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。     

Target-controlled infusion of alfentanil for postoperative analgesia: a feasibility study and pharmacodynamic evaluation in the early postoperative period

We have examined the feasibility of target-controlled infusion of alfentanil (TCIA) and the pharmacodynamics of alfentanil in the early postoperative period. Patients were allocated randomly to one of the three groups to receive balanced anaesthesia with bolus injections of fentanyl (group F), sufentanil (group S) or alfentanil (group A). In the recovery room all patients received the same analgesic regimen, comprising TCIA. To evaluate the efficacy of postoperative analgesia, pain scores were measured on a visual analogue scale (VAS) and patients indicated a need for additional analgesia. EC50, the concentration at which, with a 50% probability, patients reported adequate analgesia, was estimated using logistic regression. Six patients did not complain of pain. The time from the last intraoperative bolus injection of opioid until patients complained of postoperative pain was shorter (P < 0.05) in group A (mean 68 min) than in group F (101 min) and group S (136 min). The time to onset of satisfactory analgesia was comparable in the three groups (median 18 min in group F, 15 min in group S and 14 min in group A). EC50 of alfentanil was determined in 28 patients; mean values were 26 ng ml-1 (group F), 39 ng ml-1 (group S) and 52 ng ml-1 (group A). We conclude that TCIA, under the conditions studied, resulted in a fast onset of adequate analgesia, irrespective of the opioid administered during operation. Also, there was no effect of opioids administered during operation on postoperative pharmacodynamics of alfentanil.      

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…     

Recirculatory and compartmental pharmacokinetic modeling of alfentanil in pigs: the influence of cardiac output

BACKGROUND: Cardiac output (CO) is likely to influence the pharmacokinetics of anesthetic drugs and should be accounted for in pharmacokinetic models. The influence of CO on the pharmacokinetic parameters of alfentanil in pigs was evaluated using compartmental and recirculatory models. METHODS: Twenty-four premedicated pigs were evaluated during halothane (0.6-2%) anesthesia. They were assigned randomly to one of three groups. One group served as control. In the other groups, the baseline CO was decreased or increased by 40% by pharmacologic intervention (propranolol or dobutamine). Boluses of alfentanil (2 mg) and indocyanine green (25 mg) were injected into the right atrium. Blood samples were taken for 150 min from the right atrium and aortic root. Arterial concentration-time curves of indocyanine green and alfentanil were analyzed using compartmental models (two-stage and mixed-effects approach) and a recirculatory model, which can describe lung uptake and early distribution. RESULTS: The CO of individual pigs varied from 1.33 to 6.44 l/min. Three-compartmental modeling showed that CO is a determinant of the central compartment volume (V1, r2 = 0.54), fast peripheral compartment volume (V2, r2 = 0.29), steady state distribution volume (Vss, r2 = 0.29), fast distribution clearance (Cl12, r2 = 0.39), and elimination clearance (Cl10, r2 = 0.51). Recirculatory modeling showed that CO is a determinant of total distribution volume (r2 = 0.48), elimination clearance (r2 = 0.54), and some distribution clearances. The pulmonary distribution volume was independent of CO. CONCLUSIONS: Cardiac output markedly influences the pharmacokinetics of alfentanil in pigs. Therefore, accounting for CO enhances the predictive value of pharmacokinetic models of alfentanil.     

Exercise Doppler echocardiography in patients with pure mitral stenosis

Exercise increases heart rate and cardiac output and is helpful in the determination of dynamic mitral gradient in patients with mitral stenosis. However exercise is difficult to perform during cardiac catheterization in a premedicated recumbent patient and is only feasible when the brachial approach is used. Therefore, in the haemodynamic laboratory, exercise has important practical limitations. In order to obtain similar information using a reproducible and non-invasive technique, we tested the feasibility of combined two-dimensional and continuous wave Doppler echocardiography during exercise in a selected number of patients with pure mitral stenosis and in sinus rhythm. Seven patients, ranging from 14 to 48 years (average: 35 +/- 13), underwent baseline two-dimensional and continuous wave Doppler examinations, repeated after 2 minutes of supine bicycle exercise at a workload of 25, 50, 75 watts. The following parameters were derived and averaged: mean velocity of flow across the mitral valve, mean mitral valve gradient, diastolic filling period and heart rate. The increase in mitral valve flow was from 1.5 +/- 0.3 to 2.2 +/- 0.5 m/s (p less than 0.001); the corresponding increase in mean pressure gradient was from 11 +/- 3 to 21 +/- 8 mmHg (p less than 0.001). The decrease in the diastolic filling period was from 424 +/- 170 to 272 +/- 73 msec (p less than 0.005). The increase in heart rate was from 60 +/- 10 to 100 +/- 18 beats/minute (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Three-dimensional echocardiography of the thoracic aorta

OBLECTIVES: The feasibility and diagnostic potential of three-dimensionalechocardiography, using transoesophageal multiplane echocardiographyfor the assessment of thoracic aortic pathology, has not beenevaluated. METHODS: We studied 21 patients (10 women, 11 men), mean age 52·1years (range 20–78). Images for three dimensional reconstructionwere acquired during a diagnostic multiplane transoesophagealechocardiographic examination. In all, 30 acquisitions wereperformed: 19 of the ascending aorta and 11 of the arch anddescending aorta. Three-dimensional reconstruction was performedto visualize normal aortic segments in three patients with anormal thoracic aorta, postoperative anatomy in seven, chronicaortic dissection in two, non-dissecting aneurysm in seven (threepatients had coexisting thrombi) and protruding aortic atheromain two. RESULTS: Three-dimensional image quality was scored excellent in 17 acquisitions(57%), adequate in 10 (33%) and inadequate in three (l0%). Anyplanetwo-dimensional views of regions of interest of the aorta werereconstructed off-line from the data sets, which provided improvedanalysis with potential for quantitation. Advanced computerassisted imaging modalities (electronic vivisection, lumen castdisplay, detail extraction) were feasible. CONCLUSIONS: We conclude that three-dimensional echocardiography of the thoracicaorta is feasible. Adequate image quality is obtained in thevast majority of patients, which adds additional qualitativeand quantitative information to routine multiplane transoesophagealechocardiographic studies. (Eur Heart J 1996; 17: 1584–1592)