Mary Jo Geyer

A randomized control trial to evaluate pressure-reducing seat cushions for elderly wheelchair users.

OBJECTIVE To determine if the use of pressure-reducing wheelchair cushions for elderly nursing home resident wheelchair users who are at high risk for developing sitting-acquired pressure ulcers would result in a lower incidence rate of pressure ulcers, a greater number of days until ulceration, and lower peak interface pressures compared with the use of convoluted foam cushions over a 12-month period. To determine the feasibility of conducting a subsequent full-scale definitive trial to evaluate the use of pressure-reducing seat cushions for elderly nursing home resident wheelchair users. DESIGN Randomized control trial SETTING 2200-bed skilled nursing facilities (1 suburban and 1 urban academic medical center) PATIENTS 32 male and female at-risk nursing home residents who were wheelchair users > or = 65 years of age. Participants had Braden Scale scores < or = 18, Braden Activity and Mobilitysubscale scores < or = 5, no sitting surface pressure ulcers, and a daily wheelchair sitting tolerance of more than 6 hours. All met criteria for using the ETAC Twin wheelchair. INTERVENTIONS Seating evaluation with pressure-mapping and subsequent seating prescription. Subjects were assigned to either a foam (n=17) or pressure-reducing cushion (n=15) group and weekly assessments of skin and pressure ulcer risk were made. MAIN OUTCOME MEASURES Incidence of pressure ulcers, days to ulceration, and peak interface pressure. MAIN RESULTS At a 95% confidence interval, a 2-tailed analysis showed no differences between the FOAM and pressure-reducing cushion groups for pressure ulcer incidence, total days to pressure ulcer, or initial peak interface pressure. Pressure-reducing cushions were more effective in preventing sitting-acquired (ischial) pressure ulcers (P<.005). Higher interface pressures were associated with a higher incidence of pressure ulcers (P<.001). CONCLUSIONS A definitive randomized control multicenter cushion trial is feasible with a sample size of 50 to 100 per study group. In the definitive trial, the definition of sitting-acquired pressure ulcers should be limited to lesions occurring over the ischial tuberosities.

A randomized clinical trial on preventing pressure ulcers with wheelchair seat cushions.

OBJECTIVES: To determine the efficacy of skin protection wheelchair seat cushions in preventing pressure ulcers in the elderly nursing home population.

Wavelet-Based Spectrum Analysis of Sacral Skin Blood Flow Response to Alternating Pressure

OBJECTIVES To provide insight into the physiologic mechanisms associated with alternating pressure, using wavelet analysis of skin blood flow (SBF) oscillations, and to determine whether the application of alternating pressure induces myogenic responses, thereby enhancing SBF as compared with constant loading. DESIGN Repeated-measures design. SETTING University research laboratory. PARTICIPANTS Healthy, young adults (N=10; 5 men, 5 women; mean age +/- standard deviation, 30.0+/-3.1 y). INTERVENTION Alternating pressure for 20 minutes (four 5-min cycles with either 60 mmHg or 3 mmHg) and constant loading for 20 minutes at 30 mmHg on the skin over the sacrum. MAIN OUTCOME MEASURES A laser Doppler flowmeter was used to measure sacral SBF response to both alternating pressure and constant loading. Wavelet-based spectrum analysis of SBF oscillations was used to assess underlying physiologic mechanisms including endothelium-related metabolic (.008-.02 Hz), neurogenic (.02-.05 Hz), and myogenic (.05-.15 Hz) controls. RESULTS Alternating pressure stimulated an increase in sacral SBF of compressed soft tissues as compared with constant loading (P<.01). SBF during the high-pressure phase of 4 alternating pressure cycles showed an increasing trend. An increase in power in metabolic frequency range and a decrease in power in the myogenic frequency range during alternating pressure were observed compared with SBF prior to loading. Power increased in the myogenic frequency range during the low-pressure phase of alternating pressure and decreased during the high-pressure phase. CONCLUSIONS SBF control mechanisms, as assessed by the characteristic frequencies embedded in SBF oscillations, show different responses to 2 loading pressures with the same average pressure but different patterns. Our study suggests that optimization of operating parameters and configurations of alternating pressure support surfaces to compensate for impaired SBF control mechanisms in pathologic populations may be possible using wavelet analysis of blood flow oscillations.

Analysis of week-to-week variability in skin blood flow measurements using wavelet transforms.

The study of skin blood flow responses is confounded by temporal variability in blood flow measurements. Spectral analysis has been shown useful in isolating the effects of distinct control mechanisms on various stimuli in the microcirculatory system. However, the sensitivity of spectral analysis to temporal blood blow variability has not been reported. This study was designed to assess week‐to‐week variability in blood flow measurements using wavelet‐based spectrum analysis. Ten healthy, young subjects (mean age ± SD, 30·0 ± 3·1 years) were recruited into the study. Incremental heating (35–45°C, 1° step min−1) was applied on the skin over the sacrum once per week for three consecutive weeks. Wavelet analysis was used to decompose the laser Doppler blood flow signal into frequency bands determined to be associated with endothelial nitric oxide (0·008–0·02 Hz), neurogenic (0·02–0·05 Hz), myogenic (0·05–0·15 Hz), respiratory (0·15–0·4 Hz), and cardiac (0·4–2·0 Hz) control mechanisms. The results showed that coefficients of variation for the power in each frequency band at baseline are smaller than the coefficients of variation of blood flow at baseline or at maximal blood flow ratio (P<0·05). Myogenic and respiratory frequency bands showed the highest coefficients of variation among the five frequency bands. An increase in power in the endothelial nitric oxide frequency band and a decrease in power in the myogenic frequency band of the maximal blood flow response were reproduced in three consecutive weeks. Our study suggests that wavelet analysis is an effective method to overcome temporal variability in skin blood flow measurements.

