Beware of the toilet: The risk for a deep tissue injury during toilet sitting.

A pressure injury (PrI) compromises quality of life and can be life-threatening. The fundamental cause of PrIs is sustained deformations in weight-bearing soft tissues, e.g., during prolonged sitting on inadequate surfaces such as a toilet seat. In nursing homes and geriatric facilities, patients need assistance using the restroom, and patients being left on the toilet for tens-of-minutes is a real-world scenario, unfortunately. Nevertheless, there are no published studies regarding sustained tissue loads during toilet sitting and their effects on tissue physiology. Here, the biomechanical and microcirculatory responses of the buttock tissues to toilet sitting were investigated using finite element modeling and cutaneous hemodynamic measurements, to explore the potential etiology of PrIs occurring on the toilet. We found that prolonged sitting on toilet seats involves a potential risk for PrI development, the extent of which is affected by the seat design. Additionally, we found that specialized toilet seat cushions are able to reduce this risk, by lowering instantaneous tissue exposures to internal stresses (by up to 88%) and maintaining reduced interface pressures. Furthermore, hemodynamic variables were altered during the toilet sitting; in particular, tcPO2 was decreased by 49% ± 7% (44 ± 2[mmHg] to 22 ± 4[mmHg]) during sitting. The current study confirms that investing in expensive PrI prevention (PIP) products is likely to be ineffective for an immobilized patient who is left to sit on a bare toilet seat for long times. This argument highlights the need for a holistic-care approach, employing PIP devices that span across the entire environment where bodyweight forces apply to tissues.

Impact of a mechanical massage on gene expression profile and lipid mobilization in female gluteofemoral adipose tissue.

BACKGROUND: Gluteofemoral adipose tissue areas are known to be poorly metabolically reactive. Mechanical massage has previously been reported to show morphological and functional impact on this tissue. The present study was carried out to delve more deeply into the mechanistic considerations regarding the incidence of a mechanical massage technique on gene expression profile and ß-adrenergic-mediated lipid mobilization in female femoral adipose tissue. METHODS: Twelve premenopausal healthy women were included and received 12 sessions of calibrated mechanical massage (Endermologie®). Total RNA was extracted from femoral adipose tissue biopsies for gene expression studies. Microdialysis was carried out in the femoral adipose tissue in order to assess lipolytic responsiveness (via glycerol determination) and changes in local blood flow following perfusion of a lipolytic agent, isoproterenol. Evaluations were performed before and after the 6-week experimental period. RESULTS: Mechanical massage initiated important modifications in gene expression profile. The lipid-mobilizing effect of isoproterenol was enhanced after the experimental period. Basal local blood flow and isoproterenol-induced vasodilatation were also improved. CONCLUSION: The protocol of mechanical massage used in the study promoted noticeable changes in the expression of genes involved in metabolic pathways. The lipolytic and local adipose tissue blood flow responses initiated by isoproterenol were significantly enhanced.

Arteriovenous malformation arising on persistent sciatic vessels.

BACKGROUND: A persistent sciatic artery is a rare congenital anomaly, and an arteriovenous malformation arising on persistent sciatic vessels is extremely rare. METHODS: This report presents the case of a 30-year-old female with persistent sciatic vessels complicated with an arteriovenous malformation in the right buttock. It was surgically inaccessible, and a three-staged transcatheter embolization using 20% N-butyl-cyanoacrylate/80% lipiodol was performed. RESULTS: The arteriovenous malformation was shown to have been extinguished by multidetector computed tomography. CONCLUSIONS: This report presents the first case of persistent sciatic vessels complicated with an arteriovenous malformation treated by transcatheter embolization.

New technique for real-time interface pressure analysis: getting more out of large image data sets.

Recent technological improvements have led to increasing clinical use of interface pressure mapping for seating pressure evaluation, which often requires repeated assessments. However, clinical conditions cannot be controlled as closely as research settings, thereby creating challenges to statistical analysis of data. A multistage longitudinal analysis and self-registration (LASR) technique is introduced that emphasizes real-time interface pressure image analysis in three dimensions. Suitable for use in clinical settings, LASR is composed of several modern statistical components, including a segmentation method. The robustness of our segmentation method is also shown. Application of LASR to analysis of data from neuromuscular electrical stimulation (NMES) experiments confirms that NMES improves static seating pressure distributions in the sacral-ischial region over time. Dynamic NMES also improves weight-shifting over time. These changes may reduce the risk of pressure ulcer development.

Relationship of inferior gluteal nerves and vessels: target for application of stimulation devices for the prevention of pressure ulcers in spinal cord injury.

A study was carried out to determine whether the location of the inferior gluteal nerve could be reliably predicted using external anatomy or vascular imaging. This study was motivated by our group's development of an electrical stimulation system to provide direct gluteal stimulation in paralyzed individuals, in particular those with spinal cord injury (SCI). Pressure ulcers are a common complication for many individuals with reduced mobility. Numerous approaches have been employed to treat and prevent pressure ulcers; however no procedure or nursing care regimen has been successful in eradicating them completely. Our group seeks to prevent skin breakdown in susceptible patients by direct electrical stimulation of the paralyzed gluteal muscle, leading to improved circulation and increased muscle mass (hypertrophy) in the treated area. Currently, percutaneous electrodes are placed through an extensive probing process to select the motor point of the target muscle. We examined 15 cadaver gluteal regions to identify the relationship between the internal anatomy of the inferior gluteal artery and nerve as well as the relationship to external anatomic landmarks. The cadavers displayed variability with regard to the morphology of the branches of both nerve and artery. Furthermore, there did not appear to be any relationship between the relative positions of the nerve and artery. However, the potential target area of the proximal origin of the inferior gluteal nerve could reliably be predicted from the external bony anatomy of the lower pelvis.

