Armando A. Almeida-Junior

Capnografia volumétrica na identificação da não homogeneidade da ventilação em crianças e adolescentes com asma persistente controlada

OBJECTIVES To study changes in the variables of volumetric capnography in children and adolescents with asthma compared with a control group and to investigate their changes with the use of bronchodilators and bronchial provocation test with methacholine. METHODS One hundred and three patients with controlled persistent asthma and 40 healthy volunteers participated in the study. All of them underwent volumetric capnography and spirometry. All asthmatics repeated the tests after bronchodilator use. Among 103 asthma patients, 33 underwent methacholine challenge test, and measures were recorded on three occasions: before and after methacholine and after bronchodilator use. RESULTS Compared with the control group, asthmatics had an increase in the slope of phase III normalized by tidal volume and decreases in tidal volume, forced expiratory volume in one second, forced vital capacity, rate of obstruction and forced expiratory flow between 25 to 75% of forced vital capacity. After bronchodilator use, there was an increase in spirometric variables, volume of anatomic dead space, and decrease in the slope of phase II normalized by tidal volume, but the slope of phase III normalized by tidal volume did not change. After methacholine, there was an increase in this variable, which decreased after bronchodilator use. CONCLUSIONS The increase in the slope of phase III normalized by tidal volume in asthma patients suggests that these patients have ventilation inhomogeneity in the distal air spaces, which may reflect chronic structural disorders or reversible acute changes seen on the bronchial provocation test.

Associação entre índice de ventilação e tempo de ventilação mecânica em lactentes com bronquiolite viral aguda

OBJETIVO: Avaliar a associacao entre tempo de ventilacao mecânica e variaveis antropometricas, clinicas e de funcao pulmonar, precocemente, em lactentes com insuficiencia respiratoria por bronquiolite viral aguda em ventilacao mecânica invasiva, e a evolucao temporal das variaveis significativamente correlacionadas. METODOS: Foram estudados 29 lactentes admitidos na unidade de terapia intensiva pediatrica do Hospital de Clinicas da UNICAMP, com diagnostico de bronquiolite viral aguda, definido por criterios clinicos e radiologicos. Lactentes com doencas cronicas ou instabilidade hemodinâmica foram excluidos. Todas as medidas foram feitas entre 24 e 72 horas em ventilacao mecânica, usando capnografia volumetrica e analise dos gases sanguineos. O tempo de ventilacao mecânica foi dividido em: menor ou igual que 7 dias e maior que 7 dias. A associacao entre o tempo de ventilacao e as variaveis analisadas foi determinada pelo coeficiente de correlacao de Spearman (rs) RESULTADOS: O tempo de ventilacao mecânica apresentou correlacao positiva significativa com a PaCO2 (rs = 0,45, p = 0,01) e com o indice de ventilacao (rs = 0,51, p = 0,005), e negativa com o pH (rs = -0,40, p = 0,03). Indice de ventilacao com valor de 37, avaliado do primeiro ao quinto dia, foi associado a risco progressivamente aumentado de tempo de ventilacao mecânica maior que 7 dias (OR = 4,2 no primeiro dia a 15,71 no quarto dia) CONCLUSOES: Indice ventilatorio, PaCO2 e pH, precocemente medidos, foram associados com tempo prolongado em ventilacao mecânica, refletindo a gravidade do disturbio ventilatorio e necessidade de suporte.

Volumetric capnography as a tool to detect early peripheric lung obstruction in cystic fibrosis patients

OBJECTIVE To compare spirometry and volumetric capnography (VCap) to determine if the capnographic values add more information about early lung disease in cystic fibrosis (CF) patients. METHODS This was a cross-sectional study involving CF patients: Group I (42 patients, 6-12 years of age); and Group II (22 patients, 13-20 years of age). The corresponding control groups were comprised of 30 and 50 healthy subjects, respectively. Forced vital capacity (FVC), forced expiratory volume in one second (FEV(1)), and the FEV(1)/FVC ratio was determined by spirometry. Using VCap, we measured peripheral oxygen saturation (SpO(2)), respiratory rate (RR), inspiratory time (IT), expiratory time (ET), and the phase III slope normalized by expiratory volume (phase III slope/Ve). RESULTS In comparison with control groups, all CF patients presented higher phase III slope/Ve values (p < 0.001) independent of the pulmonary disease stage. The phase III slope/Ve was significantly higher in the 24 patients who presented normal spirometry results (p = 0.018). The Group II patients showed lower FVC, FEV(1), FEV(1)/FVC (p < 0.05), and also lower SpO(2) values (p < 0.001) when compared with Group I patients. In comparison with Control Group II, the Group II patients presented higher RR (p < 0.001), and lower IT and ET values (p < 0.001). CONCLUSIONS Compared to the controls, all studied CF patients showed an increase in phase III slope/Ve values. VCap identified the heterogeneity of the ventilation distribution in the peripheral airways of CF patients who presented normal spirometry.

