Are the tidal volumes used in intensive care units suitable for lung protective ventilation? Can training ensure compatibility?

Abstract

Objective: Low tidal volume (VT) and lung protective ventilation (LPV) are recommended to prevent lung injury associated with invasive mechanical ventilation (IMV). Present study aimed to determine the patients with risk of high VT application, whether VT calculated according ideal body weight (IBW) values are suitable for the recommended (6-8 mL/kg) and whether a questionnaire on the issue contributes to IMV suitable for LPV.Materials and Methods: Present study is conducted as a multicenter point - prevalence study in the intensive care units of three hospitals in Bursa. Non-ARDS patients receiving IMV and patients who were older than 18 years were included in the study. IMV parameters and demographic data of the patients were collected. Then, the physicians responsible of ventilatory management completed a questionnaire about LPV strategies and VT values required according to the IVA were shown. After 24 hours, mechanical ventilation parameters were re-collected. Body mass index (BMI), average tidal volume applied [VTmean = minute volume (MV)/respiratory rate (RR)] and VTmean for IBW (VTmean/IBW) values were calculated.Results: Fifty-six patients were included in the study. There were 33 male patients (58.9%) and the mean age of the patients was 65.43 +/- 18.87 years. The mean BMI of the patients was 27.84 +/- 7.0. The most commonly used ventilation mode was synchronized intermittent mandatory ventilation (75%). The VTmean was 549.32 +/- 151.00 mL (VTmean/IBW =9.31 +/- 3.07 mL/kg). According to VTmean/IBW, for the use of large VTs, being female (10.77 +/- 2.74 mL/kg) and having BMI >= 30 (10.82 +/- 3.80 mL/kg) posed significantly higher risk than being male (8.31 +/- 2.91 mL/kg) and having BMI <30 (8.67 +/- 2.47 mL/kg) (p=0.002, p=0.015 respectively). The results showed a significant decrease (p=0.026) in VTmean/IBW (8.81 +/- 3.49 mL/kg) values after the physicians completed LPV questionnaire and were shown the VT values (predicted by IBW).Conclusion: VTmean/IBW values were found to be higher than 6-8 mL/kg, the recommended value for LPV. Ventilation with high VT was associated with female gender and having a BMI of >= 30. Completing the LPV questionnaire and seeing the VT values (predicted by IBW) contributed to the number of the patients ventilated with VT values suitable LPV.