2001 OPEN FORUM Abstracts
Sedation and neuromuscular blocking agent (NMBA) requirements during initiation of low VT ventilation in patients with acute lung injury (ALI)
RH Kallet, MS RRT, M Eisner MD, JM Luce MD. NHLBI ARDS Clinical Trials Networkat San Francisco General Hospital (SFGH)
Background: Theamount of sedation and use of NMBA required to treat respiratory distress and/orpatient-ventilator dyssynchrony (distress/dyssynchrony) during low VTventilation is unknown. Methods: The medical records of all 43 patients enrolledinto the ARDS Network low VT study at SFGH and randomized to eitherlow VT (6mL/kg) or traditional VT (12 mL/kg) ventilationwere reviewed retrospectively to determine both sedation/NMBA use, and the incidenceof distress/ dyssynchrony during the first 24 h of protocol management. Totalsedation requirements and Ramsey sedation scores were calculated. All analgesicsand sedatives were converted to fentanyl and lorazepam equivalents and expressedin mg/day.1 Data was expressed as mean (± standard deviation) andcomparisons were made using Mann-Whitney tests. NMBA use was assessed by two-sidedFisher?s Exact test. Alpha was set at 0.05.
Results: Distress/dyssynchrony was documented in 67% (14/21) of the patients in the low VTgroup, and in the 36% (8/22) of the patients randomized to traditional VT.Yet the total amount of analgesics and sedatives administered were not different.A trend towards higher NMBA use was found in the 12 mL/kg VT group(relative risk = 1.64; p = 0.24). NMBA?s were administered prior to enrollmentin all 6 patients in the 12 mL/kg VT group, and after enrollmentin both patients in the 6 mL/kg VT group. When sedation/analgesicrequirements were assessed in each VT group based upon the presenceof distress/ dyssynchrony, only the benzodiazepam dosages were different inthe low VT group.
|Fentanyl (mg/d)||2.7 ± 2.3||2.5 ± 2.4||0.55|
|Lorazepammg/d||19.4 ± 10.6||17.5 ± 14.8||0.37|
|Propofol (g/d)||2.94 ± 1.63||2.70 ± 3.05||0.86|
|Baseline Ramsey||3.5 ± 1.5||3.8 ± 1.6||0.42|
|Day 1 Ramsey||4.2 ± 1.6||3.6 ± 1.8||0.28|
|Low VT Group||Dyssynchrony||Synchrony||p|
|Lorazepammg/d||14.7 ± 10||28.2 ± 4.6||0.007|
Conclusion: Distress/dyssynchronywas higher in the low VT group despite equivalent administrationof sedatives/analgesics. This may suggest that higher levels of analgesics/sedatives(particularly benzodiazepams) may be required to treat distress/dys-synchronyduring low VT ventilation. However, the trend towards higher NMBAuse in the traditional VT group may have masked the opportunity todetect distress/dyssynchrony.
1. Cammarrano WB, etal. Acute withdrawl syndrome realted to the administration of analgesic andsedative medications in adult intensive care unit patients. Crit Care Med. 1998;26(4): 676-684. (NIH R01-HL51856)