Effect of changing the lying posture angle by changing the bed posture on the average pressure, maximum pressure, and pressure area in the hip region

BACKGROUND: An electric bed can easily change posture from a lying position and was effective in preventing pressure ulcer. OBJECTIVE: This study aimed to identify the optimal posture for the prevention of pressure ulcers by analyzing pressure changes applied to the pelvic region. METHODS: Pressure changes resulting from lateral rotations of the body using an electronic adjustable bed and changes in the posture and angles of the trunk and knees were assessed. Twelve conditions with varying angles of the trunk and knees (15–35∘ in 5∘ increments) and varying lateral angles (20–35∘ in 5∘ increments) were tested. The pressure (maximum and average) and contact area in the pelvic region of 20 individuals without disabilities were calculated. RESULTS: The conditions in which the average and maximum pressures did not increase according to the increase in angle were 25∘ for the upper body and knee angles and 35∘ for the side. CONCLUSIONS: The body pressure changed according to the posture rather than according to physical characteristics. Lateral rotation combined with changes in the angles of the trunk and knees effectively prevented pressure ulcers. Changes in the posture at various angles prevented an increased pressure on the body.

Repositioning mattress: how a lateral tilt position reshapes the prevention of pressure ulcers in bedridden patients

Pressure ulcers have been part of tissue damage without effectiveness in medical, surgical, and intensive care units. This study aims to focus on developing lateral tilt positions for effective pressure ulcer relief for bedridden patients. A repositioning mattress was placed in the side-lying left lateral tilt position (15°, 30°, 45°), sheering (0.680, 1.323, 1.870), interface pressure (2.550, 2.290, 2.830), and placed at 1.5 m long piece of polyethylene rubber. The design strength was set at 6000 N and 2100 mm x 1105 mm (σt,0,d = 42, σc,0,d = 34). The design shows the greatest supine position at 30°, 1.323, 2.290, pressure load (Δp0 = 1.125 (1820) ≈ 2050 psi, Δp3000 = 1.125 (620) ≈ 700 psi), tensile stress (σt,0,d (MPa) = 42), compressive stress (σc,0,d (MPa) = 34), and FOS (σt,0,d = 42, σc,0,d = 34). The factor of safety illustrated that the 30° lateral tilt position is more consistent in repositioning for pressure ulcer prevention compared to the supine-to-tilt region. Further, an application of repositioning mattresses was developed to test in bedridden patients with tissue ulcers in nursing homes.

Reducing the Incidence and Prevalence of Pressure Injury in Adult ICU Patients with Support Surface Use: A Systematic Review

GENERAL PURPOSE

To provide information on the effectiveness of active and reactive support surfaces in reducing the incidence and prevalence of pressure injuries (PIs) in adult ICU patients.

TARGET AUDIENCE

This continuing education activity is intended for physicians, physician assistants, nurse practitioners, and nurses with an interest in skin and wound care.

LEARNING OBJECTIVES/OUTCOMES

After participating in this educational activity, the participant will: 1. Distinguish features of active and reactive support surfaces used in the ICU.2. Compare the PI incidence in patients using a variety of support surfaces.3. Synthesize recommendations for the use of support surfaces to reduce the risk of PI in adult ICU patients.

Predicting the cut-off point for interface pressure in pressure injury according to the standard hospital mattress and polyurethane foam mattress as support surfaces

This study aimed to investigate the interface pressure (IP) of patients using a standard hospital mattress and polyurethane foam mattress as support surfaces and present cut‐off points for IP in patients who exhibited skin changes. A total of 189 inpatients enrolled from six general wards and three intensive care units at a Korean University Hospital. Skin changes were classified, and peak IP at the sacral and occipital regions was measured using a pressure scanner. Differences in IPs according to mattress type were analysed using independent t‐tests. The receiver operating characteristic curve was constructed to determine the cut‐off point, and the area under the curve with a 95% confidence interval was obtained using the Stata 15.1.program. The IP for a standard hospital mattress was significantly higher than that of a polyurethane foam mattress. The cut‐off points for IP at the sacral region were 52.90 and 30.15 mm Hg for a standard hospital mattress and polyurethane foam mattress, respectively. The cut‐off point for IP at the occipital region was 36.40 mm Hg for a polyurethane foam mattress. Using IP measurements to prevent pressure injuries is important and employ individualised interventions based on the cut‐off points for different support surfaces.

