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1.
体外循环术后早期氧动力学变化   总被引:2,自引:0,他引:2  
目的:观察体外循环术后病人早期氧动力学变化。方法:19例病人分别于术前、术毕及术后12、24、48、72和96小时测定全身氧供给(DO2)、氧消耗(VO2)及氧摄取率(ExtO2)等。结果:存活与死亡两组病人术毕始VO2、ExtO2即明显增加,DO2升高不显著。24小时后两组DO2均明显升高,存活组VO2、ExtO2恢复至术前水平,VO2对DO2呈非氧供依赖关系;死亡组则VO2、ExtO2仍显著增加,呈氧供依赖关系,且伴有血乳酸浓度升高。结论:氧供依赖关系的出现反映了组织氧债存在及微循环功能的失调。  相似文献   

2.
急性等容血液稀释对组织氧供氧耗的影响   总被引:9,自引:0,他引:9  
目的:通过观察急性等容血液稀释(ANHD)时组织DO2、VO2的变化,寻找ANHD的生理极限。方法:10只健康成年杂种犬,用戊巴比妥钠、维库溴铵静脉麻醉后行气管内插管,控制呼吸。每只犬进行三个水平即中度(HD1)、深度(HD2)、极深度(HD3)ANHD,然后回输自家血,测定血流动力学指标,动脉及混合静脉血气,动脉血乳酸等,以观察ANHD时DO2、VO2的变化。结果:HD1(HCT=19.43%±1.97%),HD2(HCT=14.73%±0.99%)时,DO2分别降低42%和52%,ERO2分别升高40%和88%,CI升高41%和48%,而VO2只降低4.8%和5.2%,动脉血乳酸末升高。HD3(HCT=9.50%±0.88%)时,DO2降低73%,ERO2升高200%,CI降低,VO2降低35%,动脉血乳酸显著增加。回输自家血后,DO2、VO2及血乳酸均恢复。结论:中、深度HD时,DO2减少,VO2可通过增加ERO2和CI代偿;极深度HD时VO2降低显著,出现无氧代谢,HD达极限。  相似文献   

3.
为了解高原地区感染性休克患组织灌流及氧合情况,我们对西宁地区25例感染性休克患采用了Swan-Ganz导管及热稀释法心排量测定技术,将其整个病程中的氧动力学指标结果进行了回顾性分析。结果发现,全部患氧(DO2)及氧耗(VO2)均有不同程度增加,VO2对DO2出现病理性氧供依赖:成活组患DO2达到0.7L·min^-1·m^-2以上时,VO2的增加趋于缓慢,但未出现明显平台趋势,而死亡组呈持  相似文献   

4.
目的从血流动力学、心肌力学及代谢等方面探讨高张氯化钠右旋糖酐液(7.5%氯化钠+6%右旋糖酐70,HSD)在烧伤休克延迟复苏中的作用。方法采用犬35%TBSAⅢ度烧伤模型,伤后6h分别用乳酸林格液及HSD进行复苏,并以每h尿量为10ml/kg及心输出量为伤前值的70%~80%来调整输液速度及输液量,观察HSD在复苏中容量负荷、左心室等容收缩期最大压力变化速率及左心室舒张期压力下降最大变化速率(±dp/dtmax)、心脏指数(CI)、氧供给(DO2)及氧消耗(VO2)等的变化。结果HSD在烧伤休克延迟复苏伤后第一个24h输液量比乳酸林格液复苏少3056%,其中复苏后4h的输液量比乳酸林格液少5950%,在复苏后05~2h,+dp/dtmax、CI、DO2及VO2的增加幅度明显高于乳酸林格液复苏。结论HSD在烧伤休克延迟复苏中具有容量负荷小、改善心肌功能及促进组织代谢等作用。  相似文献   

