Is the combination of morphine with ketamine better than morphine alone for postoperative intravenous patient-controlled analgesia?

BACKGROUND: The addition of ketamine to morphine for patient-controlled analgesia (PCA) is supported by previous basic and clinical research, but has been challenged by subsequent negative studies. Important limitations of previous studies are the low number of patients analyzed, the use of morphine-ketamine combinations that may not the optimal, and that not all the relevant outcomes have been analyzed. In this study, we compared the combination of morphine and ketamine with morphine alone for postoperative PCA in large patient groups. We used a morphine-ketamine combination identified by an optimization procedure in our previous study. METHODS: After major elective orthopedic surgery, 352 patients received either PCA with morphine bolus 1.5 mg (Group M, n = 176) or a bolus of morphine plus ketamine 1.5 mg each (Group MK, n = 176) in a randomized, double-blind fashion. Unsatisfactory treatment was defined as the occurrence of either inadequate analgesia or unacceptable side effects. In addition, total consumption of PCA drugs, duration of PCA use, direct medical costs, and number of patients with chronic postoperative pain 3 and 6 mo after operation were recorded. RESULTS: The incidence of unsatisfactory treatment was 33.0% in Group M and 36.9% in Group MK (P = 0.50). No significant differences were found between the groups with respect to secondary end points. CONCLUSIONS: Small-dose ketamine combined with morphine for PCA provides no benefit to patients undergoing major orthopedic surgery and cannot be recommended for routine use.

Efficacy of gatifloxacin alone and in combination with cefepime against penicillin-resistant Streptococcus pneumoniae in a rabbit meningitis model and in vitro

Gatifloxacin penetrated well into cerebrospinal fluid (CSF) (49 +/- 11%), measured by comparison of AUC(CSF)/AUC(serum), and showed good bactericidal activity (leading to a decrease of 0.75 +/- 0.17 log10 cfu/mL/h) in the treatment of experimental meningitis in rabbits caused by a penicillin-resistant pneumococcal strain (MIC 4 mg/L). It was significantly more effective than the standard regimen, ceftriaxone with vancomycin, which led to a decrease of 0.53 +/- 0.17 log10 cfu/mL/h. The addition of cefepime to gatifloxacin slightly improved the killing rates (giving a decrease of 0.84 +/- 0.14 log10 cfu/mL/h). In vitro, synergy was demonstrated between cefepime and gatifloxacin by the chequerboard method (fractional inhibitory concentration index = 0.5) and by viable counts over 8 h.

Meropenem alone and in combination with vancomycin in experimental meningitis caused by a penicillin-resistant pneumococcal strain

In a rabbit model of meningitis caused by a pneumococcus highly resistant to penicillin (MIC, 4 microg/ml), meropenem, a broad-spectrum carbapenem, was bactericidal (-0.48+/-0.14 deltalog10 cfu/ml h) and slightly superior to ceftriaxone (-0.34+/-0.23 deltalog10 cfu/ml x h) and vancomycin (-0.39+/-0.19 deltalog10 cfu/ml x h). Although the combination of vancomycin with ceftriaxone was significantly more active than ceftriaxone alone (-0.55+/-0.19 deltalog10 cfu/ml x h), only an insignificant gain was observed by the addition of vancomycin to meropenem (-0.55+/-0.28 deltalog10 cfu/ml x h).

Evaluation of cefepime alone and in combination with vancomycin against penicillin-resistant pneumococci in the rabbit meningitis model and in vitro

Cefepime, a broad-spectrum, fourth-generation cephalosporin, showed excellent CSF penetration with levels ranging between 10 and 16 mg/L after two intravenous injections (100 mg/kg). The bactericidal activity of cefepime (-0.60 +/- 0.28 Deltalog(10) cfu/mL/h) was superior to that of ceftriaxone (-0.34 +/- 0.23 Deltalog(10) cfu/mL/h, P < 0.05) and vancomycin (-0.39 +/- 0.19 Deltalog(10) cfu/mL/h, P < 0.05) in the treatment of rabbits with meningitis caused by an isolate highly resistant to penicillin (MIC of penicillin G: 4 mg/L). The addition of vancomycin to both cephalosporins did not significantly increase the killing rate compared with monotherapies (P > 0.05). Similar results were obtained in time-killing experiments in vitro.

