2004 OPEN FORUM Abstracts
Volume Targeted Pressure Limited Ventilation Decreases Peak Airway Pressure and Mean Airway During Mechanical Ventilation in Neonates with ARDS
Brian
K. Walsh, RRT-NPS, David Kaufman M.D.; University of Virginia
Children’s Medical Center
Background:
Current management of neonatal RDS has greatly reduced mortality and
airleaks with the use of prenatal steroids and administration of
surfactant. Once infants receive surfactant and as their endogenous
surfactant pool increases, surface tension decreases and the lungs
experience rapid changes in compliance. Conventionally, ventilator
changes are made every few hours despite the fact that improvement of
lung compliance often occurs minute to minute. Newer ventilation
modality of volume targeted pressure limited ventilation (VTPL),
designated Volume Guaranteed Ventilation (Dräger, Maheim,
Germany), which targets a preset tidal volume at the lowest peak
inspiratory pressure (PIP) required. This mode accommodates for
compliance changes based on the previous breath’s expiratory
tidal volume. This volume guarantee automatically regulates
the inspiratory pressure allowing for the optimal pressure to be
delivered to the lungs with each breath.
Methods:
13 intubated infants less than 30 weeks gestational age and less than
1000gm, 10 intubated infants more than 1000gm who were intubated with
ARDS requiring surfactant treatment and infants less than 48 hours
old who after admission to the NICU develop ARDS requiring surfactant
therapy. Study subjects were randomized to either VTPL or PLV using
the Babylog 8000 plus ventilators (Dräger)
for 96 hours. Surfactant treatment and ventilation management
guidelines were developed to ensure consistency among the 2 groups.
Following this experimental period, infants were returned to what
ever ventilation mode the primary team considered appropriate.
Results:
Primary outcome measures at 96 hours demonstrated significantly lower
(average) peak airway pressures with VTPL and lower (average) mean
airway pressures than with PLV.
| VTPL | PLV | P value | |
| n | 11 | 12 | |
| PIP (cmH2O) | 15.49 | 20.92 | 0.007 |
| MAP (cmH2O) | 5.68 | 7.82 | 0.015 |
| Weight (grams) | 1171 | 1402 | 0.564 |
| Gestational age (wks) | 27.91 | 27.92 | 0.997 |
| Ventilator Days | 11.13 | 17.14 | 0.613 |
| HFOV | 2 | 7 | 0.048 |
While the
size and prenatal risk factors were not different, duration of
mechanical ventilation and the need for high frequency ventilation
rescue were higher in the PLV group.
Conclusion:
Volume targeted pressure limited ventilation reduces peak
inspiratory pressure and mean airway pressure while achieving the
same ventilation and oxygenation goals. Future multi-center studies
need to be developed to determine if VTPL ventilation statistically
reduces mortality, the need for HFOV, and ventilator days.