A Comparison of Epidural Anesthesia and Lumbar Plexus-Sciatic Nerve Blocks for Knee Surgery

OBJECTIVES: The efficacy of combined lumbar plexus-sciatic nerve blocks was compared to epidural anesthesia in patients undergoing total knee surgery. PATIENTS AND METHODS: The study included 80 American Society of Anesthesiologists (ASA) Physical Status I-III patients (age range 18 to 65) undergoing knee surgery. The patients were randomly divided into one of two groups. Epidural anesthesia was performed in the epidural anesthesia (EA) group (n=40), and the lumbar plexus and sciatic nerves were blockedin the lumbar plexus-sciatic nerve blocks (LPSB) group (n=40). For each patient, onset of sensory and motor block, degree of motor block, sign of sensory block in the contralateral lower limb for the lumbar plexus-sciatic nerve blocks group, success in providing adequate anesthesia, hemodynamic changes, time of first analgesic request, and patient and surgeon satisfaction with the anesthetic technique were recorded. RESULTS: One patient in the epidural anesthesia group and three patients in the lumbar plexus-sciatic nerve blocks group required general anesthesia due to failed block. There were no significant differences between the two groups regarding the success of providing adequate anesthesia. Eight patients in the lumbar plexus-sciatic nerve blocks group developed contralateral spread. The onset of sensory-motor block and the time of the first analgesic request were significantly later in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. Although there were no significant differences regarding patient satisfaction with the anesthetic technique between the two groups, surgeon satisfaction was significantly higher in the lumbar plexus-sciatic nerve blocks group than in the epidural anesthesia group. CONCLUSION: The lumbar plexus -sciatic nerve blocks provide effective unilateral anesthesia and may offer a beneficial alternative to epidural anesthesia in patients undergoing total knee surgery

The One Year Outcome after KTP Laser Vaporization of the Prostate According to the Calculated Vaporized Volume

The aim of this study was to develop a new simple method for measuring the vaporized volume and to evaluate the outcome of high-power potassium-titanyl-phosphate (KTP) photoselective laser vaporization. A total of 65 patients, with a mean age of 67.7 yr (range 53 to 85), were included in the primary analysis. The vaporized volume was calculated as the pre-operative volume minus the immediate post-operative volume plus the volume of the defect. For all patients, the subjective and objective parameters improved significantly after surgery. Six and 12 months after surgery, the group with a smaller vaporized volume (<15 g) had a lower reduction of the mean International Prostate Symptom Score (P=0.006 and P=0.004) and quality of life index (P=0.006 and P=0.004) when compared to the group with a greater vaporized volume (≥15 g). There were no differences in the change of the maximum flow rate and post-void residual based on the vaporized volume. Our findings suggest that the subjective improvement, after a high-power KTP laser vaporization, may be dependent on the vaporized volume obtained after the procedure

National-wide data on the treatment of BPH in Korea

The healthcare system in Korea provides coverage to all the people who are residing in Korea, so the data of the Korea healthcare system are national-wide and relatively accurate. We obtained the recent 5-year data (2004–2008) on the treatment of BPH from the national health insurance system. We tried to determine the trends or changes of BPH treatments in Korea. Over 3.8 million men visited clinics and were prescribed one or more BPH medications, and more than 44 000 men underwent surgical treatment during 2004–2008. Compared with the year 2004, two times the patients were prescribed BPH medications in 2008. With respect to the surgical treatment, the number of cases was increased 1.6 times in 2006 compared with the previous years. The most commonly used surgical option was TURP before 2006, but laser therapy was carried out as much as TURP in 2006 and in the following years. The relative risk of laser therapy in the 50 s is 1.53 (95% CI is 1.47–1.59). In conclusion, our national-wide data for the Korean BPH patients show that these patients' medical treatment increased during the 5 years from 2004 to 2008. Laser treatment had increased and it might replace TURP in several years

Hedging strategy for a portfolio of options and stocks with linear programming

This paper extends the model proposed by Papahristodoulou [ C. Papahristodoulou, Option strategies with linear programming, European Journal of Operational Research 157 ( 2004) 246 - 256] to a multi-asset setting to deal with a portfolio of options and underlying assets. General linear programming model is given and it is applied to Novartis, Sanofi and AstraZeneca's call and put options. A portfolio of options and their underlying assets is constructed under a hedging strategy that considers all the Greek letters such as delta, gamma, theta, rho and vega. The impact of each Greek constraint on the portfolio's return is investigated considering the shadow prices. (C) 2007 Elsevier Inc. All rights reserved

A comparison of lattice based option pricing models on the rate of convergence

An American option differs from a European one by the early exercise possibility. An American option can be exercised at any time up to the maturity date. In general, there is unfortunately no analytical solution to the American option problem. Binomial and trinomial approximations are useful to solve this problem but using a lattice model introduces approximation error. Both models have the property of convergence to Black & Scholes true prices thus, can be used alternatively to solve the Black & Scholes partial differential equation. This paper compares the rate of convergence of the lattice based option pricing models. The comparison is based on the number of nodes produced, computer time used and the approximation error. An illustrative example is used to compare the convergence speed of these two models. Comparing the lattice based option pricing models with respect to different stock prices is taken into consideration. (C) 2006 Elsevier Inc. All rights reserved