A target backrest elevation of 45deg was not feasible for mechanically ventilated patients; elevations achieved did not prevent ventilator associated pneumonia

摘要

VAP prevention guidelines recommend that intubated patients maintain a semirecumbent position;this recommendation is based on 1 randomised trial that reported lower VAP rates with semirecumbent compared with supine positioning.Additional suppoil is provided by studies that showed a reduction in feed aspiration, a risk factor for VAP, in the semirecumbent position.Because semirecumbenl was defined as 45 deg backrest elevation, early recommendations promoted this angle of elevation; unfortunately, implementation has proven to be more difficult than anticipated. Barriers include patient discomfort and traditional pressure ulcer prevention guidelines that discourage high Fowler's positioning.In an effort to increase compliance, some backrest elevation goals have been modified to 30deg; however, no evidence exists to support the efficacy of this lower angle.In an attempt to validate the findings of the previous trial/ van Nieuwenhoven et al compared an intended backrest elevation of 45 deg with standard care (10deg rather than true supine positioning). Study strength-include rigorous methods for assessing adherence to group assignment and measurement of true backrest elevation every 60 seconds by transducer. Although backrest elevation was adjusted 2-3 times per dc;y (compared with once daily in the previous trial ), mean elevation in the semirecumbent group was only 28 deg and 23 deg on days 1 and 7 respectively, compared with 10 deg and 16 deg in the control group. VAP rates did not differ between groups.Although these findings validate concerns about the feasibility of 4s backrest elevation, new questions have been raised. Was 45 deg elevation truly achieved in the previous trial? Was 28 deg too low, was 10 deg hicjh enough, and was the achieved elevation in the semirecumbenf group too similar to that used in the control group to show an outcome difference? Until definitive evidence about the optimal angle of elevation ii available, nurses should continue to maintain backrest elevation at the highest level tolerated (unless contraindicated). Side to side repositioning is important to reduce the risk of complications, and diligent skin integriv monitoring promotes early detection and intervention.