A randomized trial of remote ischemic preconditioning and control treatment for cardioprotection in sevoflurane-anesthetized CABG patients.

BACKGROUND: Remote ischemic preconditioning (RIPC) efficacy is debated. Possibly, because propofol, which has a RIPC-inhibiting action, is used in most RIPC trials. It has been suggested that clinical efficacy is, however, present with volatile anesthesia in the absence of propofol, although this is based on one phase 1 trial only. Therefore, in the present study we further explore the relation between RIPC and cardioprotection with perioperative anesthesia restricted to sevoflurane and fentanyl, in CABG patients without concomitant procedures. METHODS: In a single-center study, we aimed to randomize 46 patients to either RIPC (3x5 min inflation of a blood pressure cuff around the arm) or control treatment (deflated cuff around the arm). Blood samples were obtained before and after RIPC to evaluate potential RIPC-induced mediators (Interleukin (IL)-6, IL-10, Tumor Necrosis Factor-α, Macrophage Inhibitory Factor). An atrial tissue sample was obtained at cannulation of the appendix of the right atrium for determination of mitochondrial bound hexokinase II (mtHKII) and other survival proteins (Akt and AMP-activated protein kinase α). In blood samples taken before and 6, 12 and 24 h after surgery cardiac troponin T (cTnT) and C-reactive protein (CRP) were determined. Surgery was strictly performed under sevoflurane anesthesia (no propofol). RESULTS: We actually randomized 16 patients to control treatment and 13 patients to RIPC. The mean 24 h area under the curve (AUC) cTnT was 11.44 (standard deviation 4.66) in the control group and 10.90 (standard deviation 4.73) in the RIPC group (mean difference 0.54, 95% CI -3.06 to 4.13; p = 0.76). The mean 24 h AUC CRP was 1319 (standard deviation 92) in the control group and 1273 (standard deviation 141) in the RIPC group (mean difference 46.2, 95% CI -288 to 380; p = 0.78). RIPC was without effect on survival proteins in atrial tissue samples obtained before surgery (mitochondrial hexokinase, Akt and AMPK) and inflammatory mediators obtained before and immediately after RIPC (IL-6, IL-10, TNF-α, macrophage migration inhibitory factor). CONCLUSION: Many factors can interfere with the outcome of RIPC. Trying to correct for this led to strict inclusion criteria, which, in combination with a decreased institutional frequency of CABG without concomitant procedures and a change in institutional anesthetic regimen away from volatile anesthetics towards total intravenous anesthesia, caused slow inclusion and halting of this trial after 3 years, before target inclusion could be reached. Therefore this study is underpowered to prove its primary goal that RIPC reduced AUC cTnT by < 25%. Nevertheless, we have shown that the effect of RIPC on 24 h AUC cTnT, in cardiac surgery with anesthesia during surgery restricted to sevoflurane/fentanyl (no propofol), was between a decrease of 27% and an increase of 36%. These findings are not in line with previous studies in this field. TRIAL REGISTRATION: The Netherlands Trial Register: NTR2915 ; Registered 25 Mei 2011.

Elderly patients benefit from minimally invasive mitral valve surgery: perioperative risk management matters.

OBJECTIVES: The goal was to assess the single-centre results of minimally invasive mitral valve surgery (MIMVS) in the elderly population. METHODS: All patients referred for minimally invasive valve surgery underwent a standardized preoperative screening. We performed a retrospective analysis of 131 consecutive elderly patients (≥75 years) who underwent endoscopic MIMVS through a right mini-thoracotomy. Survival and postoperative course were assessed in 2 groups: a repair group and a replacement group. RESULTS: Eighty-five patients underwent mitral valve repair, and 46 had mitral valve replacement. The mean age was 79 ± 2.9 years, and the median follow-up duration was 3.8 years. The cardiopulmonary bypass time (128.7 min vs 155.9 min, P = 0.012) and the cross-clamp time (84.9 min vs 124.1 min, P = 0.005) were significantly longer in the replacement group. Except for more reinterventions for bleeding in the replacement group (10.9% vs 0%, P = 0.005), there were no significant differences in the postoperative course between the 2 groups. Low mortality rates at the midterm follow-up were observed in both groups, and no differences were observed between the 4-and the 12-month follow-up. Survival rates after 1 year and 5 years were 97.6% and 88.6%, respectively, with no significant differences between the 2 groups. CONCLUSIONS: MIMVS is an excellent treatment option in vulnerable elderly patients with excellent short- and long-term results. Although other studies suggest that repair could be superior to replacement even in older patients, our experience suggests that replacement is equivalent to repair in terms of mortality and major adverse cardiac and cerebrovascular events. Experience and standardized preoperative screening are mandatory to achieve optimal results.

Excimer laser in situ keratomileusis for myopia.