A Comparative Study of 2-Hour Interface Pressure in Different Angles of Laterally Inclined, Supine, and Fowler's Position

Insufficient research exists for position change intervals to eradicate pressure ulcers. We tried to provide evidence for the position change interval by comparing peak pressure, risk area ratio, and the time to reach 30 mmHg and 60 mmHg, and presented this in detail, according to the angle in the three positions. The study conducted RCTs on a total of 64 healthy adults. For two hours, interface pressure measurements were compared with 30° and 90° tilting at the inclined, 0° and 45° head-of-bed (HOB) elevation at the supine, and 30° and 45° HOB elevation at the Fowler’s position. The peak pressure on 30° tilting remained less than 60 mmHg for 2 h, unlike 90° tilting. To reach 60 mmHg took 78.18 min at 30° tilting, within 30 min at the 30° supine, 30° and 45° at the Fowler’s position, and 39.55 min at 0° supine. The pressure difference according to the angles was only significant at 30° and 90° tilting, with no difference in the other groups. To prevent pressure ulcers, position changes are required every 2 h in the 30° tilting position, every 1.5 to 2 h at 0° supine, and at least every 1.5 h for all the other positions.

Effect of interface pressure and skin surface temperature on pressure injury incidence: a turning schedule pilot study

OBJECTIVE

This study aimed to evaluate the interface pressure and skin surface temperature in relation to the incidence of pressure injury (PI) using three different turning schedules.

METHOD

This was a pilot study with a three-armed randomised clinical trial design. Participants at risk of PI and treated in the high dependency care unit in a regional hospital in Makassar, Indonesia participated in this study. Patients were repositioned at three different turning schedules (two-, three- and four-hourly intervals). Interface pressure measurement and skin surface temperature were measured between 14:00 and 18:00 every three days. The incidence of PI was assessed during the two-week observation period.

RESULTS

A total of 44 participants took part in the study. A one-way ANOVA test revealed no difference in interface pressure among the three different turning schedule groups within two weeks of observations: day zero, p=0.56; day four, p=0.95; day seven, p=0.56; day 10, p=0.63; and day 14, p=0.92. Although the average periumbilical temperature and skin surface temperature were not significant (p>0.05), comparison between these observation sites was significant on all observation days (p<0.05). Regarding the incidence of PI, the proportional hazard test for the development of PI in the three groups was considered not different (hazard ratio: 1.46, 95% confidence interval: 0.43-4.87, p=0.54).

CONCLUSION

No difference in interface pressure and incidence of PI on the three turning schedules was observed; however, there was a potential increase in skin surface temperature in comparison with periumbilical temperature for all three turning schedules.

Tissue temperature, flux and oxygen of sacral and trochanteric area under pressure of healthy subjects: A quasi-experimental study

AIM

To evaluate the changes that take place in the perfusion, oxygenation and local temperature of the skin of the sacrum and trochanter when subjected to direct pressure for 2 h.

METHODS

Quasi-experimental study in the preclinical phase with healthy subjects acting as their own controls (intrasubject control). The outcome variables were measured with a laser Doppler system (local temperature and oxygenation) and by near-infrared spectroscopy (perfusion). The pressure exerted was measured with a capacitive pressure sensor. No more than one week elapsed between the sacrum and trochanter measurements.

RESULTS

The study sample consisted of 18 persons. The comparative analysis of the fluctuations in the parameters measured on the skin of the trochanters and sacrum, according to the time elapsed, revealed a statistically significant increase in temperature and in the pressure exerted. On the other hand, the changes in capillary blood flow and in SaO2 were not statistically significant.

CONCLUSION

Our study results show that changes found in terms of temperature and pressure should be taking into account when planning personalised repositioning to patients according to biomechanical and biological situations that vary between anatomical areas. In future research, the changes reported could be evaluated in patients with risk factors for the development of pressure ulcers, thus facilitating the introduction of more personalised planning in the care and prevention of these injuries.

