7-甲氧基-4′-羟基-3′-二乙胺甲基异黄酮(MHDF)对大鼠血流动力学和主动脉的作用

本实验观察了MHDF对整体大鼠血流动力学和离体大鼠胸主动脉的作用。结果表明iv MHDF(3～12.8 mg/kg)能降低大鼠左心室±dp/dt_max,V_max,V_pm和LVSP,延长T-dp/dt_max,减慢心率。MHDF还能舒张大鼠胸主动脉,ED₅₀为6.5×10^-6mol/L;非竞争拮抗NA和CaCl₂致主脉收缩,pD₂′为3.11±0.21和3.73±0.07;抑制高K⁺致主动脉收缩,IC₅₀为1.76×10^-5mol/L。提示MHDF对血管的作用与α受体阻断剂不同,而可能与钙拮抗有关。     

Hepatic and renal clearances of lidocaine in conscious and anesthetized sheep

Sheep were implanted with cannulae to study blood flow through, and drug extraction by, the lungs, kidneys, liver, and gut. Lidocaine, infused to a steady state in conscious sheep, caused no significant changes in cardiac output or regional blood flow, and was cleared principally by the liver, where the extraction ratio usually exceeded 0.9, and by the kidneys, where the extraction ratio was 0.1-0.2. There was no detectable clearance by lungs or gut. Under general anesthesia with 1.5% halothane, the cardiac output and renal and hepatic blood flows were decreased to means of 77, 44, and 79% of mean control values, respectively, but hepatic and renal extraction ratios of lidocaine were not systematically altered, so that regional clearances of lidocaine were not significantly different from those in conscious animals. There was evidence that the total body clearance of lidocaine exceeded the sum of the directly measured regional clearances in both control and general anesthesia studies. These equivocal findings of the effects of general anesthesia on lidocaine clearance are at variance with unequivocal findings of reduced regional clearances of other drugs tested in this preparation.     

Beckman EL-ISE电解质分析仪准确性及故障的分析判断

0 引言为了克服离子选择电极（ISE）法的微量电位信号极易受环境温度变化及电子噪声的干扰问题,该仪器采用了参考电极,把参考电极与其测定电极装在同一测量室内,保持其相同的物理环境,使干扰源对所有电极的影响相同. 以内参液作为参考电极的测量对象,测得一个参考电极电位值,再测样品的电极电位值,二者相抵就消除了所叠加的干扰信号.     

心脏直视手术围术期自体血回输335例的监护

0　引言　自体输血是采集患者体内血或回收自体失血,再输回同一患者,献血者与受血者为同一个体,既可以节约临床用血,减少患者费用,更重要是可以避免或减少同种输血传播感染性疾病.我科对335例体外循环心内直视手术患者实行自体血回输,收到较好的社会效益和经济效益.1　临床资料　1998-09/1999-02,我科心脏直视手术共445例,围术期采用自体输血335例,其中先心病226例,瓣膜手术59例,复杂心内畸形37例,冠心病、大血管13例,占同期体外循环心内直视手术75%.患者主要适应证:心脏及大血管外科手术,术前一般情况尚好,无肝、肾、呼吸功能障碍;术前检查…     

Sympathomimetic amines

The autonomic nervous system may play an important role in tissue autoregulation as the neurohumoral transmission process has been shown to constitute the final common pathway by which the effects of many physiological and pharmacological substances are mediated. The effects of the administration of a sympathomimetic amine cannot be accurately predicted in a subject. Choice of which sympathomimetic amine to use should be determined on the basis of data obtained in relevant clinical circumstances, but the dose should always be titrated against the effect in each individual. It is interesting that adrenaline, "the original autonomic drug" with its "venerable history", is still a first line drug in many of the situations for which it was being prescribed in 1907. It is the drug of first choice in anaphylactic reactions and for severe allergic bronchospasm, and is widely used as a vasoconstrictor in surgery and with local anaesthetic agents. Adrenaline in "physiological" doses is a satisfactory and cheap alternative to other available drugs for use in septic shock and in emergence from cardiopulmonary bypass.     

Inadequate pre-operative evaluation and preparation: a review of 197 reports from the Australian incident monitoring study

The Australian Incident Monitoring Study database was examined for incidents involving inadequate pre-operative patient preparation and/or evaluation. Of 6271 reports, 727 had appropriate keywords, of which 197 (3.1%) were used for subsequent analysis. All surgical categories were represented. In 10% of reports the patient was not reviewed pre-operatively by an anaesthetist, whilst in 23% the anaesthetist involved in the operating theatre had not performed the pre-operative assessment. Death followed in seven cases, major morbidity in 23 cases, admission to a high-dependency unit or intensive care unit in 17 cases, and surgery was cancelled in nine cases. Poor airway assessment, communication problems and inadequate evaluation were the most common contributing factors. Respondents indicated that the incident was preventable in 57% of cases. Proposed corrective strategies include improved communication, quality assurance activities, development of protocols and additional training. A structured assessment of the airway, along with improvements in information exchange, patient assessment, and use of clearly defined patient management plans and pathways would prevent most of the incidents reported.