5.
静脉注射不同剂量异丙酚对血流动力学及通气功能的影响   总被引:76,自引:0,他引:76  
应用阻抗法和分气流监测法观察静脉注射不同剂量异丙酚(Propofol,PRO)后患者血流动力学(MAP、NR、SLCI、IFI、VET、EVI、SVRI、IC、PFI、LSWI)与通气功能(VT、RR、VE、FEV1%、ETCO2、SPO2、 I-EtO2)的变化。 40例(ASAⅠ~ Ⅱ)随机分成四组,PRO剂量分别为 1.0mg/kg、1.5mg/kg、2.0mg/kg、2.5mg/kg。结果:(1)1~4组呼吸暂停发生率为0%、20%、30%、80%,苏醒时间分别为3 0±1.5、7.4±2.3、9.1±3.6、9.6±4.2分钟:(2)静脉注射不同剂量PRO启SAP、DAP、MAP、SI下降,HR、CI、SVRI无明显变化,心肌收缩性(IC、PFI、EVI)明显减弱,SVRI减少;(3)PRO对呼吸有抑制作用,以VT和VE影响最大,与剂量呈正相关;对面罩吸氧患者SpO2、RR、ETCO2无明显改变,I-EtO2减少;舌后坠者托起下颌对VT、VE的恢复颇为有效。  相似文献   

6.
心脏瓣膜置换术期间的氧代谢变化   总被引:6,自引:2,他引:4  
目的:研究心脏瓣膜手术期间的氧代谢变化情况。方法:采用Fick原理对24例择期瓣膜手术病人作研究。结果:在CPB开始前阶段,DO2及VO2明显减低,O2ext无改变,SvO2略有增高,血液酸碱状态呈代谢性酸血症方向发展。CPB期间DO2及VO2进一步减少,O2ext明显降低,SvO2异常增高,并需间断补充碱性药物纠正代谢性酸血症,5%碳酸氢钠平均输入量为5.8ml·kg-1·h-1。CPB后VO2较麻醉前显著增加达18%~22%。结论:CPB前VO2减低与DO2不足和氧摄取利用受限有关;CPB中VO2减低主要不是DO2不足而是组织对氧的摄取和利用受限所致;CPB停止后VO2增加。消除血液稀释及维持较高心排血量对于保障此阶段的氧耗增高极为重要。  相似文献   

7.
重症心脏瓣膜置换患者围手术期氧耗与氧供关系   总被引:1,自引:0,他引:1  
对17例重症瓣膜患者围术期VO2与DO2关系的研究。结果:CPBI小时VO2与DO2相关良好(r=0.60,P<0.01,n=17);CPB停止后18小时内相关仍存在(r=0.45,P<0.01,n=102),但有个体差异,其中8例呈明显氧供依赖,另9例为非氧供依赖,后者ABL呈两种不同的动态变化。上述提示,CPB期间及停止后18小时内氧供依赖均存在,都有个体差异。非氧供依赖不能排除组织缺氧存在。  相似文献   

8.
山莨菪碱对ARDS的氧输送及血流动力学改变的作用   总被引:3,自引:0,他引:3  
早期、大剂量山莨菪碱治疗外科术后成人呼吸窘迫综合征(ARDS),观察病程第1 ̄4天氧输送与血流动力学等指标。治疗组用山莨菪碱+常规治疗,对照组用常规治疗。结果:第2 ̄4天治疗组Cl、DO2、VO2、O2Ext、PaO2/FiO2分别显著高于对照组(P〈0.05);A-aDO2、PVRI显著低于对照组(P〈0.05)。VO2与DO2呈直线相关(r=0.58,P〈0.05)。治疗组8例死亡1例,对照组  相似文献   

9.
采用蒸汽吸入造成实验犬急性肺损伤,探讨伤后心输出量(CO)、氧供量(DO_2)、氧耗量(VO_2)、氧摄取率(ERO_2)、动脉和混合静脉血氧分压(PaO_2和PvO_2)、动脉和混合静脉血氧饱和度(SaO_2和SvO_2)、肺泡氧分压(P_AO_2)以及肺泡-动脉氧分压差(P_(A-a)O_2)等变化。结果表明,蒸汽吸入4h内,CO、D0_2、PaO_2、PvO_2、SaO_2、SvO_2、PAO_2和pH值均显著下降(P<0.01)、P_(A-a)O_2、ERO_2和PaCO_2均显著升高(P<0.01和0.05),VO_2则无显著变化。提示,蒸汽吸入性损伤后2~4h即可出现组织缺氧,其直接原因是组织灌注和供氧不足。  相似文献   

