丙泊酚闭环靶控输注在腹腔镜子宫切除术镇静中的应用

目的评价脑电双频谱指数(bispectral index,BIS)作为丙泊酚靶控输注的反馈控制变量用于硬膜外麻醉下腹腔镜子宫切除术病人镇静的效果. 方法 60例择期在硬膜外麻醉下行腹腔镜子宫切除术的病人,随机分为两组:反馈靶控输注组(FTCI,n=30)和靶控输注组(TCI,n=30).丙泊酚的血浆靶控浓度均设定为2 mg/L,TCI组整个手术期维持不变,FTCI组BIS作为控制变量设定在70.记录并比较两组BIS值、平均动脉压(MAP)和心率(HR)的最高值和最低值、丙泊酚的单位标准化剂量、定向力恢复时间、术中的遗忘程度和满意度. 结果 FTCI及TCI组BIS最高值分别为76.1±6.4、86.0±8.6,最低值分别为69.0±4.5、60.9±11.8,组间对比有统计学意义(t = -5.058,-3.513;P=0.000);平均动脉压的最高值分别为(90.9±14.2)、(100.4±11.6)mm Hg,最低值分别为(74.2±12.5)、(63.8±13.8) mm Hg,组间对比有统计学意义(t=-2.838,-3.059;P=0.006,0.003);定向力恢复时间分别为(440.8±141.0)s、(576.4±120.5)s,两组也有统计学差异(t=-4.004,P=0.000);FTCI组丙泊酚总剂量明显低于TCI输注组[分别为(510.48±82.75)mg与(620.65±76.79)mg,t =-5.345,P=0.000],单位标准化剂量亦较低[分别为(5.08±1.26)mg和(6.02±0.86)mg,t =-3.375,P=0.001];两组术中的遗忘程度、满意度无统计学意义. 结论 BIS作为丙泊酚镇静的反馈控制变量可行,镇静深度适宜,且丙泊酚用量少,定向力恢复快,术中血流动力学稳定.     

硬膜外麻醉患者异丙酚闭环靶控输注清醒镇静的可行性

硬膜外麻醉中，应用脑电图双频谱指数(BIS)反馈异丙酚闭环靶控系统辅以适度镇静报道较少。本文旨在探讨异丙酚靶控输注(TCI)的反馈控制变量用于硬膜外麻醉患者清醒镇静的可行性，并与异丙酚开环靶控系统相比较，为临床应用提供依据。     

硬膜外阻滞辅以丙泊酚闭环靶控镇静

目的对硬膜外阻滞中以脑电双频指数(BIS)作为反馈的闭环靶控输注丙泊酚镇静的效果和性能进行评价。方法11例ASAⅠ～Ⅱ级择期行下腹部或下肢手术患者，男5例，女6例，年龄28～67岁。硬膜外阻滞期间采用以BIS作为反馈的闭环靶控输注(CLTCI)丙泊酚进行镇静，开始的靶浓度设定为1．5μg／ml，然后每分钟逐步增加或减少0．5μg／ml，直到患者的镇静深度稳定于OAA／S评分3分以下，这时候的BIS值作为反馈变量，通过CLTCI系统自动输注丙泊酚。每5分钟记录血压、心率、BIS和OAA／S评分。记录诱导时间及丙泊酚诱导剂量、丙泊酚总用量、苏醒时间及不良反应，并评价CLTCI系统的性能。结果所有患者镇静期间血液动力学平稳，无严重呼吸抑制。OAA／S评分3分时平均BIS值76．6。CLTCI系统的偏离性1．9％，精确度7．1％，摆动度4．1％。结论在硬膜外麻醉期间以BIS为反馈的闭环靶控输注丙泊酚进行清醒镇静是可行的。该系统性能稳定，有临床推广价值。     

