胸腹部手术患者靶控输注舒芬太尼复合异丙酚的药效学

目的研究复合靶控输注(TCI)异丙酚致患者意识消失时,胸腹部手术患者对切皮刺激无体动反应所需舒芬太尼效应室靶浓度的EC50和EC95。方法择期胸腹部手术患者50例,ASAⅠ或Ⅱ级,年龄18-57岁,随机分为5组(n=10),舒芬太尼效应室靶浓度分别设定为0．07、0．10、0．14、0．20、0．28 ng／ml。持续监测患者平均动脉压、心率、脉搏血氧饱和度、呼气末二氧化碳分压、心电图。麻醉诱导:起始血浆靶浓度(Cp)为3．0μg／ml,以0．3μg／ml为浓度梯度递增,持续TCI异丙酚致意识消失,并维持该浓度至试验结束,记录此时异丙酚的Cp和效应室靶浓度(Ce)。随后按预设的不同Ce持续TCI舒芬太尼,待效应室和血浆室浓度平衡后,静脉注射琥珀胆碱1．5 mg/kg,行气管插管。观察并记录切皮刺激时的体动反应和心血管反应,计算抑制切皮体动时舒芬太尼Ce的EC50和EC95。结果患者意识消失时各组间异丙酚的血浆和效应室靶浓度及给予琥珀胆碱后插管至切皮的时间比较差异无统计学意义(P>0．05);随着舒芬太尼Ce的增高,每组切皮刺激体动发生率依次降低,对切皮刺激无体动反应的舒芬太尼Ce的EC50为0．12 ng/ml,其95％可信区间为0．09-0．14 ng/ml,EC95为0．20 ng/ml,其95％可信区间为0．17-0．31 ng/ml。结论复合TCI异丙酚[Cp(3．1±0．3)μg/ml]致意识消失时,抑制胸腹部手术患者切皮反应的舒芬太尼Ce的EC50为0．12 ng/ml,EC95为0．20 ng／ml。     

Acute surgery in heart surgery patients under preventive use of anticoagulants

Studies were conducted into indications, courses of operations, and postoperative complications of 17 surgical patients hospitalised or treated in the outpatient department who were on anticoagulant medication because of previous cardiac surgery and required acute re-operations for manifestations of secondary surgical diseases. Particular attention was given to Quick values for an assessment of the present coagulation situations. The point is made that Quick values between 25 and 30 per cent do not yet constitute contraindications to surgical intervention. Reservation is recommended with values below 20 per cent. Therapeutic recommendations are given for treatment of surgical patients with low Quick values.     

The pharmacokinetics of the intravenous formulation of fentanyl citrate administered orally in children undergoing general anesthesia

The bioavailability of oral transmucosal fentanyl citrate (OTFC) in children is similar to that of fentanyl solution administered orally to adults. We hypothesized that administering an oral fentanyl solution to children would result in similar fentanyl plasma concentrations and pharmacokinetic variables as administering comparable doses of OTFC. In this pilot study, 10 healthy children requiring postoperative analgesia were enrolled. Each received the undiluted IV fentanyl formulation orally (approximately 10-15 microg/kg; maximum, 400 microg). Venous blood samples were collected from 15 to 600 min after administration. Pharmacokinetic variables were determined using noncompartmental analysis and were compared with a previously studied population of children who received a similar dose of OTFC. Pharmacokinetic variables for the orally administered IV fentanyl formulation were as follows: time to reach peak concentration = 1.7 +/- 1.6 h, peak concentration = 1.83 +/- 1.19 ng/mL, half-life = 4.7 +/- 2.8 h, area under the plasma concentration time curve = 6.46 +/- 3.96 h . ng(-1) . mL(-1), apparent oral volume of distribution (V/F) = 17.5 +/- 7.2 L/kg, apparent oral clearance (CL/F) = 3.33 +/- 2.25 L . kg(-1) . h(-1). Although both OTFC and orally administered IV fentanyl resulted in similar pharmacokinetic variables and plasma concentrations for a given dose, there was marked interpatient variability, particularly in the early hours after oral administration of the IV formulation of fentanyl. This suggests that this method of administration be used with caution until further data are available.     

Ultrasound bone mass in patients undergoing chronic therapy with oral anticoagulants

The purpose of this study was to assess the effects of chronic oral anticoagulant (OAC) treatment on bone mass using quantitative ultrasound (QUS) techniques. A total of 120 patients (47 women and 73 men) undergoing treatment with OAC and 57 healthy subjects (27 women and 30 men) participated in this study. Bone status was assessed using QUS devices that measure the amplitude-dependent speed of sound (Ad-SoS) in phalanges and the broadband ultrasound attenuation (BUA) in the calcaneus. Men undergoing OAC treatment had lower Ad-SoS, Z-score, T-score, and BUA values (all p < 0.005) and higher levels of undercarboxylated osteocalcin (u-OC) and tartrate-resistant acid phosphatase (TRAP) (both p < 0.0001) than controls. Women receiving OAC treatment had lower BUA values (p < 0.005) and total osteocalcin (OC) levels (p < 0.0001) and higher levels of u-OC and TRAP (both p < 0.0001) than controls. There was a statistically significant negative correlation between u-OC levels and Ad-SoS values in both men (r = −0.432, p = 0.0328) and women (r = −0.332, p = 0.0269) undergoing OAC treatment. In conclusion, patients undergoing OAC treatment had a loss of trabecular and cortical bone mass, possibly due to a decrease in the γ-carboxylation of osteocalcin resulting from the vitamin K antagonism of these drugs.     

