液体复苏加山莨菪碱对烧伤兔心肌功能的影响

目的探讨山莨菪碱对烧伤兔心肌功能的影响。方法采用新西兰兔２５％Ⅲ度烫伤模型，分别于伤前，伤后即刻，１，３，５，７小时测定左心室内压峰值、左心室内压最大变化速率，并观察严重烧伤休克期液体复苏加山莨菪碱对上述指标的影响。结果严重烧伤后早期即发生心肌的收缩功能和舒张功能障碍，并呈进行性减退。单纯给予山莨菪碱或单纯输液治疗对兔严重烧伤后的心功能在短期内有支持作用，但治疗效果欠佳，且单纯山莨菪碱治疗组心功能下降早于单纯补液组。而在给予山莨菪碱同时进行液体复苏，可使心肌收缩性和舒张性在伤后７小时维持在同时相点的假烫组同一水平。结论提示在液体复苏的同时应用山莨菪碱可改善心肌功能，并有利于休克的恢复。     

液体复苏加山莨菪碱对烧伤兔心肌功能的影响

目的 探讨山莨菪碱对烧伤兔心肌功能的影响。方法 采用新西兰兔２５％Ⅲ度烫伤模型，分别于伤前，伤后即刻１，３，５，７小时测定左心室内压峰值，左心室内压最大变化速率，并观察严重烧伤休克期液体复苏加山莨菪碱对上述指标的影响。结果 严重烧伤后早期即发生心肌的收缩功能和舒张功能障碍，并呈进行性减退。单纯给予山莨菪碱或单纯输液治疗对兔严重烧伤后的心功能在短期内有支持作用，但治疗效果欠佳，且单纯山莨菪碱治疗组心     

液体复苏加1-6-FDP对严重烧伤家兔心肌功能变化的研究

采用家兔25％Ⅲ度烫伤模型,分别于伤前、伤后即刻、伤后1、3、5、7 h 测定左心室内压峰值、左心室内压最大变化速率及血浆容量(不测伤后即刻值),并观察了液体复苏加1-6-FDP 对严重烧伤休克期家兔 LVSP、LV±dp/dt max 的影响,结果表明严重烧伤后心肌的收缩性和舒张性均立即受到抑制,并呈进行性减退,单纯的液体复苏并不能明显改善心肌的收缩性和舒张性;单用1-6-FDP 治疗可在伤后一定时间内对心功能有支持作用;而在液体复苏同时给予1-6-FDP 可使心肌的收缩性和舒张性得到明显改善,其与烧伤未治疗组和液体复苏组比较差异有非常显著性意义,提示在液体复苏的同时.应用1-6-FDP,可改善心肌功能,有利于休克的复苏。     

液体复苏加1－6－FDP对严重烧伤家兔心肌功能变化的研究

采用家兔２５％Ⅲ度烫伤模型，分别于伤前、伤后即刻、伤后１、３、５、７ｂ测定左心室内压峰值、左心室内压最大变化速率及血浆容量（不测伤后即刻值），并观察了液体复苏加１－６－ＦＤＰ对严重烧伤休克期家兔ＬＶＳＰ、ＬＶ±ｄｐ／ｄｔｍａｘ的影响，结果表明严重烧伤后心肌的收缩性和舒张性均立即受到抑制，并呈进行性减退，单纯的液体复苏并不能明显改善心肌的收缩性和舒张性；单用１－６－ＦＤＰ治疗可在伤后一定时间内对心功能有支持作用；而在液体复苏同时给予１－６－ＦＤＰ可使心肌的收缩性和舒张性得到明显改善，其与烧伤未治疗组和液体复苏组比较差异有非常显著性意义，提示在液体复苏的同时，应用１－６－ＦＤＰ，可改善心肌功能，有利于休克的复苏。     

烧伤休克时心脏对复苏治疗反应的差异

烧伤能损害高龄豚鼠心肌收缩功能。作者应用离体的幼年和老年豚鼠灌流心脏测定了左心室压(LVP)、最高左心室压(+dP/dt max)及最低左心室压(-dP/dtmax)等参数,证明老年豚鼠心脏的LVP、+dP/dt max及-dP/dt max均明显低于对照组。同时证明高龄豚鼠左心收缩功能不全不能被增加心率、细胞外钙浓度和心肌纤维长度以及补液复苏治疗所纠正。作者认为:严重烧伤使高龄鼠原已受损的心脏功能进一步降低,并影响了烧伤休克及液体复苏治疗的效果。     

