Do we practise low tidal-volume ventilation in the intensive care unit? a 14-year audit

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Mechanical Ventilation

Background:

• Low tidal volume ventilation (LTVV) reduces mortality in acute lung injury (ALI) and benefits patients without ALI.
• Despite proven benefits, clinical uptake of LTVV remains suboptimal.
• Recent evidence highlights long-term survival advantages of LTVV.

Purpose of the Study:

• To assess the adherence rates of LTVV in mechanically ventilated patients.
• To identify factors influencing adherence to LTVV in an intensive care unit (ICU) setting.

Main Methods:

• Retrospective analysis of ventilator settings from a tertiary referral hospital's ICU.
• Data collected from January 2000 to May 2013, including 4923 patients.
• Analysis focused on mandatory mechanical ventilation (MV) with volume or pressure control, defining LTVV as ≤6.5 mL/kg predicted body weight (PBW).

Main Results:

• Overall adherence to LTVV was low at 13.4%, with a median tidal volume of 8.15 mL/kg PBW.
• A total of 249,450 ventilator measurements were analyzed across 4923 patients.
• Factors associated with higher adherence included female sex, higher inspiratory pressures, higher positive end-expiratory pressure, and lower PaO2/FiO2 ratios.

Conclusions:

• Adherence to LTVV in a general ICU population is low.
• Adherence was notably better in patients with more severe lung disease.
• Potential overestimation of predicted body weight and the need for regular auditing of LTVV adherence are highlighted.