ObjectiveTo evaluate the accuracy of the new dynamic approach in the measurement of respiratory mechanics with different pressure support (PS) level during pressure support ventilation (PSV) via oral-nasal mask.MethodsThe Respironics V60 ventilator was connected to a ASL5000 lung simulator, which simulate lung mechanics in patients with chronic obstructive pulmonary disease ［system compliance (Crs)=50 mL/cm H2O, airway resistance (Raw)=20 cm H2O/(L·s), inspiratory time (TI)=1.6 s, breathing rate=15 beats per minute］. PSV were applied with different levels of PS ［positive end-expiratory pressure=5 cm H2O, PS=5/10/15/20/25 cm H2O) and back-up rate=10 beats per minute］. Measurements were conducted at system leaks with 25 – 28 L/min. The performance characteristics and patient-ventilator asynchrony were assessed, including flow, airway pressure, time and workload. Crs and Raw were calculated by using new dynamic approach.ResultsTidal volume (VT) was increased with increasing PS level ［(281.45±4.26)mL at PS 5 cm H2O vs. (456.81±1.91)mL at PS 10 cm H2O vs. (747.45±3.22)mL at PS 20 cm H2O, P<0.01］. Severe asynchronous was occurred frequently when PS is at 25 cm H2O. Inspiration cycling criterion (CC) was up-regulated accompanied by increasing PS level ［(15.62±3.11)% at 5 cm H2O, vs. (24.50±0.77)% at 20 cm H2O, P<0.01］. Premature cycling was always existed during PSV when PS < 20 cm H2O, which could be eliminated as PS level increasing. Delay cycling was found when PS was at 20 cm H2O, and cycling delay time was (33.60±15.91)ms (P<0.01). The measurement of Crs was (46.19±1.57)mL/cm H2O with PS at 10 cm H2O, which was closer to the preset values of simulated lung. The underestimate of Crs was observed during high level PS support. The calculation of inspiratory and expiratory resistance was approximate to 20 cm H2O/(L·s) when PS level was exceeded 15 cm H2O.ConclusionsThe new dynamic approach can continuously assess the respiratory mechanics during non-invasive ventilation, which is no need to interrupt the patient's spontaneous breathing. Higher inspiratory flow during PSV is beneficial for Raw measurement, whereas the accuracy of Crs was influenced by the value of actual VT.
Objective To explore the influence of discectomy and artificial disc replacement on the upper lumbar facet joint and to provide the evidence for use of artificial disc replacement. Methods Under the loads of 200-2 000 N axis pressure and 1-10 Nm back-extending/side-bending pressure on the 7 fresh adult corpses, the pressure of L3,4facet joint was measured in the case of L4,5disc integrity, discectomy and artificial disc replacement and the statistical analysis was done.ResultsUnder the same load (axis, back-extending/side bending), there were significant differences (Plt;0.01) in the pressure of upper lumbar facet jointboth between disc integrity and discectomy and between discectomy and artificial disc replacement, and there was no difference(Pgt;0.05) between disc integrity and artificial disc replacement. Conclusion The stress ofupper lumbar facet joint reduced after discectomy, it implies that simply discectomy may change biomechanics of lumbar and lead to secondary lumbar structure degeneration. The stress of upper lumbar facet joint is close to the normal value after artificial disc replancement, it implies that artificial disc replacement may protect lumbar structure. It provides some biomechanics foundation and evidence for artificial disc replacement.
Objective To compare the effect of two types of intermittent pressure on formation of pressure ulcer in rabbit hind l imbs and to investigate the mechanism of gradually changed intermittent pressure produced by waves bed in the prevention of pressure ulcer. Methods Gracil is (3 cm2) in both hind l imbs of 12 adult Japanese white rabbits were randomlyloaded with gradually changed intermittent pressure (50-160 mm Hg, 1 mm Hg=0.133 kPa) and sustained pressure (100 mmHg) serving as the experimental group and the control group, respectively. The experiment was terminated after 4 cycles, and a single cycle included 2 hours of compression and 30 minutes of compression-release. Blood velocity of hind l imbs and blood perfusion of wound were detected by bidirectional doppler blood flow detector and laser doppler perfusion imaging detection system before compression and at every 10 minutes in compression-release period of each cycle (0, 10, 20 and 30 minutes). After the termination, gross observation of the wound was conducted, pathomorphological changes of tissues from compressed area were observed by HE staining, and contents of NO, malondialdehyde (MDA), and superoxide dismutase (SOD) in muscle tissue were measured using colorimetry method. Results No significant difference was evident between two groups in terms of blood flow velocity before compression (P gt; 0.05); the blood flow velocity of two groups decreased significantly at 0 minute in every compressionrelease period of each cycle, and no significant differences were noted between two groups (P gt; 0.05); the blood flow velocity of theexperimental group was higher than that of the control group at 10, 20 and 30 minutes (P lt; 0.05). No significant difference was noted between two groups in terms of wound blood perfusion before compression (P gt; 0.05); the wound blood perfusion of two groups decreased significantly at 0 minute in every compression-release period of each cycle, and no significant differences were noted between two groups (P gt; 0.05); the difference between two groups was not significant at 10 minutes in the first cycle (P gt; 0.05), and the experimental group was higher than the control group at 20 and 30 minutes in the first cycle (P lt; 0.05). In the following 3 cycles, the recovery of perfusion in the experimental group was faster than that of the control group (P lt; 0.05). Gross observation showed the experimental group had less effusion than the control group. The experimental group had intact cutaneous appendage, less inflammatory cell infiltration, and no obvious ulcer formation, whereas the control group had obvious skin ulcer, depletion of cutaneous appendage, and more inflammatory cells infiltration. Significant differences were noted between two groups in terms of NO, MDA, and SOD content (P lt; 0.05). Conclusion Gradually changed intermittent pressure can maintain the blood perfusion of tissue, reduce ischemia-reperfusion injury and cell apoptosis, and prevent the formation of pressure ulcer.
