双功能彩色多普勒超声对静脉性阳萎血流动力学研究

１６例静脉性阳萎在海绵体血管活性药物注射后，采用双功能彩色多普勒超声（ＤＣＤＳ）来监测血流动力学变化，并用３２例功能性阳萎作对照组。背深动脉监测指标：１．舒张期内径（ＡＤ），２．最大收缩期流速（ＰＳＶ），３．舒张末期流速（ＥＤＶ），４．阻力指数（ＲＩ），５．血流加速度（ＡＣＣ）。背深静脉监测指标：１．静脉内径（ＶＤ），２．血液流速（ＶＶ）。研究结果提示静脉性阳萎ＥＤＶ＞Ｏｃｍ／ｓｅｃ，ＲＩ＜１，均Ｐ＜０．０１。背深静脉显示持续性、高流速血液回流。我们认为采用ＤＣＤＳ监测对客观评估静脉性阳萎血流动力学变化和静脉性阳萎的诊断均有一定价值。     

磁共振血管造影对门静脉高压症患者门静脉系统解剖的研究

目的　探讨磁共振血管造影（ Ｍ Ｒ Ａ） 对门静脉高压症（ Ｐ Ｈ Ｔ） 患者门静脉系统的成像价值。 方法　实验组１５ 例 Ｐ Ｈ Ｔ患者,对照组为１０ 例正常人; Ｍ Ｒ Ａ 参数： Ｇｄ Ｄ Ｔ Ｐ Ａ０２ ｍ ｍｏｌ／ｋｇ 肘静脉注射,３ Ｄ Ｆ Ｉ Ｓ Ｐ序列扫描门静脉系统, Ｍ Ｉ Ｐ 法重建血管; Ｐ Ｃ 法测定门静脉流向、流速、流量。 Ｓ Ｔ Ａ Ｔ Ａ 软件对结果进行非配对ｔ 检验。 结果　（１） 门静脉高压症患者门静脉主干（ Ｍ Ｐ Ｖ） 、脾静脉（ Ｓ Ｐ Ｖ） 、肠系膜上静脉（ Ｓ Ｍ Ｖ） 直径、 Ｍ Ｐ Ｖ／ Ａ Ｏ 分别为（１５８ ±０１７） ｃｍ 、（１２８ ±０１７） ｃｍ 、（１１０ ±０１９） ｃｍ 、０９５ ±０１０ ,都明显大于对照组（１１３ ±０１０） ｃｍ 、（０９０ ±０１０） ｃｍ 、（０８０ ±０１９） ｃｍ 、０６６ ±０１０ 。（２） Ｃｈｉｌｄ Ａ、 Ｂ 级患者间 Ｍ Ｐ Ｖ、 Ｍ Ｐ Ｖ／ Ａ Ｏ 分别为（１５３ ±０２１） ｃｍ 、（１６２ ±０１７） ｃｍ 、０９６ ±０１２ 、０９５ ±０２０ ,两组无差别。（３） Ｐ Ｈ Ｔ患者的曲张静脉、侧支循环显影良好。 结论　 Ｍ Ｒ Ａ 对于门静脉高压症患者的门静     

药物性阴茎双功能超声对静脉性勃起功能障碍血流循环阻力的评估

本文自１９９５年５月～１９９６年６月对１６例静脉性勃起功能障碍（ＶＥＤ组）应用药物性阴茎双功能超声检测（ＰＰＤＵ）来观察静脉关闭机制受损所致阴茎血流循环阻力变化。阴茎血流循环阻力监测指标（１）阻力指数（ＲＩ），（２）Ａ／Ｂ比值，（３）搏动指数（ＰＩ）。并以３２例心理性勃起功能障碍（ＰＥＤ组）作对照。研究结果提示ＶＥＤ组ＲＩ＜１，Ａ／Ｂ比值＞０。ＰＥＤ组ＲＩ≥１，Ａ／Ｂ比值≤０。ＶＥＤ组ＰＩ平均数低于ＰＥＤ组，但参数有重叠现象，两组３项阻力指标参数有非常显著性差异（Ｐ＜０．０１）。我们认为静脉关闭机制障碍使海绵体内压下降，并引起阴茎血流循环阻力改变，阻力指标ＲＩ＜１和Ａ／Ｂ比值＞０可作为静脉关闭机制障碍判断标准，而ＰＩ的价值有待进一步探讨。     

双功能彩色多普勒超声对静脉性阳萎血流动力学研究

１６例静脉性阳萎在海绵体血管活性药物注射后，采用双功能彩色多普勒超声（ＤＣＤＳ）来监测血流动力学变化，并用３２例功能性阳萎作对照组，背深动脉监测指标，１．舒张期内径（ＡＤ）２．最大收缩期流速（ＰＳＶ），３舒张末期流速（ＥＤＶ）４．阻力指数（ＲＩ）５．血流加速度（ＡＣＣ）。背深静脉监测指标，１．静脉内径（ＶＤ），２．血液流速（ＶＶ）。研究结果提示静脉阳萎ＥＤＶ〉Ｏｃｍ／ｓｅｃ，ＲＩ〈１，均Ｐ〈０．０     

