Single Washout Research Articles

Risk assessment of washout by slope flow along long-distance-pipeline based on quantitative index cloud reasoning-integrated weighting

The washout by slope flow along long-distance oil & gas pipelines is a common geological hazard that occurs when pipelines pass through the alluvial-proluvial fan section of mountain piedmont. Accurate and effective evaluation of the risk of single washout by slope flow is an important basis for disaster prevention and control decisions. According to the characteristics of the lack of basic research data in the development area of washout by slope flow, the complexity of the risk assessment structure and the strong randomness and ambiguity of the multi-index system, on the basis of rapid acquisition of initial data of indicators through field survey, simple experiment and sampling analysis, a quantitative index cloud reasoning risk evaluation model for slope flow washout of pipeline was established by introducing single-condition and single-rule cloud reasoning with summation integration weighting algorithm, and carry out instance verification. The evaluation results of 11 samples showed medium and relatively high risks, and the overall distribution trend is relatively concentrated. Compared with the results obtained by the entropy weight-extension method and the standard recommendation method, the proposed method is more in line with the small-scale disaster background analysis and the reality of the study area, and it’s also more beneficial to ensure the safe operation of pipelines. In this method, the obtainment of the source data is reliable, objective, and the preprocessing is simplified, the index weighting and classification are more reasonable, and the evaluation process takes into consideration of both the randomness and ambiguity of the system, which improves the accuracy and effectiveness of the evaluation results. It also provides a new way of thinking to other related research.

Wash, Rinse, Repeat: Which Patients Undergo Serial Joint Irrigation in Pediatric Septic Hip Arthritis?

The purpose of this study is to identify risk factors associated with repeat surgical irrigation in pediatric septic hip arthritis. A single center retrospective case-control study was performed. Patients who underwent ≥2 washouts (cases) were compared with those who had only 1 washout (controls). Demographic, clinical, laboratory, microbial, and magnetic resonance imaging data were compared between cases and controls and a prediction model was developed using logistic regression. A risk score was then constructed by counting the number of risk factors from the model that were present in each patient. We identified 26 patients between 1994 and 2015 who underwent ≥2 washouts for septic hip arthritis, and 63 control patients who had only a single washout. Twenty-two patients had 2 washouts, 3 had 4 washouts, 1 had 5 washouts. Median number of days between first and second washout was 5 (interquartile range, 4 to 8). The most common reason for repeat washout was persistent fever (N=21), followed by persistently elevated laboratory values (N=13), abnormal magnetic resonance imaging findings (N=12), and continued pain (N=12). Repeat washout cases demonstrated higher temperature preoperatively (P<0.001), had more frequent initial misdiagnosis (P=0.002), and had a longer time from symptom onset to surgery (P=0.02). Laboratory values in these cases showed higher C-reactive protein (P=0.003), and more frequent left shift (P=0.03) at presentation, with a greater proportion of positive cultures (P<0.001). Postoperatively, repeat washout cases had higher temperatures (P<0.001), more frequent wound drainage (P=0.02), and complications (P=0.001). A risk score for predicting the likelihood of undergoing repeat washout was constructed by counting the number of the following factors present: presence of left shift in CBC, positive blood or synovial fluid cultures, and postoperative temperature over 39°C. Seventy percent of cases had ≥2 of these risk factors and 80% of controls had ≤1 risk factor. Cases of pediatric septic arthritis which undergo repeat washout are associated with left shift, high postoperative temperatures, and positive cultures. They have more frequent misdiagnosis leading to delayed treatment and subsequent medical complications. Level III.

Erratum: Methicillin-Resistant Staphylococcus aureus Infection Is a Risk Factor for Unplanned Return to the Operating Room in the Surgical Treatment of a Septic Knee.

