Assisting immobile individuals with regular repositioning to adjust pressure distribution on key prominences such as the back and buttocks is the most effective measure for preventing pressure ulcers. However, compared to active self-repositioning, passive assisted repositioning results in distinct variations in force distribution on different body parts. This incongruity can affect the comfort of repositioning and potentially lead to a risk of secondary injury, for certain trauma or critically ill patients. Therefore, it is of considerable practical importance to study the passive turning comfort and the optimal turning strategy. Initially, in this study, the load-bearing characteristics of various joints during passive repositioning were examined, and a wedge-shaped airbag configuration was proposed. The airbags coupled layout on the mattress was equivalently represented as a spring-damping system, with essential model parameters determined using experimental techniques. Subsequently, different assisted repositioning strategies were devised by adjusting force application positions and sequences. A human-mattress force-coupled simulation model was developed based on rigid human body structure and equivalent flexible springs. This model provided the force distribution across the primary pressure points on the human body. Finally, assisted repositioning experiments were conducted with 15 participants. The passive repositioning effectiveness and pressure redistribution was validated based on the simulation results, experimental data, and questionnaire responses. Furthermore, the mechanical factors influencing comfort during passive assisted repositioning were elucidated, providing a theoretical foundation for subsequent mattress design and optimization of repositioning strategies.
Objective To quantitatively evaluate the effect of 2 types of pressures induced injury by using threedimensional (3D) reconstruction of rats loaded tibial is anterior muscle from two-dimensional (2D) image of serial histological sections. Methods Twenty female or male Sprague Dawley rats, aged 10-12 weeks and weighing 280-300 g, were randomlydivided into experimental group (n=10) and control group (n=10). The random side of tibial is anterior muscle was givenintermittent gradient (8.0-21.3 kPa) and sustained (13.3 kPa) pressure in 0.12 cm2 area in experimental group and controlgroup, respectively; the experiment was terminated and the general condition of rats was observed after 3 cycles, and a single cycle included 2 hours of compression and 30 minutes of release. The general observations of pressed skin and tibial is anterior muscle were done after 24 hours of pressure rel ief, and the tibial is anterior muscle was harvested integrally from the loaded side, then made into interval 4 μm serial sections. After HE staining, 2D images were obtained. Necrosis and injury areas were distinguished by Image Pro Plus (IPP) 6.0 software and image registration was conducted by Photoshop 8.0.1 after 2D panorama images acquired by digital microscope (× 40) and IPP mosaic software. 3D reconstruction was establ ished via data processing using Mimics 10.1 software so as to get the volume, the surface area, and 3D images of the whole piece of tibial is anterior muscle and injury areas respectively. Results All rats of 2 groups survived till experiment terminated and no skin ulcers occurred after 24 hours. Edema and indentation were observed on press side skin and tibial is anterior muscles of 2 groups, fadeless maroon area was observed in control group. A total of 994 sl ices were obtained from 20 samples of tibial is anterior muscles. 3D images suggested that injury of control group was severe, which penetrated the whole piece of tibial is anterior muscle and expandedalong the tibia bony prominence. By contrast, injury of experimental group was less, but had similar width to the contact surface of indentor. There was no significant difference in the volume and the surface area of tibial is anterior muscle between 2 groups (P gt; 0.05), while the injury volume and the injury surface area were significantly smaller in experimental group than in control group (P lt; 0.05). Conclusion 3D reconstruction is an effective method to quantitatively evaluate pathological changes inside the integrity tissue and can provide the visual basis for the mechanical property distributed in the loaded muscle. Intermittent gradient pressure can reduce deep tissue injury.
