Evaluating Delivery of Low Tidal Volume Ventilation in Six ICUs Using Electronic Health Record Data*

Abstract

Objective: Mechanical ventilation with low tidal volumes is recommended for all patients with ARDS, and may be beneficial to other intubated patients, yet consistent implementation remains difficult to obtain. Using detailed electronic health record data, we examined patterns of tidal volume administration, the effect on clinical outcomes, and alternate metrics for evaluating low tidal volume compliance in clinical practice. Design: Observational cohort study. Setting: Six intensive care units in a single hospital system. Patients: Adult patients who received invasive mechanical ventilation more than 12 hours. Intervention: none Measurements and Main Results: Tidal volumes were analyzed across 1,905 hospitalizations. Although mean tidal volume was 6.8 mL/kg predicted body weight (PBW), 40% of patients were exposed to tidal volumes > 8 mL/kg PBW, with 11% for more than 24 hours. At a patient level, exposure to 24 total hours of tidal volumes > 8 mL/kg PBW was associated with increased mortality (odds ratio = 1.82, 95% CI 1.20 – 2.78), while mean tidal volume exposure was not (odds ratio = 0.87 per 1 mL/kg increase, 95% CI 0.74 – 1.02). Initial tidal volume settings strongly predicted exposure to volumes > 8 mL/kg for 24 hours, the adjusted rate was 21.5% when initial volumes were > 8 mL/kg PBW and 7.1% when initial volumes were < 8 mL/kg PBW. Across ICUs, correlation of mean tidal volume with alternative measures of low tidal volume delivery ranged from 0.38 to 0.66. Conclusion: Despite low mean tidal volume in the cohort, a significant percentage of patients were exposed to a prolonged duration of high tidal volumes which was correlated with higher mortality. Detailed ventilator records in the electronic health record provide a unique window for evaluating low tidal volume delivery and targets for improvement.

Performance Measure Development, Use, and Measurement of Effectiveness Using the Guideline on Mechanical Ventilation in Acute Respiratory Distress Syndrome. An Official American Thoracic Society Workshop Report

“…The 72-hour time window is based on prior research showing that 93–97% of mechanically ventilated patients with ARDS meet ARDS diagnostic criteria within 48 hours of intubation and that 76% of patients with ARDS meet criteria at the onset of mechanical ventilation ( 27 , 32 ). Thus, applying the PM to this early yet discrete time window both captures the vast majority of patients with ARDS and incentivizes application of LTVV early, when a failure to do so increases patient mortality ( 33 ).…”

Lung-Protective Ventilation Over 6 Years at a Large Academic Medical Center: An Evaluation of Trends, Adherence, and Perceptions of Benefit

“…Despite the vast majority of survey respondents acknowledging the benefits of LPV in both our results and in the literature ( 6 , 7 ), many did not precisely calculate TV and found it challenging to use the EMR to do so. Respondents used a wide array of tools to estimate TV, including MD calculator, the ARDSnet table ( 14 ), and smart phone applications.…”

“…Despite strong evidence of the benefits of LPV, numerous studies have demonstrated variable adherence ( 3 , 5 ). Surveys of critical care physicians, nurses, and respiratory therapists (RTs) demonstrated low utilization despite few perceived barriers and positive attitudes toward low tidal volume ventilation (LTVV) ( 6 , 7 ). Our objective was to evaluate tidal volume (TV) trends over 6 years at a 1,541-bed academic medical center.…”

Implementation of Protocolized Care in ARDS Improves Outcomes

“…10,11 Despite extensive literature detailing the use of these strategies, significant variability exists in their application at the bedside. 12,13 This heterogeneity in the adoption and widespread application of these therapies despite ample scientific evidence can have significant impact on the outcome of patients with ARDS. 14 Lack of physician and institute expertise, concerns around potential lack of benefit, and the potential for adverse events have all been cited as significant barriers to the consistent application of these therapies.…”

“…14 Lack of physician and institute expertise, concerns around potential lack of benefit, and the potential for adverse events have all been cited as significant barriers to the consistent application of these therapies. 12,13,15,16 Protocols are dynamic guides based on the best available evidence to develop effective pathways for patient care. Studies have shown that implementation of individual protocols to ensure lung-protective ventilation strategies, conservative fluid management, and adjunctive therapies are associated with improved outcomes in patients with ARDS.…”