Surgical irrigation and debridement is the mainstay of treatment after the diagnosis of a septic knee. Arthroscopic treatment has been validated as a treatment option, but there is limited literature comparing it to an open arthrotomy regarding risk factors for failing single-stage surgical treatment. A retrospective review of surgically treated native adult septic knees at one urban tertiary care center was conducted to evaluate rates of unplanned return to the operating room (OR) following both arthroscopic and open treatment of an adult septic knee. The primary outcome studied was unplanned return to the OR for persistent infection within 4 months of the initial surgery. Demographics, laboratory, and microbiology data were collected to identify factors associated with unplanned return visits to the OR. Fisher's exact tests and two-tailed paired Student's t-tests were used for categorical and continuous data comparisons, respectively. A multivariate analysis was performed to identify independent risk factors of initial washout failure. Thirty-three patients underwent arthroscopy and 47 had open arthrotomy. Eight failed arthroscopy and nine failed open treatment (75.8 and 80.9% success rates, p = 0.59). Unplanned repeat washouts in arthroscopically treated knees was associated with methicillin-resistant Staphylococcus aureus (MRSA) (62.5 vs. 12%, p = 0.01) and increased synovial white blood cell (WBC) count (160,000 vs. 52,000, p = 0.004). Unplanned return for repeat washout after open treatment was associated with lower American Society of Anesthesiologists scores (2.3 vs. 2.9, p = 0.019). MRSA was the only independent predictor of failure of single washout in a multivariable logistic regression analysis (p = 0.017). This study did not detect a difference in success of single washout between arthroscopic and open treatment of septic arthritis. However, MRSA was identified as a risk factor for an unplanned return to the OR after arthroscopic treatment. Consideration should be made for open surgical treatment in the setting of MRSA infections of a native knee.

Reduced Stress and Improved Sleep Quality Caused by Green Tea Are Associated with a Reduced Caffeine Content.

Caffeine, one of the main components in green tea, can interfere with sleep and block the effect of theanine. Since theanine, the main amino acid in tea leaves, has significant anti-stress effects in animals and humans, we examined the effects of green tea with lowered caffeine content, i.e., low-caffeine green tea (LCGT), on stress and quality of sleep of middle–aged individuals (n = 20, mean age 51.3 ± 6.7 years) in a double-blind crossover design. Standard green tea (SGT) was used as the control. These teas (≥300 mL/day), which were eluted with room temperature water, were consumed over a period of seven days after a single washout term. The level of salivary α-amylase activity (sAA), a stress marker, was significantly lower in participants that consumed LCGT (64.7 U/mL) than in those that consumed SGT (73.9 U/mL). Sleep quality was higher in participants that consumed a larger quantity of LCGT. In addition, a self-diagnostic check for accumulated fatigue was significantly lower in those participants that consumed LCGT than SGT. These results indicate that LCGT intake can reduce stress in middle-aged individuals and improve their quality of sleep. The reduction in caffeine is suggested to be a valid reason for enhancing the anti-stress effect of green tea.

Methicillin-Resistant Staphylococcus aureus Infection Is a Risk Factor for Unplanned Return to the Operating Room in the Surgical Treatment of a Septic Knee.

Surgical irrigation and debridement is the mainstay of treatment after the diagnosis of a septic knee. Arthroscopic treatment has been validated as a treatment option, but there is limited literature comparing it to an open arthrotomy regarding risk factors for failing single-stage surgical treatment. A retrospective review of surgically treated native adult septic knees at one urban tertiary care center was conducted to evaluate rates of unplanned return to the operating room (OR) following both arthroscopic and open treatment of an adult septic knee. The primary outcome studied was unplanned return to the OR for persistent infection within 4 months of the initial surgery. Demographics, laboratory, and microbiology data were collected to identify factors associated with unplanned return visits to the OR. Fisher's exact tests and two-tailed paired Student's t-tests were used for categorical and continuous data comparisons, respectively. A multivariate analysis was performed to identify independent risk factors of initial washout failure. Thirty-three patients underwent arthroscopy and 47 had open arthrotomy. Eight failed arthroscopy and nine failed open treatment (75.8 and 80.9% success rates, p = 0.59). Unplanned repeat washouts in arthroscopically treated knees was associated with methicillin-resistant Staphylococcus aureus (MRSA) (62.5 vs. 12%, p = 0.01) and increased synovial white blood cell (WBC) count (160,000 vs. 52,000, p = 0.004). Unplanned return for repeat washout after open treatment was associated with lower American Society of Anesthesiologists scores (2.3 vs. 2.9, p = 0.019). MRSA was the only independent predictor of failure of single washout in a multivariable logistic regression analysis (p = 0.017). This study did not detect a difference in success of single washout between arthroscopic and open treatment of septic arthritis. However, MRSA was identified as a risk factor for an unplanned return to the OR after arthroscopic treatment. Consideration should be made for open surgical treatment in the setting of MRSA infections of a native knee.

