尼卡地平控制性降压对家犬脊髓血流的影响

目的　观察尼卡地平控制性降压对家犬脊髓血流的影响。方法　成年杂种犬 6只 ,体重 12 5～ 16kg ,以 2 5 %硫喷妥钠麻醉。股动脉置管监测MAP。以尼卡地平 8μg·kg 1·min 1持续静脉注射控制性降压。以激光多普勒血流仪测定脊髓血流 (SCBF)。结果　降压前MAP为 (12 5 7±10 6 )mmHg ,降压后为 (72 0± 11 2 )mmHg ,平均下降 4 2 8%。降压前SCBF为 (9 80± 1 0 5 )v ,降压后为 (8 0 4± 0 96 )v ,降低幅度为 18%。结论　尼卡地平控制性降压对SCBF影响较小 ,可安全用于脊髓手术。     

尼卡地平控制性降压对腹腔镜下行直肠癌根治术老年患者术后认知功能的影响

为探讨尼卡地平控制性降压对腹腔镜下行直肠癌根治术的老年患者术后认知功能的影响,将择期腹腔镜下行直肠癌根治术的老年患者80例,随机分为控制性降压组和对照组各40例。控制性降压组于手术开始后静脉输注尼卡地平0．5～6μg／（kg·min）行控制性降压,维持平均动脉压（MAP）较麻醉前降低30％左右（不低于60mmHg）。对照组不行控制性降压。两组于麻醉诱导前（基础状态）及术后24h、48h应用简易智能状态检查法（MMSE）评估认知功能。结果显示,控制性降压组术中MAP较对照组明显降低（P〈0．05）;与基础值比较,术后24h、48h两组MMSE评分差异无统计学意义（P〉0．05）;两组患者均未发生术后认知功能障碍。结果表明,尼卡地平0．5～6μg／（kg·min）行控制性降压,对腹腔镜下行直肠癌根治术老年患者术后认知功能无明显影响。     

常压及控制性降压下脊髓急性牵拉损伤比较研究

目的 评价控制性降压是否增加脊髓对牵拉损伤的易感性。材料与方法健康成年杂种犬6只，随机分为常压和控制性降压脊髓牵拉损伤组。观察常压及控制性降压水平下相同程度牵拉损伤后脊髓血流(SCBF)、体感诱发电位(SEP)、神经源性运动诱发电位(NMEP)改变的差异。结果 外周血有创动脉压(MABP)平均下降幅度为40．5％。经SSPS统计软件独立样本t检验，不同牵拉水平下，常压组及低压组的SCBF(％)、SEP波幅(Asep)(％)及NMEP波幅(％)无显著差异。结论 尼卡地平控制性降压不增加脊髓对牵拉损伤的易感性。     

正颌手术中尼卡地平行控制性降压对术后全身炎症反应综合征的影响

目的 观察尼卡地平用于正颌术中控制性降压对术后全身炎症反应综合征（SIRS）的影响。方法 选取2019年10月-2023年4月于我院拟行正颌手术的199例患者为研究对象，随机分为加深麻醉组（P组） 98例、尼卡地平组（N组）101例。P组采用增加丙泊酚泵注剂量行控制性降压，N组复合泵注尼卡地平行 控制性降压，目标将MAP降至65 mmHg以下，比较两组术后第1天SIRS发生率，术中不同时刻平均动脉压 （MAP）、心率（HR）和麻醉深度患者状态指数（PSI）、术中麻醉用药剂量及拔管时间。结果 N组术后 第1天SIRS发生率为33.66%，低于P组的40.82%，但差异无统计学意义（P ＞0.05）；两组T1~T8时刻MAP 比较，差异无统计学意义（P＞0.05）；N组T2~T7时刻HR高于P组（P ＜0.05）；除T7时刻外，N组T2~T8 时刻适宜麻醉深度例数多于P组，麻醉过深例数少于P组（P ＜0.05）；N组术中丙泊酚使用量小于P组，拔 管时间短于P组（P＜0.05）。结论 尼卡地平用于正颌术中控制性降压效果满意，且有助于维持合适麻醉深 度，缩短拔管时间，但对术后全身炎症反应综合征发生率无明显影响。     

尼卡地平控制性降压对局部脑氧饱和度的影响

目的观察颅内动脉瘤夹闭术中控制性降压对局部脑氧饱和度(rScO2)的影响。方法 15例ASAⅠ级的择期颅内动脉瘤夹闭手术患者,丙泊酚-瑞芬太尼全凭静脉麻醉,暴露动脉瘤期间静脉泵注尼卡地平0.5～1μg·kg-1·min-1,逐渐降低术前基础MAP的10%、20%和30%,夹闭动脉瘤后停止降压,观察降压过程中MAP、HR和rScO2的变化趋势。结果尼卡地平控制性降压过程中,随着MAP的逐渐下降,rScO2略有升高,T5时rScO2恢复至T1水平,各时点MAP、HR、PETCO2、BIS和rScO2差异均无统计学意义。结论颅内动脉瘤夹闭术中应用尼卡地平行控制性降压安全可行,不会影响脑氧供需平衡。     

