Chest
Airway Pressure Release Ventilation (APRV): A Human Trial
Section snippets
METHODS
After institutional approval, 14 consenting patients received radial arterial cannulae and balloon-tipped, flow-directed pulmonary artery catheters before cardiac revascularization operations. General anesthesia was induced with an intravenous infusion of fentanyl, 50 to 100 μg/kg or sufentanil, 10 μg/kg. Pancuronium bromide, 0.1 mg/kg, provided muscle relaxation. Postoperatively, ventilation was controlled with a tidal volume of 12 ml/kg delivered at a rate sufficient to maintain pHa between
RESULTS
While patients were paralyzed and apneic, PPV and APRV supported ventilation and arterial oxygenation equally successfully in all cases. Mean arterial PO2, PCO2, pH, and PaO2/FIO2 did not differ when apneic patints were ventilated with PPV or APRV (Table 1).
Mechanical ventilatory rate and minute ventilation were similar during APRV and PPV while patients were apneic. However, mean peak Paw was greater during PPV (38 ± 6 cm H2O) (mean ± SD) than during APRV (11 ± 2 cm H2O) (p<0.0001). Measured
DISCUSSION
Cardiopulmonary bypass results in mild acute lung injury by increasing lung water,3, 4 reducing lung volume, and creating mismatching of ventilation and perfusion.5, 6 After cardiopulmonary bypass, CPAP effects an increase in lung volume, lung compliance, and PaO2.6 Patients who receive narcotic-oxygen anesthesia require full ventilatory support in the immediate postoperative period, and partial ventilatory support thereafter, while narcosis and muscle relaxation resolve. Thus, patients who
ACKNOWLEDGMENTS
The authors wish to thank Michael Hodges for assistance with statistical analyses and Nancy Hatch for secretarial assistance.
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Response of pulmonary venous admixture: a means of comparing therapies?
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Airway pressure release ventilation: a new concept in ventilatory support Editorial
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Airway pressure release ventilation
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Cited by (0)
Manuscript received December 28; revision accepted March 8.