The Science Journal of the American Association for Respiratory Care

2004 OPEN FORUM Abstracts

RETROSPECTIVE REVIEW IN PEDIATRICS: RESPONSE TIME TO AIRWAY PRESSURE RELEASE VENTILATION (APRV).

Roberta L. Hales BS, RRT-NPS, RN, Shawn Colborn AS, RRT-NPS, Lisa Tyler BS, RRT-NPS, Vinay Nadkarni MD. The Children’s Hospital of Philadelphia, Philadelphia, PA.

Background: APRV is a non-conventional mode of mechanical ventilation that evolved in 1987. It has been described as continuous positive airway pressure (CPAP) with intermittent pressure release, which provides ventilatory support in patients with Acute Lung Injury (ALI).1 Hypoxemia with ALI is associated with alveolar collapse which causes a reduction in functional residual capacity.1 The primary purpose of this retrospective review was to evaluate the change in Oxygen Index (OI) after the initiation of APRV.

Methods:
This is a retrospective review of patients on APRV between July 2003 to May 2004. Twelve patients were placed in three groups classified by initial mode of ventilation. Groups were: High Frequency Oscillatory Ventilation (HFOV), Conventional ventilation, and APRV. Study variables included OI at time intervals of 0,8,16, and 24 hours.

Results:
Of the twelve patients reviewed, two were excluded from data analysis. Patient 2 did not have an arterial line and patient 8 was ventilated with APRV as Inverse Ratio Pressure Control Ventilation. HFOV group consisted of patients 1, 3, 9 and 11. Conventional ventilation group consisted of patients 4, 5, 10, and 12. The APRV group consisted of patients 6 and 7. Patient 1 had no improvement at the 8 hour interval. Patient 3 and 7 had no improvement in OI with APRV. Patient 4 had no improvement at the 16 hour interval. Patient 9 had no arterial blood gas at the 16 hour data point. Patient 10 was converted back to SIMV at the 20 hour point, so a 24 hour data point was not obtained. Patient 12 had no arterial blood gas at 8 hours and no improvement at 24 hours. Patient 6 had the greatest improvement in OI in the first 24 hour period.



Conclusion: APRV is an acceptable alternative to conventional ventilation and HFOV in the management of pediatric ALI. After analysis, we concluded there may be a prolonged period of time before there is a positive response to this mode of ventilation. There was a persistent improvement in OI over the first 24 hours in seven of the ten patients. We feel the response time may be correlated with alveolar recruitment directly related to the severity of low-compliance lung disease. Successful use of APRV is dependent upon the education of the medical staff. Future research is warranted to identify its best application in the pediatric population.

1. Frawley PM, Habashi N. AACN Clinical Issues 2001; 12 (2): 234-246.