Interface Pressure at Different Degrees of Backrest Elevation With Various Types of Pressure-Redistribution Surfaces

Abstract

Background Increased elevation of the head of the bed is linked to a higher risk for sacral pressure ulcers. A semirecumbent position of at least 30° is recommended for the prevention of ventilator-associated pneumonia in patients treated with mechanical ventilation. Therefore, prevention of pressure ulcers and prevention of pneumonia seem to demand contradictory, possibly incompatible, positioning. Objectives To measure pressure at the interface between sacral skin and the supporting surface in healthy volunteers at different degrees of upright position with different types of mattresses. Methods An open, prospective, randomized crossover trial was conducted with 20 healthy volunteers. Interface pressure was measured by using a pressure mapping device with the participant in a supine position at 0, 10°, 30°, and 45° elevation and in the reverse Trendelenburg position at 10° and 30°. Four types of mattresses were examined: 2 different foam mattresses and 2 air suspension beds, 1 of the latter with low-air-loss technology. Results Peak sacral interface pressures increased significantly only at 45° of backrest elevation (P < .001). A mattress system with low-air-loss technology significantly reduced peak interface pressures at all angles (P < .001).The reverse Trendelenburg position led to lower peak pressures for all positions (P = .01). Conclusions Backrest elevation up to 30° might be a compromise between the seemingly incompatible demands of skin integrity and the prevention of ventilator-associated pneumonia. The reverse Trendelenburg position and a mattress system with low-air-loss technology could be additional useful tools to help prevent skin breakdown at the sacrum.

Tissue interface pressure and skin integrity in critically ill, mechanically ventilated patients

“…Critical tissue interface pressure levels associated with changes in skin integrity are not standardised and a critical magnitude above which ischaemia occurs has not been established. While some authors have used the 32 mmHg (Defloor, 1999;Lippoldt et al, 2014; Peterson et al, 2008) others have used higher levels (Behrendt et al, 2014; Gunningberg and Carli,2014; Sakai et al, 2009). As these data suggest, in addition to tissue interface pressure, other factors are contributory to the development pressure, including diastolic and systolic blood pressure, sheer forces, patient age, hydration and metabolism (Cox and Cwocn, 2011; Cox, 2013; Lachenbruch et al, 2013).…”

“…Therefore, we investigated several maximum interface pressure levels based on values previously tested by others (Behrendt et al, 2014; Defloor, 1999; Gunningberg and Carli, 2014;Landis, 1930; Lippoldt et al, 2014; Peterson et al, 2008;Sakai et al, 2009). We identified three maximum pressure levels, greater than or equal to 32, 45 and 60 mmHg.…”

“…We also found that inter-face pressure decreased as backrest elevation increased in the scapula, but not in the sacrum, heels or trochanter (Grap et al, 2016). However, there are few data that fully describe tissue interface pressure over time and the effect on skin integrity in critically ill, mechanically ventilated patients (Lippoldt et al, 2014; Sprigle and Sonenblum, 2011;van Nieuwenhoven et al, 2006). Therefore, the purpose of this secondary, descriptive, longitudinal study in critically ill mechanically ventilated adults, was to describe tissue inter-face pressure, time spent above critical pressure levels and the effect on skin integrity at seven anatomical locations with high risk for development of pressure ulcers.…”

The Comparison of the Effect of the Head of Bed Elevation to 30 and 45 Degreess on the Incidence of Ventilator Associated Pneumonia and the Risk for Pressure Ulcers: A Controlled Randomized Clinical Trial

“…A greater weight increases the pressure on the body and the use of low-air-loss mattresses reduces such pressure. As a result, the use of low-air-loss mattresses with the reverse trendelenburg position and HOB elevation to 30 to 45 degrees prevents skin damage in the sacral area (35).…”

Recent Advances in Multidisciplinary Critical Care

“…In an open, prospective, randomized cross-over trial, the interface pressure was measured over distinct body positions by using a pressure-mapping device. 62 Interface pressure with patients supine at various angles of head-of bed elevation and during reverse Trendelenburg position was measured in 20 healthy volunteers. Four types of mattresses were evaluated as well: 2 different foam mattresses and 2 air suspension beds one of which had low-air-loss technology.…”