伤后立即切痂对30%Ⅲ度烧伤大鼠心肌力学的影响

目的研究伤后立即切痂对大鼠心肌力学特别是左心室舒缩功能的影响。方法采用大鼠30％TBSAⅢ度烧伤模型,随机分为烧伤组、烧伤补液组和切痂组。切痂组伤后按 Parkland 公式补液并立即切痂植以正常大鼠皮肤。颈动脉插管至左心室测量心肌力学参数。结果烧伤组心肌力学参数下降非常显著,烧伤补液组各点参数大多降低,但明显高于烧伤组,除左心室舒张末压(LVEDP)外,切痂组心肌力学参数与烧伤补液组相近。伤后24小时烧伤补液组心肌收缩功能显著低于切痂组。结论在有效复苏下,30％Ⅲ度烧伤大鼠伤后立即实施切痂是可行且有益的。     

伤后立即切痂对30% Ⅲ度烧伤大鼠心肌力学的影响

目的研究伤后立即切痂对大鼠心肌力学特别是左心室舒缩功能的影响。方法采用大鼠３０％ＴＢＳＡⅢ度烧伤模型，随机分为烧伤组、烧伤补液组和切痂组。切痂组伤后按Ｐａｒｋｌａｎｄ公式补液并立即切痂植以正常大鼠皮肤。颈动脉插管至左心室测量心肌力学参数。结果烧伤组心肌力学参数下降非常显著，烧伤补液组各点参数大多降低，但明显高于烧伤组，除左心室舒张末压（ＬＶＥＤＰ）外，切痂组心肌力学参数与烧伤补液组相近。伤后２４小时烧伤补液组心肌收缩功能显著低于切痂组。结论在有效复苏下，３０％Ⅲ度烧伤大鼠伤后立即实施切痂是可行且有益的     

口服补液复苏对严重烧伤家兔心肌力学指标的改善作用

目的 了解口服补液复苏对严重烧伤家兔心脏功能的保护作用. 方法 150只家兔随机分为正常对照组(6只)、烧伤组(42只)、立即补液组(42只)、延迟补液组(30只)和延迟快速补液组(30只).正常对照组不致伤不补液.其余4组家兔均造成40%TBSAⅢ度烧伤,烧伤组不补液,余下3组伤后用灌胃的方式进行口服补液复苏.经家兔颈动脉左心室内置管,测量正常对照组及4组致伤家兔伤后2、6、8、12、24、36、48 h的平均动脉压(MAP)、左心室收缩压(LVSP)、左心室舒张末期压(LVEDP)以及左心室压力最大上升/下降速率(LV±dp/dt max),另检测休克期尿量. 结果烧伤组家兔LVSP、LV±dp/dt max较正常对照组显著下降.立即补液组和延迟快速补液组上述指标在伤后24 h内高于烧伤组,其中立即补液组LV+dp/dt max在伤后8 h达峰值[(892±116)kPa/s,1 kPa=7.5 mm Hg],LV-dp/dt max在伤后6 h达峰值[(724±149)kPa/s];伤后8 h,延迟快速补液组LV±dp/dt max均达峰值.延迟补液组伤后各时相点LVSP、LV±dp/dt max与烧伤组接近.各组家兔MAP、伤后第1个24 h尿量的比较情况大致与以上指标相似.烧伤组与其余4组比较,各时相点LVEDP差异无统计学意义(P>0.05). 结论严重烧伤家兔伤后24 h内给予有效的口服补液,可改善心肌力学指标;延迟复苏的家兔按照延迟复苏补液公式预估补液量,才能进行有效复苏.     

冬眠药物对兔烧伤早期血浆皮质酮和儿茶酚胺水平的影响

目的探讨烧伤早期液体复苏同时给予冬眠药物是否能削弱神经内分泌的过度反应。方法用兔15％TBSAⅢ度烫伤模型。冬眠药物组在液体复苏的同时给予冬眠合剂,而对照组仅液体复苏。分别于伤后4,8,24,48和72小时测定血浆皮质酮和儿茶酚胺水平。结果冬眠药物组血浆皮质酮和血浆去甲肾上腺素水平显著低于对照组(P<0.05),而肾上腺素水平差异无显著意义。结论冬眠药物可以削弱烧伤早期的神经内分泌反应对机体的损害。     

严重烧伤早期心肌收缩性与钙转运功能变化

目的研究烧伤早期心肌肌浆网(SR)钙转运功能变化,探讨其在烧伤后心肌收缩功能下降发病中的作用。方法采用30％TBSAⅢ度烧伤大鼠模型,离体心脏灌流,测定伤前及伤后心肌室内压最大变化速率(±dp/dtmax)变化,制备心肌肌浆网,应用微孔滤膜过滤技术测定心肌SR~(45)Ca~(2 )转运功能改变。结果与对照组相比,烧伤组左心室±dp/dtmax明显降低(P<0.01),心肌SRCa~(2 )-ATPase活性及SR~(45)Ca~(2 )摄取初速度、摄取容量均明显降低(P<0.01),偶联率比对照值大幅度下降。结论烧伤后早期心肌肌浆网Ca(2 )转运功能严重障碍,其是烧伤后心肌收缩功能降低的重要因素之一。     

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.     

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.     

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.     

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.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

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.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.