Using support surfaces to manage tissue integrity.

PURPOSETo provide the clinician with an overview of support surfaces used to manage tissue integrity as well as a review of how pressure ulcers develop. TARGET AUDIENCEThis continuing education activity is intended for physicians and nurses with an interest in understanding how available support surfaces can impact the development and treatment of pressure ulcers. OBJECTIVESAfter reading the article and taking the test, the participant should be able to:Describe the types and characteristics of support surface technologies.Discuss the development of pressure ulcers.

Quantifying fibrosis in venous disease: mechanical properties of lipodermatosclerotic and healthy tissue.

OBJECTIVES:To quantify the mechanical properties of medioposterior bulk calf tissue in patients with lipodermatosclerotic venous-insufficient tissue and individuals with apparently healthy tissue using a novel ultrasound indentometry method, and to identify parameters with the potential for quantifying fibrosis in subsequent studies. DESIGN:2-group, quasi-experimental design SETTING:Soft Tissue Mechanics Laboratory, University of Pittsburgh, Pittsburgh, PA PARTICIPANTS:9 healthy and 9 venous-insufficient individuals aged 35 to 85 years INTERVENTIONS:Ultrasound indentometry and computed tomography (CT) of calf tissue MAIN OUTCOME MEASURES:Between group differences and associations among quasi-linear viscoelastic (QLV) tissue parameters and CT descriptors MAIN RESULTS:Established the accuracy, validity, and reliability of the QLV model and ultrasound indentometry method. Demonstrated a range of significant differences between the groups (P <.020 to P <.004) for selected QLV parameters. Also found significant correlations between CT measures of fibrosis and dermal thickness and QLV elastic measures (P <.034 to P <.005). CONCLUSION:Attempts to quantify fibrosis in lipodermatosclerosis have included histologic exams, palpation/pitting, durometer readings, and imaging techniques, but these efforts have failed to produce a clinically practical, noninvasive method. A novel ultrasound indentometry method was used to acquire in vivo data from which tissue parameters were derived. These data support the further development of ultrasound indentometry as a method to quantify fibrosis in venous disease.

Wheelchair Seating: A State of the Science Report

Regardless of the field, agenda-setting processes are integral to establishing research and development priorities. Beginning in 1998, the National Institute on Disability and Rehabilitation Research mandated that each newly funded Rehabilitation Engineering and Research Center (RERC) hold a state-of-the-science consensus forum during the third year of its 5-year funding cycle. NIDRRs aim in formalizing this agenda-setting process was to facilitate the formulation of future research and development priorities for each respective RERC. In February 2001, the RERC on Wheeled Mobility, University of Pittsburgh, conducted one of the first such forums. The scope encompassed both current scientific knowledge and clinical issues. In preparation, expert interviews were carried out to establish the focus for the forum. Because a stakeholder forum on wheelchair technology had recently been held, opinion favored wheelchair seating as the focus and included the following core areas: seating for use in wheelchair transportation, seated postural control, seating discomfort, and tissue integrity management. The aim of this report is to present a summary of the workshop outcomes, describe the process, and increase awareness of this agenda-setting process in order to enhance future participation in a process that critically influences the field of wheeled mobility.

Design and development of a telerehabilitation self-management program for persons with chronic lower limb swelling and mobility limitations: preliminary evidence.

This paper describes design and development of a self-management program, delivered by telerehabilitation (TR), to address the problem of chronic lower limb swelling in persons with limited mobility. The 18.6 million persons with limited mobility in the USA are at increased risk for chronic lower limb swelling and related secondary complications, including cellulitis and skin ulcers. Over time, chronic swelling often progresses to lymphedema, an incurable condition requiring lifelong care. Without successful self-management, lymphedema and its related complications inevitably worsen. Access and adherence to appropriate treatment are challenging for persons with limited mobility. Program development involved a structured process to establish content validity (videos and manuals), readability, suitability, and selection of a TR platform to deliver the educational program. Our goal was to develop a program that would engage patients in self-management skills. The TR software platform chosen, Versatile and Integrated System for Telerehabilitation (VISYTER) was designed to facilitate face-to-face delivery of an interactive home-based self-management program via the internet in real time. Results demonstrated validity of the educational program and ease of use with TR. Future plans are to evaluate ability of this approach to promote self-management skills, home monitoring, and improved management of persons with lymphedema and limited mobility.

Teaching Self-Management Skills in Persons with Chronic Lower Limb Swelling and Limited Mobility: Evidence for Usability of Telerehabilitation

The purpose of this study was to evaluate the usability of telerehabilitation as a method of teaching self-management for chronic swelling of the lower limbs in persons with limited mobility. An in-home telerehabilitation self-management education protocol for chronic swelling of the lower limbs, termed Telerehabilitation to Empower You to Manage and Prevent Swelling (TR-PUMPS), was implemented using the Versatile and Integrated System for Telerehabilitation (VISYTER) software platform. Participants (n=11) were 36–79 years old, predominately female (72.7%) and diagnosed with a variety of health conditions. Participants’ perceived usability scores of the remote delivery of TR-PUMPS was high with a median score of 6.67 (range 4.90 – 7.00) on a Likert scale: 1= disagree to 7= agree. There was no correlation between participants’ familiarity with information technology and their perception of telerehabilitation usability. These results support telerehabilitation as a viable method for teaching a home-based, self-management protocol for chronic swelling.