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 operation and effect of pressure ulcers group (PUG) on the procedure of clinical management of pressure ulcers.
MethodsThe in-hospital patients with high-risk pressure ulcers and patients with pressure ulcers from outside of the hospital (n=145) before the founding of PUG in 2011 were regarded as group A, and patients in this group were treated by traditional therapies. After PUG was founded in our hospital in January 2012, 192 patients with high-risk pressure ulcers and from outside of the hospital in 2012 were considered as group B. In addition, group C contained 380 patients treated in 2013. Group B and C were both treated by PUG that developed a management system of pressure ulcers and took active measures to control and prevent pressure ulcers. PUG trained 30 clinical nurse supervisors, who were recommended from relevant clinical departments. The incidence of inevitable pressure ulcer of hospitalized patients, the cure rate of patients with pressure ulcers from outside of the hospital, pressure ulcer knowledge level of clinical nurse supervisors were comparatively analyzed between group A and B, and between group A and C, respectively.
ResultsAfter the establishment of PUG, the incidence of inevitable pressure ulcer of hospitalized patients in group A, B, and C was 76.20%, 17.02%, and 14.61%, respectively. The cure rate of patients from outside of the hospital was 54.84%, 86.84%, and 87.97%, respectively. Differences between group A and B, and between group A and C both were significant (P<0.01). The pressure ulcer knowledge level of all nurse supervisors improved significantly (P<0.001).
ConclusionThe establishment of PUG makes the clinical pressure ulcer management more scientific and objective. Furthermore, it can effectively reduce the incidence of pressure ulcers, and also improve the quality of medical care and ensure the safety of patients.
Objective To evaluate the prel iminary cl inical outcomes of percutaneous endoscopic lumbar discectomy (PELD) for patient with discogenic chronic low back pain (CLBP) and fail ing to respond to conservative treatment. Methods From June 2007 to May 2008, 52 patients with CLBP and fail ing to respond to conservative treatment were treated, including 15 males and 37 females aged 29-46 years old (average 38.2 years old). Those patients were diagnosed ith discogenic pain by low pressure discography. Duration of CLBP was 6-110 months with an average of 32.1 months. MRI exam revealed 108 “black intervertebral discs” low in signal on T2 image, including 3 discs of L2,3, 17 of L3,4, 48 of L4,5 and 40 of L5-S1. Pressure-controlled discography showed positive response, fluoroscopy or intraoperative CT confirmed annulus fibrosus tears of posterior intervertebral disc in 79 discs. PELD was performed. Visual analogue scale (VAS) was evaluated before operation, 1 month after operation and at the final follow-up. The cl inical outcome was determined by modified Macnab criteria at the final follow-up. Results The average operation time of each disc was 30.7 minutes (range 21-36 minutes), and the mean length of postoperative hospital stay was 3.7 days (range 2-5 days). No compl ications such as infection and the injury of blood vessels and nerves occurred. Transient paralysis of nerve occurred in 5 cases on operation day, and those symptoms were disappeared at the final follow-up visit without special treatment. Fifty-two cases were followed up for 3-15 months (average 7.3 months). VAS score before operation, 1 month after operation and at the final follow-up was (7.34 ± 1.52), (3.62 ± 0.92) and (1.57 ± 0.48) points, respectively, indicating there were significant differences compared with preoperative score (P lt; 0.01). According to the modified Macnab criteria, 11 cases were graded as excellent, 23 as good, 13 as fair, 5 as bad, and the excellent and good rate was 65.38%. Conclusion Prel iminary study suggests that PELD is safe and effective in treating patient with discogenic CLBP and fail ing to respond to conservative treatment.
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.
Objective
To investigate the change law of the intracapsular pressure in vitro without outside force and the pressure of the expander upon the skin soft tissue in vivo during clinical routine expansion so as to provide some references for the safe application of the expander.
