Registered Nurses' Association of Ontario

Support Surfaces - Entrapment

A risk of entrapment exists when the therapeutic support surface is not the same size as the original mattress creating excess space between the surface and the bed frame. The interprofessional team should be aware that entrapment can occur in the home and in various health-care settings in seven ways:


1. within the rail

2. under the rail (between the rail supports or next to a single rail support)

3. between the rail and mattress

4. under the rail (at the ends of the rail)

5. between split bed rails

6. between the end of the rail and the side edge of the headboard or footboard

7. between the headboard or footboard and the mattress end


To minimize the risk of entrapment, the interprofessional team should consider the following:

  • Selecting a surface that has a transfer border, as it may be less likely to compress as the person approaches the side of the surface.
  • Evaluating the use of bed rails (e.g., the risk may be reduced when these are not in place)
  • Implementing other devices (such as positioning wedges or a mattress cover with built-in bolsters).
  • Consulting with an occupational therapist or physical therapist skilled in this area, in order to complete an assessment and make specific recommendations.
  • Once the appropriate support surface has been selected and installed, the expert panel recommends that the support surface continue to be monitored for effectiveness.
Clinical Management
Assessment and Management of Pressure Injuries for the Interprofessional Team, Third Edition
Point of Care Resources