Pulmonary pressure-volume relationships in premature fetal and newborn rabbits.

Taeusch, H W; Wyszogrodski, Issie; Wang, N S; Avery, Mary Ellen

doi:10.1152/jappl.1974.37.6.809

Cited by 28 publications

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“…This was accomplished by the administration of a lethal dose of phenobarbital to rats while they were breathing 100% oxygen. Using a device similar to that described by Taeusch et al (35) lungs were inflated with air to a pressure of 30 cm of H20 and allowed to stabilize for 5 min. If the pressure drop during the stabilization period was less than 5 cm of HzO, the preparation was accepted for study.…”

Section: Methodsmentioning

confidence: 99%

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The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

Bucher

Roberts

1981

Pediatr Res

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Pediatr. Res. 15: 999-1008 (1981) SummaryTo examine the dose-response relationships of oxygen-induced lung changes, newborn rats were exposed to various patterns of concentrations of hyperoxia (0.4,0.8, and >0.95 FiOz) for up to 12 days. Prominent findings included microscopic evidence of lung injury and retarded alveolar development (secondary septa1 development delayed by as much as 88%), lower whole lung DNA (50% of control), lung-to-body-weight ratios (by as much as 18%), and significantly less compliance in the lungs after exposures of 6-or 12-day durations to all concentrations of hyperoxia. Significant increases in the activities of the lung protective enzymes superoxide dismutase (129 to 160% of control), catalase (112 to 274% of control), and glutathione peroxidase (118 to 256% of control) were noted when activity was expressed on a DNA basis after 12-day exposures to the various patterns of hyperoxia.Lung changes noted after a 7-day recovery period in air included interstitial thickening (117% of control), persistance of the microscopic injury, and retarded alveolar development seen immediately after initial 6-day hyperoxic exposures. At the conclusion of a second wk of recovery in air, the lungs of hyperoxic exposed animals resembled controls in most respects, but a significantly altered compliance was exhibited by the-lungs of animals initiaiy exposed to 6 days of 0.4 or >0.95 FiOz.The dose dependency of oxygen-induced lung injury is complex. Straightforward, stepwise dose-response adequately describes the evolution of microscopic injury and slowing of alveolar develop ment in hyperoxia, but the dose dependency is not as clearly identified in the oxygen-induced retardation of lung growth including DNA content and in changes in antioxidant enzyme activities. Changes in lung compliance clearly do not follow expected doseresponse relationships. SpeculationThe toxic influence of oxygen on the lung and on lung develop ment varies depending upon the concentration and duration of oxygen exposure. In addition, individual vulnerability to the toxic effects of oxygen on the lung may vary depending upon the stage of maturation of the lung at the time of oxygen exposure. The variety of clinical presentations and morphologic features of chronic lung disease in premature infants (e.g., Wilson Mikity, chronic pulmonary insufficiency of the premature, and bronchopulmonary dysplasia) may represent a spectrum of oxygen effects on the lung rather than diseases with distinctly different pathogenesis.Exposure to elevated oxygen concentrations is a commonly used therapy for many conditions including the respiratory distress 99 syndrome of the newborn. Toxic consequences of such therapy in neonates are now recognized in the conditions of retrolental fibroplasia (29) and bronchopulmonary dysplasia (25). Experimental lung injury resulting from exposure to normobaric hyperoxia has been extensively investigated (2, 8, 13) and found to vary with factors such as age and species (1, 12, 38). However, the assumption which pre...

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Section: Methodsmentioning

confidence: 99%

“…The pressure was returned to 30 cm of H20 before being reduced in graded increments at a set rate. Data were collected from the deflation phase only during the initial inflation-deflation cycle (35).…”

Section: Methodsmentioning

confidence: 99%

The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

Bucher

Roberts

1981

Pediatr Res

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“…19 Moreover, avoiding endotracheal intubation is of benefit for mucociliary transport and humidification of inspired air, as well as decreasing the risk of airway damage and secondary infection 20,21 and the occurrence of lung barotrauma and volutrauma secondary to MV. 22 …”

Section: Early Extubation Among Preterm Infants With Irdsmentioning

confidence: 99%

Early Extubation and Nasal Continuous Positive Airway Pressure After Surfactant Treatment for Respiratory Distress Syndrome Among Preterm Infants <30 Weeks’ Gestation

