Effects of Support Surface Relief Pressures on Heel Skin Blood Flow in Persons with and without Diabetes Mellitus

Do Magnetic Fields Have a Place in Treating Vascular Complications in Diabetes?

The use of electromagnetic field therapy (EMFT) is a non-invasive, potential alternative or complementary choice in the treatment of wounds, chronic pain, neuropathy, and other medical conditions, including tissue repair and cell proliferation. Static magnetic fields (SMFs) have been reported to increase microcirculatory blood flow by mediating vasodilation via nitric oxide. Studies report that SMF exposure causes homeostatic, normalizing effects on the vascular tone that may have beneficial effects in situations where tissue perfusion is limited, such as may be present in diabetes. Pulsed electromagnetic fields (PEMFs) have also shown promise in treating diabetic wounds by improving wound healing rates and other attributes. Our purpose was to critically review prior applications of EMFT for relevancy and effectiveness in treating diabetic complications. The goal was to provide information to allow for informed decisions on the possible use of these modalities in the treatment of persons with diabetic complications. The focus was on the following major areas: wound healing, neuropathy, blood glucose control, blood flow, inflammation and oxidative stress.

Using an alternating pressure mattress to offload heels in ICU

The heel continues to be one of the most common sites of pressure damage. This article reviews the anatomy and physiology of the heel and explores significant risk factors, including those found in the critically ill patient. Interventions to prevent heel pressure ulceration by offloading the heel are explored. An evaluation of the Nimbus 4 alternating pressure mattress was undertaken within an intensive care unit (ICU) to consider the efficacy of its unique Wound Valve Technology, which is designed to help prevent heel pressure ulceration. During the evaluation period none of the patients using the Nimbus 4 developed a pressure ulcer. Staff observed that the Wound Valves provided effective pressure redistribution and, although the cells frequently needed to be adjusted, patient safety was maintained throughout. The Wound Valves were most effective on patients who were less prone to voluntary movement.

A quantitative analysis of microcirculation in sore-prone pressure areas on conventional and pressure relief hospital mattresses using laser Doppler flowmetry and tissue spectrophotometry

BACKGROUND

Pressure ulcers are associated with severe impairment for the patients and high economic load. With this study we wanted to gain more insight to the skin perfusion dynamics due to external loading. Furthermore, we evaluated the effect of different types of pressure relief mattresses.

METHODS

A total of 25 healthy volunteers were enrolled in the study. Perfusion dynamics of the sacral and the heel area were assessed using the O2C-device, which combines a laser light, to determine blood flow, and white light to determine the relative amount of hemoglobin. Three mattresses were evaluated compared to a hard surface: a standard hospital foam mattress bed, a visco-elastic foam mattress, and an air-fluidized bed.

RESULTS

In the heel area, only the air-fluidized bed was able to maintain the blood circulation (mean blood flow of 13.6 ± 6 versus 3.9 ± 3 AU and mean relative amount of hemoglobin of 44.0 ± 14 versus 32.7 ± 12 AU.) In the sacral area, all used mattresses revealed an improvement of blood circulation compared to the hard surface.

CONCLUSION

The results of this study form a more precise pattern of perfusion changes due to external loading on various pressure relief mattresses. This knowledge may reduce the incidence of pressure ulcers and may be an influencing factor in pressure relief mattress selection.

Heel blood flow during loading and off-loading in bedridden older adults with low and normal ankle-brachial pressure index: a quasi-experimental study

The purpose of this study was to evaluate the differences in heel blood flow during loading and off-loading in bedridden adults older than 65 years. The patients were divided into three groups based on ankle-brachial pressure index (ABI) and transcutaneous oxygen tension (tcPO₂): (1) patients with an ABI ≥ 0.8 (Group A); (2) patients with an ABI < 0.8 and heel tcPO₂ ≥ 10 mmHg (Group B); and (3) patients with an ABI < 0.8 and heel tcPO₂ < 10 mmHg (Group C). Heel blood flow was monitored using tcPO₂ sensors. Data were collected with the heel (1) suspended above the bed surface (preload), (2) on the bed surface for 30 min (loading), and (3) again suspended above the bed surface for 60 min (off-loading). Heel blood flow during off-loading was assessed using three parameters: oxygen recovery index (ORI), total tcPO₂ for the first 10 min, and change in tcPO₂ after 60 min of off-loading. ORI in Group C (n = 8) was significantly shorter than in Groups A (n = 22) and B (n = 15). Total tcPO₂ for the first 10 min of off-loading in Group C was significantly less than that in Groups A and B. Change in tcPO₂ after 60 min of off-loading in Group C was less than in Group A. Based on these findings, additional preventive care against heel blood flow decrease in older adults with an ABI < 0.8 and heel tcPO₂ < 10 mmHg might be necessary after loading.

