2005 OPEN FORUM Abstracts
Volume Targeted Ventilation Improves Gas Exchange Stability in Chronic Premature Infants With Severe Respiratory Compromise
John Emberger BS RRT, Robert Locke DO, Michael Western AS RRT and Kathleen Russo BS RRT Departments of Respiratory Care and Neonatology, Christiana Care Health System, Newark, DE
Background: Chronically ventilated infants with severe respiratory compromise may have unstable gas exchange on time cycled pressure limited ventilation (TCPL). Improvements in gas exchange stability have been theorized when utilizing volume targeted ventilation (VTV). We investigated if there was an improvement in gas exchange stability when patients were changed from TCPL to VTV ventilation.
Methods: Retrospective chart review of twenty premature infants who received VTV ventilation (Drager Evita 4 Neoflow) after receiving TCPL. Ventilator settings, vital signs and subjective progress notes were reviewed. Data was averaged for the 24 hours (on TCPL) preceding VTV and the first 24 hours on VTV.
Results: Demographic information: EGA 25 ± 1.4 weeks and weight 756 ± 164 grams. Post-natal age and weight at time of study: 26 ± 11 days, 1006 ± 264 grams. When switched from TCPL to VTV ventilation the following were noted (See Table): Tidal volume per kilogram of body weight (Vt/kg) increased. The mean airway pressure (MAP) and FiO2 requirements decreased. There was a significant decrease in the coefficient of variation (COV) for minute ventilation and tidal volume. The table also displays the subjective clinical notes during TCPL and after switching to VTV ventilation.
Conclusions: These findings indicate that in this subset of premature infants with respiratory compromise, the change to VTV from TCPL led to improved gas exchange, improved gas exchange stability, improved tidal volume stability and improved minute volume stability while simultaneously reducing ventilator support requirements (lower MAP and lower FiO2).
| Data Item | TCPL | Volume Targeted | p-value |
| Vt/kg (ml/kg) | 6.9 ± 1.4 | 8.1 ± 1.9 | (p=0.007) |
| MAP (cmH2O) | 11.2 ± 1.8 | 10.1 ± 1.7 | (p=0.002) |
| FiO2 | 0.60 ± 0.15 | 0.47 ± 0.10 | (p< 0.001) |
| SpO2 (%) | 93 ± 2 | 98 ± 1 | (p< 0.001) |
| Minute Ventilation COV | 37% | 10% | (p< 0.001) |
| Tidal Volume COV | 39% | 3% | (p< 0.001) |
| Subjective Progress Notes: | |||
| Multiple Significant Desaturations | 70% of infants | 20% of infants | |
| Not Tolerating Hands-on Care | 50% of infants | 0% of infants | |
| Manual Bagging Required | 45% of infants | 0% of infants | |
| Not tolerating Feeding | 20% of infants | 0% of infants | |
| Bradycardia Events Noted | 15% of infants | 0% of infants | |