Comparative ventricular electrophysiologic effect of racemic bupivacaine, levobupivacaine, and ropivacaine on the isolated rabbit heart

BACKGROUND: Numerous local anesthetics have an asymmetric tetrahedron carbon, which confers stereoselective differences between the isomers. The authors attempted to quantify the depressant effect of racemic bupivacaine, levobupivacaine, and ropivacaine on myocardial ventricular conduction and on myocardial contractility. METHODS: The authors studied the pharmacokinetics (outflow concentration) and pharmacodynamics (QRS widening) of the three drugs infused in an isolated rabbit heart preparation. All data were fitted simultaneously with use of mixed-effect modeling, thus allowing precise statistical comparison between the three drug parameters. The rate dependence of QRS widening was fitted separately. RESULTS: Racemic bupivacaine, levobupivacaine, and ropivacaine induced a calculated maximum increase in QRS duration in the ratio 1:0.4:0.3. Css50, the dose which caused half the maximum increase in QRS duration at steady state, was similar for all three drugs (22 micrometer free concentration). A rate dependence of QRS widening was observed, which was in the ratio 1:0.5:0.25 for racemic bupivacaine, levobupivacaine, and ropivacaine, respectively. CONCLUSIONS: In the isolated rabbit heart, racemic bupivacaine, levobupivacaine, and ropivacaine induce an increase in QRS duration in the respective ratio of 1:0.4:0.3, which was rate dependent in approximately the same ratio.     

Sedation with sufentanil and midazolam decreases pain in patients undergoing upper limb surgery under multiple nerve block

Multiple nerve blocks may be painful and a source of discomfort. We assessed the efficacy of sufentanil 5 microg combined with midazolam 1 mg in decreasing pain in outpatients after a midhumeral multiple nerve stimulation technique. Visual analog scores for pain were significantly lower in those patients who received sedation before the block, both at the time of block performance (14 +/- 1 vs 27 +/- 2 mm, P < 0.0001) and at discharge (11 +/- 1 vs 24 +/- 2 mm, P < 0. 0001). We conclude that the association of sufentanil and midazolam produced minimal sedation while significantly reducing pain experienced by patients undergoing multiple nerve stimulation.     

Accident vasculaire cérébral ischémique : une complication rare du kyste hydatique du foie

Hydatid cyst of the liver (HCL) is a widespread disease in North African countries. We report the case of a 39-year-old patient who was admitted in our intensive care unit because of anaphylactic shock due to a cracked HCL fortuitously discovered. This accident was also complicated by an ischemic stroke witch underline mechanisms are discussed.     

Unilateral permanent loss of vision after nefopam administration

Acute glaucoma angle closure is a rare complication of anaesthesia and multimodal analgesia. However it is a medical emergency, hence any delay in its treatment may have catastrophic consequences. We present a case of postoperative glaucoma, which had evolved to permanent blindness. We also reviewed the French pharmacovigilance database between 1996 and 2006 and found four other cases of acute glaucoma angle closure in postoperative period possibly related to the administration of nefopam.     

Protective effect of aqueous extract of Allium sativum against zearalenone toxicity mediated by oxidative stress

Zearalenone (ZEN) is a non-steroidal estrogenic mycotoxin produced by several species of Fusarium in cereals and agricultural products. It has been implicated in several mycotoxicosis in farm animals and in humans. Several reports suggest that oxidative damage seems to be a key determinant of ZEN induced toxicity in vitro and in vivo.The aim of the current study was to evaluate the protective effects of aqueous extract of Allium sativum (AEA), against ZEN-induced cytotoxicity, reactive oxygen species (ROS) generation and DNA fragmentation in cultured Vero cells. Indeed, cytotoxicity effects were studied using MTT viability assay, ROS generation measurement and catalase activity induction. To check whether the oxidative stress induction was associated to DNA lesions, we looked for DNA fragmentation using Comet test.Our results indicated that ZEN induced several toxic effects and significant alterations mediated by oxidative stress mechanism. Treatment by ZEN combined to the lowest dose of AEA (250 μg/ml) showed a significant reduction of ZEN induced damages for all tested markers and a noticeable reduction of DNA fragmentation. It could be concluded that A. sativum aqueous extracts is effective in the protection against ZEN hazards. This could be relevant, particularly with the emergent demand for natural products which may counteract the detrimental toxic effects mediated by oxidative stress process and therefore prevents multiple human diseases.     

The in vitro effects of zearalenone and T-2 toxins on Vero cells

The aim of the present study was to investigate in vitro, whether cytolethality and oxidative damage is enhanced by combination of both mycotoxins as compared to their individual effect. In our paper, we applied a tiered in vitro experimental approach in order to predict the possible health risk effects of two interactive fusarial toxins. Considering the concomitant production of zearalenone (ZEN) and T-2 toxin, it is very likely that humans and animals are always exposed to the mixture rather than to individual compounds.Our results clearly showed that cultured renal cells respond to individual (ZEN) or T-2 toxin exposure by a moderate inhibition of cell proliferation, respectively. However, when combined, they exert a more significant decrease in cell viability. Similar results were found for the investigated oxidative status endpoints. When combined, ZEN and T-2 toxin increased ROS production and heat shock protein (Hsp) 70 expression as compared to the effect of each mycotoxin taken alone.We can conclude that the mixture of ZEN and T-2 toxin increased their toxic effects. The health risk is heightened by the interactions between co-occurring mycotoxins.