Helping students to understand physiological aspects of regional distribution of ventilation in humans: a experience from the electrical impedance tomography.

Undergraduate biomedical students often have difficulties in understanding basic concepts of respiratory physiology, particularly respiratory mechanics. In this study, we report the use of electrical impedance tomography (EIT) to improve and consolidate the knowledge about physiological aspects of normal regional distribution of ventilation in humans. Initially, we assessed the previous knowledge of a group of medical students ( n = 39) about regional differences in lung ventilation. Thereafter, we recorded the regional distribution of ventilation through surface electrodes on a healthy volunteer adopting four different decubitus positions: supine, prone, and right and left lateral. The recordings clearly showed greater pulmonary ventilation in the dependent lung, mainly in the lateral decubitus. Considering the differences in pulmonary ventilation between right and left lateral decubitus, only 33% of students were able to notice it correctly beforehand. This percentage increased to 84 and 100%, respectively ( P < 0.01), after the results of the ventilation measurements obtained with EIT were examined and discussed. A self-assessment questionnaire showed that students considered the practical activity as an important tool to assist in the understanding of the basic concepts of respiratory mechanics. Experimental demonstration of the physiological variations of regional lung ventilation in volunteers by using EIT is feasible, effective, and stimulating for undergraduate medical students. Therefore, this practical activity may help faculty and students to overcome the challenges in the field of respiratory physiology learning.

Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis.

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

Assessment of regional lung ventilation by electrical impedance tomography in a patient with unilateral bronchial stenosis and a history of tuberculosis / Avaliacao da ventilacao pulmonar regional por tomografia de impedancia eletrica em paciente com estenose bronquica unilateral pos-tuberculose

Bronchial stenosis can impair regional lung ventilation by causing abnormal, asymmetric airflow limitation. Electrical impedance tomography (EIT) is an imaging technique that allows the assessment of regional lung ventilation and therefore complements the functional assessment of the lungs. We report the case of a patient with left unilateral bronchial stenosis and a history of tuberculosis, in whom regional lung ventilation was assessed by EIT. The EIT results were compared with those obtained by ventilation/perfusion radionuclide imaging. The patient was using nasal continuous positive airway pressure (CPAP) for the treatment of obstructive sleep apnea syndrome. Therefore, we studied the effects of postural changes and of the use of nasal CPAP. The EIT revealed heterogeneous distribution of regional lung ventilation, the ventilation being higher in the right lung, and this distribution was influenced by postural changes and CPAP use. The EIT assessment of regional lung ventilation produced results similar to those obtained with the radionuclide imaging technique and had the advantage of providing a dynamic evaluation without radiation exposure.

A estenose brônquica pode comprometer a ventilação pulmonar regional devido a limitações anormais e assimétricas ao fluxo aéreo. A tomografia de impedância elétrica (TIE) é uma técnica que possibilita a avaliação da ventilação pulmonar regional por imagem e, portanto, pode complementar a avaliação funcional dos pulmões. Relatamos o caso de uma paciente com estenose brônquica unilateral à esquerda, pós-tuberculose, em que se avaliou a ventilação pulmonar regional através da TIE, relacionando-a com a cintilografia de ventilação/perfusão. Foram estudados os efeitos das mudanças posturais e da aplicação de continuous positive airway pressure (CPAP, pressão positiva contínua nas vias aéreas) nasal, uma vez que a paciente usava esse tratamento para síndrome da apneia obstrutiva do sono. A TIE demonstrou distribuição heterogênea da ventilação pulmonar regional com maior ventilação no pulmão direito, sendo essa distribuição influenciada pelas mudanças de decúbitos e pela aplicação de CPAP. A análise da ventilação pulmonar regional pela TIE se mostrou similar aos achados da cintilografia pulmonar de ventilação com a vantagem de possibilitar uma avaliação dinâmica e sem exposição à radiação.

Percepção corporal de adolescentes em ambientes escolares / Body perception of teenagers in school environments

Objetivo: Analisar a percepção corporal de adolescentes em ambientes escolares. Métodos: Realizou-se estudo qualitativo em uma escola pública de ensino fundamental da cidade de Fortaleza-CE, Brasil, com estudantes do nono ano escolar, entre 14 a 16 anos e independente do sexo, no período de março a junho de 2009. A primeira fase constituiu da seleção de dez alunos, utilizando um desenho esquematizado do corpo humano. Na segunda, conduziu-se um grupo focal com questionamentos norteadores sobre a percepção corporal e desejo de mudanças. Resultados: Para os estudantes, a ideia de boa postura seria uma pessoa que tivesse boa educação e estar reta ao andar e sentar. Percebem-se insatisfação e equívocos importantes em relação ao seu corpo e postura, e houve unanimidade quanto ao desejo de obter mudanças. Conclusão: Sentimentos confusos relacionados ao corpo existem, por parte dos estudantes adolescentes, ao se indagar sobre sua imagem e seu desejo de mudança. Se, por um lado, afirmam perceber-se com postura correta e adequada; por outro, anseiam por mudanças, facilmente identificadas com o padrão corporal vigente divulgado na mídia e cultuado como ?corpo ideal?. Torna-se urgente e necessário consolidar cultura de promoção da saúde na escola, bem como construir ambiente educacional saudável

Objective: To assess body perception of teenagers in school environments. Methods: We conducted a qualitative study in a secondary public school from the city of Fortaleza-CE, Brazil, with students from the ninth grade, aged 14 to 16 years old, independent of sex, from March to June, 2009. The first phase consisted of the selection of ten students, using a schematic drawing of the human body. In the second phase, there was a focal group with guiding questions about body awareness and desire for change. Results: For the students, the idea of good posture would be a person who had good education and to be straight when walking and sitting. We perceived dissatisfaction and important misunderstanding in relation to their body and posture, and there was unanimity concerning the desire of achieving changes. Conclusion: There are mixed feelings related to the body, by teenage students, when you inquire about their image and desire to change. If, on one hand, they refer to perceive themselves with proper and correct posture, on the other hand, they are eager for change, easily identified with present standard body reported in the media and worshiped as ?ideal body?. It is urgent and necessary to consolidate the culture of health promotion in schools as well as build healthy educational environment.