It's about numbers, not pictures

the article in the current issue by Horn and colleagues ([4][1]) from Sheffield presents a significant change in the manner in which MRI in the lung using hyperpolarized gas (3He in this case, but also potentially 129Xe) is used. Since its inception, hyperpolarized gas imaging has shown an ability

Computational Fluid Dynamics of Gap Flow in a Biocentrifugal Blood Pump

The centrifugal blood pump with a magnetically suspended impeller has shown its superiority as compared to other artificial heart pumps. However, there is still insufficient understanding of fluid mechanics related issues in the clearance gap. The design nature of the pump requires sufficient washout in the clearance between the impeller and the stationary pump housing inner surface. In this study, numerical simulations were carried out to investigate the flow fields in the gap of the Kyoto-NTN centrifugal blood pump. The flow patterns in the gap region of the blood pump were presented and regions of high and low velocity were identified. It was found that the radial velocity of the blood in the gap was closely related to the pressure distribution at the exit of the impeller, both the highest pressure gradient and the highest radial velocity in the gap occurred at an angular position of 170 degrees . The mass flow rate in the gap was estimated to be 25.2% of the pump outflow, which is close to the measurement results of a five times enlarged test pump. The wall shear stresses on the gap surface were found to be over 21 Pa and below 300 Pa, which is correspondingly higher than the threshold of thrombi formation and is lower than the shearing threshold of red blood cells. Comparison of the 1 : 1 simulation model with the measurement results on a five times enlarged test pump indicates that there are some differences in the resulting radial velocity distributions in the gap and thus the washout mechanism. Two symmetrical high washout regions at both the cutwater and splitter plate were observed in the simulation instead of a single washout region at the splitter plate found in the experimental study. This may be due to the scaling effect of the enlarged test pump; also the medium used in the experiment is different from the simulation.

The dissolution of urinary catheter encrustation.

To identify the optimum volume of acidic bladder washout solution to dissolve catheter encrustations and to compare the effectiveness of different bladder washout delivery devices. Urinary catheter encrustation was generated in vitro using a model of the catheterized bladder adapted from previous work. An acidic bladder washout solution (Suby G) was applied via the catheter in the model and retained for 15 min. The amount of encrusting material dissolved was measured by colorimetric analysis of the magnesium and calcium content of the solution returned after the washout procedure. The relative effectiveness of different volumes of washout solution and different washout delivery devices (Optiflow, Bard Ltd, Crawley; UroTainer, B/Braun Medical Ltd, Aylesbury; and a bladder syringe) in dissolving catheter encrustations was compared to the 'standardized' conditions commonly used in practice. There was no statistically significant difference between washouts with 100 mL and washouts with 50 mL for any of the delivery devices tested. Gentle agitation with 50 mL Suby G did not significantly improve the dissolution of encrustation but the total amount of material dissolved when two washouts with 50 mL Suby G were used sequentially was significantly better than a single washout with either 100 mL or 50 mL. Under controlled laboratory conditions, smaller volumes of acidic bladder washout solution (50 mL) are as effective as the 100 mL commonly used in practice, but two sequential washouts with 50 mL are more effective than a single washout. The newly designed Optiflow delivery device is at least as effective as the other devices tested. This study provides new evidence which may contribute to decision-making by practitioners in relation to catheter care.

Multiple laparotomies for severe intra-abdominal infection.

Mortality rates for patients with severe peritoneal infection are high. The present study was undertaken in order to examine mortality rates in patients with severe peritoneal infection who were managed by planned re-laparotomy. Retrospective analysis of patients presenting at the King Faisal Specialist Hospital and Research Centre between 1992 and 1994 with severe peritoneal infection was undertaken. A total of 52 patients underwent either single (n = 30) or multiple (n = 22) peritoneal lavage, and Acute Physiology and Chronic Health Evaluation (APACHE II) scores and predicted mortality rates were calculated for these patients. The predicted mortality rate for patients undergoing a single washout was 42.4%, actual mortality: 23%. The predicted mortality for patients undergoing multiple washouts was 55.6%, actual mortality: 36.3%. No patient with a predicted mortality of < 30% who underwent multiple washouts died. Of nine patients with a predicted mortality between 31 and 60%, one died (11.1%). For a predicted mortality of 61-80%, five of six patients died (83.3%), and for patients with a predicted mortality of > 80%, two of three died (66.7%). The utilization of planned re-look laparotomy and peritoneal lavage in patients with severe peritonitis may result in a significant decrease in mortality as predicted by APACHE II scoring.