Extended Operation Time Research Articles

Mandibular third molar removal: Risk indicators for extended operation time, postoperative pain, and complications

Objectives The aim of this study was to identify risk indicators for extended operation time and postoperative complications after removal of mandibular third molars. Study design There were 388 molars included in the study. The teeth were removed using the buccal approach under local anesthesia. Four hours postoperatively the patient recorded his or her pain perception on a visual analogue scale (VAS). After surgery a surgeon recorded parameters regarding the tooth and if the mandibular nerve had been visible during the operation. One week postoperatively the postoperative pain and complications were recorded. Logistic regression models were made to identify risk indicators for extended operation time, postoperative pain, and complications. Results Females were at higher risk for postoperative pain and dry socket than males. Older patients were at higher risk for extended operation time than younger patients. Radiographically fully impacted molars increased the risk of postoperative general infection. If the nerve was visible during surgery there was a higher risk of a high VAS score, postoperative pain, and general infection than if the nerve had not been visible. Conclusion Several indicators were found to increase the risk of postoperative complications, but a visible alveolar inferior nerve during the operation was repeatedly found to be the highest single risk indicator.

Elective laparoscopic cholecystectomy

Efficient use of operating time has become a key concern. The aim of this study was to determine preoperative factors that can predict extended duration of operating time (>90 min) for laparoscopic cholecystectomy (LC). Data collected prospectively on 827 consecutive patients who underwent elective LC between 1990 and 1997 were analyzed. Factors evaluated included age, gender; body mass index; comorbidity; duration of symptoms; history of jaundice, pancreatitis, or abdominal surgery; dilated common bile duct or thick-walled gallbladder on ultrasound; preoperative endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy (ES); and surgeon experience. Univariate and multivariate analyses were performed to identify factors predicting a long operation. Operating time was longer than 90 min in 276 patients (33%). Predictors of extended operation time were age older than 55 years (odds ratio [OR] = 9.7), preoperative ES (OR = 2.8), and a thick-walled gallbladder on ultrasound (OR = 2.5). These predictors may be useful in planning theater lists and anesthesia management, and in selecting patients for day surgery.

Inert COD production in a membrane anaerobic reactor treating brewery wastewater

In this study, inert COD production in a crossflow ultrafiltration membrane anaerobic reactor (CUMAR) system treating brewery wastewater, was investigated. The system was operated at a wide range of influent chemical oxygen demand (COD) concentrations and solid retention times (SRT) in order to determine residual non-biodegradable COD produced by biomass in the anaerobic reactor. Previous studies showed that the wastewater had practically no inert soluble COD. The inert soluble COD in the effluent would, therefore, have been produced in the anaerobic reactor by the biomass. Significant increases in the effluent COD concentration were observed during the operation of the CUMAR system at SRT lower than 100 days. It was also calculated from the results that the soluble microbial products measured in terms of COD were found to be an average of 2.2% of the influent COD. These microbial products were not removed from the effluent even with extended operation times. Throughout the operation, a maximum of 28.5 kg COD/m 3 day was applied, at which point COD removal efficiencies of no lower than 97% in the anaerobic reactor and 99% in the membrane permeate were achieved during the steady-state operation of the CUMAR system.

In Situ Cr(VI) Reduction within Coarse-Textured, Oxide-Coated Soil and Aquifer Systems Using Fe(II) Solutions

Batch and column techniques were used to evaluate the in situ Cr(VI) reduction and immobilization using Fe(II) solutions within the sediments of the Atlantic Coastal Plain. Remediation treatments included Cr-free groundwater and buffered and unbuffered Fe(II) solutions as either FeCl2 and FeSO4. The slow release of Cr(VI) from the Fe-oxide rich subsurface sediment following exposure to Cr-free solutions indicated that simple pump-and-treat procedures would require extended operation time to meet regulatory standards. In situ reduction was confirmed by the loss of Cr(VI) and Fe(II) from solution and a drop in pH compared to control systems. Batch and column-effluent Cr(VI) decreased with increasing Fe(II), generally falling below detection limits as the persistence of Fe(II) occurred. However, CrDissolved, presumably Cr(III), exceeded regulatory limits due to the low pH (≈3.0) induced by oxidation and hydrolysis of Fe(II). Acetate-buffered Fe(II) solutions maintained an elevated pH in the presence of Cr(VI...

A prospective study of wound infection in coronary artery surgery

The incidence of wound infection in coronary artery surgery is low, but there is an appreciable mortality associated with sternal infection. In other fields of surgery there is evidence that an all disposable paper gown and drape system has protective advantages over a fabric system. Using an established wound scoring system (ASEPSIS), we investigated this in a prospective, randomised trial of patients undergoing cardiac surgery. 505 patients undergoing isolated coronary artery surgery in a single hospital over an 18 month period were randomised to either a disposable, paper drape system or re-usable fabric drapes. Allocation was stratified according to whether or not the patient had had previous coronary artery surgery. Patients were followed for 3 months. Total infection scores for each wound were calculated from daily scores collected in hospital together with the scores at six weeks and three months. The two randomised groups were otherwise well matched. Full follow-up information was available for 464 (92%) patients. There was no evidence of any difference in rates of sternal or leg wound infection between the two groups (P = 0.87 and 0.62, respectively). Women were more likely to have infected sternal wounds (P = 0.17) and significantly more likely to have infected leg wounds (P = 0.04). Patients with sternal wound infections had a significantly higher body mass index (P = 0.001). High Parsonnet scores and increased time on ventilation were significantly associated with leg wound but not sternal infections. For both wound sites, patients with infections had spent longer in the operating theatre. In a randomised controlled study of patients undergoing coronary artery surgery we found that the use of paper drapes and gowns conferred no benefit over a reusable fabric in terms of post-operative wound infection. Although females and diabetics are more likely to experience this complication, an important additional risk factor is an extended operating time.

