Effect of ventilation on surface forces in excised dogs' lungs.

Faridy, Edmund E.; Permutt, S.; Riley, Richard L.

doi:10.1152/jappl.1966.21.5.1453

Cited by 166 publications

(69 citation statements)

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“…Decreased compliance after periods up to 4 h of increased ventilation were attributed to altered surfactant function because extracts from these lungs exhibited increased minimal surface tensions (6)(7)(8)(9)(10). Increased alveolar surfactant phospholipids were found by Oyarzun and Clements (8, 9) after hyperventilation of adult rabbits for periods up to 4 h. They postulated that increased secretion of tissue pools occurred followed by inactivation.…”

Section: Resultsmentioning

confidence: 99%

Surfactant Metabolism during Hyperventilation of Newborn Lambs with Atrial Right to Left Shunts

et al. 1989

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ABSTRACT. We studied the effect on surfactant metabolism of 8 h of mechanical ventilation at tidal volumes of 13 2 0.3 ml/kg and very high tidal volumes of 28 f 1.5 ml/kg, with and without added COz, in the presence of an atrial right to left shunt in 4-to 8-day-old lambs. Similarly aged, spontaneously breathing lambs were used as controls. Right to left atrial shunts were created by inflating a balloon in the right atrium after a Rashkind atrial septostomy, thus creating a stable, easily controlled atrial shunt. Radiolabeled surfactant phospholipid precursors were used to probe incorporation into and secretion of surfactant phosphatidylcholine, whereas intratracheally administered labeled natural surfactant was used to evaluate alveolar clearance. Protein leak from the vascular space to the lungs was measured using radioactive iodine-labeled albumins. At the end of the 8-h study period, tissue association of alveolar surfactant was significantly increased to 63% in the mechanically hyperventilated lambs as compared to 44% in those lambs mechanically ventilated but not hyperventilated (p < 0.05) and to 39% in the spontaneously breathing control animals (p < 0.05). No increased surfactant secretion or decreased compliance was detected with hyperventilation. However, the lambs had very large surfactant-saturated phosphatidylcholine pool sizes, and a large portion (50%) was already in the alveolar pool, even in the spontaneously breathing lambs. Precursor incorporation into saturated phosphatidylcholine was similar in all groups, and very low and comparable protein leaks were seen in the different groups of lambs. These experiments did not detect any adverse effects of 8 h of mechanical ventilation, large atrial shunts or mechanical hyperventilation on the surfactant system of newborn lambs. (Pediatr Res 25:83-88,1989) In neonates with persistent pulmonary hypertension, hyperventilation has been considered an essential part of the ventilatory support ( I ) . Suprasystemic pulmonary arterial pressures cause right to left shunts at the patent foramen ovale and ductus arteriosus levels which result in progressive hypoxemia. The goal of hyperventilation is to attain a critically low P a c o~ and alkaline pH which may promote reversal of the right to left shunt by decreasing pulmonary artery pressures to less than systemic levels (1). However, infants often become less responsive to the same

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Section: Resultsmentioning

confidence: 99%

Surfactant Metabolism during Hyperventilation of Newborn Lambs with Atrial Right to Left Shunts

et al. 1989

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confidence: 84%

“…This effect was first shown on the excised lungs of dogs by Faridy [11] by ventilation at different frequencies and volumes. It is evident that permitting the lung to return to airlessness on end-expiration increases the change of the alveolar surface area with each breath and the consequent large ventilatory excursions accelerate surfactant utilization [11]. The remarkable benefit of continuous distending airway pressure, whether applied as a positive end-expiratory pressure, or continuous negative pressure around the chest serves to illustrate the significant improvement in ventilation-perfusion relations in a lung prevented from returning to airlessness on expiration.…”

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confidence: 84%

What is New in Our Understanding of Perinatal Pulmonary Problems? Presidential Address to the Society for Pediatric Research, May 19, 1973

Avery

1973

Pediatr Res

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“…Deep inhalations either can increase or decrease the airway resistance depending on many variables 8 . The role of deep breathing on release of surfactant and consequent change in pulmonary compliance and other lung functions has been extensively studied, both in cultured pulmonary epithelial cells 9 and in isolated and intact lungs of many different animals 9,10,11 . But whether the same type of phenomenon occurs in intact human subjects and whether that can alter any of the parameters of respiratory functions has not been studied in detail.…”

Section: Deep Breathingmentioning

confidence: 99%

Effect of Deep Breathing on Respiratory Parameters in Healthy Young Individuals

Sunitha¹,

Ravi²

2013

jemds

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Context:Breathing is the most vital function for maintenance of life. Slow and deep breathing is an integral part of Pranayama and it reduces dead space ventilation and renews air throughout the lungs. The reported beneficial effects of deep breathing as a part of either long term or short term practice of pranayama on pulmonary functions are well documented. However our knowledge about the effects of deep breathing on human respiratory parameters is poor. In the present study, we examined the relationship between exposure to deep breathing and performance on Respiratory parameters before and after the deep breathing. Aim: The present study was done to evaluate the effect of deep breathing on respiratory parameters. Settings & Design: The present study was a comparative prospective study consisting of 30 male healthy subjects of 18-20 years age. Materials and Methods: This study was conducted in the Department of physiology, Adichunchanagiri institute of medical sciences, Mandya after the institutional ethical clearance and written consent from each participant. The participants were asked to perform deep breathing. The duration of the study was twelve weeks. Pre and post deep breathing respiratory functions were assessed by measuring respiratory rate, chest expansion and breath holding time. The parameters were analyzed by Student't' test and p<0.05 was considered the level of significance. Results: There was significant decrease in respiratory rate, and significant increase in chest expansion and breath holding time compared to pre deep breathing practice. Conclusions: This study showed beneficial effects of deep breathing on respiratory functions in normal healthy individuals.

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Effect of ventilation on surface forces in excised dogs' lungs.

Cited by 166 publications

References 0 publications

Surfactant Metabolism during Hyperventilation of Newborn Lambs with Atrial Right to Left Shunts

Surfactant Metabolism during Hyperventilation of Newborn Lambs with Atrial Right to Left Shunts

What is New in Our Understanding of Perinatal Pulmonary Problems? Presidential Address to the Society for Pediatric Research, May 19, 1973

Effect of Deep Breathing on Respiratory Parameters in Healthy Young Individuals

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