脑电双频谱指数反馈调控异丙酚靶控输注静脉麻醉

目的 评价BIS作为异丙酚靶控输注的反馈控制变量在腹腔镜胆囊切除术麻醉中的可行性。方法 40例行择期腹腔镜手术的病人随机分为两组，反馈靶控输注组和靶控输注组，每组20人。BIS作为反馈控制变量设定在50。诱导前3min一次性静注芬太尼3μg/kg，异丙酚的血浆靶浓度设定为3μg/ml，诱导及维持期间保持不变。记录并比较两组间的实时BIS值、术中收缩压和舒张压的最高值和最低值、附加药物剂量、呼唤睁眼反应恢复和定向力恢复时间、术中知晓情况和异丙酚的单位标准化使用剂量。结果 反馈组的异丙酚总剂量低于靶控组（P＜0．01），单位标准化剂量亦较低（P＜0．01），血液动力学相对稳定，所用升压药少（P＜0．01），停药药呼唤反应恢复时间较短（P＜0．05），但定向力恢复时间两组间无统计学差异（P＞0．05）。术中BIS的最高值、最低值及清醒值、定向力恢复时的数值，两组间无统计学差异（P＞0．05）。芬太尼均可以使反馈输注组BIS值和靶控输注组BIS值显著下降（P＜0．01）。结论 BIS作为异丙酚靶控输注麻醉的反馈控制变量是可行的，具有这种特性的输注系统能够满足腹腔镜胆囊切除手术的麻醉要求，具有异丙酚用药量少、苏醒快、术中血压比较稳定的优点，使得麻醉深度的调控更加精确。由于不同药物对BIS的影响不同，BIS作为麻醉深度监测指标仅对某些药物是特异的。     

异丙酚靶控输注用于硬膜外麻醉病人清醒镇静的可行性

目的探讨异丙酚靶控输注用于硬膜外麻醉病人清醒镇静的可行性及所需靶控血药浓度.方法50例在硬膜外麻醉下行下腹部及下肢手术病人,以血浆室为靶控目标,予以异丙酚TCI清醒镇静.靶控血药浓度最初设定为0.5μg/ml,在与效应室异丙酚浓度达平衡后3min以0.1μg/ml递增,直至OAA/S评分降至3分,并抽取病人各时点静脉血3mi,采用高效液相色谱分析法测定异丙酚血药浓度,确定不同OAA/S评分时对应靶控血药浓度及其与BIS相关性,评估靶控输注系统的性能.结果预期误差的中位数MDPE=-23.1%,预期误差绝对值的中位数MDAPE=27.6%6,清醒镇静深度(OAA/S评分3分)时所需的异丙酚靶控血药浓度为(1.74±0.13)μg/ml.BIS与TCI血药浓度具有良好的相关性(r=-0.80,P＜0.05).结论异丙酚靶控输注用于硬膜外麻醉病人清醒镇静具有可控性良好,病人镇静深度适宜,血液动力学影响小,适用于临床推广.     

反馈靶控输注和自控输注丙泊酚用于硬膜外麻醉病人的镇静

目的 比较反馈靶控输注(TCI)和病人自控镇静(PCS)在硬膜外麻醉下择期手术病人中的应用。方法 选择50例ASAⅠ～Ⅱ级、年龄18～70岁的妇科择期手术病人,随机分成T组(TCI)和P组(PCS),每组25例。硬膜外穿刺成功后,使麻醉平面维持在T6以下,同时连接TCI系统和PCS系统并设置参数。切皮前5min开始系统给药,手术结束前5min停止给药,持续观察脑电双频指数(BIS)、频谱边界频率(SEF)、高频(HF)、低频(LF)的变化,并评定镇静深度(OAA／S评分法)。术毕记录丙泊酚的总用量及按压次数、苏醒时间和手术医师的满意度评分。结果 P组丙泊酚用量明显少于T组(P＜0．01),而各时间点MAP、BIS、SEF、HF、LF、LF／HF、HRV的变化无显著性差异(P＞0．05),两组病人及手术医师的满意度一致(P＞0．05)。结论 PCS和反馈TCI是两种安全有效的镇静方法。     