Capnografia volumétrica como meio de detectar obstrução pulmonar periférica precoce em pacientes com fibrose cística

OBJECTIVE: To compare spirometry and volumetric capnography (VCap) to determine if the capnographic values add more information about early lung disease in cystic fibrosis (CF) patients. METHODS: This was a cross-sectional study involving CF patients: Group I (42 patients, 6-12 years of age); and Group II (22 patients, 13-20 years of age). The corresponding control groups were comprised of 30 and 50 healthy subjects, respectively. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and the FEV1/FVC ratio was determined by spirometry. Using VCap, we measured peripheral oxygen saturation (SpO2), respiratory rate (RR), inspiratory time (IT), expiratory time (ET), and the phase III slope normalized by expiratory volume (phase III slope/Ve). RESULTS: In comparison with control groups, all CF patients presented higher phase III slope/Ve values (p < 0.001) independent of the pulmonary disease stage. The phase III slope/Ve was significantly higher in the 24 patients who presented normal spirometry results (p = 0.018). The Group II patients showed lower FVC, FEV1, FEV1/FVC (p < 0.05), and also lower SpO2 values (p < 0.001) when compared with Group I patients. In comparison with Control Group II, the Group II patients presented higher RR (p < 0.001), and lower IT and ET values (p < 0.001). CONCLUSIONS: Compared to the controls, all studied CF patients showed an increase in phase III slope/Ve values. VCap identified the heterogeneity of the ventilation distribution in the peripheral airways of CF patients who presented normal spirometry.

Does Experience Influence the Performance of Neonatal and Pediatric Manual Hyperinflation

BACKGROUND: Manual hyperinflation (MH) is used to improve mucociliary clearance and alveolar expansion in mechanically ventilated patients. Despite the popularity of MH, studies with adults have shown considerable variability in the results from its use. This study assessed if professional training on the application of MH influences its performance. METHODS: An experimental study was conducted with physiotherapists, including 11 with previous professional experience (experienced) and 11 without previous experience (inexperienced). They applied MH in a test lung model using self-inflating bags in 2 sizes (infant and pediatric) from 3 manufacturers (Hudson, Laerdal, and JG Moriya). The test lung simulated the lung mechanics of a newborn and a pediatric patient in 2 different clinical situations: at normal and reduced compliance. The professionals were instructed to perform MH as described in the literature. Measurements of inspiratory volume, peak inspiratory pressure, peak inspiratory flow, and peak expiratory flow were recorded using a pneumotachograph in each condition. RESULTS: The delivered peak inspiratory flow was higher in the experienced group (P = .03) than in the inexperienced group. This result was observed in both neonatal and pediatric self-inflating bags. There was no difference in the parameters delivered between the experienced and inexperienced groups. CONCLUSIONS: The experienced and inexperienced groups were similar in their overall MH performance; the only difference was the observation of the highest PIF in the results from the experienced group.

Neonatal and Pediatric Manual Hyperinflation: Influence of Oxygen Flow on Ventilation Parameters

BACKGROUND: Although self-inflating bags are widely used for manual hyperinflation, they do not allow ventilation parameters, such as pressure or volume, to be set. We studied the ventilation performance of neonatal and pediatric self-inflating bags. METHODS: We asked 22 physiotherapists to manually hyperinflate 2 lung models (neonatal and pediatric), using self-inflating bags from 3 manufactures (Hudson, Laerdal, and JG Moriya), with flows of 0, 5, 10, and 15 L/min. A pneumotachograph recorded tidal volume (VT), peak inspiratory pressure (PIP), peak inspiratory flow (PIF), peak expiratory flow (PEF), and inspiratory time. RESULTS: The VT, PIP, and inspiratory time delivered by the Hudson, Laerdal, and JG Moriya bags, in both neonatal and pediatric self-inflating bags, were significantly different (P < .001). The PEF and PIF delivered were different only when using the neonatal self-inflating bags (P < .001). The VT, PIP, and PIF delivered with a flow of 0 L/min were lower than with 15 L/min (P < .05) with all the tested bags, in both the neonatal and pediatric sizes. CONCLUSIONS: The performance of the tested neonatal and pediatric bags varied by manufacturer and oxygen flow. There was an increase in VT, PIP, and PIF related to the increase of oxygen flow from 0 L/min to 15 L/min. The neonatal bags showed higher ventilation parameters variation than the pediatric bags.