Methods
The rectangle expanders of 50, 80, 100, 150, 200, 250, 300, and 400 mL were used for in vitro expansion at room temperature to 400% volume of the expander capacity. The pressures before and after saline injection were recorded. Twelve patients who needed scar plastic surgery were enrolled; 17 rectangle expanders were implanted in 5 areas (cheek, trunk, forehead and temporal, limb, and head) and expanded routinely. The pressures before and after saline injection were recorded. The pressure of the expander upon the skin soft tissue was calculated and the values of the pressure at 50%, 100%, 150%, and 200% volume of 5 areas were chosen and analyzed statistically.
Results
The intracapsular pressure of the expanders at different volumes in vitro without outside force during routine expansion before and after saline injection was beyond 0 mm Hg (1 mm Hg=0.133 kPa) at around 100% volume, increased rapidly from 100% to 250% volume, and kept stable from 250% to 400% volume. In vivo, 16 expanders within 200% volume had the maximum pressure before saline injection, 15 had the maximum pressure after saline injection. Before saline injection, the pressure of the expander upon the skin soft tissue was lowest in the cheek, showing significant difference when compared with those of the forehead and temporal and head (P lt; 0.05); the pressure in the trunk was significantly lower than that in the head (P lt; 0.05); and there was no significant difference between the other body sites (P gt; 0.05). After saline injection, the pressure of the expander upon the skin soft tissue was lowest in the cheek, and showed an increasing trend in the trunk, the limb, the forehead and temporal, and the head; no significant difference was found between in the cheek and in the trunk, and between in the forehead and temporal and in the limb (P gt; 0.05), and significant differences were found between the other body sites (P lt; 0.05).
Conclusion
The pressure of expander upon skin soft tissue at early stage or middle stage is higher than that at late stage during expansion. The pressure is high in the head, and low in the cheek comparatively, and the pressures in the trunk, the forehead and temporal, and the limb are between them.
Objective?To observe the changes of force bearing area and pressures of the rabbit tibiofemoral contact area and the biomechanical reconstruction level of joint after meniscal allograft.?Methods?A total of 28 Japanese rabbits were involved, weighing 3.0-3.5 kg, male or female. Of 28 rabbits, 7 were selected as meniscus donors, the remaining 21 rabbits were randomized into group A (n=7), group B (n=7), and group C (n=7). Group A underwent single knee opening and suturing, group B underwent medial meniscus excision and suturing, and group C underwent medial meniscus allograft after medial meniscus excision and suturing. The rabbits were sacrified at 12 weeks after operation for biomechanical observation through biomechanical machine and color imaging system. The meniscus tissue specimens were harvested from groups A and C to perform histological and immunohistochemical staining.?Results?After operation, all rabbits in 3 groups survived to the end of experiment. There were significant differences in the force bearing area and pressures at 0-90° flexion between group B and groups A, C (P lt; 0.05) at 12 weeks, showing no significant difference between group A and group C (P gt; 0.05); and there were significant differences in the force bearing area and pressures at 120° flexion among 3 groups (P lt; 0.05). The histological observation showed that the number of cartilage cells and collagen fibers returned to normal in group C, and the immunohistochemical staining showed that transplanted meniscus of group C contained large amounts of collagen fibers consisting of collagen type I and collagen type II. After 12 weeks of operation, the collagen type I contents were 0.612 5 ± 0.059 8 in group A and 0.587 2 ± 0.063 9 in group C, showing no significant difference (t=0.765, P=0.465); the collagen type II contents were 0.772 4 ± 0.081 5 and 0.814 3 ± 0.051 7, respectively, showing no significant difference (t= —0.136, P=0.894).?Conclusion?The allograft of rabbit meniscus can significantly increase the force bearing area of the tibiofemoral contact area and reduce the average pressure. Therefore, biomechanically speaking, the meniscus allograft can protect the articular cartilage and reconstruct the biomechanical balance.
Objective To formulate an evidence-based nursing strategy of turning over for a patient with the risk of pressure ulcer. Methods The personalized clinical questions were put forward based on the PICO and patient’s condition, and the following databases such as NGC, The Cochrane Library of DARE, CDSR, CCTR, MEDLINE, PubMed and CBM were searched to collect the best clinical evidences of turning over for preventing pressure ulcer. Results One clinical guideline, one systematic review and three randomized controlled trials were included finally. According to the retrieval outcomes, patient’s clinical condition, and patients and their family members’ willingness, a reasonable nursing plan of turning over was formulated: lie on the visco-elastic foam decompression bed, turn over every 4 hours, and combine supine position with alternation of left-oblique 30° position and right-oblique 30° position. During hospitalization, the grade-I pressure ulcer in size of 4×6 cm2 on patient’s sacrococcygeal region was clear, dry and not broken, and the other part of body with pigmentation had no occurrence of pressure ulcer. Conclusion Evidence-based approaches are helpful to provide patient with a nursing plan that meets the needs of both scientificalness and individualization.