核素动态肾显像和CDFI监测犬肾移植排斥的评价

目的：通过动物实验，对￣（９９ｍ）Ｔｃ－ＤＴＰＡ动态肾显像和彩色多普勒血流成像（ＣＤＦＩ）在肾移植检查中的应用做一评价。方法：建立犬异体肾移植模型，应用以上两项技术，对１５只犬异体肾移植后进行连续监测。结果与结论：（１）￣（９９ｍ）Ｔｃ－ＤＴＰＡ动态肾显像诊断早期排斥标准：Ｋ／Ａ比值＜３，Ｂ／Ｋ比值＜１，其阳性预测率为１００％，随着排斥加重，Ｋ／Ａ比值进行性降低，肾显像模糊；（２）ＣＤＦＩ诊断急性排斥标准：ＲＩ值＞０．８，其阳性预测率为８２％，严重排斥时，肾内弓形动脉闭塞消失，肾动脉舒张期血流反向。     

药物性阴茎双功能超声对静脉性勃起功能障碍血流循环阻力的评估

本文自１９９５年５月￣１９９６年６月对１６例静脉性勃起功能障碍（ＶＥＤ组）应用药物性阴茎双功能超声检测（ＰＰＤＵ）来观察静脉关闭机制受损所致阴茎血流循环阻力变化。阴茎血流循环阻力监测指标（１）阻力指数（ＲＩ），（２）Ａ／Ｂ比值，（３）搏动指数（ＰＩ）。并以３２例心理性勃起功能障碍（ＰＥＤ组）作对照。研究结果提示ＶＥＤ组ＲＩ〈１，Ａ／Ｂ值〉０。ＰＥＤ组Ｒ１≥１，Ａ／Ｂ比值≤０。ＶＥＤ组ＰＩ平均数低于     

阴茎血流动力学研究（附30例报告）

１９９５年５月～１９９６年１月，３０例功能性阳萎在海绵体血管活性药物注射诱导勃起前后，采用双功能彩色多普勒超声（ＤＣＤＳ）研究阴茎勃起血流动力学变化。背深动脉监测指标：舒张期内径（ＡＤ），最大收缩期流速（ＰＳＶ），舒张末期流速（ＥＤＶ），阻力指数（ＲＩ）。背深静脉监测指标：静脉内径（ＶＤ），血液流速（ＶＶ）。本研究结果提示：（１）ＰＳＶ≥２５ｃｍ／ｓ可作为判断有正常背深动脉功能。（２）ＥＤＶ≤０ｃｍ／ｓ，ＲＩ≥１可认为有完整静脉关闭机制存在。阴茎勃起后，静脉回流血量增加，静脉关闭机制间歇性开放。     

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

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。     

~（99m）Tc－MIBI显像用于诊断门静脉高压症的实验研究

作者通过实验性肝硬变大鼠心、肝对￣（９９ｍ）Ｔｃ－ＭＩＢＩ（￣（９９ｍ）Ｔｃ－甲氧基异腈）的显像考察了其诊断门静脉高压症的价值。经直肠或结肠中静脉注入￣（９９ｍ）Ｔｃ－ＭＩＢＩ后定时行心、肝区γ－摄像，由此求得心／肝比（Ｎ／Ｌ）和分流指数（ＳＩ）。结果显示，肝硬变鼠的Ｈ／Ｌ。明显高于正常鼠；直肠给药时Ｈ／Ｌ与自由门静脉压力（ＦＰＰ）的相关性较结肠中静脉给药时为好，说明经直肠给药是可靠的。经直肠给药的肝硬变鼠的Ｈ／Ｌ与ＦＰＰ呈正相关（γ＝０．８３，Ｐ＜０．０１），由回归方程ＦＰＰ（ｋＰａ）＝０．２４＋４．０６（Ｈ／Ｌ）推算的肝硬变大鼠的门静脉压力与实测的ＦＰＰ有良好的相关性（γ＝０．８５，ｐ＜０．０１），表明该方法可用于肝硬变时门静脉压力的预测。     

腰麻下剖宫产术及血流动力学变化的观察

观察腰麻用于剖宫产术对血流动力学的影响，以探求腰麻用于剖宫产术的安全性。一般资料ＡＳＡＩ或Ⅱ级拟行剖宫产术４０例，年龄２６．４±３．２岁，体重６５．１±８．９ｋｇ，身高１５９±４．６ｃｍ。以ＮＣＣＯＭ３型无创心功能监测仪（美国）观察心排血量（ＣＯ）、每搏量（ＳＶ）、心率（ＨＲ）、射血流速指数（ＥＶＩ）、心室射血时间（ＶＥＴ）、胸腔液体指数（ＴＦＩ），分别于腰麻注药后１、２、５、１０、２０分观察上述指标并与基础值进行统计学比较（ｆ检验）。术中持续监测ＥＣＧ和血压，将收缩压下降＞４ｋＰａ或低于１２ｋ…     

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.