ObjectiveTo investigate the effect of human adipose-derived stem cells (hADSCs) on pressure ulcers in mouse.MethodsThe subcutaneous adipose tissue from voluntary donation was harvested. Then the hADSCs were isolated and cultured by mechanical isolation combined with typeⅠcollagenase digestion. The 3rd generation cells were identified by osteogenic, adipogenic, chondrogenic differentiations and flow cytometry. The platelet rich plasma (PRP) from peripheral blood donated by healthy volunteers was prepared by centrifugation. The pressure ulcer model was established in 45 C57BL/6 mice by two magnets pressurized the back skin, and randomly divided into 3 groups (n=15). The wounds were injected with 100 μL of hADSCs (1×106 cells) transfected with a green fluorescent protein (GFP)-carrying virus, 100 μL human PRP, and 100 μL PBS in hADSCs group, PRP group, and control group, respectively. The wound healing was observed after injection. The wound healing rate was calculated on the 5th, 9th, and 13th days. On the 5th, 11th, and 21st day, the specimens were stained with HE staing, Masson staining, and CD31 and S100 immunohistochemical staining to observe the vascular and nerve regeneration of the wound. In hADSCs group, fluorescence tracer method was used to observe the colonization and survival of the cells on the 11th day.ResultsThe cultured cells were identified as hADSCs by induced differentiation and flow cytometry. The platelet counting was significantly higher in PRP group than in normal peripheral blood group (t=5.781, P=0.029). General observation showed that the wound healing in hADSCs group was superior to those in PRP group and control group after injection. On the 5th, 9th, and 13th days, the wound healing rate in hADSCs group was significantly higher than those in PRP group and control group (P<0.05). Histological observation showed that compared with PRP group and control group, inflammatory cell infiltration and inflammatory reaction were significantly reduced in hADSCs group, collagen deposition was significantly increased, and skin appendage regeneration was seen on the 21st day; at each time point, the expression of collagen was significantly higher in hADSCs group than in PRP group and control group (P<0.05). Immunohistochemical staining showed that the number of neovascularization and the percentage of S100-positive cells in hADSCs group were significantly better than those in PRP group and control group on the 5th, 9th, and 13th days (P<0.05). Fluorescent tracer method showed that the hADSCs could colonize the wound and survive during 11 days after injection.ConclusionLocal transplantation of hADSCs can accelerate healing of pressure ulcer wounds in mice and improve healing quality by promoting revascularization and nerve regeneration.
ObjectiveTo investigate the physiologic effects of different pressure assist (PA) on ventilatory status,oxygenation and work of breathing (WOB) when a new generation of proportional assist ventilation (PAV) is applied in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MethodsA prospective,crossover randomized physiologic study was performed.80%PA,60%PA and 40%PA was sequentially randomized to be applied with the duration of 30 minutes,and pressure support ventilation (PSV) with the duration of 30 minutes was applied before each PA.Ventilatory status, oxygenation,dyspnea indexes in PSV and different PA were compared,and WOB of patients and ventilator were compared in different PA. ResultsTwenty-eight patients were recruited into the study.With the decrease of PA,peak inspiratory pressure (PIP),mean airway pressure (Pm),and tidal volume (VT) decreased gradually (P>0.05),respiratory rate (RR) increased gradually (P<0.05),while minute volume (MV),heart rate (HR),systolic blood pressure (SBP),mean arterial pressure (MAP),pH,arterial carbon dioxide tension (PaCO2),and arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) did not change significantly (P>0.05).Compared with PSV mode,PIP increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).Pm did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).VT increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).RR did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).MV did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).With the decrease of PA,Borg score and scale for accessory muscle use increased gradually (P<0.05).Compared with PSV mode,Borg score and scale for accessory muscle use did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).WOB of patients in 40%PA was significantly higher than that in 60%PA (P=0.000) and that in 80%PA (P=0.000),while which in 60%PA was significantly higher than that in 80%PA (P=0.000).On the contrary,WOB of ventilator in 40%PA was significantly lower than that in 60%PA (P=0.004) and that in 80%PA (P=0.000),while which in 60%PA was significantly lower than that in 80%PA (P=0.000). ConclusionThe new generation of PAV can safely and effectively provide respiratory support to patients with AECOPD.Respiratory pattern,levels of dyspnea and accessory muscle use in 80%PA are similar with those in PSV.With the decrease of PA,levels of spontaneous breathing and WOB increase and dyspnea worsens.PAV can promote spontaneous breathing and prevent respiratory muscle disuse atrophy even more, but easily lead to respiratory muscle fatigue with inappropriate use.