Cost-effective screening for urinary tract infections in urogynaecological patients

This study aims to test the cost-effectiveness of reagent-strip urine nitrite compared with microbiological laboratory testing for screening of urinary tract infections (UTI). The study is a retrospective review of 708 female patients who underwent cystometry during a 1-year period. Urine dipstick nitrite was used as a screening test for UTI while urine cultures were taken as an outcome. Symptoms of UTI were noted. Of 708 patients screened, 70 (9.9%) had a significant UTI. Only 32 (4.5%)of 708 patients were nitrite positive. Urine dipstick nitrite has sensitivity of 40%, specificity of 99%, positive predictive value (PPV) of 88 % and negative predictive value (NPV) of 94%. If the screening test included symptoms for UTI together with urine nitrite, the results are: sensitivity 89%, specificity 31%, PPV 12% and NPV 96%. A combination of screening with urine nitrite and UTI symptoms can increase sensitivity to 89%. A total of 29% of specimens (screen negative=nitrite negative/asymptomatic) can then be excluded from UFEME/culture testing, thus resulting in cost savings.     

Magnesium in patients undergoing open-heart surgery

Measurements of serum and urinary magnesium levels were made together with the other electrolytes, haematocrit, pH, and albumin in patients comprising two groups—one group of 50 patients undergoing heart valve replacement, and the other, 30 patients undergoing non-perfusion thoracic operations.     

新型口服抗凝药在围术期的合理应用

背景抗凝是重要的临床问题,目前传统抗凝药正逐渐被新型口服抗凝药（new oral anticoagulants,NOACs）取代。NOACs的优势包括可口服、起效迅速、消除快、抗凝效果具有可预测性、无需常规监测等。目的综述NOACs在围术期应用的最新研究进展。内容概述NOACs的药理学特点及临床应用,探讨其在围术期的合理应用。趋向NOACs应根据患者肾功能和具体手术操作在术前尽量停用适当的时间。     

Epidural anesthesia in patients undergoing thoracic surgery

Epidural anesthesia has been reported to exert beneficial effects in surgical procedures. Over the past 3 years at the Veterans Administration Medical Center in Washington, DC, thoracic surgical procedures have been done using a combined technique of epidural anesthesia with light general anesthesia. A retrospective review of this experience from January 1984 to November 1987 was done in 90 consecutive patients. Postoperative extubation of patients was accomplished immediately in 32%, within 1 hour in 34%, within 3 hours in 28%, within 18 hours in 4%, and was prolonged in only 1% of patients. Mortality was 2% and morbidity was 3%. This analysis indicates that the technique of epidural anesthesia with light general anesthesia provided satisfactory anesthesia with low mortality and morbidity in a high-risk group of patients undergoing surgery.     

C-reactive protein in patients undergoing cardiac surgery

Among 25 patients undergoing cardiac surgery with the aid of cardiopulmonary bypass, 13 who recovered uneventfully all had normal (less than 2 mg/litre) levels of serum C-reactive protein pre-operatively. In contrast, 10 of the 12 patients who suffered from various postoperative complications, including two who died, had abnormally raised levels of C-reactive protein pre-operatively. All patients showed a major acute phase response to surgery with peak C-reactive protein levels at about 46 hours but, whereas the uncomplicated cases showed a characteristic smooth biphasic pattern of declining levels thereafter, the complicated cases all exhibited significant alterations of this pattern. The occurrence during the postoperative period of a secondary rise in C-reactive protein or the failure of the level to continue falling, generally preceded clinical evidence of intercurrent infection. Pre-operative measurement of serum C-reactive protein may thus make a valuable contribution to the assessment of patients requiring elective cardiac surgery; regular postoperative monitoring can provide early warning of serious complications.     

Concurrent drug therapy in patients undergoing surgery

In a retrospective study of 57,176 patients and a prospective study of 216 patients undergoing surgery, 24-32% of patients were receiving some concurrent medication. Between 10 and 16% were taking drugs for cardiovascular disease. Of these, only 71% had their normal medication prescribed before surgery and only 41% received their drugs on the day of surgery.     

Abdominal surgery in patients undergoing chronic hemodialysis

The reports on surgical techniques that specifically focus on the management and outcome of patients on chronic hemodialysis (CHD) who undergo major intra-abdominal procedures--particularly of an emergency nature--are few. It is hoped that by analysis of our experience the nature of the problem can be further clarified and guidelines for clinical care can be formulated. Thirty-two cases which encompass a 7-year period (1978 to 1985), were reviewed. Seventeen patients underwent elective surgery and fifteen underwent emergency intervention. There was a wide range of cases that were similar to those most generally seen in an acute-care teaching hospital. The morbidity and mortality rates in elective surgery patients were 12% and 6%, respectively, while in the emergency cases, these rates were 62% and 47%. Patients with diabetes had the highest morbidity and mortality. These results were analyzed, and we conclude that CHD patients at risk with a surgically correctable condition should be considered for elective intervention, even if they are currently free of symptoms. This may be particularly true for CHD patients with diabetes.