Effectiveness of oolong tea and simethicone solution for lens cleansing during colonoscopy: A double-blinded randomized study.

BACKGROUND AND AIMS: water is an imperfect agent for lens cleansing during endoscopy due to its incompetence to clean hydrophobic dirt, whereas amphiphilic surfactants have the potential to overcome the limitation of water. The trial was aimed to evaluate the cleansing effectiveness of 2 typical surfactants (simethicone solution and oolong tea) for colonoscopic lens. METHODS: Oolong tea (O-), low concentration simethicone solution (S1-), high concentration simethicone solution (S2-) and distilled water (D-) were used as washing solutions for colonoscopic lens. Study I: The tip of the colonoscope was immersed in lard oil in order to simulate the blur, and photographs were taken toward a standard colonoscopy image in-vitro pre- and post- each cleansing procedure. The blurred areas of each image were quantified and compared. Study II: 395 consecutive patients who were due to colonoscopy examination were enrolled and randomized into O-, S2-, D-group. The volume of washing solution used and cleansing level during the examination procedure, adenoma and polyp detected per colonoscopy, insertion time and withdraw time were analyzed. RESULTS: Study I: There were no differences in 4 groups for the blurred areas on images before lens cleansing. The blurred areas after lens cleansing were significantly smaller in 3 groups (O- 8.47 ±â€Š20.91 vs S1- 13.06 ±â€Š10.71 vs S2- 6.76 ±â€Š8.49 vs D- 38.24 ±â€Š29.69, P < .05) than water. The decline range of blurred areas after lens cleansing in oolong tea, low concentration simethicone solution, high concentration simethicone solution groups were significantly higher than that in distilled water group (O- 87.35 ±â€Š20.81 vs S1- 78.12 ±â€Š19.24 vs S2- 89.57 ±â€Š8.50 vs D- 53.39 ±â€Š28.45, P < .05). Study II: The volume of washing solution used in S2-group was significantly smaller than that in O-group and D-group. The cleansing level of the colonoscopic lens of O-group was significantly superior than that of S2-group and D-group. CONCLUSIONS: The in-vitro test showed oolong tea and simethicone solution can effectively cleans the colonoscopic lens. The clinical trial demonstrated that oolong tea instead of water is effective to provide better visualization during colonoscopy.Registration: Chictr.org.cn No: ChiCTR1900025606.

Implementation of an Anaesthesia Quality Improvement Programme to Reduce Fibreoptic Bronchoscope Repair Incidents.

BACKGROUND: This study was aimed at investigating the effectiveness of the implementation of a comprehensive quality improvement programme (QIP) for reducing the repair rate of the fibreoptic bronchoscope (FOB). METHODS: A three-stage improvement strategy was implemented between January 2013 and December 2016. Stage one is the acquisition of information on violations of practice guidelines, repair rate, cost of repair, and incidence of unavailability of FOB during anaesthesia induction of the previous year through auditing. Stage two is the implementation of a quality improvement campaign (QIC) based on the results of stage one. Stage three is the programme perpetuation through monitoring compliance with policy on FOB use by regular internal audits. The effectiveness was retrospectively analyzed on a yearly basis. RESULTS: The annual repair rate, repair cost, and incidence of FOB unavailability before the QIP implementation were 1%, 18,757 USD, and 1.4%, respectively. After QIC, the repair rate in 2013 dropped by 81% (from 1% in 2012 to 0.19% in 2013, p < 0.05). The annual repair cost fell by 32% from 18,758 USD (2012) to 12,820 USD (2013). Besides, the incidence of FOB unavailability plummeted by 71% from 1.4% to 0.4% during the same period. The annual repair rates and incidence of FOB unavailability remained lower in subsequent three years than those before QIP implementation. CONCLUSION: Implementation of a quality improvement programme was effective for reducing the rate and cost of FOB repair as well as unavailability rate, highlighting its beneficial impact on cost-effectiveness and patient safety in a tertiary referral center setting.

The Outcomes of a Comprehensive Program for Maintenance of Goldmann Applanation Tonometer.

