2001 OPEN FORUM Abstracts
CLINICAL MANAGEMENTOF ACUTE LUNG INJURY (ALI) PATIENTS WITH THE NIH ACUTE RESPIRATORY DISTRESSSYNDROME (ARDS) NETWORK?S LOW TIDAL VOLUME (VT) VENTILATION PROTOCOL
RH Kallet MS RRT, JM LuceMD, RM Jasmer MD, AR Campbell MD, J Tang MD Departments of Anesthesia, Surgeryand Pulmonary Critical Care Medicine, San Francisco General Hospital (SFGH)
Background: The NIH ARDS Networktrial compared traditional VT ventilation at 12 mL/kg to 6 mL/kgand demonstrated a significant mortality reduction (39.8 vs. 31% respectively)in ALI/ARDS patients. SFGH has commenced voluntary utilization of the NIH ARDSNetwork protocol to manage ALI/ARDS patients. We inquired how closely the studytarget goals for lung protective ventilation could be maintained during clinicalpractice.
Methods: We gathered dataon all 36 ALI/ARDS patients managed with the NIH ARDS Network protocol betweenSeptember 2000 and June 2001. Ventilator parameters including VTin mL/kg PBW, end-inspiratory plateau pressure (PPLAT), positiveend-expiratory pressure (PEEP), fractional oxygen concentration (FIO2),respiratory rate (f), arterial oxygen tension (PaO2), arterial carbondioxide tension (PaCO2) and arterial pH were extracted from 2 referenceventilator checks on days 1,3,7 and 14 of protocol management. Data were analyzedusing Kruskal-Wallis tests and Dunn?s Multiple Comparisons tests. The incidenceof data being within target range was analyzed using 2-sided Fisher?s Exacttests. Alpha was set at 0.05.
Results: Lung protective ventilationgoals were maintained during the first 3 days of protocol management, although,the percentage of data meeting ARDS Network target specifications fell belowthe levels achieved during the clinical trial. The ability to achieve protocolmanagement goals deteriorated by the second week of management.
| Variable | Day 1 | Day 3 | Day 7 | Day 14 |
VT (mL/kg) | 6.02 ± 0.96 | 6.18 ± 1.18 | 6.98 ± 1.49? | 7.75 ± 2.11? |
PPLAT (cm H2O) | 27.4 ± 5.8 | 28.7 ± 9.6 | 25.8 ± 6.8 | 29.2 ± 11.8 |
PEEP (cm H2O) | 10.0 ± 3.2 | 10.0 ± 4.0 | 8.3 ± 3.9 | 7.5 ± 3.0? |
FIO2 | 0.60 ± 0.18 | 0.58 ± 0.19 | 0.48 ± 0.14 | 0.45 ± 0.16 |
pH | 7.36 ± 0.08 | 7.37 ± 0.08 | 7.39 ± 0.05 | 7.37 ± 0.05 |
| PaCO2mm Hg | 41.3 ± 7.9 | 45.2 ± 7.1? | 47.2 ± 9.3? | 46 ± 6.9 |
PaO2 mm Hg | 83.2 ± 31.6 | 78.6 ± 20.3 | 82.7 ± 20.3 | 111.6±30.4? |
Percentage of variablesthat met ARDS Net ?On-Target? Criteria | ||||
VT | 78% | 71% | 37%? | 43%? |
PPLAT | 69% | 63% | 68% | 50%? |
VT/PPLAT | 63% | 58% | 26%? | 14%? |
PEEP/FIO2 | 90% | 75%? | 74%? | 84% |
f/pH | 91% | 91% | 83% | 88% |
? p < 0.05 compared toDay 1 data | ||||
Conclusion: The NIH ARDS Networklung protective ventilation protocol can be successfully adapted to clinicalpractice. However, the ability to sustain the target ranges achieved by thestudy appear more difficult to maintain over an extended period of mechanicalventilation during clinical practice.