Do high frequency ultrasound images support clinical skin assessment?

High frequency ultrasound imaging has been reported as a potential method of identifying the suspected tissue damage in patients "at risk" of pressure ulceration. The aim of this study was to explore whether ultrasound images supported the clinical skin assessment in an inpatient population through identification of subcutaneous tissue damage. Skin on the heels and/or sacral coccygeal area of fifty vascular surgery inpatients was assessed clinically by tissue viability nurses and with ultrasound pre operatively and at least every other day until discharge. Images were compared to routine clinical skin assessment outcomes. Qualitative classification of ultrasound images did not match outcomes yielded through the clinical skin assessment. Images corresponding to 16 participants were classified as subgroup 3 damage at the heels (equivalent to grade 2 pressure ulceration); clinical skin assessment rated no heels as greater than grade 1a (blanching erythema). Conversely, all images captured of the sacral coccygeal area were classified as normal; the clinical skin assessment rated two participants as grade 1b (non-blanching erythema). Ultrasound imaging is a potentially useful adjunct to the clinical skin assessment in providing information about the underlying tissue. However, further longitudinal clinical assessment is required to characterise images against actual and "staged" pressure ulceration.

Impact of sitting time on seat-interface pressure and on pressure mapping with multiple sclerosis patients.

OBJECTIVE: To examine changes in seat-interface pressure with multiple sclerosis (MS) patients. DESIGN: Case series. SETTING: Multiple Sclerosis Society's Resource Centre and community. PARTICIPANTS: Convenience sample of 15 MS wheelchair users and 12 MS non-wheelchair users. INTERVENTION: Interface pressure was measured for 8 minutes using the Force Sensing Array pressure mapping system. MAIN OUTCOME MEASURES: Number of activated sensors, standard deviation, average and maximum pressures. RESULTS: With the wheelchair users, significant decreases were found in the standard deviation and average and maximum pressures during 0 to 2 minutes of sitting ( P <.01). Average pressure was the only parameter to show a significant decrease in the non-wheelchair users ( P <.01) during 0 to 2 minutes. Significant increases were found in all output parameters during 2 to 4 minutes with both groups ( P <.05). Non-wheelchair users showed no significant changes in the output parameters after 4 minutes, but wheelchair users showed significant continued increases in the output parameters from 4 to 8 minutes ( P <.05). CONCLUSIONS: Because no significant changes in interface pressure occurred after 4 minutes of sitting with the non-wheelchair users, 4 minutes may be a reasonable sitting time before interface pressure is recorded with this group. Significant changes in interface pressure continued up to 8 minutes with the wheelchair users, therefore 8 minutes or beyond may be a reasonable sitting time before recording with this group.

Seat-interface pressure: a pilot study of the relationship to gender, body mass index, and seating position.

OBJECTIVES: To investigate the relationship between interface pressure and gender, body mass index (BMI), and seating positions, and to evaluate the implications for clinical practice. DESIGN: Group design. SETTING: Pressure mapping laboratory. PARTICIPANTS: Sixty-three student volunteers (44 women, 19 men; mean age, 22.2+/-5.1y). INTERVENTIONS: Seated-interface pressure was measured using the Force Sensing Array pressure mapping system. Seating positions used included recline (10 degrees, 20 degrees, 30 degrees ), foot support, and foot elevation. MAIN OUTCOME MEASURES: Interface pressure in the form of both average pressure (mean of the pressure sensor values) and maximum pressure (highest individual sensor value). RESULTS: Both average and maximum pressures were independent of gender, while average pressure had a significant positive correlation with BMI (r=.381, alpha=.01 level). Recline of the chair by 30 degrees significantly reduced average pressure (P<.001), whereas recline by 10 degrees or 20 degrees had no significant effect. Recline by 10 degrees, 20 degrees, and 30 degrees did not significantly alter maximum pressure. Elevation of the feet on a footstool reduced average pressure to a level approaching statistical significance, while supporting participants' feet versus leaving them unsupported significantly increased average pressure at a 0 degrees, 10 degrees, 20 degrees, and 30 degrees recline (P<.01) and maximum pressure at 0 degrees, 10 degrees (P<.01), and 30 degrees (P<.05). CONCLUSIONS: Elevating clients' feet and reclining their chair by 30 degrees reduced interface pressure and the associated risk of pressure ulcer development. Additional research is required, however, to replicate this study with participants at increased risk of pressure ulcer development.