Explaining of the experts' points of view about the types and importance of man-made hazards in Iran's process industries: A qualitative study.

Introduction: Process industries may have different hazards that can cause serious injury to humans, the environment, and the economy. Considering the importance of man-made risks in process industries, Experts' Points of View should be considered to apply risk reduction strategies Hence, the present study was performed to explain the views of experts regarding the types and importance of man-made hazards in process industries. Materials and methods: This study was conducted using a qualitative method of directed content analysis with a deductive approach. The participants included 22 experts in the field of process industries. The selection of samples started purposeful and continued until data saturation. Data collection was done through semi-structured interviews. Results: Based on experts' points of view, 5 man-made hazards in process industries were classified into 14 subcategories. The man category was divided into three subcategories: human error, technical knowledge error, and management error, the Material category was divided into 3 sub-categories of leakage and rupture, chemical properties, physical properties, Medium category was divided into two sub-categories of incorrect location selection and placement and harmful environmental factors, Machines category was divided into three sub-categories of failure in design, failure in Preventive Maintenance (PM), failure in Safety Instrumented System (SIS), and the Methods category was classified into three sub-categories: defects in inspection, defects in information, defects in executive instructions. Conclusion: Technical training to reduce personnel errors, conducting risk-based inspections to control leaks and possible ruptures, careful design and site selection in the initial phase of the project, is recommended. The use of engineering methods and artificial intelligence to obtain the risk number and control methods to reduce the harmful effects of risks can be helpful.

Application of multidisciplinary team conference for neuromodulation candidates facilitates patient selection and optimization.

Introduction: Psychological evaluation is required by insurance companies in the United States prior to proceeding with a spinal cord stimulation or a dorsal root ganglion stimulation trial. Since January 2017, we implemented a Multidisciplinary Team Conference for Neuromodulation in our center to facilitate the collaboration between pain physicians and psychologists and to optimize screening of neuromodulation candidates. This study aims to report the impact of this team conference on improvement of neuromodulation outcome in our center. Methods: Appropriateness of neuromodulation were discussed in the team conference after initial visit with the pain specialist and psychological evaluation. For this study, we prospectively and retrospectively collected data on neuromodulation candidates who went through the team conference and those who did not as controls. Results: We discussed 461 patients in the team conference sessions from January 2017 to July 2023. Out of these, a spinal cord stimulator or a dorsal root ganglion stimulator trial was performed in 164 patients with 80.5% (132 cases) trial success rate leading to 140 implants. Out of these implants, 26 (18.6%) explanted and 21 (15%) required revision in 41 (29.3%) patients. We performed neuraxial neuromodulation trial for 70 patients without going through the team conference from January 2016 to July 2023 with a trial success rate of 45.7% (32 cases). In this group, 7 (21.9%) and 6 (18.8%) patients underwent explant and revision. The differences between the groups were statistically significant for trial success rate (odds ratio of 4.9 with p-value of <0.01) but not for explant (odds ratio of 0.8 with p-value of 0.627) or revision (odds ratio of 0.8 with p-value of 0.595). Conclusion: Implementing Multidisciplinary Team Conference increased trial success rate in our center. Team conference provides therapeutic benefit for patients, and also provides the opportunity for an educational discussion for trainees.

A Systematic Literature Review Identifying the Dimensions and Components of Simulation of the Hospital Emergency Department During Emergencies and Disasters.