PRECIS: We checked 190 tonometers every month and repaired faulty ones. Calibration error (CE) frequency reduced from 23% to 0.6% at 1 year. Tonometers needing one or >1 CE repair differed in survival but not in age. PURPOSE: The purpose of this study was to report the outcomes of a comprehensive program to maintain calibration status of the Goldmann applanation tonometer. METHODS: This prospective cohort study was carried out at 2 tertiary eye care referral centers. We included 190 slit-lamp mounted Goldmann applanation tonometers (Model AT 900 C/M). Health care providers (error checking and reporting) and clinical engineers (maintenance) participated. The team carried out CE check once a month, and repair of faulty tonometers, if any, within 24 hours. Failure of tonometer was defined as development of unacceptable CE beyond the third repair. The main outcome measures were the frequency of CE and survival function of the tonometer over 1 year. RESULTS: The median age of the tonometers was 10.7 (range, 0.2 to 25.1) years. The total number of repairs was 86. The proportion (95% confidence interval) of faulty tonometers reduced from 23.1% (17.7, 29.6) in the first month to 0.6% (0.1, 3.3) at 1 year (P<0.01). The median age of the tonometer did not differ between those needing (n=63, 9.4 y) and not needing (n=127, 10.7 y; P=0.24) repair. All tonometers requiring 1 CE repair (n=49, 25.7%) survived until 1 year. The survival of tonometers requiring >1 CE repair (n=14, 7.3%) was 40% at 1 year. CONCLUSIONS: Our in-house program maintained 92.6% tonometers error free. Number of repairs rather than age determined the need for replacement/sending back the tonometer to the manufacturer. Our simple and easy to follow maintenance program has the potential for wide application.

Using a 2D detector array for meaningful and efficient linear accelerator beam property validations.

Following linear accelerator commissioning, the qualified medical physicist is responsible for monitoring the machine's ongoing performance, detecting and investigating any changes in beam properties, and assessing the impact of unscheduled repairs. In support of these responsibilities, the authors developed a method of using a 2D ionization chamber array to efficiently test and validate important linear accelerator photon beam properties. A team of three physicists identified critical properties of the accelerator and developed constancy tests that were sensitive to each of the properties. The result was a 14-field test plan. The test plan includes large and small fields at varying depths, a reduced SSD field at shallow depth for sensitivity to extra focal photon and electron components, and analysis of flatness, symmetry, dose, dose profiles, and dose ratios. Constancy tests were repeated five times over a period of six weeks and used to set upper and lower investigation levels at ± 3 SDs. Deliberate variations in output, penumbra, and energy were tested to determine the suitability of the proposed method. Measurements were also performed on a similar, but distinct, machine to assess test sensitivity. The results demonstrated upper and lower investigation levels significantly smaller than the comparable TG-142 annual recommendations, with the exception of the surrogate used for output calibration, which still fell within the TG-142 monthly recommendation. Subtle changes in output, beam energy, and penumbra were swiftly identified for further investigation. The test set identified the distinct nature of the second accelerator. The beam properties of two photon energies can be validated in approximately 1.5 hrs using this method. The test suite can be used to evaluate the impact of minor repairs, detect changes in machine performance over time, and supplement other machine quality assurance testing.

Personal exposures to asbestos fibers during brake maintenance of passenger vehicles.

INTRODUCTION: Brake linings and brake pads are among the asbestos-containing products that are readily available in Colombia. When sold separated from their support, brake linings require extensive manipulation involving several steps that include drilling, countersinking, riveting, bonding, cutting, beveling, and grinding. Without this manipulation, brake linings cannot be installed in a vehicle. The manipulation process may release asbestos fibers, which may expose brake mechanics to the fibers. METHODS: Three brake repair shops located in Bogotá (Colombia) were sampled for 3 or 4 consecutive days using US National Institute for Occupational Safety and Health (NIOSH) methods 7400 and 7402. Standard procedures for quality control were followed during the sampling process, and asbestos samples were analyzed by an American Industrial Hygiene Association accredited laboratory. Personal samples were collected to assess full-shift and short-term exposures. Area samples were also collected close to the brake-lining manipulation equipment and within office facilities. Activities were documented during the sampling process. RESULTS: Using Phase Contrast Microscopy Equivalent counts to estimate air asbestos concentrations, all personal samples [i.e. 8-h time-weighted averages (TWAs) and 30-min personal samples] were in compliance with the US Occupational Safety and Health Administration standards. Personal asbestos concentrations based on transmission electron microscopy counts were extremely high, ranging from 0.006 to 3.493 f cm(-3) for 8-h TWA and from 0.015 to 8.835 f cm(-3) for 30-min samples. All asbestos fibers detected were chrysotile. Cleaning facilities and grinding linings resulted in the highest asbestos exposures based on transmission electron microscopy counts. There were also some samples that did not comply with the NIOSH's recommended exposure limits. CONCLUSION: The results indicate that the brake mechanics sampled are exposed to extremely high asbestos concentrations (i.e. based on transmission electron microscopy counts), suggesting that this occupational group could be at excess risk of asbestos-related diseases.

Influence of flue gas cleaning system on the energetic efficiency and on the economic performance of a WTE plant.

