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.

Alterations in peak inspiratory pressure and tidal volume delivered by manually operated self-inflating resuscitation bags as a function of the oxygen supply rate

Alterações da pressão de pico inspiratório e do volume corrente fornecidos por reanimadores manuais com balão auto-inflável em função do fluxo de entrada de oxigênio utilizado

Armando Carlos Franco de Godoy, Ronan José Vieira, Eduardo Mello De Capitani

J Bras Pneumol.2008;34(10):817-821

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Relationship of Reviewers volume 46 (1-6) 2020

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J Bras Pneumol.2020;46(6):.

Index of Issues

Índice remissivo de assuntos do volume 44 (1-6) 2018

J Bras Pneumol.2018;44(6):533-534

Index of Authors

Índice remissivo de autores do volume 44 (1-6) 2018

J Bras Pneumol.2018;44(6):535-538

List of reviewers

Relação de revisores do volume 44 (1-6) 2018

J Bras Pneumol.2018;44(6):539-542

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Jornal Brasileiro de Pneumologia

J Bras Pneumol.2022;48(6):rev2022

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Relação de revisores do volume 49 (1-6) 2023

Jornal Brasileiro de Pneumologia

J Bras Pneumol.2023;49(6):.

Original Article

Low tidal volume mechanical ventilation and oxidative stress in healthy mouse lungs

Ventilação mecânica com baixo volume corrente e estresse oxidativo em pulmões saudáveis de camundongos

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

Understanding the link between interstitial lung disease and obstructive sleep apnea: is lung volume involved?

Pedro Rodrigues Genta1, Paulo Mateus Madureira Soares Mariano1

J Bras Pneumol.2024;50(5):e20240356

Original Article

Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

Tomografia computadorizada cervical em pacientes com apneia obstrutiva do sono: influência da elevação postural na avaliação do volume das vias aéreas superiores

Fábio José Fabrício de Barros Souza1, Anne Rosso Evangelista2, Juliana Veiga Silva2, Grégory Vinícius Périco3, Kristian Madeira4,5

J Bras Pneumol.2016;42(1):55-60

Correspondence

Cervical computed tomography in patients with obstructive sleep apnea: influence of head elevation on the assessment of upper airway volume

Tomografia computadorizada cervical em pacientes com apneia obstrutiva do sono: influência da elevação postural na avaliação do volume das vias aéreas superiores

Shailendra Singh Rana1, Om Prakash Kharbanda1

J Bras Pneumol.2016;42(5):395

Original Article

Measuring forced expiratory volume in one second alone is not an accurate method of assessing response to bronchodilators in chronic obstructive pulmonary disease

O volume expiratório forçado no primeiro segundo não é suficiente para avaliar resposta broncodilatadora em doença pulmonar obstrutiva crônica

Felícia de Moraes Branco Tavares, Luiz Carlos Corrêa da Silva, Adalberto Sperb Rubin

J Bras Pneumol.2005;31(5):407-414

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