Background: The use of simulation in medical education is evolving widely around the world. Hospital emergency services in the event of accidents and disasters affect the quality of health care. It is critical to determine the fundamental features for developing a hospital emergency department simulation to improve emergency services. In this regard, the current study conducted a comprehensive assessment of studies with the determinations and components of hospital emergency department simulation during accidents and disasters. Methods: In this systematic literature review, all studies between January 2010 and July 2021 were searched in MEDLINE/PubMed, EMBASE, ProQuest, Scopus, Web of Science, Iran medex Google Scholar, and Scientific Information Database (SID), MagIran databases and were analyzed with the thematic analysis approach and results were expressed based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines. The quality of the included studies was assessed using related checklists. Results: The findings of this study were divided into 3 main categories and 10 subcategories, including factors related to manpower (manpower arrangement, performance-awareness-skills, safety, and communication), factors related to medical services (triage, time, and transfer of the injured), and factors related to resource management and support (physical environment, equipment, and the information system). Conclusion: Through systematic planning, simulation allows for the identification of emergency department difficulties during accidents and disasters. Identifying dimensions and components, such as resource management and support, manpower, and medical services, is effective in designing the simulation of the hospital emergency department during accidents and disasters. Therefore, it is recommended to conduct future studies with a qualitative approach and focus on the factors affecting the simulation of the hospital emergency department during disasters, which has been done by the same researchers.

Identifying the Challenges of Simulating the Hospital Emergency Department in the Event of Emergencies and Providing Effective Solutions: A Qualitative Study.

INTRODUCTION: Emergencies and disasters occur in any society, and it is the hospitals and their emergency department staff who must be prepared in such cases. Therefore, 1 of the effective methods of training medical care staff is the use of simulators. However, when introducing new simulation approaches, we face many challenges. The aim of this study was to identify challenges of the simulation of the hospital emergency department during disasters and provide effective solutions. METHODS: This conventional content, thematic, analysis study was conducted in 2021. Participants were selected from Iranian experts using purposeful and snowball sampling methods. Data were collected using semi-structured interviews and were analyzed by the content analysis. RESULTS: After analyzing the data, the challenges of simulating the hospital emergency department during disasters were identified in 2 main components and 6 perspectives, which included organizational components (inappropriate and aimless training methods, lack of interaction and cooperation, lack of funding, and inadequate physical space) and technological components (weak information management and lack of interdisciplinary cooperation). Solutions included management (resource support) and data sharing and exchange (infrastructures, cooperation and coordination). CONCLUSION: The simulation technology can be used as a method for training and improving the quality of health care services in emergencies. Considering that most of these challenges can be solved and need the full support of managers and policy makers, by examining these issues, supporting staff of health care centers are advised to make a significant contribution to the advancement of education and problem reduction in the event of disasters.

Modern concepts of transport in multiple trauma: a narrative review.

Multiple variables can influence triage decision in multiple trauma. Recognition of priorities and selection of the destination can be successfully achieved by field triage and individualized clinical judgment. This narrative review summarizes the new options and protocols for transport of injured subjects. There are four levels of emergency medical providers including first responders and three levels of emergency medical technicians. Two distinct accepted protocols for transport are known as scoop and run and treat and then transfer. The former provides minimum lifesaving treatment at the scene of accident followed by transferring the patient(s) as soon as possible, and the latter mainly emphasizes the need for complete stabilization as a prerequisite for safe transport. The destination and mode of transport are selected according to clinical capabilities of the receiving hospital, transfer time from the scene to the facility, patient's medical condition, accessibility of the scene, and weather. Two common methods of transfer are ground transport, including various type of ambulances, and air medical transport, i.e. helicopter and airplane.

Sildenafil attenuates TNBS-induced colitis in rats: possible involvement of cGMP and KATP channels.

The involvement of cGMP/KATP pathway in effects of sildenafil on experimental colitis was investigated. Sildenafil significantly attenuated colonic injury markers. These effects were reversed by the addition of glibenclamide or ODQ, indicating the involvement of ATP-sensitive potassium channels (KATP) and cGMP, respectively.

Pattern of animal-related injuries in Iran.