Gas cleaning systems of MSW (Municipal Solid Waste) incinerators are characterised by the process employed to remove acid gases. The commonly used technologies for acid gas removal are: (1) dry treatment with Ca(OH)(2) or (2) with NaHCO(3), (3) semi-dry process with Ca(OH)(2) and (4) wet scrubbing. In some recent plants beside a wet cleaning system, a dry neutralization with Ca(OH)(2) is used. The goal is to reduce the amount of acid to be removed in the wet treatment and the liquid effluents produced. The influence of these different technologies on the electrical efficiency was investigated by a detailed simulation of a WTE (Waste To Energy) plant with a capacity of about 100,000 t/y of MSW. The effects of the different gas cleaning systems on electrical efficiency were significant. The difference of efficiency between the most advantageous technology, which is dry treatment with NaHCO(3), and the least advantageous technology which is semi-dry treatment, is about 0.8%. A simple economic analysis showed that the few advantages of dry technologies can often be lost if the costs of chemicals and the disposal of products are considered.

A fuzzy inference system to evaluate contract service provider performance.

This paper puts forward a fuzzy inference system for evaluating the quality performance of service contract providers. An Application Service Provider was designed and put online, featuring surveys to establish the most useful indicators to evaluate the quality of the service. This model was implemented in 10 separate hospitals. As a result, the service cost-acquisition cost ratio in these cases was reduced from 16.14% to 6.09% in the period 2001-January 2003.

Portable ophthalmic microscopes in the Philippines: an overview.

BACKGROUND: Demonstrations were held all over the Philippines to teach local microscope operators basic maintenance skills and troubleshooting for their portable microscopes. METHODS: Fifteen microscopes were examined and feedback was obtained from 16 microscope operators. The different parameters of the microscope were evaluated as follows: (i) user-friendliness, (ii) demand and availability of technical services and spare parts, (iii) portability and (iv) frequent problems encountered. Some suggestions for improvement are proposed. RESULTS: There was a general satisfaction among the operators with their microscopes; however, there was a lack of technical support services. Most microscopes were portable and the original casing was adequate for transport. Even though most microscopes were functioning, their quality could be improved with maintenance. The three most common problems identified were: mouldy/dirty lenses, expired mould pellets and poor alignment. CONCLUSIONS: The portable operating ophthalmic microscope has an important role in the prevention of international blindness. The archaic attitude of sending microscopes to professional technicians for simple maintenance and repair should be abandoned. Instead demonstrations aimed at teaching these skills to local operators and surgeons should be held, in order to improve the technical support available. Different microscope operators can help provide microscope designers with feedback for future improvements. Similar demonstrations could be considered for other countries with a similar scarcity of technical support services.

A system for the calculation and visualisation of radiation field for maintenance support in nuclear power plants.

A system has been developed to improve the efficiency of maintenance work while decreasing the radiation exposure of maintenance personnel in nuclear power plants. The input data for dose rate calculation are automatically generated by using computer-aided design data. Changes for the input data corresponding to the progress of maintenance work, such as installation of a radiation shield and removal of a component, are easily input interactively on a graphical user interface (GUI). A new method was proposed which searches the sets of source and detector points between which gamma-ray attenuation is changed by the component movement. The calculation is performed only for the changed sets, so that the change of the three-dimensional dose rate distribution is calculated rapidly according to the work progress. The dose rate distribution and the radiation exposure of maintenance personnel are displayed three-dimensionally in colour with plant components and pipes on the GUI.

A database management system for radiation safety program activities.

The Database Management System includes a data retrieval system for most aspects of the radiation safety program at our institution. Originally, this program was designed to simplify the retrieval of data related to radioisotope use at the institution. After several modifications and changes, the present system is more elaborate and uses current commercial software, which is more readily available to the entire university and hospital community. The data included in the database are radioactive material receipts and inventory; radioisotope waste inventory and disposal; quarterly laboratory inspection results; contamination (wipe tests) results and instrument inventory and calibration; and support staff training. Both the authorized users and the Radiation Safety Office personnel maintain records independently using the same format, which makes for easy comparison and verification. Data for and from laboratory inspections are readily accessed, analyzed, and reported. The system allows for modifications as necessitated by changes in local and federal regulations or in-house policies.

Risk-based maintenance of ethylene oxide production facilities.

