Effect of ventilation on movement of surfactant in airways

Faridy, Edmund E.

doi:10.1016/0034-5687(76)90061-x

Cited by 80 publications

(29 citation statements)

References 12 publications

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“…2). This lack of RD S in the presence of immature LIS ratios has been reported by others using different methods (7,9) and may reflect the fact that the movement of surfactant from the alveoli into the central airways is dependent on adequate alveolar ventilation (15). This may also explain the large and rapid increases seen with time in several non-RDS infants (Fig.…”

Section: Resultsmentioning

confidence: 52%

Lecithin/Sphingomyelin Ratios in Tracheal Aspirates from Newborn Infants

1987

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MATERIALS AND METHODSmethod is noted for its laborious and time-consuming aspects and for the many variable factors which can influence the ratio (11). In the human infant the amount of tracheal fluid normally available in single aspirations is usually quite small and therefore a sensitive procedure is desirable. We have developed and clinically validated a sensitive and rapid HPLC method for LIS ratios in amniotic fluid (12) and now report on its application to the measurement of LIS ratios in tracheal fluid aspirates from newborn infants.Patients. Over an 18-method period tracheal fluid was aspirated from 115 newborn infants of high risk pregnancies during resuscitation at birth for the assessment of pulmonary maturity; GA ranged widely from 24 to 40 wk and birth weights from 570 to 4050 g. The numbers of babies related to GA groups and sex are listed in Table 1. Following resuscitation at delivery, chest radiographs determined the working clinical diagnosis for infants with clinical respiratory distress requiring intubation and assisted ventilation and for those needing only supplementary oxygen. RDS was diagnosed in 41 ventilated infants (GA 24 to 35 wk) based on x-ray presence of a diffuse reticular-granular pattern in the lung parenchyma and air bronchograms ( Table I); six of these infants died. Wet lung was noted in 19 infants (GA 24-34 wk) where chest radiographs showed normal lung aeration with increased perihilar markings and fluid in the fissures and 11 required mechanical ventilation (Table 1). Five infants were ventilated for other causes, three with focal pneumonias, one with pulmonary hypoplasia, and one with septicemia. Ten infants were ventilated for apnea of prematurity (GA <30 wk, birth weight <1420 g). These babies had normal initial chest xrays. A 32-wk infant who was ventilated for severe apnea died of herpes encephalitis at the age of 9 days (Table I).All samples were obtained within 3 h of delivery using no. 6 DeLee suction catheters (Argyle, St. Louis, MO) introduced either into the endotracheal tube in the intubated baby or directly below the cords into the trachea under direct vision laryngoscopy during resuscitation. In 27 of the intubated babies an additional 41 serial tracheal aspirates were obtained (43% within the 1st h oflife, 34% in the 2nd h, and 16% in the 3rd h) in order to assess changes in tracheal fluid LIS with time after birth . Amniotic fluid, sampled within 2 h ofdelivery, was comapred with tracheal fluid obtained in 24 infants. Twenty (83%) were amniocentesis samples obtained during Cesarian section deliveries while four were collected at the time of artificial rupture of the membranes within 2 h of delivery.LIS ratio determination . A new analytical procedure for the determination of LIS in amniotic fluid has been described and is based on the separation oflecithin and sphingomyelin in Folch extracts of amniotic fluid by normal phase HPLe. This method has proved to be very sensitive, rapid and precise (12). A 1O-lLm silica column (Waters microporasil 3.9 X 30 em) wa...

