经单鼻孔蝶窦入路显微手术治疗垂体脓肿六例

目的 探讨垂体脓肿的诊断和治疗效果.方法 分析6例经单鼻孔蝶窦入路切除鞍区占位术后垂体脓肿患者的临床资料.均采用经单鼻孔蝶窦入路垂体脓肿切除术,术后有效、足量抗生素治疗4周.结果 6例术前3例正确诊断,误诊3例.术后均恢复良好,随访10～220个月均未见复发.结论 经单鼻孔蝶窦入路显微手术行脓肿切除术及术后应用有效、足量抗生素治疗是改善患者预后的关键.     

经单鼻孔蝶窦入路显微手术治疗垂体脓肿六例

目的 探讨垂体脓肿的诊断和治疗效果.方法 分析6例经单鼻孔蝶窦入路切除鞍区占位术后垂体脓肿患者的临床资料.均采用经单鼻孔蝶窦入路垂体脓肿切除术,术后有效、足量抗生素治疗4周.结果 6例术前3例正确诊断,误诊3例.术后均恢复良好,随访10～220个月均未见复发.结论 经单鼻孔蝶窦入路显微手术行脓肿切除术及术后应用有效、足量抗生素治疗是改善患者预后的关键.     

经单鼻孔蝶窦入路显微手术治疗垂体脓肿六例

目的 探讨垂体脓肿的诊断和治疗效果.方法 分析6例经单鼻孔蝶窦入路切除鞍区占位术后垂体脓肿患者的临床资料.均采用经单鼻孔蝶窦入路垂体脓肿切除术,术后有效、足量抗生素治疗4周.结果 6例术前3例正确诊断,误诊3例.术后均恢复良好,随访10～220个月均未见复发.结论 经单鼻孔蝶窦入路显微手术行脓肿切除术及术后应用有效、足量抗生素治疗是改善患者预后的关键.     

经单鼻孔-蝶窦入路垂体腺瘤显微手术治疗及其策略

目的 总结采用经单鼻孔-蝶窦入路显微手术治疗垂体腺瘤的临床疗效.方法 从2003年1月至2007年12月,经单鼻孔-蝶窦入路显微手术治疗垂体腺瘤241例,并对其临床表现、肿瘤病理、肿瘤切除率、术后并发症进行总结分析.结果 垂体腺瘤241例中,全切除171例(71%),次全切除28例(11.6%),大部分切除26例(10.7%),部分切除16例(6.6%).术后多饮、多尿38例(15.8%)、术后视力一过性下降12例(4.9%)、术后脑脊液漏4例(1.6%)、一侧动眼神经损伤2例(0.8%),无死亡病例.除动眼神经损伤的2例外,其余病例的术后并发症在出院时已治愈.随访1-36个月,所有病例的临床症状均有不同程度改善.结论 经单鼻孔-蝶窦人路显微切除垂体腺瘤手术时间缩短,创伤小,手术效果好.     

单侧鼻孔经蝶微侵袭垂体腺瘤手术治疗

目的总结单侧鼻孔经蝶入路垂体腺瘤切除术的手术经验及体会。方法对115例垂体腺瘤病人采用经单鼻孔蝶窦入路行显微镜下垂体腺瘤切除手术，其中垂体微腺瘤7例，大腺瘤79例，巨大腺瘤29例(其中累及海绵窦者6例，肿瘤卒中2例)。结果100例肿瘤获全切，目前4例复发，其中3例二次手术，10例大部切除，5例部分切除。所有病人术后内分泌症状均有不同程度改善。术后尿崩症15例，经治疗出院时均恢复正常，1例术后单眼视力较术前明显下降，脑脊液鼻漏2例，术后嗅觉丧失2例。结论此入路有手术距离缩短、损伤小、省时、简单、并发症身等优点。     

单鼻孔经蝶显微手术切除垂体瘤的体会

目的探讨单鼻孔经蝶窦入路垂体腺瘤切除术的临床疗效。方法回顾性分析采用经鼻蝶入路显微手术切除的31例垂体腺瘤患者的临床资料,其中微腺瘤10例,大腺瘤15例,巨大腺瘤6例。结果肿瘤全切除22例,大部分切除8例,部分切除1例,手术无死亡病例,术后脑脊液漏3例,垂体功能低下1例,对症处理后均好转出院。结论经单鼻孔蝶窦入路显微手术切除肿瘤彻底、创伤小、并发症较少,是治疗垂体瘤常用的术式。     