This paper discusses a methodology for the design of an optimum inspection and maintenance program. The methodology, called risk-based maintenance (RBM) is based on integrating a reliability approach and a risk assessment strategy to obtain an optimum maintenance schedule. First, the likely equipment failure scenarios are formulated. Out of many likely failure scenarios, the ones, which are most probable, are subjected to a detailed study. Detailed consequence analysis is done for the selected scenarios. Subsequently, these failure scenarios are subjected to a fault tree analysis to determine their probabilities. Finally, risk is computed by combining the results of the consequence and the probability analyses. The calculated risk is compared against known acceptable criteria. The frequencies of the maintenance tasks are obtained by minimizing the estimated risk. A case study involving an ethylene oxide production facility is presented. Out of the five most hazardous units considered, the pipeline used for the transportation of the ethylene is found to have the highest risk. Using available failure data and a lognormal reliability distribution function human health risk factors are calculated. Both societal risk factors and individual risk factors exceeded the acceptable risk criteria. To determine an optimal maintenance interval, a reverse fault tree analysis was used. The maintenance interval was determined such that the original high risk is brought down to an acceptable level. A sensitivity analysis is also undertaken to study the impact of changing the distribution of the reliability model as well as the error in the distribution parameters on the maintenance interval.

Suppression of dark current radiation in step-and-shoot intensity modulated radiation therapy by the initial pulse-forming network.

The effect of the initial pulse forming network (IPFN) on the suppression of dark current is investigated for a Siemens Primus accelerator. The dark current produces a spurious radiation, which is referred to as dark current radiation (DCR) in this study. In the step-and-shoot delivery of an intensity modulated radiation therapy (IMRT), the DCR could be of some concern for whole body dose along with leakage radiation through collimator jaws or multileaf collimator. By adjusting the IPFN-to-PFN ratio to >0.8, the DCR can be measured with an ion chamber during the "PAUSE" state of the accelerator in the IMRT mode. For 15 MV x rays, the magnitude of the DCR is approximately equal to 0.7% of the dose at dmax for a 10 x 10 cm2 field. The DCR has a similar central axis depth dose as a 15 MV beam as determined from a water phantom scan. When the IPFN-to-PFN ratio is lowered to <0.8, no DCR is detected. For low energy x rays (6 MV), no DCR is detected regardless of the IPFN-to-PFN ratio. Although the DCR is studied only for the Siemens Primus model accelerator, the same precaution applies to other models of modern accelerators from other vendors. Due to the large number of field segments used in a step-and-shoot IMRT, it is imperative therefore, that dark current evaluation be part of machine commissioning and annual calibration for high-energy photon beams. Should DCR be detected, the medical physicist should work with a service engineer to rectify the problem. In view of DCR and whole body dose, low-energy photon beams are advisable for IMRT.

Instrument for scanning the angular variation of irradiance in ultraviolet phototherapy cabinets.

An instrument is described that measures irradiance and the angular distribution of the intensity of ultraviolet radiation sources inside phototherapy cabinets. Failed lamps and lamps with higher or lower outputs are readily identified. The measurements are controlled from outside the cabinet, thus reducing the risk to staff from exposure to ultraviolet radiation.

Role of instrument cleaning and maintenance in the development of diffuse lamellar keratitis.

OBJECTIVE: To determine if instrument cleaning techniques affect the rate of diffuse lamellar keratitis (DLK) after laser in situ keratomileusis (LASIK). DESIGN: Retrospective case series. PARTICIPANTS: Two hundred ten eyes of 109 patients. METHODS: A record review was performed of all patients who underwent LASIK at the Jules Stein Eye Institute from April 1 through June 24, 1999. During the first 6 weeks, the instruments used in LASIK surgery were cleaned according to our conventional protocol. At the end of this 6-week period, the cleaning protocol was modified and used for a subsequent 6-week period. For each eye during the two periods, the status of DLK on the first postoperative day was recorded. MAIN OUTCOME MEASURES: Presence of DLK. RESULTS: During the first 6-week period, 118 eyes of 60 patients underwent LASIK surgery. In the subsequent 6 weeks, 92 eyes of 49 patients underwent LASIK surgery. The two groups included patients with similar demographic background: gender, age, and target correction. Diffuse lamellar keratitis was present in 13 of 118 eyes (11%) using our conventional protocol. In only 2 of 92 eyes (2%) did DLK develop after the protocol was modified. Using the chi-square test, the difference between the two groups was statistically significant (P = 0.01). CONCLUSIONS: Diffuse lamellar keratitis is a fairly uncommon phenomenon after LASIK surgery. Although the cause remains to be elucidated, these results demonstrated a reduced incidence of DLK associated with alteration of cleaning procedures and a decrease in stagnant instrument cleaning fluids. The authors recommend that refractive centers avoid the use of stagnant fluids in their instrument cleaning and sterilizing protocols to minimize the occurrence of DLK outbreaks.