Influence of Chest Wall Distortion and Esophageal Catheter Position on Esophageal Manometry in Preterm Infants

Neto, Galdino Silva; Gerhardt, Tilo; Claure, Nelson; Duara, Shahnaz; Bancalari, Eduardo

doi:10.1203/00006450-199505000-00010

Cited by 14 publications

(3 citation statements)

References 16 publications

(30 reference statements)

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“…26,27 However, there is evidence to suggest that many of the esophageal manometry relate to the use of unsuitable tools rather than uneven pleural pressure. 28 For ethical reasons it is no longer permissable to withhold exogenous surfactant from infants with RDS. Hence, it was not possible to make a comparison between surfactant-treated and untreated or placebotreated infants.…”

mentioning

confidence: 99%

Functional Residual Capacity and Static Compliance During the First Year in Preterm Infants Treated With Surfactant

Winter

Merth²,

Brand³

et al. 2000

Am J Perinatol

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Individual lung development during the first year of life was studied in surfactant treated preterm infants with respiratory distress syndrome (RDS) and healthy controls, as well as in a group who subsequently developed chronic lung disease of the newborn (CLDN). Lung development was assessed from functional residual capacity (FRC) and compliance of the respiratory system (Crs). Twenty-one infants with RDS after preterm birth received surfactant treatment. Six of them developed CLDN. Eighteen preterm infants without RDS served as a control group. Lung function measurements were performed at term age and 4, 8, and 12 months afterwards. FRC was obtained by means of the closed-system helium dilution technique whereas static Crs was obtained by means of the weighted spirometer technique. At term age, FRC was lower in the CLDN group compared with uncomplicated RDS and controls (p < 0.05). No significant differences between groups were found in the development of FRC during the first year of life (p = 0.4). No differences were found in Crs during the first year of life in surfactant treated infants who recovered from uncomplicated RDS and the control group. However, lower values were found in the CLDN group (p < 0.05). We conclude that surfactant treated infants without CLDN have similar lung development during the first year of life as control preterm infants.

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mentioning

confidence: 99%

Functional Residual Capacity and Static Compliance During the First Year in Preterm Infants Treated With Surfactant

Winter

Merth²,

Brand³

et al. 2000

Am J Perinatol

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“…However, we reexamined this question recently and found that CWD does not affect Pes measurements adversely (30,31). Therefore, it can be assumed that the measurements provided here are a reliable reflection of pleural pressure changes.…”

Section: Discussionmentioning

confidence: 99%

Proportional Assist Ventilation Decreases Thoracoabdominal Asynchrony and Chest Wall Distortion in Preterm Infants

et al. 2001

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Thoracoabdominal asynchrony (TAA) and chest wall distortion (CWD) are commonly seen in preterm infants secondary to a highly compliant rib cage and poor compensation of distorting forces by inspiratory rib cage muscles. Continuous positive airway pressure (CPAP) reduces TAA and CWD by stenting the chest wall. We hypothesized that application of positive airway pressure only during inspiration and in proportion to an infant's inspiratory effort should have a similar but more pronounced effect than CPAP alone. A ventilator providing airway pressure changes in proportion to flow and volume generated by an infant (proportional assist ventilation) was used to unload the respiratory pump during inspiration. Ten preterm infants were studied [birth weight, 745 (635-1175) g; gestational age, 26.5 (24 -31) wk; postnatal age 3 (1-7) d; medium (range)]. TAA and CWD were determined by respiratory inductive plethysmography. TAA was expressed as the phase angle between the rib cage and abdominal motion and CWD as the total compartmental displacement ratio. In addition, we measured tidal volume with a pneumotachograph and esophageal and airway pressure deflections with pressure transducers. Measurements were obtained during alternating periods of CPAP and two different degrees of support (Gain 1 ϭ 1.09 Ϯ 0.68, Gain 2 ϭ 1.84 Ϯ 0.84 cm H 2 O/mL) that were provided by a proportional assist ventilator. Phase angle and the total compartmental displacement ratio decreased with increasing gain compared with CPAP alone. Peak airway pressure increased from 0.6 to 3.8 to 7.6 cm H 2 O above positive end-expiratory pressure (PEEP) with CPAP, Gain 1, and Gain 2, respectively, as tidal volume increased from 2.8 to 4.1 to 4.7 mL/kg. Esophageal pressure changes decreased only little with increasing gain. Chest wall excursion increased and abdominal movement decreased, indicating a redistribution of tidal volume between chest and abdomen. We conclude that proportional assist ventilation reduces TAA and CWD by generating a small increase in airway pressure that occurs in synchrony and in proportion to each inspiratory effort. TAA, in which the rib cage and abdomen move out of phase due to inward CWD, are commonly seen in spontaneously breathing preterm infants. TAA and CWD are more pronounced in the presence of decreased lung compliance or increased airway resistance but can also be seen in preterm infants without lung disease or in term infants during REM sleep (1-4). The phenomenon is caused by mainly two factors: the negativity of the pleural pressure generated during inspiration and the compliance of the chest wall (5-7). For the chest wall to move along the pressure/volume curve seen during passive inflation of the respiratory system, active compensation from the inspiratory chest wall muscles, counteracting the distorting pleural force, is necessary (8). It has been shown that the more immature the infants are, the less well developed is their active compensation (9). It may be completely absent in very immature infants, leading to a 180...