Objective To explore the correlations between nutritional markers and pressure injury (PI) in elderly patients with chronic obstructive pulmonary disease (COPD). Methods Retrospective analysis was conducted on elderly patients with COPD and PI who were admitted to the geriatric department of West China Hospital of Sichuan University or Dujiangyan People’s Hospital between January 2020 and December 2021. The blood biochemical indicators mainly including nutritional markers were collected, and their correlations with PI risk factor index Braden score and PI severity index PI stage were analyzed. Results A total of 293 patients with COPD and PI were included. Among the five Braden score groups, the differences in the levels of albumin and prealbumin were statistically significant (P<0.05), and the Braden score was positively correlated with albumin (rs=0.241, P<0.001), prealbumin (rs=0.179, P=0.002), and hemoglobin (rs=0.199, P=0.001). Among the six PI stage groups, the differences in the levels of albumin, globulin, red blood cell count, serum sodium, blood chloride and C-reactive protein were statistically significant (P<0.05), and the PI stage was negatively correlated with albumin (rs=?0.192, P=0.001), and positively correlated with serum sodium (rs=0.139, P<0.001), blood chloride (rs=0.184, P<0.001), and C-reactive protein (rs=0.177, P=0.020). Conclusion When PI risk assessment and severity assessment are performed on elderly COPD patients, it is necessary to pay more attention to nutritional markers and assess whether the patients are at risk of protein malnutrition, which will help to improve the accuracy of PI risk assessment and severity prediction, and effectively improve the efficacy of PI prevention and treatment.
ObjectiveTo explore the relationship between the pressure level within the scope of promoting proliferation and cell injury of human bladder smooth muscle cells (HBSMCs). MethodHBSMCs in vitro were divided into the experimental group and control group. The cells in the experimental group were exposed to 40 cm H2O (1 cm H2O=0.098 kPa) pressure and those in the control group were cultured in normal condition for 24 hours. We investigated the cell morphology and cytoskeleton with indirect immunofluorescence staining for α-actin. Propidium iodide (PI) staining was applied to evaluate the level of cell apoptosis. ResultsThere was no significant difference in the cell morphology between the two groups. However, the expression of α-actin in the experimental group[(50.93±1.99)%] was significantly reduced comparing with that in the control group[(24.70±1.61)%] (t=32.404, P<0.001). The results of PI staining showed that compared with the control group[(3.50±2.12)%], the number of PI staining positive cells in the experimental group [(9.00±1.41)%] was significantly higher (t=6.110, P<0.001). ConclusionsPressure condition can promotes cell proliferation, but at the same time, it can also lead to cell injury of HBSMCs.
ObjectiveTo investigate the effect of pressure control ventilation-volume guaranteed (PCV-VG) for patients undergoing da Vinci robotic-assisted pulmonary lobotomy. MethodA total of 40 patients undergoing Da Vinci robotic-assisted pulmonary lobotomy were randomly divided into two groups:a PCV-VG group (G group) and a volume-controlled ventilation (VCV) group (V group). There were 20 patients in each group with 13 males and 7 females at age of 49.0±5.5 years in the G group, 16 males and 4 females at age of 51.0±3.9 years in the V group. Haemodynamics indexes and oxygenation parameters were recorded at different times and compared between the two groups. ResultsDuring one-lung ventilation (OLV) period, the peak inspiratory pressure (Ppeak), respiratory index (RI) and arterial partial pressure of carbon dioxide (PaCO2) in the G group were statistically lower than those in the V group (P<0.05). While the Cdyn and inspired oxygen fraction(OI) were higher in the G group than those in the V group (P<0.05). ConclusionCompared with the traditional VCV ventilation mode, the PCV-VG ventilation mode improves Ppeak, Cdyn, OI, and RI of the patients undergoing da Vinci robotic-assisted pulmonary lobotomy.