10.
目的:观察重症瓣膜置换术患者围术期氧供需平衡和氧合状态的变化。方法:监测26例重症瓣膜置换术患者围术期氧供(DO2)、氧耗(VO2、氧摄取率(ERO2)、混合静脉血氧饱和度(SvO2)和动脉血乳酸含量(ABL)的动态变化。结果:麻醉诱导后至CPB前(DO2)、VO2、ERO2均下降,SvO2升高,与麻醉前比较差异显著或非常显著(P<0.05,P<0.01)。停CPB后20小时内DO2、VO2、ERO2持续升高,停CPB8小时内SvO2持续下降,ABL持续升高,与CPB前时值差异显著或非常显著(P<0.05,P<0.01)。结论:停CPB后氧供需平衡障碍、组织缺氧明显存在,且有在一定时间内加重的趋势。  相似文献   

11.
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 (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.  相似文献   

12.
Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.  相似文献   

13.
Don Dame 《Artificial organs》1996,20(5):613-617
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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.  相似文献   

18.
Background: The duration of action of muscle relaxants is poorly correlated to the rate of decay of their plasma concentration. The plasma concentration of mivacurium may rapidly decrease below its active concentration because of the extensive hydrolysis of mivacurium. By inflating a tourniquet on one upper limb for 3 min after the administration of atracurium, mivacurium or vecuronium, we studied the influence of the initial decline of their plasma concentration on their effect. Methods: In 50 patients anaesthetised with thiopental, isoflurane and fentanyl, the effect of bolus doses of 0.15 or 0.25 mg . kg?1 mivacurium (MIV 15, MIV 25), 0.3 or 0.5 mg . kg?1 atracurium (ATR 30, ATR 50) and 0.06 or 0.1 mg . kg?1 vecuronium (VEC 06, VEC 10) were measured on both arms (evoked response of the adductor pollicis to train-of-four stimulation every 12 s), a tourniquet being applied on one arm just before and during 3 min after the muscle relaxant bolus. Results: Tourniquet inflation of 3 min almost abolished the neuromuscular effect of mivacurium. In the vecuronium groups and in the ATR 50 group, tourniquet inflation did not modify the maximum degree of depression of the twitch response. Also, the duration of action of vecuronium was unaffected by the tourniquet. In the ATR 30 group, times to return of the twitch response to 25% (duration 25%) and 75% (duration 75%) of control response were significantly shorter in the cuffed arm, 23 min vs 27 min, and 41 min vs 45 min, respectively. In the ATR 50 group, only duration 25% was significantly shorter in the cuffed arm (41 min vs 45 min). Conclusion: The results suggest that the rate of decline of the plasma concentration of mivacurium is so rapid, that a very low and almost clinically ineffective concentration is present as soon as 3 min after its administration. The results also indicate that the recovery from a mivacurium-induced neuromuscular blockade is not influenced by the rate of decay of its plasma concentration in patients with genotypically normal plasma cholinesterase.  相似文献   

19.
Abstract: Membrane processes play a pivotal and enabling role in modern replacement therapy for acute and chronic organ failure and in the management of immunologic diseases. In fact, virtually all contemporary extracorporeal blood purification methods employ membrane devices, and the next generation of artificial organs and tissue engineering therapies are almost certain to be similarly grounded in membrane technology. In this short essay, we comment on the similarities and differences among synthetic membranes and their natural counterparts and also provide a critical overview of the demographics and technology of hemodialysis, hemofiltration, apheresis, oxygenation, and emerging membrane technologies and applications.  相似文献   

20.
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.  相似文献   

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