Hormone replacement therapy can augment vascular relaxation in post-menopausal women with type 2 diabetes.

BACKGROUND: Diabetes is a major risk factor for coronary heart disease in women and event rates increase substantially after the menopause. Observational studies have suggested that estrogens may provide cardioprotection by regulating endothelial nitric oxide synthase. METHODS: In order to examine the effect of hormone replacement therapy (HRT) on endothelium-dependent and -independent vascular relaxation in post-menopausal women with type 2 diabetes, an open study was conducted in which gluteal biopsies were collected from 17 women before and after 6 months of transdermal 17 beta-estradiol (80 microg twice weekly) in combination with oral norethisterone (1 mg daily). Small arteries (<550 microm) were dissected from fat and mounted on a wire myograph for assessment of relaxation in response to acetylcholine (ACh), bradykinin (BK) and sodium nitroprusside (SNP). RESULTS: Maximal relaxation responses to ACh, BK and SNP in women with diabetes and non-diabetic control subjects were 52 +/- 8 versus 96 +/- 2% (P < 0.05), 76 +/- 7 versus 97 +/- 1%, (P < 0.05) and 91 +/- 2 versus 98 +/- 1% (P < 0.05) respectively. After 6 months of HRT, maximal relaxation responses to ACh, BK and SNP in women with diabetes (compared with pre-HRT) were: 88 +/- 4 (P < 0.05), 93 +/- 3 (P < 0.05) and 98 +/- 1% (P < 0.05) respectively. At baseline and after HRT, EC50 (concentration required to obtain 50% of maximum response) data exhibited similar changes. CONCLUSIONS: HRT had potentially beneficial effects on vascular relaxation. Data were consistent with improvements in endothelial function, vascular smooth muscle function, or both. Controlled studies are required to confirm and extend these findings.

Effects of dietary marine oil supplementation on reactivity of human buttock subcutaneous arteries and forearm veins in vitro.

1. The vascular reactivity of resistance arteries isolated from gluteal skin biopsies and veins isolated from forearms of subjects fed marine oils were examined. 2. Twenty seven healthy adult males were randomly allocated to one of two different treatment groups. The first group received maxEPA (eicosapentaenoic acid 0.178 g g-1; docosahexaenoic acid 0.116 g g-1) capsules 10 g per day for 28 days while the second group received an equivalent amount of mixed oil placebo capsules. Biopsies were performed on day 29 (13 for gluteal sections; 14 for forearm vein biopsies). Subcutaneous arteries and veins were mounted in myographs and standard organ baths, respectively. 3. The internal diameter of the subcutaneous arteries at a calculated transmural pressure of 100 mmHg averaged 183.7 +/- 10.3 microns in the maxEPA group and 182.6 +/- 19.8 microns in the placebo controls. Arteries from subjects on maxEPA demonstrated increased sensitivity to angiotensin II (maxEPA vs placebo: -log EC50 (M) -8.36 +/- 0.18 vs -7.91 +/- 0.14) but not to noradrenaline or 5-hydroxytryptamine. Concentration-response curves to acetylcholine, substance P and sodium nitroprusside obtained for noradrenaline precontracted vessels were unaltered with marine oil treatment as was the concentration-response curve to calcium in K(+)-depolarized vessels. 4. Vein internal diameter at a calculated transmural pressure of 20 mmHg averaged 3.06 +/- 0.23 mm in the maxEPA group and 2.96 +/- 0.89 in the placebo group. Responses to noradrenaline, 5-hydroxytryptamine, angiotensin II and endothelin-1 were obtained in the absence and presence of indomethacin (1 microM) in veins from both maxEPA and placebo-treated subjects. Neither dietary supplementation with marine oils nor indomethacin had any effect on the responses obtained to these agonists.5. The major finding of the present study was that in general, maxEPA supplementation did not affect responses to various vasoactive substances on isolated subcutaneous arteries or forearm veins. An exception was the observation of an enhanced response to angiotensin II in subcutaneous resistance arteries studied in vitro. This effect was selective for angiotensin II and was not apparent in veins isolated from the forearm.

Blood flow in the gluteus maximus of seated individuals during electrical muscle stimulation.

Blood flow was measured under the ischial tuberosites of seated individuals during electrical stimulation of the gluteus maximus muscles. Eight able-bodied and six spinal cord injured subjects were studied. Muscle blood flow was measured via radioactive tracer (133xenon) clearance. Retention of xenon in adipose tissue prevented accurate measurement of blood flow in cutaneous and subcutaneous tissue. Average muscle blood flow for both subject groups was increased during stimulation as compared to rest. All subjects showed an increase in muscle blood flow during stimulation. The statistical significance from a paired student t-test was greater for able-bodied subjects (p less than .05) than for spinal cord injured subjects (p = .12). The increase in muscle blood flow produced by electrical muscle stimulation in seated individuals supports the hypothesis that electrical muscle stimulation can help prevent pressure sores.