Lubricant for Paper Coating

Coating lubricant is used as an anti-dusting agent at calendering and printing process, a releasing agent at cast coating process, a slipping and an anti-blocking agent of paper and smoothness and gloss improver of paper.For paper coating lubricant, calcium stearate dispersion which San Nopco introduced from USA about 30 years ago is still widely used.Recent coating technology enables them to use SBR with lower Tg for gravure grade coated paper but it requires new lubricant which prevents dusting at supercalendering process. Modern high speed cast coater needs a lubricant which has better releasing property and can extend operation time without break for cleaning casting drum. Soft nip calender requires a lubricant which shows good releasing property at higher temperature. As above mentioned, recent progress in paper coating requires various performance to lubricant. San Nopco i developing new lubricants to meet these requirements and supplying them to paper manufacturers.In this report, I introduce the performance and function of our high performance lubricants.

Electron cyclotron resonance plasma source for conductive film deposition

We have developed an electron cyclotron resonance (ECR) plasma source for conductive film deposition. In this source, 2.45 GHz microwaves are divided into two directions by an E-plane divider and pass through a quartz window into the composer, where the microwave electric field is parallel to the external magnetic field. The quartz windows are set in the blind space from the ECR plasma and in a region of higher magnetic field than that of the ECR condition (875 G). The composed microwaves are transported from the higher magnetic field region to the ECR magnetic field region in the plasma source. Highly ionized plasma of over 10 mA/cm2 has been generated by preventing plasma generation in the composer. A good uniformity of ±5% over a 6 in. diameter has been obtained. TiN films and Al films have been deposited with high reliability over an extended operation time.

Gas discharge ion source. I. Duoplasmatron

The effects of the plasma expansion cup on the operation of a duoplasmatron ion source have been investigated by measuring the total ion current and the distributions of the ion energy, mass, and current density. A copper expansion cup did not affect the magnetic field near the anode of the ion source and consequently the ion current density distribution was sharply peaked near the center of the cup. Ion energy distributions were approximately symmetrical about anode potential. The dominant ionic species were D(+) (3) and D(+) at low and high arc currents, respectively. Changes in the electrical potential of the copper cup with respect to the anode produced negligible changes in the above data. A mild steel plasma expansion cup caused the magnetic field to diverge and intercept the cup walls, resulting in ion current density distributions that were flatter and more amenable to focusing than the ones with the copper cup. With the steel cup at anode potential, the ion mass distribution was similar to that from the copper cup; however, the ion energy distribution was asymmetrical about the anode potential with a peak about 10-20 V above anode potential. The total ion current from this mode of operation was about one-third the value from the copper cup. If the steel cup assumed floating potential, about 50 V below anode potential, the total current increased to the level observed from the copper cup and the ion energy distribution was similar to that observed with the copper cup but the current density distribution was much flatter than that of the copper cup. The ion mass distribution was 60%-70% atomic ions over the entire arc current range investigated. Based on these data, a modified plasma expansion cup was designed with tapered steel walls lined with a boron nitride insert. The overall performance of the duoplasmatron ion source with this cup was superior to any of the previous three modes of operation. The improved design uses a molybdenum anode insert which is far superior to copper in regard to erosion over extended operating times. A total beam current of 200 mA was produced at an arc current of 24 A.

Laparoscopic and Robotic-Assisted Extended Pelvic Lymph Node Dissection for Invasive Bladder Cancer: A Review

Minimally invasive surgical techniques, including laparoscopic and robotic-assisted radical cystectomy (RC), are emerging as the preferred treatment options for invasive bladder cancer. Mounting evidence has demonstrated that laparoscopic and robotic-assisted RC with extended pelvic lymph node dissection (PLND) is a viable alternative for managing invasive bladder cancer. In this review, we summarized recent advances and critically assessed the min-imally invasive approaches and risk factors associated with extended PLND in patients undergoing laparoscopic or robotic-assisted RC. The findings indicated that laparoscopic and robotic-assisted PLND, employing either a standard or extended approach, is technically feasible and offers benefits such as minimal invasiveness, superior visualiza-tion, reduced blood loss, and expedited recovery. The risk factors involved in the laparoscopic extended PLND are minimal. Clinically, laparoscopic and robotic-assisted extended PLND is significantly advantageous in that it sticks to the principles of open surgery and respects anatomical boundaries. Nevertheless, laparoscopic and robotic-as-sisted extended PLND is technically challenging and necessitate extended operation time. Furthermore, large-scale, prospective, multicenter trials are warranted to validate the long-term efficacy of laparoscopic and robotic-assisted extended PLND in terms of disease-specific survival.