Supreme喉罩和气管插管全麻在老年患者腹腔镜胆囊切除手术中的比较

目的：比较Supreme喉罩与气管插管全麻对腹腔镜胆囊切除手术老年患者的血流动力学和气道通气的临床影响。方法择期行老年患者腹腔镜胆囊切除手术126例,年龄61～79岁,随机均分为S组（Supreme喉罩）和T组（气管内插管组）。观察记录术中误吸反流、拔除气管导管／喉罩时引起的呛咳、拔管后低氧血症以及咽痛的情况。结果与T组相比较,S组喉罩一次性置入的成功率较高（P〈0.05）、置入时间显著缩短（P〈0.01）;S组T2、T3-1、T3-2、T4时SBP、DBP、MAP与HR显著低于T组（P〈0.05）,拔除喉罩后咽部痛及低氧血症发生率均较低（P〈0.01）,且无呛咳病例。两组术中SpO2、PETCO2及Ppeak等值均在正常范围内,无误吸情况发生。结论 Supreme喉罩操作简单且便利,置入／拔除时对血流动力学均无显著影响,无呛咳反应,术后不良反应减少,用于腹腔镜胆囊切除术高龄患者麻醉优于气管插管。     

腹腔镜下前列腺癌根治术中呼气末CO2分压的变化及意义

目的观察腹腔镜前列腺癌根治术中动脉血CO2分压（PaCO2）与呼气末CO2分压（PetCO2）差值Pa-ETCO2变化及其临床意义。方法腹腔镜前列腺癌根治术患者28例，于气管插管全身麻醉下完成手术，术中PETCO2维持在30～35mmHg左右，分别在麻醉后（T0），气腹第30min（T1），60min（T2），120min（T3），180min（T4）取桡动脉血行血气分析测PaCO2，据监测的PETCO2及血气分析获得的PaCO2，计算每个时间点的Pa-ETCO2。结果气腹后各时间点PaCO2，MBP，PPEAK，Pa-ETCO2明显增高（P〈0．05），人工气腹60min后，Pa-ETCO2发生显著变化（P〈0．01），部分患者出现CO2蓄积。气腹后PH值明显下降（P〈0．01）。结论腹腔镜前列腺癌根治术中人工气腹60min后PETCO2不能真实反映PaCO2，当PETCO2维持在30-35mmHg时应监测PaCO2避免发生高碳酸血症。     

腹腔镜结直肠癌手术的麻醉管理

目的总结腹腔镜结直肠癌手术麻醉管理的经验。方法回顾性分析2007年10月~2009年6月178例腹腔镜下结直肠癌手术的麻醉资料,其中结肠癌根治手术76例,直肠癌根治手术102例,98例(55.1%)合并一种以上的全身性疾病。均采用气管内插管全身麻醉,术中监测无创血压(blood pressure,BP)、心率(heart rate,HR)、脉搏血氧饱和度(saturation of pulse oxygen,SpO2)、呼气末CO2分压(end-tidal carbon dioxide pressure,PETCO2)。结果气腹后10min平均动脉压(mean arterial pressure,MAP)、HR、PETCO2较气腹前显著性升高,经处理,气腹后30min MAP、HR明显降低,PETCO2无明显升高。术中130例(73.0%)使用一种以上的血管活性药,61例(34.3%)使用2种以上的血管活性药。132例在手术间或麻醉恢复室拔除气管导管,停止麻醉至拔除气管导管时间(39±25)min(6~140min),恢复室停留时间(71±36)min(25~209min)。46例(25.8%)带气管导管送入ICU病房。结论术前全面评估病人,完善围术期监测,加强术中管理,及时纠正处理合并症,腹腔镜结直肠癌手术患者的麻醉是安全的。     

