Posterior approach to the lumbar plexus combined with a sciatic nerve block using lidocaine

A combination of lumbar plexus block, by a posterior technique, and sciatic nerve block can be a useful technique for outpatient anaesthesia. The purpose of this study was to examine the clinical characteristics of these blocks using lidocaine and to measure the serum lidocaine concentrations. Forty-five patients, undergoing lower extremity surgery, were studied. Sciatic nerve and lumbar plexus blocks were made with lidocaine, 680 mg with adrenaline 0.3 mg. For each patient the following data were collected: weight, age, sex, site of surgery, time to perform each block, needle depth, speed of onset of the sensory and motor blocks in the territories of the sciatic, femoral, obturator and lateral cutaneous (sensory) nerves and postoperative analgesic requirements. Lidocaine serum concentrations were measured in ten of these patients at 0, 2, 5, 10, 30, 60, 90 and 120 min after the second block. Analgesia was complete in 88% (40/45) of the patients. The remaining five patients needed analgesics (fentanyl 150 μg or less). Despite the high dose of lidocaine, the serum concentrations were within safe limits (mean ± SD) (C_MAX = 3.66 ± 2.21 μg · ml^?1). Only one patient had a serum concentration > 5 μg · ml^?1 (C_MAX = 9.54 μg · ml^?1). This was associated with a contra-lateral extension of the block. We conclude that this combination of blocks is a valuable alternative for unilateral lower extremity anaesthesia. However, clinicians must be aware of the implications of a contra-lateral extension of the block.     

Comparison of transarterial and multiple nerve stimulation techniques for axillary block using a high dose of mepivacaine with adrenaline

BACKGROUND: High-dose transarterial (TA) technique results in high effectiveness of the axillary block. The technique is fast and simple, but does not produce a satisfactory success rate when using the manufacturer's recommended dose of mepivacaine. The multiple nerve stimulation (MNS) technique requires more time and experience. This double-blind study compared effectiveness, safety and the time used to obtain an effective analgesia in 101 patients, having an axillary block by either TA or MNS techniques. METHODS: Mepivacaine with adrenaline (MEPA), 850 mg, was used for the initial block. Five millilitres of 1% solution was injected subcutaneously. In the TA group, 20 mL of 2% solution was injected deep to, and 20 mL superficial to the axillary artery. In the MNS group, four terminal motor nerves were electrolocated in the axilla, and injected with 10 mL each. Analgesia was assessed every 10 min and, when needed, supplemented after 30 min. The block was effective when analgesia was present in all sensory nerve areas distal to the elbow. RESULTS: The MNS group required median 11 min for block performance compared with 8 min for the TA group (P < 0.001). Latency of the initial block was shorter and the frequency of supplemental analgesia lower in the MNS group (median 10 min and 6%) than in the TA group (30 min and 36%, respectively), P < 0.001. All incomplete blocks were successfully supplemented. However, the total time to obtain an effective block was shorter in the MNS group (23 min) than in the TA group (37 min), P < 0.001. Two patients in each group had signs and symptoms of systemic toxicity, the most serious being atrial fibrillation and temporary loss of consciousness in a cardiovascularly medicated patient. The local adverse effects (intravascular injections and haematomas) were fewer in the MNS group, P < 0.001. CONCLUSION: The MNS technique of axillary block by four injections of 10 mL of 2% MEPA produces faster and more extensive block than the TA technique by two injections of 20 mL. Therefore, the MNS technique requires fewer supplementary blocks and results in faster patient readiness for surgery. However, high doses of MEPA may result in dangerous systemic toxic reactions.     

Growth of Escherichia coli in propofol, lidocaine, and mixtures of propofol and lidocaine

BACKGROUND: Microorganisms grow rapidly in propofol. Extrinsic contamination of propofol is thought to be a source of postoperative sepsis and wound infection. We studied growth of a strain of Escherichia coli in thiopental, propofol, lidocaine, and mixtures of propofol and lidocaine. METHODS: The pathogen was exposed to 2.5% thiopental; 1.0% propofol; 1.0%, 2.0% and 4.0% preservative-free lidocaine; and propofol solutions containing 0.25%, 0.5%, 1.0%, 2.0%, or 4.0% lidocaine for 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, and 24 h at room temperature, respectively. The inocula from these suspensions were cultured for 48 h at 37 degrees C after the antimicrobial activity of the local anesthetics in the inocula was inactivated by a 1:1000 dilution with distilled water. RESULTS: No organisms grew after exposure to 2.5% thiopental. The exposure of E. coli to propofol increased the colony count to approximately 90 times the control count. The colony counts of E. coli after exposure to 1.0%, 2.0% and 4.0% lidocaine and 0.25%, 0.5%, 1.0%, 2.0% and 4.0% lidocaine in 1.0% propofol were lower than the counts after exposure to 1.0% propofol (P = 0.0048, 0.0027, 0.0003, 0.0503, 0.0188, 0.0080, 0.0044, and 0.0001, respectively). The growth rate of the microorganism was significantly higher in cultures exposed to 1.0% propofol than that in cultures exposed to lidocaine alone or lidocaine-propofol mixtures (P < 0.0001, respectively). CONCLUSION: Lidocaine possesses bacteriostatic activity against E. coli. Addition of lidocaine to propofol confers its bacteriostatic activity to the mixture and may decrease the hazard of infection associated with the extrinsic contamination of propofol.     