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“…[21][22][23] Despite the well-known methodological problems of esophageal manometry, [24][25][26] measurements of esophageal pressure are a suitable and, for clinical decisions, a reliable method for the assessment of lung mechanics, especially in preterm infants. 27 Combination of esophageal manometry with the FTT improves the usefulness of this technique considerably. An important advantage of the FTT is the possibility to adjust the F I,O 2 and to continuously measure air leaks of the mask.…”

Section: Fig 6 Changes In V T / P Esmax (Absolute Values and Percementioning

confidence: 99%

Changes in pulmonary function in preterm infants recovering from RDS following early treatment with ambroxol: Results of a randomized trial

1999

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Several studies have demonstrated that ambroxol stimulates surfactant synthesis and has antioxidative and antiinflammatory effects. We investigated the effect of ambroxol on lung function in newborns with respiratory distress syndrome (RDS) weighing <1,500g. In all, 102 newborns were enrolled (52 received ambroxol and 50 placebo). After extubation, lung function tests were performed weekly using a face mask for ventilatory measurements and a catheter tip pressure transducer (diameter 1.7 mm) for esophageal pressure measurements (Pes). The flow‐through technique was used to eliminate apparatus dead space and to allow long‐term measurements during quiet sleep. Percentile curves of pulmonary function parameters from healthy newborns were used for comparison. During the first 28 days, 42 newborns were extubated in the ambroxol group and 36 in the placebo group. The ventilatory parameters of both treatment groups were in the normal range and there were no significant differences between the two groups at any time. After extubation, the ratio of tidal volume to maximal esophageal pressure changes (VT/ Pes,max) was below the 10th percentile in the ambroxol and placebo‐treated groups. In the ambroxol group the 10th percentile was reached on day 10, whereas in the placebo group the 10th percentile was reached significantly later (P < 0.05) on day 23. Modeling of power expenditures was used to identify the optimal breathing pattern so that small differences in ventilatory parameters between the two groups could be analyzed. We conclude that early ambroxol treatment has only a modest effect on lung function in newborns with established RDS. The sensitivity of tidal breathing parameters is not sufficient to detect these small changes in lung mechanics, but small improvements could be demonstrated in lung mechanics 10 days after extubation in the ambroxol‐treated group. Pediatr Pulmonol. 1999; 27:104–112. © 1999 Wiley‐Liss, Inc.

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Influence of Chest Wall Distortion and Esophageal Catheter Position on Esophageal Manometry in Preterm Infants

Cited by 14 publications

References 16 publications

Functional Residual Capacity and Static Compliance During the First Year in Preterm Infants Treated With Surfactant

Functional Residual Capacity and Static Compliance During the First Year in Preterm Infants Treated With Surfactant

Proportional Assist Ventilation Decreases Thoracoabdominal Asynchrony and Chest Wall Distortion in Preterm Infants

Changes in pulmonary function in preterm infants recovering from RDS following early treatment with ambroxol: Results of a randomized trial

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