Air and saline P-V curves were run on the excised lungs of rats starved 1-4 days. Stability estimates based on % of maximum volume retained on deflation tended toward decreases, but atelectasis was not increased according to buoyancy measurements. Compliance was not significantly affected, with whatever trend existed being toward increases. Average air P-V curves for day 3 and 4 of starvation were essentially superimposable on control curves. Surface tension of lung lavage fluid was measured (Surfactometer) during cyclic compression and expansion of the film. Min and max γ were elevated, and the activity index (s) depressed, but the area of the hysteresis loop was relatively unchanged. It is concluded that despite increases in γ of lung washings, pulmonary mechanics was little affected by 1-4 days of food deprivation. The effects on surface tension may be due to a decrease in quantity of surfactant extractable, without any change in composition.

Made available in DSpace on 2016-01-26T12:51:50Z (GMT). No. of bitstreams: 1 liliangoraieb_dissert.pdf: 2524026 bytes, checksum: 35df67e734bc16baa9fa59b0adee085f (MD5) Previous issue date: 2005-12-12 / Objective: To evaluate the behavior of the pulmonary compliance and resistance of the airway passage in patients with high blood flow congenital heart disease undergoing surgical treatment with cardiopulmonary bypass. Method: The static pulmonary compliance and the airway resistance were evaluated in 35 patients during the intraoperative period, in four distinct instants: the first, before the thorax opening, with the infants being already anesthetized, under mechanical ventilation; the second, after thorax and pericardium opening, with the retractors in position; the third, five minutes after the end of cardiopulmonary bypass; the forth, after thorax closing. Pulmonary measurements were performed non-invasively by means of the airway occlusion at the end of inspiration, and the use of proper mathematical formula. In different periods, the observed and related variables with the pulmonary changes were: preoperative, the age, weight and systemic and pulmonary blood flow; intraoperative, the perfusion and the anoxia duration and the minimum body temperature; and, postoperative, duration of mechanical ventilatory support and the length of stay in the ICU. Results: At the end of the surgery, the pulmonary compliance showed a significant and immediate increase (P<0.001) in all the patients. Patients over 30-months as well as the ones with weight over 10kg showed greater increase; P=0.0004, P=0.0006, respectively. Patients with 50-minute duration of cardiopulmonary bypass delayed more to present increase of pulmonary compliance (P=0.04). The resistance of the airway passage did not present significant alteration at the end of surgical correction (P=0.393). Conclusion: All the patients presented pulmonary compliance improvement at the end of the surgery. It was influenced significantly by the age, weight and duration of cardiopulmonary bypass; however, the resistance of the airway passage has not changed. / Avaliar o comportamento da complacência pulmonar e resistência da via aérea nos pacientes portadores de cardiopatias congênitas com hiperfluxo pulmonar submetidos a tratamento cirúrgico com auxílio de circulação extracorpórea. Método: Trinta e cinco pacientes foram avaliados com medidas de complacência estática e resistência da via aérea em quatro instantes distintos durante a cirurgia: O primeiro antes da abertura do tórax, com a criança já anestesiada e sob ventilação mecânica. O segundo, após a abertura do tórax e pericárdio, com os afastadores posicionados. O terceiro, cinco minutos após a saída de circulação extracorpórea e o quarto, após o fechamento do tórax. As medidas pulmonares foram feitas de forma não invasiva com o método de oclusão da via aérea ao final da inspiração e uso de fórmulas matemáticas específicas. As variáveis observadas e relacionadas às alterações pulmonares foram: No período pré-operatório, idade, peso e a relação entre fluxo sanguíneo sistêmico e pulmonar, no intra-operatório, tempos de perfusão, de anóxia e temperatura mínima, no pós-operatório, tempo de ventilação mecânica e tempo de permanência na unidade de terapia intensiva. Resultados: A Complacência pulmonar ao final da cirurgia mostrou aumento significativo imediato (P<0,001) em todos os pacientes. Pacientes maiores de 30 meses tiveram maior aumento (P=0,0004). Os com peso superior a 10kg também apresentaram maior aumento (P=0,0006). Pacientes com tempo de circulação extracorpórea maior que 50 minutos demoraram mais para apresentar aumento da complacência pulmonar (P=0,04). A resistência da via aérea não apresentou alteração significativa ao final da correção cirúrgica (P=0,393). Conclusão: A complacência pulmonar apresentou melhora ao final da cirurgia em todos os pacientes, sendo influenciada de forma significativa pela idade, peso e tempo de circulação extracorpórea. A resistência da via aérea, entretanto, não se alterou.