Radiation and Local Control in Early Invasive Breast Cancer

▪ Abstract: Local control in the breast after breast-conserving surgery and radiation for the treatment of early invasive breast carcinoma has long been viewed as important to the patient to avoid later need for mastectomy. Now several studies support the hypothesis that local control is related to and impacts upon a patient's survival as well. The factors that predict for local control with this treatment are reviewed. The recent studies that support the link between local breast failure and distant disease are also discussed. ▪     

Preparation and local anaesthetic activity of benzotriazinone and benzoyltriazole derivatives

Two sets of benzotriazinone and benzoyltriazole derivatives were prepared and tested for local anaesthetic activity in comparison with lidocaine. Several of the prepared compounds exhibited a fairly good activity comparable or superior to that of lidocaine. The presence of a benzotriazinone or a benzoyltriazole moiety as an aromatic system was quite profitable for both the intensity and duration of activity. The acute toxicity in mice of the four most potent compounds of the series was also assessed. Compound 1b, which has an anaesthetic activity comparable to that of lidocaine, was also characterized by a more favourable therapeutic index. All compounds were tested in vitro to evaluate their negative chronotropic action in isolated rat right atria.     

胰原性区域性门脉高压症血流动力学的临床研究

目的：研究胰原性区域性门脉高压症静脉血流动力学改变。方法：利用彩色多普勒及直接测量法测量血流动力学及脾静脉压力。结果：门静脉、肠系膜上静脉的血管直径、平均流速在两组间无差异。实验组脾静脉直径扩张,流速降低且静脉压力明显升高（Ｐ＜０．０５）。结论：胰原疾病可导致区域性门脉高压,正确的治疗方法是行脾脏切除术。     

Local Enhanced Topical Delivery (LETD) of Drugs: Does It Truly Exist?

There is considerable uncertainty over whether and to what extent topically applied drugs can be delivered directly to anatomical sites beneath the skin, without prior entry into the systemic blood circulation. The in vivo studies reported in this work were designed to assess whether local enhanced topical delivery (LETD) can be achieved with piroxicam, a nonsteroidal antiinflammatory drug. Equivalent doses of tritium-labeled drug were administered by the i.v. or topical routes to male rats. The topical plasma profile reveals a maximum concentration (Cp_max) at 12 hr, compared to a typical, multiexponential decline in plasma concentration after i.v. dosing. All four muscles from the topically dosed shoulder exhibit two distinct peaks, the first at 4 hr and a later one at 12 hr (which coincides with the topical Cp_max). The contralateral muscles from the non-dosed shoulder, in contrast, produce only a single peak at 12 hr after topical dosing. After the i.v. administration of piroxicam, the concentration-time profiles for each muscle closely parallel that seen for the i.v. plasma. Tissue-to-plasma ratios (T/P) show that the topical nondosed and the i.v. muscles are nearly constant over the entire time course of this study, indicating a pseudo-equilibrium between the plasma and those muscles. However, the early T/P ratios for the topically dosed muscles are markedly elevated and gradually decline to a constant value only after 12 hr, indicating that a similar pseudo-equilibrium is not established in this case. Thus, these results strongly imply that the topical administration of a drug can lead to LETD for tissues subjacent to the skin. Further, based on the elevated T/P ratios, these local enhanced drug levels cannot be solely attributed to entry from the systemic blood and suggest summarily that the cutaneous microvasculature is simply not an infinite sink for removal of all topically applied drugs.     

Specificity in the Development of Vertical Connections in Cat Striate Cortex

The main efferent axons of pyramidal cells in layer 2/3 in the adult cat striate cortex make collateral connections specifically within layer 2/3 and layer 5 and avoid the intervening layer 4. Intracellular dye injections in vitro were used to determine how, during early postnatal development, this precise pattern of laminar connections was achieved. These investigations revealed that the pattern of collateral outgrowth was specific from the very earliest time that axons began sprouting collaterals. During the first postnatal week, sprouts were seen exclusively within layers 2/3 and 5; no evidence for a transient connection to layer 4 was observed. Furthermore, collaterals emerged simultaneously within layers 2/3 and 5, despite the large difference in the postmigratory ages of the two layers. By the end of the second postnatal week, the adult number of collaterals was achieved. Further elaboration of the local arbors occurred by repeated branching of already existing collaterals, rather than by addition of new collaterals to the main axon. These results demonstrate that the formation of local connections between cortical layers is highly specific, in contrast to the development of clustered horizontal connections by these same cells within layers 2/3 and 5, which involves extensive remodelling of local connections.     

局部药代动力学的药物浓度时空方程初探

目的 建立局部植入给药的药物浓度时空方程。方法 将局部药物浓度时空方程构建为空间分布函数和时间分布函数(药物浓度经时方程)的积函数。并以加权平均及多元分析的数学手段予以证明及推导。结果 四维时空的局部植入给药的药物浓度时空方程的通式为：C(t，X，Y，Z)＝F(X，Y，Z)．C(t)，F(X，Y，Z)＝B0 B1X B2Y B3Z B4r3 B5r2 B6r,C(t)＝A1e^-Ket A2e^-Ket A3c^-Ket.。两维变量的简化的药物浓度时空方程为：C(t,ρ)＝F(ρ)．C(t)F(ρ)＝D0 D1ρ D2ρ2 D3ρ3，C(t)同上。结论 推导基本合理，并在初步的动物试验探索中得以验证。理论有较好科研价值，有助于揭示局部给药的药代动力学规律。     

河豚毒素与局麻药联合应用对家兔齿髓刺激所致疼痛的对抗作用

河豚毒素(tetrodotoxin，TTX)是一种毒性极高的非蛋白神经毒素。具有很强的局麻作用。其效力比目前常用局麻药强万倍以上。持续时间长。将TTX与常用局麻药联合应用于齿髓镇痛。国内外文献尚未报道。我们设想将极微量TTX与常用局麻药利多卡因、丁卡因联合给药，通过齿髓刺激试验，测定其局部镇痛作用，观察是否具有协同或增强局麻效果，以探讨TTX作为协同局麻药应用于临床的可能。