Animal related injuries as most common causes of human morbidity have different pattern by geographical zones. We aimed to explore the main descriptive epidemiology of animal-related injuries in both rural and urban areas in Iran. Between 2000 and 2004, we collected the data of all the cases of animal related trauma hospitalized for more than 24 hours in eight cities (Tehran, Mashhad, Ahwaz, Shiraz, Tabriz, Qom, Kermanshah, and Babol). Further evaluations were conducted on 17753 eligible subjects. Of 17753 traumatic patients, 40 subjects (0.2%), had animal-related injuries. The highest rate was seen in Tabriz with 11 cases. Upper and lower extremities were the most frequent sites of trauma and they were injured in 13 and 11 cases respectively. Dog bite and cow-related injuries were responsible for 40% and 32.5% of injuries respectively. Amputation of the phalanx was done in 2 cases due to dog bite and bull gore occurred. One thoracotomy, one laparatomy and one craniotomy were done. One patient needed fasciatomy due to snake bite. Educating the patients could decrease the incidence of morbidity of these injuries.

Hemodialysis adequacy and treatment in Iranian patients: a national multicenter study.

INTRODUCTION: Assessment of the hemodialysis adequacy is one of the key factors in evaluating health service system. This would provide a good background for effective future planning by healthcare authorities. In this study, we aimed to evaluate the hemodialysis adequacy in Iran. MATERIALS AND METHODS: One hundred and twenty-seven hemodialysis centers affiliated to 30 medical universities in Iran participated in this cross-sectional multicenter national study. All demographic data as well as hemodialysis prescription data, including blood flow rate, length of the hemodialysis session, hemodialysis membrane type, and composition of the dialysis solution were recorded for each patient. In addition, urea reduction ratio and Kt/V were calculated to determine the hemodialysis adequacy. RESULTS: A total of 4004 patients were included in this study, 2345 men (58.6%) and 1659 women (41.4%). Bicarbonate-based solutions and low-flux membranes were prescribed for 77.0% and 97.6% of the patients, respectively. The mean blood flow rate was 242.9 ± 39.2 mL/min. The mean length of hemodialysis session was 229.2 ± 22.2 minutes. The mean urea reduction ratio and Kt/V were calculated to be 61.0 ± 11.8% and 1.2 ± 0.4, respectively. A Kt/V less than 1.2 and a urea reduction ratio less than 65% were found in 56.7%, and 65.2% of the hemodialysis patients, respectively. CONCLUSIONS: This study showed a substantial inadequate hemodialysis in Iran as compared with the Kidney Disease Outcomes Quality Initiative guidelines. Considering the impact of dialysis adequacy on quality of life and survival rates, as well as healthcare costs, rigorous attempts to achieve the desired goals are necessary.

Blood levels of methemoglobin in patients with aluminum phosphide poisoning and its correlation with patient's outcome.

Although methemoglobinemia following aluminum phosphide (AlP) intoxication has been reported, probable effect of blood level of methemoglobin (Met-Hb) on outcome of AlP-poisoned patients has not yet been investigated. This study aimed to evaluate blood levels of methemoglobin in patients with AP intoxication and its correlation with patient's outcome. This prospective study was carried out at the Loghman-Hakim poison hospital from April 2009 to August 2009. All patients aged >12 years who had ingested AlP and were admitted at the hospital were enrolled in the study. Using the co-oximetry, blood Met-Hb level was measured at the time of admission and 24 h later if the patient survived. Forty-eight patients with AlP intoxication including 24 males were evaluated. Mean age of the patients was 25.5±9.5 years. There was significant association between blood level of Met-Hb at the time of admission and mortality (2.4%±7.1% in survivors versus 15.2%±13.5% in non-survivors, P<0.001). The same association was found at the 2nd day of admission (2.9%±8.2% in survivors versus 26.5%±9.9% in non-survivors, P=0.02). The present study found an association between blood level of Met-Hb and mortality in patients with AlP intoxication. Effect of administration of vitamin C and methylene blue on outcome of patients with AlP intoxication should be investigated in future studies.

Urethral hydrodistension for management of urethral hypoplasia in prune belly syndrome: long-term results.

