Karla Maria Pereira Pires, Adriana Correa Melo, Manuella Lanzetti, Natália Vasconcelos Casquilho, Walter Araújo Zin, Luís Cristóvão Porto, Samuel Santos Valença

J Bras Pneumol.2012;38(1):98-104

Lung volume reduction surgery in an experimental rat model of emphysema

Cirurgia de redução do volume pulmonar em modelo experimental de enfisema em ratos

Laerte Brasiliense Fusco, Marcelo Heleno Fonseca, Paulo Manuel Pêgo-Fernandes, Rogério Pazetti, Vera Capelozzi, Fabio Biscegli Jatene, Sergio Almeida Oliveira

J Bras Pneumol.2005;31(1):

Background: Lung volume reduction surgery may be a viable treatment alternative for emphysema patients suffering from severe respiratory insufficiency. Objectives: To evaluate functional and morphological aspects of emphysematous rat lungs, prior to and following lung volume reduction surgery. Method: Wistar rats were divided into two experimental groups (papain without surgery and papain with surgery) and three control groups (saline without surgery, saline with surgery and papain without mechanical ventilation). After approximately 40 days of endotracheal instillation of papain or saline solution, animals in the papain with surgery and saline with surgery groups were submitted to bilobectomy of the middle lobes by right thoracotomy along the posterior border of the superior vena cava. After 1 week, the same animals were submitted to a mechanical ventilation study, which involved measurement of lung elasticity and airway resistance. For all of the animals studied, lung tissue was analyzed in order to determine alveolar diameter and the elastic fiber quantity. Results: Morphometric analysis revealed higher mean alveolar diameter in the lungs of all animals exposed to papain as compared to those exposed to saline. Elastic fiber counts in the alveolar septa of animals treated with papain were lower than those of animals receiving saline. In the animals submitted to bilobectomy and papain, lung elasticity was greater than in those receiving papain without surgery and was statistically equal to that seen in animals receiving saline (with or without surgery). Conclusion: In the respiratory systems of animals with pulmonary emphysema submitted to lung volume reduction by bilobectomy, the capacity for elastic recoil returned to values equivalent to those of the control group animals.

Keywords: Key words: Pulmonary emphysema. Papain/drugs efects. Case-control studies. Disease models, animal. Respiratory mechanics/drugs efects. Lung/sugery. Lung/anatomy & histology.

Editorial

Forced expiratory volume in one second and bronchodilator response in chronic obstructive pulmonary disease - a needless ritual?

Volume expiratório forçado no primeiro segundo e resposta a broncodilatador em doença pulmonar obstrutiva crônica - um ritual inútil?

Carlos Alberto de Castro Pereira

J Bras Pneumol.2005;31(5):4-6

Original Article

Radiological profile of the ideal candidate for lung volume reduction surgery to treat emphysema: a systematic review

Perfil radiológico do candidato ideal à cirurgia redutora de volume pulmonar no enfisema: uma revisão sistemática

Paula Antonia Ugalde Figueroa, Martha Silvia Martinez-Silveira, Eduardo Ponte, Aquiles Camelier, Jorge L. Pereira-silva

J Bras Pneumol.2005;31(3):197-204

Volume controlled ventilation versus pressure controlled ventilation in a canine acute lung injury model: effects on cardiorespiratory parameters and oxygen cost of breathing

Ventilação mecânica volume-controlada versus pressão controlada em modelo canino de lesão pulmonar aguda: efeitos cardiorrespiratórios e sobre o custo de oxigênio da respiração

Bruno do Valle Pinheiro, Marcelo Alcântara Holanda, Célia Mallart Larges, Oswaldo Shigueomi Beppu

J Bras Pneumol.2002;28(1):15-22

Background: It is questionable whether pressure-controlled ventilation (PCV) has advantages over volume-cycled ventilation (VCV). Objectives: To compare PCV to VCV with decelerating flow profile during assisted and controlled modes in an acute lung injury experimental model. Methods: Severe acute lung injury (PaO2/FIO2 < 100 mmHg) was induced by oleic acid IV infusion (0.05 mg/kg) in seven dogs. The animals were submitted to PCV and VCV in a randomized sequence. After 40 minutes in the assisted mode, ventilation was changed to the controlled mode after neuromuscular blockade. The tidal volume and the inspiratory time were kept constant throughout the experiment. Results: There were no differences in gas exchange (PaO2 and PaCO2), cardiac output or oxygen delivery (DO2) between VCV and PCV. The same was observed regarding maximum airway and plateau pressures, and also to the static compliance. Oxygen consumption (VO2) after neuromuscular blockade was 124 ± 48 in VCV versus 143 ± 50 ml/min in PCV, p = 0.42. In the assisted mode, there was a statistical trend of a higher VO2 in PCV (219 ± 72 versus 154 ± 67 ml/min in VCV, p = 0.06), that was associated with a statistical trend of a higher oxygen cost of breathing (OCB) during assisted PCV, although without statistical significance (31 ± 77 in VCV versus 75 ± 96 ml/min in PCV, p = 0.23), and also in a lower PvO2 (34 ± 7 in PCV versus 42 ± 6 ml/min in VCV, p = 0.02). These occurred despite a higher maximum inspiratory flow in the assisted mode in PCV (58 ± 9 versus 48 ± 4 L/min in VCV, p = 0.01). In both VCV and PCV the institution of controlled ventilation reduced cardiac debit and DO2 in as much as 20% relative to the assisted mode. Conclusions: The implementation of controlled ventilation improved the oxygen delivery/consumption relationship in this severe and with high OCB acute lung injury model. The PCV offered no additional benefits to VCV and it was associated with a higher OCB during the assisted mode.

Keywords: Artificial respiration. Pulmonary gas exchange. Tidal volume.

Search Results

Original Article

Correspondence

Letters to the Editor

Case Report

Original Article

List of reviewers

Original Article

Case Report

Index of Issues

Index of Authors

List of reviewers

Original Article

Editorial

Original Article

Anos

Seções

Indexes

Official publication

Newsletters