Friction characteristics of preventative wound dressings under clinically-relevant conditions

Wound dressings can be used prophylactically or during actual treatment. Preventative dressings have become a standard of care to prevent pressure ulcers in patients while in bed. While the mechanism of the preventative benefit has not been completely explained, the friction between the dressing and linen is hypothesized as being a key performance factor. The objective of this project was to quantify the static and kinetic coefficients of friction (COF) of various brands of prophylactic dressings under the stresses experienced in situ, while the dressings are in contact with bed linen materials. The COF of six commercial dressings were calculated using tribometer measurements. The ranges of static COF were 0.333-0.542 and kinetic COF were 0.333-0.513. Four dressings exhibited COF that were consistent with skin-linen values reported in the literature and all dressing COF appear to be lower than the COF of moist skin against linen.

A Comparative Study Between Two Support Surfaces for Pressure Ulcer Prevention and Healing in ICU Patients

Objective The aim of this research was to compare the effectiveness of two mattresses used in intensive care unit (ICU) high-risk patients in terms of pressure ulcers (PUs) prevention and healing. Materials and Methods The studied sample consisted of 70 consecutive patients aged 18 to 65 years hospitalized in two ICUs of a general hospital in Athens, Greece. Virtuoso Mattress System (LINET, Slaný, Czech Republic) was used in 35 patients, and standard memory foam mattress was used in the rest of participants. Patients were firstly assessed on enrollment and then every 72 hours in order to record the appearance or not of PUs, location of PUs, and stage of PUs, with the maximum follow-up not exceeding the 21 days. A number of clinical and biochemical factors, medical treatment, and vital signs were also recorded at each time point. Results Of the 70 patients, 40 (57.1%) were men, and the mean ± standard deviation age of the sample was 46.1 ± 14.5 years. The most common area of PUs was the buttocks (34.3%) followed by the shoulders (22.3%), with no statistically significant difference detected between the two groups. Moreover, the proportion of patients having PUs at stage 2 or higher was 23.8% on the third day after admission and 61.1% on the sixth day, with no difference detected between the two groups. Cox proportional hazard model revealed that the Virtuoso mattress was associated with almost 56% lower risk of developing PUs compared with standard foam mattress (HR [95% CI]: 0.44 [0.20-0.93]). The percentage of patients healed using the Virtuoso mattress was significantly lower compared with the standard foam mattress at all time points, with the results reaching statistical significance only on the 12th day after admission (7.7% vs. 66.7%; p < 0.05). Conclusions The Virtuoso mattress seems to be more effective compared with standard foam mattresses in the prevention of PUs, whereas the standard foam mattresses are more effective in PU healing process.

Evaluating patient turn effectiveness using turn-assist technologies

Pressure ulcers are commonly developed in bedridden patients due to prolonged pressure on bony prominences. Turn-assist support surfaces have been developed to help reposition patients to redistribute interface pressure. The aim of this study was to determine if turn-assist technologies confer benefits to patients relative to manual turning, and to determine if different turn-assist functionalities influence patient outcomes differently. Interface pressure (contact area, average and peak pressure) and patient turn quality metrics (turn angle and repeatability) were recorded during manual and facilitated turns on two different turn-assist hospital beds at initial patient position, turn-assist (maximal mattress inflation) and final patient position. Manual turns produced the most repeatable turn angles, and closest to the recommended 30° compared to both turn-assist surfaces. Interface pressure differences between surfaces were most prominent in the pelvis region across all three time points. Overall, turn-assist surfaces produced interface pressure outcomes similar to manual turning, but manual turning produced more repeatable and optimal patient turn angles. Different turn-assist surfaces achieved different patient turn angles, so functionalities should be examined before device implementation.

A Systematic Review and Meta-Analysis of the Pressure-Induced Vasodilation Phenomenon and Its Role in the Pathophysiology of Ulcers

BACKGROUND

Physiologic studies show that tissue perfusion increases during moderate amounts of tissue compression. This is attributed to sensory nerves initiating a vasodilatory cascade referred to as pressure-induced vasodilation.

METHODS

PubMed, Embase, and the Cochrane Central Register of Controlled Trials were searched for studies investigating perfusion during pressure exposure longer than 10 minutes. Retrieved studies were assessed using the Office of Health Assessment and Translation Risk of Bias Rating Tool for Human and Animal Studies. Results were pooled with random effects models. The body of evidence was rated using the Office of Health Assessment and Translation approach.

RESULTS

Twenty-nine articles were included, of which 19 articles were included in meta-analyses. The evidence indicates that moderate amounts of tissue compression have the capacity to increase perfusion in healthy humans by 46 percent (95 percent CI, 30 to 62 percent). Using the Office of Health Assessment and Translation approach, the authors found a high level of confidence in the body of evidence. Pressure-induced vasodilation blockade was associated with increased pressure ulcer formation. Pressure-induced vasodilation was impaired by neuropathy and by the drugs diclofenac and amiloride.