ObjectiveFor better health interventions, blood pressure control and reducing risk of cardiovascular events, we explored the effects of health education by nurses on hypertension patients after discharging. MethodsHypertensive discharging-patients from the department of cardiology of the West China Hospital of Sichuan University were enrolled from January to October in 2011. They were divided into two groups, including a health education group and a control group. The patients in the health education group were given all-side care, health guidance, education lectures and telephone follow-up by nurses. The control group got no intervention. After one year follow-up, the information about situation of blood pressure control, new-onset cardiovascular events and changes of life habits were collected from the two groups. SPSS 19.0 was used to perform statistic analysis. ResultsA total of 300 discharged hypertensive cases were included, with 150 cases in each group. The systolic blood pressure of patients in the health education group was significantly lower than that of the control group (P < 0.05). Both blood control rates and the habit of low salt intake in the health education group were also better than those of the control group (both P < 0.05). There was no significant difference in changes of smoking, drinking, physical exercise and new-onset cardiovascular events between the two groups. ConclusionHealth education by nurses could effectively improve the management of blood pressure in patients with hypertension.
ObjectiveTo explore the effect of level management model in the application of nursing for pressure ulcers after spinal surgery. MethodA total of 3 558 patients underwent spinal surgeries between January 2014 and September 2015 were selected. We established a level management model, confirmed the personnel responsibilities, strengthened the pressure ulcers risk assessment of new inpatients, and standardized the processes of reporting pressure sores. We carried out the level management model between January and June 2014, summarized experience and formed a system file between July and December 2014, applied to the clinical work after continuous improvement between January and September 2015. High risk of pressure ulcers reporting rate, incidence of high-risk pressure ulcers, and healing rate of pressure ulcers were compared at the various stages. ResultsThe reporting rate of pressure ulcers raised, the incidence of pressure ulcers increased and the curing rate decreased after continuous improvement (P<0.05). ConclusionsLevel management model may effectively improve the quality of the nursing for spinal pressure ulcers.
ObjectiveTo establish a mouse model of pressure overload-induced heart failure via suprasternal notch approach. MethodsMale mice were separated into a sham group and an experiment group. Through suprasternal notch approach, the aortic arch port between the origin of the right innominate and left common carotid arteries was partially clipped with tantalum clip, which had a remaining opening of 0.35 mm or 0.25 mm in diameter to cause progres-sively increased afterload. Echocardiography was performed 10 weeks after aortic arch clipped or sham surgery to deter-mine left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), left ventricular posterior wall end-diastolic thickness (LVPWD), ejection fraction (EF) and fractional shortening (FS). After hemodynamic recordings were completed, mouse body weight (BW) and heart weight (HW) were measured for obtaining HW/BW ratio (mg/g). After heart function examination, mice blood sample was collected for evaluation of serum N-terminal pro-brain natriuretic peptide (NT-proBNP). At the end, part of left ventricular free wall was excised, and hematoxylin and eosin stain was made for histopathological examination. ResultsThe HW/BW, LVEDD and serum NT-proBNP significantly increased in the experiment group compared with those in the sham group (P < 0.01, respectively). The LVPWD, EF and FS significantly decreased compared with the sham group (P < 0.01, respectively). Histopathological examination showed malalignment and rupture of cardiac muscle fibers, hypertrophy and degeneration of myocardial cells, part of which had local or patchy necrosis in left ventricule postoperatively 10 weeks. ConclusionThe model of pressure overload-induced heart failure in mice established through suprasternal approach is simple, minimally invasive and reliable.