妇科腹腔镜手术采用食管引流型喉罩与气管插管全身麻醉对呼吸循环系统影响的比较

目的比较妇科腹腔镜手术采用食管引流型喉罩与气管插管全身麻醉对呼吸循环系统的影响。方法拟在腹腔镜下行全子宫切除或次全子宫切除手术60例,采用随机数字表随机分入喉罩组和气管插管组。记录气腹前后的循环变化、通气指标及插管（罩）期、拔管（罩）期的呼吸循环变化和术后不良反应情况。结果气管插管组在插管后1 min、拔管前SBP明显高于喉罩组,差异有显著性意义（t=-12.415,P=0.000;t=-5.447,P=0.000）。气管插管组在插管后1 min、拔管前、拔管后3 min DBP明显高于喉罩组,差异有显著性意义（t=-6.393,P=0.000;t=-9.579,P=0.000;t=-4.790,P=0.000）。气管插管组在插管后1 min、气腹前、拔管前、拔管后3 min HR明显高于喉罩组,差异有显著性意义（t=-5.789,P=0.000;t=-2.566,P=0.013;t=-11.828,P=0.000;t=-4.558,P=0.000）。2组PETCO2在气腹期、拔管前的变化差异无显著性意义（P〈0.05）。气管插管组在苏醒期19例发生呛咳、躁动,喉罩组无呛咳、躁动发生,2组比较差异有显著性意义（χ^2=27.805,P=0.000）;喉罩组引流的胃液量明显多于气管插管组,2组比较差异有显著性意义（t=10.850,P=0.000）。气管插管组术后11例轻度咽痛,喉罩组3例轻度咽痛,差异有统计学意义（χ^2=18.373,P=0.000）。结论静脉全身麻醉下应用食管引流型喉罩行妇科腹腔镜手术可以达到与气管插管相同的通气效果,麻醉过程平稳,术后不良反应少。     

腹腔镜治疗食管裂孔疝的麻醉

目的探讨腹腔镜行食管裂孔疝修补术对全身麻醉患者血流动力学、呼吸及动脉血气的影响。方法选择了62例（ASAI—II）食管裂孔疝患者使用腹腔镜行食管裂孔疝修补术,监测气腹前,气腹后30min血压（BP）、心率（HR）、心电图（ECG）、脉搏、氧饱和度（SPO2）及动脉血气、气道压力的变化。结果62例腹腔镜食管裂孔疝修补术全部获得成功。气腹前、后患者的血流动力学变化不明显（P〉0．05）,气道压力,动脉血气发生显著改变,出现高碳酸血症（P〈0．05）。结论腹腔镜行食管裂孔疝修补术CO2气腹对全身麻醉患者呼吸及血气产生一定的影响,术中应加强麻醉的管理及监测。     

长寿老年患者腹腔镜胆囊切除术的麻醉体会

目的:总结90岁以上患者腹腔镜胆囊切除术(LC)的麻醉经验。方法:对我院48例90岁以上患者行腹腔镜胆囊切除手术,麻醉诱导气管插管后采用静吸复合麻醉维持。结果:48例气腹后血压均升高,气腹后21例发生高CO2血症,25例出现不同程度的高血压。结论:90岁以上患者行LC手术中应维持适宜的麻醉深度,控制输液速度和输液量,术后充分止痛,监测各项生命体征,及时发现并处理高血压及并发症。     

改进型穿刺针在腹腔镜手术切口缝合中的应用

病例资料2011年1月至2012年12月期间我院腹腔镜手术术中使用改进型硬膜外麻醉穿刺针（简称改进型穿刺针）缝合切口285例,其中男87例,女198例;年龄23～72岁,平均年龄45岁。其中腹腔镜胆囊切除术246例,腹腔镜阑尾切除术20例,腹腔探查术12例,肝囊肿开窗引流术7例。采用气管插管全身麻醉,建立CO2气腹,气腹压力10～13mmHg（1mmHg=0.133kPa）。     

