2003 OPEN FORUM Abstracts
CLINICAL IMPLEMENTATION OF THE NIH ACUTE RESPIRATORY DISTRESS SYNDROME NETWORK?S (ARDS-Net) LOW TIDAL VOLUME (VT) PROTOCOL REDUCES HOSPITAL MORTALITY COMPARED TO HISTORICAL CONTROLS.
RH Kallet MS RRT, JM Luce MD, RM Jasmer MD, JF Tang MD, AR Campbell MD, R Dicker MD, C Hemphill MD, J-F Pittet MD Departments of Anesthesia, Surgery, Neurology and Pulmonary Critical Care Medicine, San Francisco General Hospital (SFGH)
Background: The NIH ARDS-Net trial demonstrated a significant reduction in mortality in ALI/ARDS patients who received mechanical ventilation with a VT of 6 mL/kg predicted body weight (PBW) compared to those who received a VT of 12 mL/kg (39.8 vs. 31% respectively). SFGH has adapted the ARDS-Net low VT protocol for routine clinical management of ALI/ARDS patients. We inquired if this change in clinical practice resulted in a lower mortality.
Methods: We reviewed the data on 180 ALI/ARDS patients managed with the ARDS-Net protocol from September 2000 to June 2003. Patients were placed on the protocol within 1.2 ± 2.7 days of meeting consensus conference criteria for ALI/ARDS (7.7% ALI and 92.3% ARDS). Day 1 protocol data was compared to Day 1 control data from 93 ARDS patients (January 1998 to January 1999) managed by routine practice. Data were analyzed using 2-sided unpaired t-tests; mortality was compared by 2-sided Fisher Exact test. Alpha was set at 0.05.
Results: Use of the ARDS-Net protocol was associated with a 40% relative-reduction in hospital mortality at our institution and an overall mortality rate similar to the ARDS-Net study.
|ARDS Net Protocol||Controls||p|
|Lung Injury Score||2.82 ± 0.49||2.70 ± 0.52||0.06|
|SAPS||41.7 ± 14.3||44.1 ± 15.9||0.22|
|Age||44.8 ± 15.0||44.7 ± 14.2||0.96|
|Pplat (cm H2O)||27.6 ± 8.5||33.8 ± 8.9||<0.0001|
|PEEP (cm H2O)||9.8 ± 3.1||7.4 ± 3.3||<0.0001|
|Pplat-PEEP (cm H2O)||17.8 ± 5.5||26.4 ± 8.4||<0.0001|
|VT (mL/kg PBW)||6.16 ± 0.98||9.75 ± 1.54||<0.0001|
CONCLUSION: Because age, lung injury and illness-severity scores were the same, the observed mortality reduction may be attributable to the marked reductions in VT, Pplat, Pplat-PEEP pressure-excursions and higher PEEP levels. At our institution, clinical adaptation of the ARDS-Net low VT protocol significantly reduced morality compared to recent routine clinical practice at approximately 10 mL/Kg PBW.