Pediatric research
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We investigated the effects of changes in mean airway pressure (Paw), oscillatory frequency and lung compliance on cardiac output (CO) and pulmonary vascular resistance in seven adult cats (3.0 +/- 0.6 kg) during high-frequency oscillatory ventilation (HFOV). The cats were anesthetized with chloralose and urethane and ventilated with a high-frequency oscillator at Paw of 4, 8, 12, and 16 cm H2O and frequencies of 3, 6, 12, 16, and 20 Hz. Saline lavage was used to reduce lung compliance. ⋯ Changes in frequency did not significantly alter CO or pulmonary vascular resistance. We conclude that the interaction between the heart and lungs during HFOV is largely mediated by Paw and compliance of the respiratory system. Furthermore, regardless of the degree of lung compliance, cardiac function may be impaired during HFOV as Paw is elevated.