咪唑安定预先给药对青年和老年病人异丙酚闭环靶控镇静的影响

目的 探讨咪唑安定预先给药对青年和老年病人异丙酚闭环靶控镇静的影响。方法24例青年病人(18-39岁)和24例老年病人(66-79岁),ASAⅠ-Ⅱ级,按照术前给药(安慰剂生理盐水或咪唑安定)不同随机分成4组:青年安慰剂组(YP组)、青年咪唑安定组(YM组)、老年安尉剂组(OP组)、老年咪唑安定组(OM组)。所有病人在硬膜外腔阻滞麻醉下,采用以脑电双频指数(BIS)为反馈的闭环靶控(CLTCI)系统输注异丙酚进行镇静。静脉注射生理盐水或咪唑安定,10min后开始异丙酚CLTCI,开始靶浓度设定为1.5μg/ml,然后每min逐步增加或减少0.5μg/ml,直到患者的镇静深度稳定于警觉镇静评分(OAAM/S)3分以下。此时的BIS作为反馈变量,通过CLTCI系统自动输注异丙酚。连续记录血压、心率、脉搏血氧饱和度、BIS,记录异丙酚的诱导用量及总用量、诱导时间(OAAMS达到3分)、清醒时间(OAA/S达到5分)。结果与YM组、OP组相比,YM组、OM组异丙酚的诱导用量及总用量明显减少(P<0.05),诱导时间明显缩短(P<0.05),而清醒时间延长(P<0.05),其中以OM组更为明显(P<0.05)。OM组低血压和呼吸抑制的发生率明显比其它组高。结论预先注射咪唑安定减少闭环靶控镇静异丙酚的用量,老年病人尤为明显,并增加老年病人异丙酚闭环靶控镇静时低血压、呼吸抑制的发生率。     

丙泊酚靶控输注在外科ICU病人清醒镇静中的应用

目的探讨丙泊酚靶控输注(TCI)应用于外科ICU(SICU)病人清醒镇静的可行性。方法60例SICU病人随机分成四组:C组使用普通微泵连续输注丙泊酚,2 mg.kg-1.h-1;Ⅰ~Ⅲ组均使用Diprifusor TCI系统输注丙泊酚,TCI浓度分别为0.5、1.0、1.5μg/ml。监测不同时点的脑电双频指数(BIS),记录出现的不良反应,并对所有病人进行镇静/警醒评分。结果Ⅰ组各时点的镇静评分、BIS均高于Ⅱ、Ⅲ组和C组(P<0.05);Ⅱ、Ⅲ组低血压、镇静不足、过度镇静的发生率比C组少(P<0.05);Ⅰ组的镇静不足发生率高于Ⅱ、Ⅲ组(P<0.05)。结论丙泊酚TCI应用于SICU病人清醒镇静对呼吸循环影响小,镇静效果理想,操作便利。     

瑞芬太尼靶控输注结合丙泊酚用于结肠镜检查的麻醉

目的研究瑞芬太尼靶控输注结合丙泊酚用于结肠镜检查的麻醉效果。方法 选择结肠镜检查病人68例,随机均分为瑞芬太尼(A)组与芬太尼(B)组。A组,瑞芬太尼以血浆靶浓度1ng/ml给药;B组单次给芬太尼1 μg/kg。1min后所有病人静注负荷量丙泊酚0.5 mg/kg,继以缓慢间断推注每次10mg,至RamsayⅢ～Ⅳ级。记录诱导、插镜、苏醒及留观时间。记录各时点MAP、HR、SpO2、PETCO2、RR及BIS值。记录术中肢动、呼吸暂停次数。记录病人满意度。结果A组病人的诱导、清醒、留观时间均显著少于B组(P<0.01)。丙泊酚用量A组显著少于B组(P<0.01),术中A组的MAP下降低于B组(P<0.01)。术中肢动A组少于B组,呼吸抑制A组大于B组。病人的满意度A组高于B组。结论静脉靶控输注瑞芬太尼结合丙泊酚镇静是门诊手术麻醉的良好选择,但需加强呼吸监护与管理。     

硬膜外麻醉下肾移植术病人异丙酚两种方式镇静的效果

为达镇静、抗焦虑等目的,硬膜外麻醉下行肾移植术常需辅助用药。传统负荷量异丙酚虽有可靠的镇静作用,但易引起气道阻塞、呼吸暂停和血压下降等副作用。本研究拟比较硬膜外麻醉下肾移植术病人异丙酚病人自控镇静术(PCS)和靶控输注(TCI)镇静术的镇静效果。资料和方法拟行肾移植术病人75例,ASAⅢ级,男46例,女29例,年龄34-61岁,体重44-72kg。经充分透析治疗,随机分为3组:对照组、PCS组及TCI组,每组25例,术前不用镇静药。     

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.     

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.     

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.     

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.