髋部手术全麻患者硝普钠或尼卡地平控制性降压的安全性

目的评价髋部手术全麻患者硝普钠或尼卡地平控制性降压的安全性。方法择期行髋部手术全麻患者20例,随机分为Ⅰ组(硝普钠组,n=10)和Ⅱ组(尼卡地平组,n=10)。在静吸复合全身麻醉下,分别于手术开始时静脉输注硝普钠(0．5-8 μg·kg-1·min-1)或尼卡地平(1-8μg·kg-1· min-1),使平均动脉压降至55-65 mm Hg,并维持此水平至术毕。用食管超声多普勒血流监测仪监测血液动力学变化,记录降压前即刻(基础值)、降压15 min、30 min、60 min及停降压药后15 min、30 min时主动脉血流量(ABF)、心输出量(CO)、主动脉每搏流量(SVa)、左室射血时间(LVETi)、左室射血峰速度 (PV)、血流加速度(Acc)、主动脉内全身血管阻力(TSVRa);记录术中出血量、输液量、尿量、术后伤口引流量及需异体输血情况;于术前和术后24 h抽取静脉血,测定肝肾功能。结果与基础值比较,两组降压过程中及停降压药后MAP及TSVRa降低,降压过程中HR增快,Ⅰ组降压过程中CVP降低, ABF、CO升高,LVETi延长(P<0．05)。与Ⅱ组比较,Ⅰ组停降压药后30 min时MAP升高,LVETi延长, 降压时间及升压时间缩短,术中出血量和异体输血率降低(P<0．05或O．01)。两种药物对肝、肾功能无明显影响。结论硝普钠及尼卡地平均可安全地用于全身麻醉患者控制性降压,但硝普钠降压的可控性优于尼卡地平,且能更有效地减少术中出血。     

瑞芬太尼复合异氟烷控制性降压对神经外科手术患者肾素-血管紧张素-醛固酮系统的影响

目的观察瑞芬太尼复合异氟烷在神经外科手术中行控制性降压的效果,比较瑞芬太尼和硝普钠对患者肾素-血管紧张素-醛固酮系统（RAAS）的影响。方法择期行控制性降压的手术患者40例,ASA Ⅰ～Ⅱ级,气管插管后,控制呼气末异氟烷浓度为1．2％±0．2％。按降压方法将患者随机分为两组,每组20例,均使平均动脉压（MAP）降低至基础值的60％～70％（目标血压）。Ⅰ组：从1．0μg·kg^-1·min^-1的速度开始给予硝普钠,每隔30s增加0．5μg·kg^-1·min^-1直至血压达到目标血压。Ⅱ组：从（0．15～0．2）μg·kg^-1·min^-1的速度开始给予瑞芬太尼,每隔30s增加0．05μg·kg^-1·min^-1直至达到目标血压。在麻醉前（T0）、控制性降压前（T1）、控制性降压后5min（T2）、控制性降压后30min（T3）及控制性降压结束后20min（T4）记录MAP、HR、CVP,同时测定血中肾素、血管紧张素Ⅱ、醛固酮含量。由术者在不知道控制性降压方式的情况下评估术野质量。结果Ⅰ组T2～4的HR较T0和T1增加;Ⅱ组T2～4的HR较T0和T1减慢,也较Ⅰ组T2-4的HR慢;Ⅰ组T4的MAP、CVP较T1高,也高于Ⅱ组T4的MAP、CVP（P〈0．05或0．01）。Ⅰ组T2～4肾素、血管紧张素Ⅱ、醛固酮含量高于T0和T1,也高于Ⅱ组相应时点三种激素的含量（P〈0．05）。而Ⅱ组三种激素的含量在T0～4未见明显变化（P〉0．05）。Ⅱ组的出血量较Ⅰ组少,6点刻度表和VAS评分均低于Ⅰ组（P〈0．05）。结论与硝普钠相比,瑞芬太尼复合异氟烷控制性降压降压过程平稳,为手术提供更清晰的术野,并在控制性降压期间抑制RAAS。     

尼卡地平控制性降压对颅内压的影响

目的 观察尼卡地平控制性降压对颅内压(ICP)的影响.方法 选择ASA Ⅰ或Ⅱ级神经外科手术患者20例,年龄19～50岁.行腰椎穿刺术直接测得ICP.尼卡地平起始剂量为0.01%～0.02%的溶液静脉滴注,维持SBP在100 mm Hg以下.记录降压前(T0)、降压10 min(T1)、20min(T2)、30 min(T3)和结束降压后10 min(T4)、20 min(T5)的ICP、rSO2、HR、MAP.结果 T1～T3时MAP显著低于T0(P<0.01).T4时MAP明显回升(P<0.05),T5时回到T0水平.降压期间ICP、rSO2、HR无明显改变.结论 尼卡地平降压起效快,降压平稳,对ICP、脑氧饱和度无明显影响.     

尼卡地平控制性降压对SMAS除皱术女性患者术后认知功能的影响

自2006年,笔者对SMAS除皱术女性患者采用尼卡地平控制性降压,以探讨尼卡地平控制性降压对SMAS除皱术女性患者术后认知功能的影响.     

三种诱发电位术中监测脊髓功能的实验研究

目的：观察常用麻醉药物及控制性降血压对猴皮层体感诱发电位（ＣＳＥＰ）、脊髓体感诱发电位（ＳＳＥＰ）和经颅磁刺激运动诱发电位（ＭＥＰ）的影响，评价诱发电位术中监测的作用及影响因素。方法：选用１０只健康猴直接模拟脊柱手术中的麻醉及控制性降压等操作，诱发电位监测。结果：ＣＳＥＰ受多种麻醉药物及控制性降压影响，特别是氯胺酮和异氟醚；ＳＳＥＰ受影响最小。结论：单独使用ＣＳＥＰ监测必须与麻醉密切配合，否则既不稳定又不可靠，ＳＳＥＰ是最佳监测方法     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Immunomodulation in Transplantation with Photopheresis

Abstract: Photopheresis is a technique in which peripheral blood mononuclear cells, in the presence of a photoacti-vatable compound, are exposed extracorporeally to ultraviolet A light and reinfused, inducing a host autoregula-tory immune response. Experimental work and ongoing clinical studies are helping to define the role of this novel, safe, and non-toxic immunomodulating technology in the field of transplantation.