Excimer laser in situ keratomileusis was done in 97 eyes of 59 patients to correct moderate and high myopia. Mean follow-up was 150 days. Mean preoperative myopia was -10.75 diopters (D). Mean reduction in myopia was -11.281 D (106.98%) at 1 month and -10.37D (98.417%) at 3 months. At 1-month, 41 eyes (42.27%) had a refraction within -1.00 D and 70 teeyes (72.16%) had a refraction within -2.00 D. At 3 months, 41 eyes (46.59% of 88 eyes) had a refraction within -1.00 D and 66 eyes (75% of 88 eyes) had a refraction within -2.00 D. Mean preoperative keratometric power was 44.00 D; mean postoperative keratometric power was 36.39 D. The keratometric change in power was 7.61 D. Preoperatively, 73 eyes (75%) had a spectacle corrected visual acuity of 20/40 or better; postoperatively, 64 eyes (65.63%) at 1 month and 75 eyes (77.01%) at 3 months reached 20/40 or better. The uncorrected visual acuity was 20/40 or better in 33 eyes (33.72%) at 1 month and in 49 eyes (49.96%) at 3 months. Mean ablation zone diameter was 4.92 mm. Astigmatism was treated separately in 10 eyes. Complications included optical zone decentration (3 eyes with more than 1 mm, epithelial implantation (1 eye), incomplete resection of the disc (2 eyes), severe hypotension, and irregular astigmatism (1 eye).

Prilezhaev dihydroxylation of olefins in a continuous flow process.

Epoxidation of both terminal and non-terminal olefins with peroxy acids is a well-established and powerful tool in a wide variety of chemical processes. In an additional step, the epoxide can be readily converted into the corresponding trans-diol. Batch-wise scale-up, however, is often troublesome because of the thermal instability and explosive character of the peroxy acids involved. This article describes the design and semi-automated optimization of a continuous flow process and subsequent scale-up to preparative production volumes in an intrinsically safe manner.

A short and scalable route to orthogonally O-protected 2-deoxystreptamine.

A seven-step synthesis of orthogonally O-protected 2-deoxy-streptamine has been developed from readily available neomycin, with an overall yield of 28%. Key chemical transformations include a chemoselective glycosidic bond hydrolysis and two regioselective protective group manipulations involving acetylation and deacetylation. The synthetic route is amenable to scale-up for the production of multigram quantities of enantiopure and orthogonally O-protected 2-deoxystreptamine, a versatile scaffold for the generation of libraries of RNA-targeting ligands.

In situ myopic keratomileusis results in 30 eyes at 15 months.

In situ myopic keratomileusis was performed in 30 eyes of 17 patients to correct high myopia. Mean follow-up was 460 days. Mean preoperative myopia was -15.66 D. The mean myopic decrease was 13.34 D, 85% of the total presurgery myopia. Postoperatively, 8 eyes (27%) were within +/- 1.00 D; 19 eyes (63%) within +/- 2.00 D; and 27 (90%) were within +/- 6.00 D. Preoperatively, 10 eyes (33%) had 20/40 or better visual acuity with spectacle correction. Postoperatively, 2 eyes (7%) had 20/40 or better without correction. Four eyes lost 2 or more Snellen lines of spectacle corrected visual acuity. Many eyes had an improved corrected visual acuity. The major complications were tear of lenticule (1 eye), epithelial implantation (4 eyes), transitory glaucoma (1 eye), irregular astigmatism (7 eyes), and undercorrection (24 eyes). Four of the latter underwent radial keratotomy.

Monoscleral fixation for posterior chamber intraocular lenses in cases of posterior capsule rupture.

A method for monoscleral fixation of posterior chamber intraocular lenses in posterior capsule rupture is described. Five lenses fixated with this technique are reviewed.

Methodological aspects of an adaptive multidirectional pattern search to optimize speech perception using three hearing-aid algorithms.

In this study we investigated the reliability and convergence characteristics of an adaptive multidirectional pattern search procedure, relative to a nonadaptive multidirectional pattern search procedure. The procedure was designed to optimize three speech-processing strategies. These comprise noise reduction, spectral enhancement, and spectral lift. The search is based on a paired-comparison paradigm, in which subjects evaluated the listening comfort of speech-in-noise fragments. The procedural and nonprocedural factors that influence the reliability and convergence of the procedure are studied using various test conditions. The test conditions combine different tests, initial settings, background noise types, and step size configurations. Seven normal hearing subjects participated in this study. The results indicate that the reliability of the optimization strategy may benefit from the use of an adaptive step size. Decreasing the step size increases accuracy, while increasing the step size can be beneficial to create clear perceptual differences in the comparisons. The reliability also depends on starting point, stop criterion, step size constraints, background noise, algorithms used, as well as the presence of drifting cues and suboptimal settings. There appears to be a trade-off between reliability and convergence, i.e., when the step size is enlarged the reliability improves, but the convergence deteriorates.