泌尿外科腹腔镜术后并发高碳酸血症的原因分析

目的 探讨泌尿外科腹腔镜手术后并发高碳酸血症的原因及防治策略。方法 回顾性研究腹腔镜手术治疗泌尿外科疾病168例，其中经血气分析诊断并发高碳酸血症9例。从年龄、体重指数、美国麻醉医师协会评分标准（ASA）分级、手术类型、手术入路、腹腔镜手术气腹时间、气腹压、出血量、有无中转等方面评价。结果 9例患者手术经后腹腔人路8例、经腹腔1例。〉58岁7例，〈50岁2例。体重指数〉10％～25％8例，标准体重指数1例。ASA分级Ⅰ级2例，Ⅱ～Ⅲ级7例（合并糖尿病、心功能不全4例，合并慢性支气管炎2例，合并轻度肝功能损害1例）。手术气腹时间〉180min6例，110、180min、〈100min各1例。气腹压力〉15mmHg7例，〈15mmHg2例。手术类型，肾切除1例，肾输尿管全长切除术1例，肾上腺或肾上腺腺瘤切除6例（嗜铬细胞瘤3例，增生1例，腺瘤1例，库兴综合征1例）、乳糜尿1例。出血量〉500ml5例、300～500ml2例、50、200ml各1例。手术中转3例。结论 过于肥胖，高龄，有心血管疾病、糖尿病、呼吸系统疾病或肝功能损害等合并症，经后腹腔入路，手术气腹时间〉180min，气腹压力〉15mmHg，出血量〉300ml等因素与术后并发高碳酸血症有关，是否中转与并发高碳酸血症可能无关。     

腹腔镜胆囊切除术对患者血气及血液流变学影响的临床研究

目的　探讨气管插管全身麻醉下腹腔镜胆囊切除术 (LC)时CO2 气腹对患者血气变化和血液流变学的影响 ,观察LC的适应性及安全性。方法　选择的 3 5例均为因胆囊炎而行择期LC手术的患者 ,无呼吸系统及循环系统疾病 ,全部采用气管插管全身麻醉。分别于麻醉后气腹前及手术结束前抽取足背动脉血进行血气分析 ;于术前 2 4h及手术结束前 ,抽取颈内静脉血进行血液流变学检查。结果　气腹前后 pH、PaO2 、T CO2 、AB值均有明显改变 ,P <0 .0 5 ;而全血粘度、血浆粘度、红细胞压积均有明显下降 ,P <0 .0 5。结论　LC手术中CO2 气腹对患者血气变化及血液流变学有一定的影响。其中 ,pH、PaCO2 、T CO2 、AB值的变化在正常范围之内 ,而血液流变学各项指标均有所下降。表明在气管插管全身麻醉下行胆囊切除术是安全可靠的 ,不会引起高碳酸血症及高粘滞血症     

腹腔镜下子宫颈癌根治术的麻醉处理

目的探讨腹腔镜下子宫颈癌根治术的麻醉处理方法。方法 2007年3月~2009年12月21例腹腔镜子宫颈癌根治术采用气管插管静吸复合全身麻醉,术中监测有创血压（BP）、心电图（ECG）、经皮脉搏血氧饱和度（SpO2）、体温、呼气末二氧化碳分压（PETCO2）,检测血气、电解质和血糖（Glu）。右颈内静脉穿刺开放输液通路和监测中心静脉压（CVP）。机械控制通气,潮气量（VT）8~10 ml/kg,根据血气分析和PETCO2调整呼吸次数。术中维持血流动力学稳定,必要时应用血管活性药。术毕清醒拔除气管导管后返病房,术后行静脉自控镇痛。分别记录气腹前,气腹后1、2、3、4 h和放气后15 min的HR、MAP、CVP、气道压（Paw）、血气、电解质和测鼻咽体温。术后24 h及48 h采用视觉模拟评分法（visual analogue scale,VAS）行镇痛评分。结果均在腹腔镜下顺利完成子宫颈癌根治术。HR在气腹后3 h和放气后15 min较气腹前增快（P〈0.05）。MAP气腹前后无明显变化（P〉0.05）。术中1例应用阿托品,1例应用麻黄碱,2例应用艾司洛尔,1例应用乌拉地尔。CVP和Paw在气腹中各时间点均较气腹前升高（P〈0.01）,PETCO2、PaCO2气腹后3 h较气腹前升高（P〈0.05）。Hb在气腹后3 h、放气后15 min降低（P〈0.01）。Glu于气腹后3 h、4 h及放气后15 min高于气腹前（P〈0.05）,1例术中血糖超10 mmol/L,给予胰岛素治疗。体温在气腹后4 h和放气后15 min低于气腹前（P〈0.05）。气腹后4 h时2例血K＋分别高达5.0、5.4 mmol/L,行控制PaCO2和呋塞米利尿处理。术后24 h和48 h的VAS评分分别为2.4±0.7和2.8±0.9。结论腹腔镜子宫颈癌根治术,围术期须加强监测;加强呼吸系统管理,及时调整呼吸参数,避免高碳酸血症;维持血流动力学、血气、电解质和血糖的稳定,避免低体温;虽然是微创手术,但术后仍需加强术后镇痛,增加患者舒适度,促进恢复。     