CONCLUSIONS

This systematic review and meta-analysis indicates that healthy humans have the capacity to increase local perfusion in response to mechanical stress resulting from tissue compression. Because pressure-induced vasodilation is mediated by sensory nerves, pressure-induced vasodilation emphasizes the importance of sensory innervation for durable tissue integrity. Pressure-induced vasodilation impairment seems to provide a complementary explanation for the susceptibility of neuropathic tissues to pressure-induced lesions.

Blood flow responses over sacrum in nursing home residents during one hour bed rest

Objectives

To describe individual BF responses in a nursing home resident population for one‐hour periods of bed rest.

Methods

BF was measured for one hour over the sacrum in 0° supine position and 30° supine tilt position in 25 individuals aged 65 y or older while lying on a pressure‐redistributing mattress. Measurements were made at three tissue depths (1, 2, and 10 mm) using the noninvasive optical techniques, LDF and PPG.

Results

Eleven participants had a PIV response at 1 mm depth in both positions and seven participants had a lack of this response at this depth and positions. The BF response at 1 mm depth appeared immediately and remained over, or below, baseline for the entire 60 min of loading in both positions. These BF patterns were also seen in deeper tissue layers.

Conclusions

The cutaneous BF response among the nursing home residents was distinct, appeared early, and remained during the one hour of loading.

A new method to evaluate the effects of shear on the skin

Currently, pressure ulcer preventive strategies focus mainly on pressure redistribution. Little attention is paid to reduce the harmful effects of shear-force, because little is known about pathophysiological aspects of shear-force. Even today, no method to measure the effects of shear-force on the skin is available. Therefore, the aim of this study was to investigate the response to shear-forces in terms of analyzing a noninvasive biomarker and reactive hyperemic parameter measured at the skin of healthy participants. A physical model was developed to produce a combination of pressure and shear or pressure alone on the skin. Ten healthy male participants were included and pressure (3.9 kPa) and a combined loading of pressure and shear (2.4 kPa + 14.5 N) was applied at the volar aspect of the forearms for 15 and 30 minutes. A Sebutape sample was used to collect IL-1α and total protein (TP) noninvasively. The reactive hyperemic parameter was derived from a laser Doppler flowmeter. The increase in IL-1α/TP-ratio after a combined loading of pressure and shear for 30 minutes of 6.2 ± 2.5 was significantly higher compared with all other test conditions (p < 0.05). The increase in cutaneous blood cell flux was already significantly higher when a combined loading of pressure and shear was applied for 15 minutes compared with pressure alone. These results shows that the IL-1α/TP-ratio and cutaneous blood cell flux can be used as robust measures of the effect of shear-force on skin in humans. Therefore, this model can be used to evaluate materials aimed at the reduction of shear.

A Sensor Array Using Multi-functional Field-effect Transistors with Ultrahigh Sensitivity and Precision for Bio-monitoring

Mechanically adaptive electronic skins (e-skins) emulate tactition and thermoception by cutaneous mechanoreceptors and thermoreceptors in human skin, respectively. When exposed to multiple stimuli including mechanical and thermal stimuli, discerning and quantifying precise sensing signals from sensors embedded in e-skins are critical. In addition, different detection modes for mechanical stimuli, rapidly adapting (RA) and slowly adapting (SA) mechanoreceptors in human skin are simultaneously required. Herein, we demonstrate the fabrication of a highly sensitive, pressure-responsive organic field-effect transistor (OFET) array enabling both RA- and SA- mode detection by adopting easily deformable, mechano-electrically coupled, microstructured ferroelectric gate dielectrics and an organic semiconductor channel. We also demonstrate that the OFET array can separate out thermal stimuli for thermoreception during quantification of SA-type static pressure, by decoupling the input signals of pressure and temperature. Specifically, we adopt piezoelectric-pyroelectric coupling of highly crystalline, microstructured poly(vinylidene fluoride-trifluoroethylene) gate dielectric in OFETs with stimuli to allow monitoring of RA- and SA-mode responses to dynamic and static forcing conditions, respectively. This approach enables us to apply the sensor array to e-skins for bio-monitoring of humans and robotics.