Combined Pressure Control/High Frequency Ventilation in Adult Respiratory Distress Syndrome and Sickle Cell Anemia: Conclusion
Clinical guidelines for the PVDV are somewhat arbitrary and still being developed.
Because our strategy for this patient included using HFV to increase alveolar recruitment and oxygenation combined with pressure control to diminish gas trapping and augment carbon dioxide removal, we did the following: (1) used a background pressure control rate similar to that used in conventional mechanical ventilation; (2) used a high-frequency rate of 500 to 600/min; (3) set PIP at about three fourths of that used in conventional mechanical ventilation; (4) chose an FI02 based on that used in conventional mechanical ventilation, measures of oxygen saturation, and therapeutic goals; (5) chose an I:E ratio for the background pressure control mode of about 1:1; and (6) set PEEP at a similar value to that used in conventional mechanical ventilation. Positive end-expiratory pressure consists of both oscillatory and nonoscillatory components, and the appropriate use of oscillatory PEEP may be associated with increased ease of mobilization of airway secretions Canadian Family Pharmacy.
Increased oxygenation can be achieved by increasing the inspiratory time of the background pressure control mode, the high frequency rate, the PEEP, or the FI02. Increased ventilation can be achieved by decreasing the inspiratory time of the background pressure control mode, by decreasing the high-frequency rate, or by any maneuver that increases the minute ventilation.
Problems associated with the PVDV, like any pressure-control ventilator, include the potential for dangerously large tidal volumes, such that the frightened, uncooperative toddler may best be treated initially in a paralyzed, sedated state. The conversion from conventional mechanical ventilation to the PVDV may be associated with mild hemodynamic instability, particularly if preload is not optimal.
Category: Respiratory Symptoms
Tags: barotrauma, high frequency ventilation, sickle cell anemia