The long-term effects of whole-tree harvest at final felling on soil properties in a Norway Spruce (Picea Abies (L) Karst.) Stand

Increased demand for forest-derived biomass has resulted in changes in harvest intensities in Finland. Conventional stem-only harvest (CH) has to some extent been replaced with whole-tree harvest (WTH). The latter involves a greater removal of nutrients from the forest ecosystem, as all the above ground biomass is exported from the site. This has raised concerns that WTH could result in large changes in the nutrient dynamics of a forest stand and could eventually lower its site productivity. Little empirical data exists to support this assumption as only a limited number of studies have been conducted on the topic. A majority of these discuss the short-term effects, thus the long-term consequences remain unknown. The objective of this study was to compare differences in soil properties after CH and WTH in a fertile Norway spruce (Picea abies (L) Karst.) stand in Southern Finland. The site was clear-felled in August 2000 and spruce seedlings were planted in the following summer. Soil sampling in the form of systematic randomized sampling was carried out in May 2011. Changes in base saturation, cation exchange capacity, elemental pools (total and exchangeable) and acidity were studied in both organic and mineral horizons. The results indicate that WTH lowered effective cation exchange capacity and base saturation particularly in the humus layer. The pools of exchangeable Al and Fe were increased in the humus layer, whereas the amount of exchangeable Ca decreased in both layers. WTH also resulted in lower Ca/Al-ratios across the sampled layers. Treatment did not have a significant effect on pH, total pools of elements or on the C/N-ratio of the soil. The results suggest that although the stand possesses significant pools of nutrients at present, WTH, if continued, could have long-term effects on site productivity.

Small-scale timber stand management techniques : a case study of woodlots in Isangati, Tanzania

Small-scale village woodlots of less than 0.5ha are the preferred use of land for local farmers with extra land in the village of Isangati, a small community located in the southern highlands of Tanzania. Farmers view woodlots as lucrative investments that do not involve intensive labor or time. The climate is ideal for the types of trees grown and the risks are minimal with no serious threats from insects, fires, thieves, or grazing livestock. It was hypothesized that small-scale village woodlot owners were not maximizing timber outputs with their current timber stand management and harvesting techniques. Personal interviews were conducted over a five month period and field data was collected at each farmer’s woodlots over a seven month period. Woodlot field data included woodlot size, number of trees, tree species, tree height, dbh, age, and spacing. The results indicated that the lack of proper woodlot management techniques results in failure to fully capitalize on the investment of woodlots. While farmers should continue with their current harvesting rotations, some of the reasons for not maximizing tree growth include close spacing (2m x 2m), no tree thinning, extreme pruning (60% of tree), and little to no weeding. Through education and hands-on woodlot management workshops, the farmers could increase their timber output and value of woodlots.

BEYOND ROOTS ALONE: NOVEL METHODOLOGIES FOR ANALYZING COMPLEX SOIL AND MINIRHIZOTRON IMAGERY USING IMAGE PROCESSING AND GIS TOOLS

Quantifying belowground dynamics is critical to our understanding of plant and ecosystem function and belowground carbon cycling, yet currently available tools for complex belowground image analyses are insufficient. We introduce novel techniques combining digital image processing tools and geographic information systems (GIS) analysis to permit semi-automated analysis of complex root and soil dynamics. We illustrate methodologies with imagery from microcosms, minirhizotrons, and a rhizotron, in upland and peatland soils. We provide guidelines for correct image capture, a method that automatically stitches together numerous minirhizotron images into one seamless image, and image analysis using image segmentation and classification in SPRING or change analysis in ArcMap. These methods facilitate spatial and temporal root and soil interaction studies, providing a framework to expand a more comprehensive understanding of belowground dynamics.