PURPOSE: The aim of the study was to evaluate the efficacy and safety of urethral hydrodistension for management of urethral hypoplasia in prune belly syndrome (PBS). METHODS: During a 10-year period, 7 infants with PBS and urethral hypoplasia presented either with open urachus or surgically created urinary diversion referred to our hospital. Five milliliters of normal saline was pushed via a 22-gauge plastic angiocatheter into the urethra with simultaneous finger pressure on the perineum to occlude the proximal urethra that was repeated with higher volumes of the solution (up to 20 mL). The procedure was continued until a 6F or 8F feeding tube catheter confirmed the urethral patency. Hydrodistension was repeated in 3-month intervals till complete patency was confirmed by imaging. RESULTS: Median age of the infants was 6 (1-8) months. All urethral hydrodistension were successful after 1 to 3 sessions. Follow-up imaging studies showed significant improvement in all patients except one. Natural and surgically created urinary diversions were closed in 6 infants. CONCLUSIONS: The hydrodistension create an equal and constant pressure into the urethral wall without any urethral damage. This technique can be considered along with the other available methods for management of urethral hypoplasia in selected cases of PBS.

Effect of risedronate on bone resorption during consolidation phase of distraction osteogenesis: a rabbit model.

PURPOSE: To evaluate the effects of continuous local injection of risedronate in the prevention of bone resorption in a lengthened segment. METHODS: 11 male rabbits underwent subperiosteal osteotomy of the left tibia and an external fixator was applied anteromedially. After a lag phase of one week, a 2-week distraction phase and a 5-week consolidation phase followed. Risedronate was continuously injected into the centre of the distracted segment at a rate of 10 micro g/kg/day during the first 14 days of consolidation by a subcutaneously implanted osmotic pump. A control group received purified buffer solution (PBS) using the same protocol. The lengthened bone segments were evaluated using radiography, quantitative computed tomography, and 3-point bending mechanical test. RESULTS: Risedronate injection prevented osteopenia as compared to PBS injection. The mean bone mineral content, volumetric density and cross-sectional area of the lengthened segments were significantly higher in the risedronate group than in controls (as much as 65%, 30%, and 25%, respectively). There was no significant difference between the 2 groups regarding the ultimate load to failure. CONCLUSION: Continuous local injection of risedronate into the lengthened segment can prevent osteopenia during distraction osteogenesis but fails to enhance mechanical strength of newly distracted segments.

Adenosine A2A receptors and uric acid mediate protective effects of inosine against TNBS-induced colitis in rats.

Inflammatory bowel disease comprises chronic recurrent inflammation of gastrointestinal tract. This study was conducted to investigate inosine, a potent immunomodulator, in 2,4,6-trinitrobenzene sulphonic acid (TNBS)-induced chronic model of experimental colitis, and contribution of adenosine A(2A) receptors and the metabolite uric acid as possible underlying mechanisms. Experimental colitis was rendered in rats by a single colonic administration of 10 mg of TNBS. Inosine, potassium oxonate (a hepatic uricase inhibitor), SCH-442416 (a selective adenosine A(2A) receptor antagonist), inosine+potassium oxonate, or inosine+SCH-442416 were given twice daily for 7 successive days. At the end of experiment, macroscopic and histopathologic scores, colonic malondialdehyde (MDA), Tumor Necrosis Factor-alpha (TNF-α) and Interleukin-1beta (IL-1ß) levels, and myeloperoxidase (MPO) activity were assessed. Plasma uric acid level was measured throughout the experiment. Both macroscopic and histological features of colonic injury were markedly ameliorated by either inosine, oxonate or inosine+oxonate. Likewise, the elevated amounts of MPO and MDA abated as well as those of TNF-α and IL-1ß (P<0.05). SCH-442416 partially reversed the effect of inosine on theses markers, while inosine+oxonate showed a higher degree of protection than each treatment alone (P<.0.05). No significant difference was observed between TNBS and SCH-442416 groups. Uric acid levels were significantly higher in inosine or oxonate groups compared to control. Inosine+oxonate resulted in an even more elvelated uric acid level than each treatment alone (P<0.05). Inosine elicits notable anti-inflammatory effects on TNBS-induced colitis in rats. Uric acid and adenosine A(2A) receptors contribute to these salutary properties.