et al. 2004

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ABSTRACT.Objective. To test the hypothesis that preterm infants with infant respiratory distress syndrome who are treated with nasal continuous positive airway pressure (NCPAP) and surfactant administration followed by immediate extubation and NCPAP application (SURF-NCPAP group) demonstrate less need for mechanical ventilation (MV), compared with infants who receive MV after surfactant administration (SURF-MV group).Methods. A prospective randomized study was conducted, in which infants <30 weeks' gestation were randomized to the SURF-NCPAP group or the SURF-MV group.Results. At 7 days of life, no patient in the SURF-NCPAP group but 6 patients (43%) in the SURF-MV group still were undergoing MV. The duration of oxygen therapy, NCPAP, and MV, the need for a second dose of surfactant, and the length of stay in the intensive care unit were significantly greater in the SURF-MV group.Conclusions. The immediate reinstitution of NCPAP after surfactant administration for infants with infant respiratory distress syndrome is safe and beneficial, as indicated by the lesser need for MV and the briefer requirement for respiratory supports, compared with the institution of MV after surfactant treatment. Moreover, this strategy contributed to reducing the need for surfactant treatment and reducing the time and costs involved in keeping the infants in the neonatal intensive care unit. Pediatrics 2004;113:e560 -e563. URL: http: //www.pediatrics.org/cgi/content/full/113/6/e560; continuous positive airway pressure, mechanical ventilation, surfactant, respiratory distress syndrome, infant.ABBREVIATIONS. a/APo 2 , arterial/alveolar oxygen tension ratio; iRDS, infant respiratory distress syndrome; MV, mechanical ventilation; NCPAP, nasal continuous positive airway pressure; SURF-MV, mechanical ventilation after surfactant treatment; SURF-NCPAP, nasal continuous positive airway pressure after surfactant treatment; Fio 2 , fraction of inspired oxygen; IVH, intraventricular hemorrhage; BPD, bronchopulmonary dysplasia; ROP, retinopathy of prematurity; PDA, patent ductus arteriosus.T he cornerstones of treatment of infant respiratory distress syndrome (iRDS) are artificial respiratory support and surfactant treatment. Among respiratory support techniques, nasal continuous positive airway pressure (NCPAP) 1 and mechanical ventilation (MV) 2 are known for their effectiveness in reducing the mortality and morbidity rates associated with iRDS. Moreover, early application of NCPAP 1 and early treatment with surfactant 3 are effective in decreasing the need for MV, with its related adverse effects. Unfortunately, these results are not always taken into account in neonatal intensive care units, and MV is often initiated after endotracheal intubation for surfactant administration, without consideration of the fact that many infants who are able to breathe spontaneously could be supported with NCPAP only. [4][5][6][7] The present study was planned to test the hypothesis that preterm infants (Ͻ30 weeks' gestation) with iRDS who were treated with N...

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“…Respiratory rates were recorded every 8 h. The animals were fed 5-6 ml of 24 cal/oz infant formula by gavage drip twice during the 48-h period. Survivors were sacrificed at 48 h and quasi-static lung deflation curves were performed after degassing the lungs with 100% oxygen (4,7,17,27). The system was checked for leaks before each use and a peak distending pressure of 25 cmHzO was maintained for 10 min.…”

Section: Methodsmentioning

confidence: 99%

The Effect of Amniotic Fluid Aspiration on Pulmonary Function in the Adult and Newborn Rabbit

et al. 1983

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SummaryAspiration of uncontaminated human amniotic fluid was investigated in adult and newborn rabbits and compared with three other experimental groups: 10% meconium solution, saline, and sham-injected controls. Fluids were injected into the trachea of adult animals (4 or 6 ml/kg body weight), newborn vaginallydelivered animals (a mean volume of 8 ml/kg), and cesareandelivered animals before their first breath (a mean volume of 11 ml/kg).In adult animals aspirating amniotic fluid or saline, arterial PO, measured over a 24-h period showed a mean difference between groups of 4% for both 4 and 6 ml/kg. Meconium aspiration produced a greater depression in Poz than amniotic fluid aspiration (a mean difference of 16 and 31% for 4 and 6 ml/kg, respectively) and animals aspirating meconium showed a deteriorating trend over 24 h, whereas animals aspirating amniotic fluid improved. One of eight adult animals aspirating amniotic fluid died versus four of five aspirating meconium. All five animals aspirating saline 6 ml/kg survived. Lung weight and resting volume of adult animals aspirating amniotic fluid were not significantly different from animals aspirating saline or nothing. Lung pressure volume curves from adult animals aspirating amniotic fluid were nearly identical to controls. Histology showed significantly greater atelectasis in adult animals that received 6 ml/kg amniotic fluid than controls, but this was not different from saline. There was no association between the number of cells in amniotic fluid and arterial Po2 after aspiration or any other aspect of pulmonary function measured. Newborn rabbits aspirating human amniotic fluid were not significantly different from those aspirating saline and non-aspirating controls with respect to mortality, respiratory rates, lung weights, static deflation curves, chest radiographs, or lung histology. This was in marked contrast to the effects of aspiration of an equal volume of 10% meconium solution, which produced a mortality of 100%. W e conclude that aspiration of human amniotic fluid is unlikely to be associated with specific lung disease.

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Pulmonary pressure-volume relationships in premature fetal and newborn rabbits.

Cited by 28 publications

References 0 publications

The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

Early Extubation and Nasal Continuous Positive Airway Pressure After Surfactant Treatment for Respiratory Distress Syndrome Among Preterm Infants <30 Weeks’ Gestation

The Effect of Amniotic Fluid Aspiration on Pulmonary Function in the Adult and Newborn Rabbit

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Pulmonary pressure-volume relationships in premature fetal and newborn rabbits.

Cited by 28 publications

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The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

The Development of the Newborn Rat Lung in Hyperoxia: A Dose-Response Study of Lung Growth, Maturation, and Changes in Antioxidant Enzyme Activities

Early Extubation and Nasal Continuous Positive Airway Pressure After Surfactant Treatment for Respiratory Distress Syndrome Among Preterm Infants &lt;30 Weeks’ Gestation

The Effect of Amniotic Fluid Aspiration on Pulmonary Function in the Adult and Newborn Rabbit

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Early Extubation and Nasal Continuous Positive Airway Pressure After Surfactant Treatment for Respiratory Distress Syndrome Among Preterm Infants <30 Weeks’ Gestation