Education, along with bedside ventilator cards, significantly increased use of correct initial tidal volume settings for mechanically ventilated patients.
The goal of the study was to correctly set the ventilator for patients based on their ideal body weight (IBW), rather than using consistent settings for all patients, said Rotem Friede, MD, medical director of the critical care unit at Mercy Philadelphia Hospital, lead author of the study. “We educated the respiratory, nursing and resident staffs on how to calculate the IBW, and then made a table that converted height and sex to IBW and the volume per kilogram,” she said. The findings were presented at the 2016 Society of Critical Care Medicine’s Critical Care Congress (abstract 879).
Previous large-scale trials have recommended that initial tidal volumes in mechanically ventilated patients be 6 to 8 mL/kg based on IBW. Dr. Friede said, “Ideal body weight is the appropriate measure, as lung volumes don’t change based on weight; they change based on height and sex.”
Compliance with these recommendations is roughly 30% nationally. “We studied the effects of bedside ventilator cards in addition to resident education on proper initial tidal volume settings,” the authors explained.
Reasons for Noncompliance
Initial tidal volumes take longer to calculate. Additionally, settings are often based on weight rather than height. A third reason for noncompliance is an educational gap about how to set an initial tidal volume, which occurs when a patient is intubated at the initiation of mechanical ventilation.
Dr. Friede said the study found that providing the education and tools to set the correct initial tidal volume settings for mechanically ventilated patients can ameliorate the clinical situation.
The retrospective review was conducted on all mechanically ventilated patients at Mercy Philadelphia Hospital between Oct. 1, 2014, and Feb. 28, 2015. After education, charts were prospectively reviewed between March 1 and May 31, 2015. Chronic tracheotomy and patients extubated immediately postoperatively were excluded. Patients were divided into pre- and post-intervention groups.
Of the 192 patients included in the study, 127 were in preintervention (group I) and 65 in post-intervention (group II). Mean age was similar (group I, 63±17 vs. group II, 59±15). Group I had a much higher rate of tidal volumes outside of the 6- to 8-mL/kg IBW range, compared with group II (31.50% vs. 12.31%; P=0.004). Compliance was significantly improved when subdividing patients by body mass index.