Use of anatomic measurement to guide injection of botulinum toxin for the management of chronic lateral epicondylitis: a randomized controlled trial.

BACKGROUND: When using botulinum toxin for the management of lateral epicondylitis, injection at a fixed distance from an anatomic landmark could result in inadequate paralysis of the intended muscle. We assessed the effectiveness of injection of botulinum toxin using precise anatomic measurement in individual patients. METHODS: In this randomized placebo-controlled trial, 48 patients with chronic refractory lateral epicondylitis were randomly assigned to receive a single injection of either botulinum toxin (60 units) or placebo (normal saline). The site of injection was chosen as a distance one-third the length of the forearm from the tip of the lateral epicondyle on the course of the posterior interosseus nerve. The primary outcome measure was intensity of pain at rest, measured with the use of a 100-mm visual analogue scale, at baseline and at 4, 8 and 16 weeks after injection. RESULTS: Compared with the placebo group, the group given botulinum toxin had significant reductions in pain at rest during follow-up (decrease at 4 weeks 14.1 mm, 95% confidence interval [CI] 5.8-22.3; at 8 weeks 11.5 mm, 95% CI 2.0-21.0; at 16 weeks 12.6 mm, 95% CI 7.7-17.8; p = 0.01). As for the secondary outcomes, the intensity of pain during maximum pinch decreased in the botulinum toxin group; there was no difference in pain during maximum grip or in grip strength between the two groups. All but one of the patients in the intervention group experienced weakness in the extension of the third and fourth fingers at week 4 that resolved by week 16. No serious adverse events were reported. INTERPRETATION: The use of precise anatomic measurement to guide injection of botulinum toxin significantly reduced pain at rest in patients with chronic refractory lateral epicondylitis. However, the transient extensor lag makes this method inappropriate for patients whose job requires finger extension.

Granisetron ameliorates acetic acid-induced colitis in rats.

Inflammatory bowel disease (IBD) is a chronically relapsing inflammation of the gastrointestinal tract, of which the definite etiology remains ambiguous. Considering the adverse effects and incomplete efficacy of currently administered drugs, it is indispensable to explore new candidates with more desirable therapeutic profiles. 5-HT( 3) receptor antagonists have shown analgesic and anti-inflammatory properties in vitro and in vivo. This study aims to investigate granisetron, a 5-HT( 3) receptor antagonist, in acetic acid-induced rat colitis and probable involvement of 5-HT(3) receptors. Colitis was rendered by instillation of 1 mL of 4% acetic acid (vol/vol) and after 1 hour, granisetron (2 mg/kg), dexamethasone (1 mg/kg), meta-chlorophenylbiguanide (mCPBG, 5 mg/kg), a 5-HT( 3) receptor agonist, or granisetron + mCPBG was given intraperitoneally. Twenty-four hours following colitis induction, animals were sacrificed and distal colons were assessed macroscopically, histologically and biochemically (malondialdehyde, myeloperoxidase, tumor necrosis factor-alpha, interleukin-1 beta and interleukin-6). Granisetron or dexamethasone significantly (p < .05) improved macroscopic and histologic scores, curtailed myeloperoxidase activity and diminished colonic levels of inflammatory cytokines and malondialdehyde. The protective effects of granisetron were reversed by concurrent administration of mCPBG. Our data suggests that the salutary effects of granisetron in acetic acid colitis could be mediated by 5-HT(3) receptors.

Spinal fractures resulting from traumatic injuries.