Diabetic heel ulcer in the Sudan: determinants of outcome

Heel ulceration, on average, costs 1.5 times more than metatarsal ulceration. The aim of this study was to analyze the determinant factors of healing in diabetic patients with heel ulcers and the late outcomes at Jabir Abu Eliz Diabetic Centre Khartoum, Khartoum, Sudan. Data were collected prospectively for 96 of 100 diabetic patients presenting with heel ulcers at the Jabir Abu Eliz Diabetic Centre Khartoum from May 2003 to January 2005. Late outcome was assessed 3 years later (February 2008). Heeling was achieved in one half of the patients (n = 48). In the remaining 48 patients, 22 ended with major lower extremity amputation and 22 were still receiving wound care. A total of 8 patients died, 4 in each group, the healed and unhealed. The most significant determinants of healing using a logistic multivariate regression model, 95% confidence intervals, and odds ratios included a shorter duration of diabetes (p < .009), adequate lower limb perfusion (p < .043), and a superficial foot ulcer (p < .012). Three years later, of the 88 patients who could be traced, 78 were alive and 59 had healed ulcers (7 had died of unrelated causes and 3 of diabetic-related complications), and no additional lower extremity amputation was recorded. Mortality in the series was 18 patients, of whom 14 had undergone a previous lower extremity amputation. Superficial heel ulcers in diabetic patients with a short history of diabetes and with good limb circulation are more likely to heal within an average duration of 25 weeks. At 3 years of follow-up, 75% showed a favorable outcome for ulcer healing, and 22 patients underwent lower extremity amputation (25%), of whom 14 were dead within 3 years.

Are pressure redistribution surfaces or heel protection devices effective for preventing heel pressure ulcers?

BACKGROUND

Heel pressure ulcers are recognized as second in prevalence only to pressure ulcer (PU) on the heel among hospitalized patients, and recent studies suggest their incidence may be higher than even sacral ulcers.

OBJECTIVES

We systematically reviewed the literature to identify and evaluate whether pressure redistribution surfaces or heel protection devices are effective for the prevention of heel ulcers.

SEARCH STRATEGY

We searched CINAHL and MEDLINE databases, using the keywords "pressure ulcer" and "heel," which we also searched the Cochrane Library, using the key terms "pressure ulcer," "heel," and "support surface." We hand searched the ancestry of pertinent research reports and review articles in order to identify additional studies. Inclusion criteria were (1) any study that compared one or more pressure redistribution surfaces or heel protection devices designed specifically to prevent heel PU and (2) any study comparing 2 or more pressure redistribution surfaces designed to prevent PU that specifically reported differences in the incidence of heel PU. Exclusion criteria were (1) studies that did not measure heel PU incidence as an outcome, (2) studies without an English language abstract, and (3) studies that reported overall PU incidence but did not analyze heel PU incidence separately.

RESULTS

Clinical evidence concerning the efficacy of pressure redistribution surfaces or heel protection devices is sparse. Existing evidence suggests that pressure redistribution surfaces vary in their ability to prevent heel pressure ulcers, but there is insufficient evidence to determine which surfaces are optimal for this purpose. A single study suggests that a wedge-shaped viscoelastic foam cushion is superior to standard foam pillows for preventing heel PU, but further research is needed before a definitive conclusion concerning this issue can be reached. There is insufficient evidence to determine whether heel protection devices are more effective than a standard hospital foam pillow for the prevention of heel PU. Research is urgently needed to determine the effectiveness of available heel protection devices for the prevention of heel PU. Studies should address efficacy among the available products and compare efficacy to standard foam pillows.