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.     

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.     

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.     

Dilemma of Membrane Biocompatibility and Reuse

Abstract: Numerous articles have been published on the multiple use of dialyzers and on the effect of different reprocessing chemicals and techniques on the dialyzer biocompatibility and performance. The results often appear contradictory, especially those comparing standard biocompatibility parameters. Despite this confusion, a discerning review of the published works allows certain limited conclusions to be drawn. Reprocessing of used hemodialyzers changes the biocompatibility profile of a dialyzer as defined by the parameters complement activation. leukopenia, and cytokine release. The effect of reprocessing depends on the chemicals and reprocessing technique applied and also on the type of membrane polymer being subjected to the reprocessing procedure. Reports of pyrogenic reactions indicate that the flux of the membrane also influences how suitable it is for safe reuse. An increased risk of allergic and pyrogenic reactions appears to be associated with dialyzer reuse. Furthermore, there has been a lack of investigations into the immunologic effect of the layer of adsorbed and chemically altered proteins that remains on the inner surface of reprocessed dialyzers. We conclude that the clinical benefit of dialyzer reuse cannot be generally accepted from a biocompatibility point of view.     

The analgesic effect of racemic ketamine in patients with chronic ischemic pain due to lower extremity arteriosclerosis obliterans

Background : Ketamine in sub-dissociative doses has been shown to have analgesic and phantom-Limb pain, where conventional treatment has often failed. Chronic ischemic pain due to lower extremity arteriosclerosis obliterans often responds poorly to analgesics, and the pain-generating mechanisms are not well understood.
Methods : Eight patients with rest pain in the lower extremity due to arteriosclerosis obliterans were given sub-dissociative doses of 0.15, 0.30, or 0.45 mg/kg racemic ketamine and morphine 10 mg as a 5-min infusion on four separate days in a cross-over, double-blind, randomised protocol. Plasma levels of (S)- and (R)-ketamine and their nor-metabolites were analysed with an enantioselective high-performance liquid chromatography (HPLC) method. Pain levels were evaluated with a visual analogue scale (VAS).
Results : Individual pain levels were highly variable during and after all the infusions but the pooled pain levels showed a dose-dependent analgesic effect of ketamine with a transient but complete pain relief in all patients at the highest dose (0.45 mg/ kg). Side-effects, mainly disturbed cognition and perception, were pronounced and dose-dependent. Morphine 10 mg had an analgesic peak at 20 min and 5/8 patients had complete pain relief. The remaining 3 patients also had high baseline pain scores, indicating a higher analgesic potency for the 0.30 and 0.45 mg/ kg ketamine doses than for morphine 10 mg.
Conclusion : We have demonstrated a potent dose-dependent analgesic effect of racemic ketamine in clinical ischemic pain. Due to a narrow therapeutic window, this analgesic effect is probably best utilised in combination with other analgesics.