OBJECTIVE: To illustrate mechanisms of spine fractures and the pattern of spinal injuries characterized by the major mechanisms in urban population of Iran. METHODS: Data regarding spinal injuries including demographics, mechanism and level of spinal injury, abbreviated injury score, associated injuries and final fate of the patients were extracted from the Iranian national trauma registry database from 1999 to 2004. RESULTS: A total of 619 patients with traumatic spine fractures were identified, of whom 68.5% were males. The peak frequency of these injuries occurred in the 21-40 year age-group. Accidental falls and road traffic crashes (RTCs) were the most common mechanisms of spinal fractures (47.2% and 44.1%, respectively). RTCs tended to occur in younger patients compared with accidental falls. The most common spinal region for spinal fracture was the lumbar spine (53.63%). Cervical spine fractures were significantly more common in RTCs, while lumbar spine fractures were more common in accidental falls (P less than 0.001). A total of 171 (27.6%) patients had associated non-spinal injuries, of whom 127 had associated extremity injuries, and 55 had head injuries. Thirty-six (5.6%) patients had spinal cord injury (SCI).The injury severity score of the RTC group was significantly higher than that of accidental falls (P equal to 0.002). Fifteen (4%) patients died of traumatic injuries. The rate of death was significantly higher in RTCs compared with accidental falls (5.1% vs 2.1%, P equal to 0.039). CONCLUSIONS: The patterns of spinal fractures are similar to those reported from developed countries. RTCs tend to affect the younger age population and are associated with a higher degree of associated injuries and mortality than accidental falls. Therefore preventive strategies should be based on reduction of the number and severity of RTCs.

Epidemiologic profile and clinical characteristics of ulcerative colitis in northwest of Iran: a 10-year review.

BACKGROUND AND AIM: There are few reports from Iran about the epidemiology and clinical features of inflammatory bowel disease (IBD). In this study, we aimed to determine the epidemiologic profile and clinical features of ulcerative colitis (UC) in Northwest of Iran. METHODS: This retrospective study covered the time period from 1998 to 2008 and included all patients of a private gasteroenterology clinic in the northwest of Iran, who had diagnosis of UC at the time of presentation or those whose diagnosis had been made later. In addition to description of epidemiology and clinical feature of disease, an attempt was made to identify factors associated with severity of disease. RESULTS: A total of 105 patients including 61 females (58.1%) were evaluated. Mean age of the patients was 33.5 +/- 13.1 years. The median time interval from initiation of symptoms to diagnosis was 9 months. The commonest presentation was proctosigmoiditis. (48.6%). Among extra-intestinal manifestations, sclerosing cholangitis had the highest frequency and was found in 2 (1.9%) patients. Among all evaluated variables, only family income (the higher the income the more severe the disease) and cigarette smoking (inverse association) were find to have significant association with severity of disease. CONCLUSION: A case profile of patients with ulcerative colitis from Northwest Iran suggests that the disease is seen most commonly in the third decade of life with a female preponderance. Family income and smoking influenced the course of ulcerative colitis in Iranian patients.

Spinal fractures resulting from traumatic injuries / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To illustrate mechanisms of spine fractures and the pattern of spinal injuries characterized by the major mechanisms in urban population of Iran.</p><p><b>METHODS</b>Data regarding spinal injuries including demographics, mechanism and level of spinal injury, abbreviated injury score, associated injuries and final fate of the patients were extracted from the Iranian national trauma registry database from 1999 to 2004.</p><p><b>RESULTS</b>A total of 619 patients with traumatic spine fractures were identified, of whom 68.5% were males. The peak frequency of these injuries occurred in the 21-40 year age-group. Accidental falls and road traffic crashes (RTCs) were the most common mechanisms of spinal fractures (47.2% and 44.1%, respectively). RTCs tended to occur in younger patients compared with accidental falls. The most common spinal region for spinal fracture was the lumbar spine (53.63%). Cervical spine fractures were significantly more common in RTCs, while lumbar spine fractures were more common in accidental falls (P less than 0.001). A total of 171 (27.6%) patients had associated non-spinal injuries, of whom 127 had associated extremity injuries, and 55 had head injuries. Thirty-six (5.6%) patients had spinal cord injury (SCI).The injury severity score of the RTC group was significantly higher than that of accidental falls (P equal to 0.002). Fifteen (4%) patients died of traumatic injuries. The rate of death was significantly higher in RTCs compared with accidental falls (5.1% vs 2.1%, P equal to 0.039).</p><p><b>CONCLUSIONS</b>The patterns of spinal fractures are similar to those reported from developed countries. RTCs tend to affect the younger age population and are associated with a higher degree of associated injuries and mortality than accidental falls. Therefore preventive strategies should be based on reduction of the number and severity of RTCs.</p>

Factors associated with pressure ulcers in patients with complete or sensory-only preserved spinal cord injury: is there any difference between traumatic and nontraumatic causes?

