Adherence to a protective ventilation strategy for patients at risk of acute lung injury

Abstract

INTRODUCTION. Patients diagnosed with acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), have a poor outcome with high airway pressures and large tidal volumes (1, 2). This audit assessed compliance with a protective ventilation protocol for patients at risk of ALI and ARDS. We re-audited after implementing recommendations and found a significant improvement in the delivery of tidal volumes (Vt) as part of a protective ventilation strategy. OBJECTIVES. To assess compliance with a protective ventilation protocol, in accordance with ARDS clinical network guidelines (ARDSnet), for patients at risk of ALI and ARDS. METHODS. A prospective audit was carried out in a district general hospital over a 4 week period in 2011 and re-audited 12 months later. Our ventilation protocol was based on international ARDSnet guidelines. These recommend tidal volumes of 6 ml/kg of ideal body weight (IBW) and plateau airway pressures below 30 cm water. Data was collected and analysed using SPSS. Inclusion criteria for patients at risk of ALI were those mechanically ventilated for over 48 h on intensive care. RESULTS. Mean daily Vt 's were recorded for 141 ventilated days in the first audit with an overall mean TV of 9.5 ml/kg of IBW. Daily mean Vt 's were recorded for 125 ventilated days for the re-audit with an overall mean (Vt) of 6.6 ml/kg IBW. The initial audit demonstrated large (Vt)'s close to conventional ventilation strategies of 10 ml/kg. This is not in keeping with ARDSnet guidelines. The re-audit showed lower Vt 's close to ARDSnet guidelines. ARDSnet recommend plateau airway pressures below 30 cm water. Average mean plateau airway pressures were 29.5 cm water for the first audit and 30.2 cm water for the re-audit. CONCLUSIONS. The standards for this audit are internationally recognised and evidence based. The first audit falls below these standards with large Vt 's. However mean plateau airway pressures met with the standard, and were similar for both audits. Recommendations to improve compliance to a safe ventilation protocol were implemented. Education on protective lung ventilation was targeted at junior doctors and intensive care nurses. Laminates with recommended ventilation parameters were made visible on ventilators in intensive care. The re-audit demonstrated lower Vt delivery in patients at risk of ALI. This suggests better compliance with ARDSnet standards after our recommendations were implemented.