Title: Management of a Piglet Model of the Meconium Aspiration Syndrome With High-Frequency or Conventional Ventilation
Abstract: <h3>• Objective.</h3> —To assess the usefulness of three methods of high-frequency ventilation in the early management of a piglet model of the meconium aspiration syndrome. <h3>Design.</h3> —Randomized, block design. <h3>Setting.</h3> —Animal research facility. <h3>Subjects.</h3> —Fifty-six mixed-breed newborn piglets aged 1 to 4 days and weighing 1.8 to 2.7 kg. <h3>Interventions.</h3> —After instillation of a 2.2-mL/kg solution of 25% meconium, 56 piglets were randomized to receive treatment with (1) a conventional positive-pressure infant ventilator, (2) the Bunnell Life Pulse high-frequency jet ventilator, (3) the Bird model VDR high-frequency flow interruptor, or (4) the Infant Star high-frequency flow interruptor. We adjusted ventilator settings to maintain partial pressures of arterial oxygen (Pao<sub>2</sub>) of 80 to 120 cm H<sub>2</sub>O and partial pressures of arterial carbon dioxide (Paco<sub>2</sub>) of 30 to 50 cm H<sub>2</sub>O during the 6 hours of ventilation. <h3>Measurements and Main Results.</h3> —We compared pulmonary histologic alterations and four physiologic parameters: (1) mean airway pressure, (2) Paco<sub>2</sub>, (3) ratio of Pao<sub>2</sub>to partial alveolar oxygen pressure (PAo<sub>2</sub>), and (4) oxygenation index ([(fraction of inspired oxygen)(mean airway pressure)(100)]/Pao<sub>2</sub>). The two measures of oxygenation were similar for all four devices except at 4 hours, when the Pao<sub>2</sub>/PAo<sub>2</sub>ratio on positive-pressure ventilation was significantly higher than that on high-frequency jet ventilation (<i>P</i>=.008). The histologic changes on positive-pressure ventilation (atelectasis, inflammation, presence of meconium, and exudative debris) were significantly worse than those on high-frequency jet ventilation or flow interruption (<i>P</i><.0001). <h3>Conclusions.</h3> —The finding of less severe pathologic alterations with various types of high-frequency ventilators justifies further investigations into the management of the meconium aspiration syndrome with these devices. (<i>AJDC</i>. 1992;146:1287-1293)
Publication Year: 1992
Publication Date: 1992-11-01
Language: en
Type: article
Indexed In: ['crossref', 'pubmed']
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Cited By Count: 44
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