OBJECT: Pressure ulcers (PUs) are common complications in patients with complete spinal cord injury (SCI) or incomplete SCI in which sensory function is spared. Most studies analyzing associated factors of PU and SCI have been performed in cases of traumatic SCI and in just a few cases of nontraumatic SCI. This study was designed to look specifically at the differences in causative factors of PU in cases of traumatic and nontraumatic SCIs. METHODS: The authors performed a retrospective, cross-sectional study evaluating patients with complete and incomplete SCIs (American Spinal Injury Association Grades A and B) under the coverage of the financial, medicosocial, and rehabilitative support provided by the State Welfare Organization of Iran (SWOI). There were 3791 cases of traumatic SCI (63.2%) and 2110 cases of nontraumatic SCI (35.2%). For 94 patients (1.6%), sufficient data were not available. RESULTS: A PU was detected in 39.2% of all patients with an SCI (71.8% of those with traumatic SCI vs 28.2% of those with nontraumatic SCI). A univariate analysis showed a significant association between occupation, education, and the presence of PU in patients with a traumatic SCI (p < 0.05). This contrasted with nontraumatic SCI in which an association between PU and age was noted (p < 0.05). Using logistic regression, traumatic cause, older age, an interval less than 1 year since the onset of SCI, male sex, and single status were found to significantly increase the risk of PU in all patients with an SCI. However, a higher education level had a preventive effect on PU. CONCLUSIONS: This study revealed some risk factors for PU in the authors' setting. The authors' findings suggest a possible difference between the risk factors for PU in patients with both types of SCI. Further study on the pathoetiology of these differences is paramount in the future.

Chronic upregulation of the endogenous opioid system impairs the skin flap survival in rats.

Recent studies suggest a detrimental role for long-term opioid receptor stimulation in different tissues. In this study, we investigated the effect of chronic over production of endogenous opioids on skin tolerance to ischemia in a rat model of cholestasis. Sixty-six rats were randomly divided into 11 groups, 6 animals each. First group served as surgical control. In first experiment, 1, 2, and 3 weeks bile duct ligation (BDL) rats and SHAM-operated controls underwent random-pattern skin-flaps by elevating a caudally based dorsal flap (2 x 8 cm). BDL was performed by midline laparotomy and ligating the common bile duct under general anesthesia. Flap survival was assessed after 7 days (14-, 21-, and 28-day cholestatic rats, respectively). In another experiment, the first effective duration of BDL on flap survival (21 days) was chosen to receive either chronic (20 mg/kg/day) or acute (20 mg/kg, 30 minutes before flap surgery) intraperitoneal naltrexone (NTX). In the first experiment, flap survival was 56.6% +/- 2.6% (mean +/- SEM) in control group and 50.2% +/- 3.9%, 37.4% +/- 3.4%, and 35.4% +/- 6.9% in groups of 14-, 21-, and 28-day cholestatic rats, which were significantly impaired in 21- and 28-day group. In the second experiment, skin flap survival was completely reversed to their SHAM control level after chronic and acute NTX treatment (63.6% +/- 7.6% and 61.9% +/- 5.6% vs. 55.1% +/- 4.2% and 54.9% +/- 4.3%, respectively, P < 0.05). Chronic cholestasis (longer than 2 weeks) decreases the skin flap survival, which is reversed by systemic NTX. This study provides evidence, for the first time, that long-term elevated opioidergic tone impairs the skin tolerance to ischemia.