经单鼻孔蝶窦入路显微手术切除垂体腺瘤

目的探讨经单鼻孔蝶窦入路显微手术切除垂体腺瘤的手术方法。方法回顾性分析46例垂体腺瘤患者的临床资料,均采用经单鼻孔蝶窦入路显微手术切除肿瘤。术前行高分辨率CT鞍区薄层扫描及MRI检查,充分了解蝶窦的气化程度、蝶窦分隔和鞍底隆突的解剖学特点。结果44例术中依靠蝶窦相关解剖标志,准确定位蝶窦及鞍底,2例出现偏差。肿瘤全切33例,大部分切除9例,部分切除3例,1例因海绵间窦出血终止手术,无手术死亡。术后一过性尿崩症12例,予药物治疗3～7d后好转 脑脊液漏4例,2例保守治疗治愈,1例予腰大池置管引流后治愈,1例再次经蝶入路修补鞍底后治愈。46例平均随访8个月（3个月～2年）,3例复发。结论单鼻孔蝶窦入路显微手术切除垂体腺瘤是一种安全有效的微侵袭手术方法 熟悉相关解剖标志,准确定位是手术成功的关键。     

经单鼻孔蝶窦入路切除垂体腺瘤的并发症及防治

目的探讨经单鼻孔蝶窦入路显微手术切除垂体腺瘤并发症的防治。方法回顾分析2003年9月～2008年8月经单鼻孔蝶窦入路手术治疗垂体腺瘤12例术中、术后出现并发症的临床资料。结果术后发生尿崩症11例,8例在术后1个月内恢复正常,2例在术后半年内恢复正常,1例术后2年存在轻度尿崩症;电解质紊乱9例,出院时均纠正;脑脊液鼻漏1例,内镜下经蝶手术修补后治愈;脑膜炎2例,经内科对症处理治愈;垂体功能低下1例,激素替代治疗后好转;鼻中隔穿孔2例,未经特殊处理;鞍内形成小血肿1例,2周后CT复查血肿自行吸收消失。12例随访4～60个月,(32±7)月,1例术后2年仍存在轻度尿崩症,1例术后3年存在垂体功能低下,其余10例均正常。结论扎实的解剖知识、娴熟的显微操作、严密的术后观察、积极防治并发症是治疗成功的重要条件。     

单鼻孔-经蝶窦入路切除垂体腺瘤70例报告

目的探讨显微神经外科技术经单鼻孔-鼻中隔根部-经蝶窦入路切除垂体腺瘤手术入路的临床效果. 方法显微镜下长鼻镜辅助观察、扩张中鼻道,扩张器置入直达蝶窦前壁、骨性鼻中隔根部,将鼻中隔自根部折断连同对侧鼻黏膜一起推向对侧,余步骤同传统经蝶手术. 结果全组70例中,62例近全切除(>95%),6例大部切除(76%～95%),2例仅为部分切除(≤75%).无手术死亡.术后24例一过性尿崩,均于3周内自愈;8例脑脊液鼻漏,5例卧床2周自愈,3例行腰大池引流治愈.48例随访3个月～2年,平均7个月,2例复发. 结论单鼻孔-鼻中隔根部-经蝶窦入路切除垂体腺瘤疗效满意,对手术通道即鼻部组织损伤小,不必分离鼻中隔及两侧黏膜,手术技术容易掌握,省时间,并发症少.     

经单鼻孔蝶窦人路切除垂体腺瘤的并发症及防治

目的分析经单鼻孔蝶窦入路显微手术切除垂体腺瘤并发症与防治。方法对14例经单鼻孔蝶窦入路切除垂体腺瘤手术并发症的临床资料进行回顾分析。结果术后发生尿崩症12例,10例在术后1个月内恢复正常,2例在术后半年内恢复正常;电解质紊乱5例,出院时均纠正;脊液漏4例,1例在内镜下经蝶手术修补后治愈;脑膜炎2例,经内科对症处理治愈;垂体功能低下2例,激素替代治疗后好转;鼻中隔穿孔2例,未经特殊处理。结论熟悉手术局部解剖、把握手术适应证、熟练掌握手术技能、严密的术后观察、积极防治并发症是治疗成功的重要条件。     

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 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.     

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.     

Is the recovery profile of mivacurium independent of the rate of decay of its plasma concentration in patients with normal plasma cholinesterase activity?

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.     

Membranes in Artificial Organs

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.     

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.