IMPLICATIONS FOR PRACTICE

Given the paucity of clinical evidence, clinical decisions about the selection of an optimal device for preventing heel PU rely on a combination of existing evidence and clinical experience. While pressure redistribution devices may reduce tissue interface pressures at the heels, expert opinion and clinical experience concur that elevation of the heel is indicated to both reduce pressure and prevent shear and friction caused by frequent movement of the heel due to restlessness, reflex movements of the legs, or voluntary movement. A variety of heel protection devices are available that are designed to both relieve tissue interface pressure and protect the heel from shear and friction. Considerations for selecting an optimal heel protection device include its ability to elevate the heel off the underlying support surface while preventing foot-drop and rotation of the leg, the boot's ability to wick away temperature, its ability to be cleaned, whether it allows patient ambulation, its ability to remain in place despite patient movement, and its ability to remain in place without causing pressure to other surfaces of the foot.

Incorporating wound healing strategies to improve palliation (symptom management) in patients with chronic wounds

BACKGROUND

Palliative wound care should be centered on symptom management and is a viable option for patients whose chronic wounds do not respond to standard interventions, or when the demands of treatment are beyond the patient's tolerance or stamina. Palliative wound care is the incorporation of strategies that prioritize symptomatic relief and wound improvement ahead of wound healing (total closure). Palliative wound care strategies must also work in conjunction with curative treatment objectives as wounds often heal completely in spite of serious illness and advanced disease. Palliative wound care is much more than pain, exudate and odor management. Common curative treatment goals such as physical correction of the underlying pathology, addressing nutrition and other supportive aspects of care, and sensible (nonharmful) local wound treatments should never be ignored.

OBJECTIVE

(1) To provide a fresh and effective approach to palliative wound care by integrating individual clinical expertise with clinical and laboratory evidence from the (curative) wound healing literature and (2) to share our (Calvary Hospital) experience and approach to palliative wound care in an inpatient, home, and outpatient setting. This approach can be summarized with the mnemonic S-P-E-C-I-A-L (S = stabilizing the wound, P = preventing new wounds, E = eliminate odor, C = control pain, I = infection prophylaxis, A = advanced, absorbent wound dressings, L = lessen dressing changes). Throughout this paper we will offer rationale, principles and recipes, for each of the steps of the "SPECIAL" approach in an effort to facilitate the caring for chronic wounds in palliative medicine.

CONCLUSIONS

A practical marriage of wound palliation (symptom management) with current wound healing concepts to provide options for the palliative care provider and improve the practice of palliative medicine.

Current perioperative treatment of patients with type 1 and type 2 diabetes

Diabetes mellitus is rapidly increasing, diabetic patients are likely to undergo surgical procedures more than non-diabetic patients, the hospital stay of diabetic patients is longer, and diabetic patients have increased mortality and morbidity. The correct treatment of diabetic patients in the perioperative period is crucial to improve clinical outcomes. Diabetic patients must be carefully evaluated for cardiovascular risk, keeping in mind micro- and macroangiopathic diabetic complications. Metabolic control deserves great attention because hyperglycemia is related to increased complications and worse outcomes. Insulin infusion regimens to achieve near normoglycemia must be implemented in surgical and critically ill patients.

Effect of oral hydration on skin microcirculation in healthy young and midlife and older adults

Clinically undetected underhydration lowers subcutaneous tissue oxygen, impairs healing and increases wound infection. This study examined the effect of supplemental oral hydration on noninvasive measures of skin temperature (T(s)), transcutaneous skin O(2) (PtcO(2)), and CO(2) (PtcCO(2)), and skin blood flow (laser Doppler fluxmetry [Flux]=concentration of moving blood cells [CMBC] x Velocity) in healthy adults. Nineteen Control and 18 Test (Hydrated) subjects participated. Ad libitum fluid intake was allowed before the experiment. Sensors were placed on the chest, lower legs, and feet. Time 1 resting supine T(s), PtcO(2)/PtcCO(2), and Flux/CMBC/Velocity were obtained. Then, the Test group ingested 500 mL of H(2)O. Time 2 measures were obtained 30 minutes later. Data were analyzed using ANOVA. Change in T(s), PtcO(2), PtcCO(2), and Velocity did not differ between groups. Flux increased more in the Test than in the Control group (p<0.01). The Flux change was explained by a CMBC increase (p<0.05). For midlife/older subjects only, the CMBC change was greater in the Test than in the Control group (p<0.01). Flux may be sufficiently sensitive to detect microvascular changes in response to supplemental oral hydration. These data also suggest that subtle levels of hypoperfusion due to underhydration may exist in community-dwelling healthy midlife/older adults in their natural state.

Perfusion confusion

We would like to congratulate Janine Jones on her paper on pressure ulcer prevention devices, published in October 2005, which clearly illustrates the complexity surrounding equipment selection.