estimated at the 50th percentile for chronological age (CA); c) by height estimated at the 50th percentile for bone age (BA). Results: The mean height was 133.3 ± 13.2 cm, and the deficit in relation to the third percentile was 5.4 ± 6.0 cm. The values obtained for FVC, FEV1, FEF25-75%, were significantly higher than those predicted by actual height. The mean FEV1 obtained was 2.42 ± 0.71 L, and the predicted (actual height) was 2.10 ± 0.64 L; according to the height estimated by BA and CA, the values were 2.27 and 2.86 L, respectively. The mean FVC1 was 2.20 ± 0.6 L, and the predicted was 1.90 ± 0.55 L. With the height estimated for bone age and chronologic age, the predicted values were 2.10 and 2.60 L, respectively. Conclusion: Children and adolescents with short stature have higher spirometric values than predicted for their actual height. These findings suggest that the height estimated at the 50th percentile for bone age can be used to evaluate pulmonary function.

Keywords: Lung function. Short stature.

Objective: To use clinical and spirometry findings in order to distinguish between the restrictive and nonspecific patterns of pulmonary function test results in patients with low FVC and a normal or elevated FEV1/FVC ratio. Methods: We analyzed the pulmonary function test results of 211 adult patients submitted to spirometry and lung volume measurements. We used the clinical diagnosis at the time spirometry was ordered, together with various functional data, in order to distinguish between patients presenting with a "true" restrictive pattern (reduced TLC) and those presenting with a nonspecific pattern (normal TLC). Results: In the study sample, TLC was reduced in 144 cases and was within the normal range in 67. The most common causes of a nonspecific pattern were obstructive disorders, congestive heart failure, obesity, bronchiolitis, interstitial diseases, and neuromuscular disorders. In patients given a working diagnosis of pulmonary fibrosis, pleural disease, or chest wall disease, the positive predictive value (PPV) for restriction was ≥ 90%. In males, an FVC ≤ 60% of predicted had a PPV for restriction of 98.8%. In females, the restrictive pattern was found in 84.4% of those with an FVC ≤ 50% of predicted. A difference of ≥ 0% between the FEV1% and the FVC% had a PPV for restriction of 89.5%. After performing logistic regression, we developed a point scale for predicting the restrictive pattern. Conclusions: In many patients with reduced FEV1, reduced FVC, and a normal FEV1/FVC ratio, the restrictive pattern can be identified with confidence through the use of an algorithm that takes the clinical diagnosis and certain spirometry measurements into account.

Keywords: Spirometry; Airway resistance; Respiratory function tests; Vital capacity.