The Big Squeeze (Lessening the Big Squeeze: The Effect of the Trunk Release on Interface Pressures of Individuals Seated in a High Fowler's Positions)

Overview

Older adults with a disability tend to spend greater periods of time in bed each day and often over a mealtime. To make it safe for them to eat in bed, the patient is placed in a high Fowler's position. This means that the head and the foot of the bed are raised to sit the person up. Sitting up in bed increases pressure over the buttocks which can lead to the development of a pressure ulcer. The purpose of this study is to evaluate the impact of the positional change called "the trunk release" on pressure over the buttocks, on breathing and on comfort. Primary Hypothesis - Performing the trunk release with an older adult population at low risk for pressure ulcer will result in a 5mmHg decrease in the peak pressure index over the sacral-coccygeal area as measured by the peak pressure index using a Force Sensitive Applications (FSA) Pressure Mapping System. Secondary Hypotheses - Performing the trunk release with an older adult population at low risk for pressure ulcer will result in: * Improved ventilation as measured by a 0.5 liter increase in slow vital capacity. * Greater comfort as measured by a two point change on a horizontal numeric scale with word anchors combined with the Wong-Baker faces scale (Appendix D). * A four-centimetre displacement of the trunk as it extends up towards the head of the bed.

Two research assistants will conduct the study. Experimenter A assists with recruitment of subjects, sets up the test environment and performs the trunk release. Experimenter B acts as the primary data collector and will be kept blind to the purpose of the study. The randomized allocation indicates if the subject is in the intervention or control group. Experimenter A sets up the study hospital bed fitted with a visco-elastic foam mattress, a fitted sheet, a flat sheet and the torso pressure-sensing mat. For standardization, the mat is aligned with markers set on the bed frame. Subjects will wear hospital pajamas over undergarments. Experimenter B records height, weight, age and gender. Subject is seated in a chair and is instructed in the spirometry maneuver. Once the subject is comfortable with the maneuver, Experimenter A asks the subject to lie supine with their body centered on the bed and with their hands resting on their abdomen. Experimenter A reminds the subject to remain completely immobile for the duration of data collection. Experimenter B takes a baseline measure of discomfort as per protocol. Experimenter A places the subject in the High Fowler's position by raising the foot of the bed to its highest position, 50 degrees, and the head of the bed to its highest position, 60 degrees. Experimenter A sets the timer for 8 minutes as per pressure mapping protocol. For more stable values, a "settling time" of 8 minutes is required to factor in creep of the pressure mapping sensors and mattress. Experimenter A aims the laser beam to the top of the scapulae where the subject's shoulder meets the mattress surface. Experimenter B initiates a FSA file with the subject's number, takes a pressure reading once 8 minutes is up, measures the trunk displacement, obtains spirometry readings as per protocol, and takes a measure of discomfort. Experimenter B leaves the room, Experimenter A sets the timer for 5 minutes and opens the allocation envelope. The Principal Investigator will conduct random spot checks to ensure consistency in set-up.