Choice of local anesthetic for epidural anesthesia in physiological labor

In comparative analysis of epidural anesthesia by bupivacaine and ropivacaine the latter was shown to give smaller motor block and so can be applied at the end of both first and second stage of labor. Adequate anesthesia provides uneventful course of the second stage of labor, decreases its duration and eliminates the disorders of central hemodynamics and hormonal homeostasis. Currently naropin seems to be anesthetic of choice for epidural anesthesia of in labor by way of natural maternal passages.     

STA无痛注射仪在口腔局部浸润麻醉中的应用

目的 探讨计算机控制下的口腔无痛注射仪(Single Tooth Anesthesia,STA)在口腔颌面外科局部浸润麻醉中的无痛效果、护理特点以及应用前景.方法 将120例行局部浸润麻醉的拔牙患者随机分为两组,使用STA注射仪注射为实验组,使用传统手动注射器注射为对照组.在注射过程中使用心率监测仪监测两组患者的心率.通过比较两组患者注射后的疼痛视觉模拟评分(VAS)以及注射前、注射中的心率变化来评价注射的疼痛程度.结果 两组患者VAS评分结果 显示88.3%的实验组患者评价注射为无痛或轻微疼痛,而对照组中80%患者评价为中等以上疼痛.实验组患者注射中的心率较注射前显著性下降(P＜0.05),而对照组患者注射前、注射中心率无统计学差异.结论 STA能降低患者的疼痛,减少患者在拔牙术前的紧张感,从而配合医生的操作,使治疗得以顺利进行.

Abstract：

Objective To explorer the effects of the STATM anesthetic delivery system in oral local infiltration anesthesia , nursing characteristics and its application prospect. Methods One hundred and twenty patients undergoing pre-orthodontic extraction were randomly divided into two groups. The STATM was used in experimental group and in the control group the traditional hand injection was performed. After each injection, patients evaluated pain during needle insertion and injection with visual analog scale. The heart rates of the patients were recorded before and during injection. Results Statistical analysis indicated that the STATM group had a lower VAS value than the control group. During injection, the heart rates of the STATM group decreased significantly compare with the control group ( P ＜ 0. 05 )Conclusions The STATM system can reduce the pain during the needle injection and anesthetic delivery, and decrease the tension before dental extraction.     

Automated anesthesia records and anesthetic incidents

A case report is presented in which the cause of an anesthetic mishap would have remained a mystery had it not been for an automated anesthesia record.     

Automated anesthesia records and anesthetic incidents

A case report is presented in which the cause of an anesthetic mishap would have remained a mystery had it not been for an automated anesthesia record.     

Prolonged contraction duration in aged myocardium.

Isometric performance at 29degreesC was measured in left ventricular trabeculae carneae from young adult (6-mo) and aged (25-mo) rats (n equals 18 in each group). Active tension and maximal rate of tension development did not differ with age, but contraction duration was 255plus or minus6 ms in the young adult and 283plus or minus6 ms in the aged group (P less than0.001). Although catecholamine content per gram heart weight was less in the aged myocardium, additional experiments showed that neither 1 times 10-6 M propranolol nor pretreatment with 6-hydroxydopamine eliminated the age difference in contraction duration. To determine if this age difference resulted from a prolonged active state, electromechanical dissociation and the overshoot of contraction duration during recovery from hypoxia were measured. During paired stimulation greater mechanical refractoriness was found in aged muscles (P less than0.01), but intracellular action potential recordings showed no age difference in the electrical refractory period. On recovery from hypoxia, contraction duration overshoot was 117plus or minus 4percent of control in the young and 138plus or minus 4percent of control in the aged muscles (P less than0.01). The greater electromechanical dissociation and greater overshoot in contraction duration following hypoxia in aged myocardium suggests that prolonged contraction duration in aged myocardium results from a prolonged active state rather than changes in passive properties or myocardial catecholamine content.     

Prolonged isoflurane anesthesia in status asthmaticus

We report a case of status asthmaticus that was unresponsive to the usual agents. The use of an inhalational anesthetic agent allowed us to ventilate the patient with lower inspiratory pressures; however, lasting improvement did not occur until she mobilized large quantities of secretions. To our knowledge, this is the first clinical report on the use of isoflurane anesthesia to treat severe asthma. Despite prolonged administration, there were no significant side-effects. This case demonstrates both the benefits and limitations of such therapy.     