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Section: Resultsmentioning

confidence: 52%

Lecithin/Sphingomyelin Ratios in Tracheal Aspirates from Newborn Infants

1987

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“…The present group have shown that modes of ventilation with large tidal volume without PEEP disturb the surfactant system in a VILI model [8]. It has been demonstrated that loss of surface active molecules due to mechanical ventilation with high inspiratory lung volumes without PEEP is produced by displacement of surfactant from the alveolar airliquid interface into the small airways [2,5]. Moreover, the surface area changes produced by the high inspiratory lung volumes lead to an increased rate of conversion of active into nonactive surfactant subtractions [7 -9].…”

Section: Discussionmentioning

confidence: 99%

Partial liquid ventilation improves lung function in ventilation-induced lung injury

Anda

Lachmann²,

Verbrugge³

et al. 2001

Eur Respir J

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Disturbances in lung function and lung mechanics are present after ventilation with high peak inspiratory pressures (PIP) and low levels of positive endexpiratory pressure (PEEP). Therefore, the authors investigated whether partial liquid ventilation can re-establish lung function after ventilation-induced lung injury.Adult rats were exposed to high PIP without PEEP for 20 min. Thereafter, the animals were randomly divided into five groups. The first group was killed immediately after randomization and used as an untreated control. The second group received only sham treatment and ventilation, and three groups received treatment with perfluorocarbon (10 mL?kg -1 , 20 mL?kg -1 , and 20 ml?kg -1 plus an additional 5 mL?kg -1 after 1 h). The four groups were maintained on mechanical ventilation for a further 2-h observation period. Blood gases, lung mechanics, total protein concentration, minimal surface tension, and small/large surfactant aggregates ratio were determined.The results show that in ventilation-induced lung injury, partial liquid ventilation with different amounts of perflubron improves gas exchange and pulmonary function, when compared to a group of animals treated with standard respiratory care. These effects have been observed despite the presence of a high intra-alveolar protein concentration, especially in those groups treated with 10 and 20 mL of perflubron.The data suggest that replacement of perfluorocarbon, lost over time, is crucial to maintain the constant effects of partial liquid ventilation. Eur Respir J 2001; 18: 93-99.

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“…The interstitial space of alveoli and bronchioles communicate, and the flow of interstitial fluid is from alveoli to bronchioles, hence, this coordination could be effected by an agent released by alveolar interstitial cells. Furthermore, since increased volume ventilation accelerates the rate at which the lining material in these terminal units moves cephalad (27,28), augmented secretion, triggered by increased volume ventilation, would serve to meet the increased replacement requirements.…”

Section: Discussionmentioning

confidence: 99%

Studies on the Regulation of Secretion in Clara Cells with Evidence for Chemical Nonautonomic Mediation of the Secretory Response to Increased Ventilation in Rat Lungs

Massaro¹,

Amado²,

Clerch³

et al. 1982

J. Clin. Invest.

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A B S T R A C T Using electron microscopy and morphometric methods to assess secretion, we previously found that two times tidal volume ventilation of isolated perfused rat lung stimulates secretion by bronchiolar Clara cells; this effect is not prevented by #-adrenergic blockade (J. Clin. Invest. 1981. 67: 345-351.). In this study we used the isolated perfused rat lung and the anesthetized mechanically ventilated rat, to further study the mechanism by which large tidal volumes stimulate secretion by Clara cells. With the perfused lung we found (a) a-adrenergic inhibition did not block the secretory effect of ventilation at two times normal tidal volume; (b) indomethacin completely blocked the secretory action of two times tidal volume ventilation; (c) medium previously used to perfuse lungs ventilated at two times tidal volume, but not medium previously used to ventilate lungs at normal tidal volume, stimulated secretion by Clara cells when used to perfuse fresh lungs ventilated at tidal volume; (d) addition of prostacyclin to the fresh perfusate increased secretion by Clara cells of lungs ventilated at normal tidal volume. In anesthetized mechanically ventilated rats, sighs stimulated secretion by Clara cells; this increased secretion was inhibited by indomethacin but not by cholinergic blockade (bilateral vagotomy

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Effect of ventilation on movement of surfactant in airways

Cited by 80 publications

References 12 publications

Lecithin/Sphingomyelin Ratios in Tracheal Aspirates from Newborn Infants

Lecithin/Sphingomyelin Ratios in Tracheal Aspirates from Newborn Infants

Partial liquid ventilation improves lung function in ventilation-induced lung injury

Studies on the Regulation of Secretion in Clara Cells with Evidence for Chemical Nonautonomic Mediation of the Secretory Response to Increased Ventilation in Rat Lungs

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