Controlled release of a local anesthetic from fatty acid dimer based polyanhydride

Prolonged reversible nerve blockade has broad applications in a number of clinical areas involving acute or chronic pain. The desired periods of reversible nerve blockade could vary from as little as one day to as long as one week. Implantation of a biodegradable controlled release local anesthetic device adjacent to nerves could potentially be a valuable dosage form. Therefore, controlled release devices based on polyanhydride polymers were prepared which would release the local anesthetic bupivacaine hydrochloride with varying rates. The parameters affecting the release of drug were studied in order to optimize the formulation. The studies were conducted with rectangular devices consisting of bupivacaine HCl dispersed homogeneously in the polymer at a loading of 10% w/w. Devices fabricated from three different copolymers, synthesized from fatty acid dimer and sebacic acid, were studied to determine the effect of comonomer on the release kinetics of the drug. Release studies were conducted at pH 7.4, 37°C, and the release profiles were analysed to determine the mechanism of release. The release of bupivacaine HCl could be best described by first order release kinetics from all the three copolymers and the release rate constant, k_r, was directly proportional to the hydrophilicity of the polymer. The first order release rate constants were linearly proportional to both, the erosion rate and drug release rate (r² = 0.999). Release profiles from all the three copolymers could also be described by an equation derived for a surface eroding cylindrical device. The erosion rate, B in cm/day, was obtained by fitting the release profile to the equation using a nonlinear regression method. The results showed that the drug release is controlled by erosion for the three copolymers, P(FAD-SA) 30:70, 20:80, and 10:90 and the release rates were 0.0004, 0.00066 and 0.0012 g/cm²/day, respectively. In addition, release profiles expressed as m_t/m_∞ (fractional agent release profile) versus t/t_∞ fitted the theoretical equation for all the three copolymers. These results suggest that polyanhydrides undergo pure surface erosion at pH 7.4 and therefore the device geometry and erosion rate determine the release kinetics. Thus, knowing the erosion rate of the fatty acid dimer based polyanhydride, would help in achieving the appropriate drug release kinetics by manipulating the geometry of the device.     

Induction of anesthesia with halogen-containing anesthetic agents in children

The study has comparatively evaluated the effectiveness and safety of halothane, enflurane, and isoflurane in children during induction. Seventy hundred and eight patients aged 1-14 years who had ASA I-II anesthetic risks were examined. Gas induction was performed as monoanesthesia through the semi-open circuit with high gas flow (100% O2 6 l/min) in combination with halothane (n = 236), enflurane (n = 236), or isoflurane (n = 236) without N2O. The authors have compared the following criteria: the speed and comfort of induction, the parameters of hemodynamics and external respiration, and the rate of adverse reactions and complications during induction. The studies have established that in terms of comfort, safety, and the rate clinical effect achievement, the drugs of choice for gas induction in children are enflurane and, to a lesser extent, halothane. Gas induction with isoflurane should not be performed in children since the agent rather frequently exerts an irritant action on the upper airways, which reduces the speed of initial narcosis and increases the likelihood of one or another adverse reactions; however; it has advantages as a less hemodynamic effect.     

100 years of local anesthesia

Although the anaesthetizing effect of cocaine had been known for a long time, it was only in 1884 that Karl Koller first carried out animal experiments, followed by clinical testing in humans of the anaesthetic effect of cocaine on the eye. Freud had shortly before directed the attention of Viennese doctors to the alkaloid cocaine in a paper. Upon Freud's suggestion K?nigstein tested the effect of cocaine therapeutically, whilst Koller independently conceived the use of cocaine as a local anaesthetic for eye operations. Jelinek introduced cocaine into laryngology and W?lfler into surgery, as further applications for the use of this local anaesthetic.     

Options for painless local anesthesia

Fear of the needle is a real issue with some patients and may be an obstacle to inducing anesthesia before minor surgical procedures are performed. Adults may express this fear verbally or, out of embarrassment, even avoid coming to the physician's office. Children may become intensely anxious and hysterical. In this article, Dr Holmes describes the use of alternative procedures and agents for reducing the pain of inducing anesthesia and thus reducing patients' anxiety.