关节面方向和终板倾斜角度对退变性腰椎滑脱的影响

目的：探讨退变性L4-5滑脱的生物力学机制。方法：测量L4-5关节面与椎体冠状面角度和L5终板倾斜的角度，并与同年龄组没有退变性腰椎滑脱的腰痛患者作对照。对有退变性滑脱病人的L4-5关节面与椎体冠状面角度和L5终板倾斜的角度与椎间隙的高度，腰椎的生理曲度进行相关性分析。结果：有L4-5退变性腰椎滑脱的患者L4关节面较对照组更偏向于矢状位，L5终板倾斜度的增大，L4-5关节面的角度变大与椎间盘高度的降低及L5终板倾斜角度增大与腰椎曲度的减小有相关。结论：在有L4-5退变性滑脱的病人中，L4-5关节面的方向更接近矢状位，L5椎体终板的倾斜度更大。     

腰椎退变性滑脱与终板Modic改变的相关性研究

目的 :观察腰椎退变性滑脱患者腰椎终板的Modic改变情况,分析退变性滑脱与终板Modic改变之间的关系。方法:回顾性分析108例腰椎退变性滑脱症患者的MRI资料,观察腰椎滑脱节段与非滑脱节段终板Modic改变各型的发生率及分布情况,分析终板Modic改变与腰椎滑脱的相关性。结果:108例腰椎退变性滑脱患者共540个椎体中,Ⅰ度滑脱149个,Ⅱ度滑脱17个;L1椎体滑脱10个,L2椎体26个,L3椎体41个,L4椎体46个,L5椎体43个。108例腰椎退变性滑脱患者共计1080个腰椎终板,351个终板存在Modic改变,其中ModicⅠ型172个(15.93%),Ⅱ型144个(13.33%),Ⅲ型3个(0.28%),混合型32个(2.96%);L1/2节段34个(3.15%),L2/3节段61个(5.65%),L3/4节段65个(6.02%),L4/5节段77个(7.13%),L5/S1节段114个(10.56%)。腰椎滑脱节段终板的Modic改变发生率为75.30%,非滑脱节段终板的Modic改变发生率为13.50%,差异有统计学意义(P0.05)。Spearman相关检验表明Modic改变和腰椎滑脱程度呈正相关(r=0.613,P0.05)。结论 :腰椎退变性滑脱患者滑脱节段终板的Modic改变多见,各型中以Ⅰ型多发,Modic改变的发生与滑脱程度呈正相关。     

脊柱骨盆矢状位参数预测退变性腰椎滑脱发生及发展的危险因素

目的探讨脊柱骨盆矢状位参数预测退变性腰椎滑脱发生及发展的危险因素。方法退变性腰椎滑脱及退变性腰椎管狭窄症病人71例,其中退变性腰椎滑脱病人36例,退变性腰椎管狭窄症病人35例。在站立位全脊柱侧位片上测量骨盆投射角(PI)、骶骨倾斜角(SS)、骨盆倾斜度(PT)、腰椎前凸角(LL)、胸椎后凸角(TK)、腰椎骨盆前凸角(PR-LI,PR-L2,PR-L3,PR-L4,PR-L5)、骨盆形态(PR-S1)、腰4椎体倾斜角(L4S)、腰5椎体倾斜角(L5S)。所测退变性腰椎滑脱病例脊柱骨盆参数分别与退变性腰椎管狭窄症及正常国人脊柱骨盆参数进行比较,采用两独立样本t检验比较两组参数间的差异。结果退变性腰椎滑脱组PI[(57.67±11.78)°]、SS[(37.83±9.17)°]、LL[(54.65±11.45)°]明显大于退变性腰椎管狭窄症组[(44.47±8.75)°,(28.18±9.02)°,(38.97±15.59)°]及正常参考值[(44.75±9.01)°,(33.57±7.64)°,(48.75±10.03)°](P0.05);退变性腰椎滑脱组L4S[(8.18±9.98)°]、L5S[(19.96±8.33)°]明显大于退变性腰椎管狭窄症组[(3.32±7.95)°,(10.87±8.02)°](P0.05);退变性腰椎滑脱PR-L4[(57.63±13.44)°]、PR-L5[(45.76±10.92)°]及PR-S1[(27.91±10.41)°]明显小于退变性腰椎管狭窄症组[(65.48±10.70)°,(56.33±9.15)°,(38.63±7.29)°](P0.05)。结论高PI可能引起退变性腰椎滑脱发生及发展,L5椎体倾斜角是退变性腰椎滑脱发生的预测因素之一,退变性腰椎滑脱下腰椎骨盆前凸明显小于退变性腰椎管狭窄症。     

退变性脊柱侧凸椎间盘-终板退变与骨性结构参数的相关性研究及意义

目的 分析退变性脊柱侧凸椎间盘-终板退变与骨性结构参数的关系,探讨其在退变性脊柱侧凸发病机制中的作用及意义.方法 回顾分析2005年3月至2010年3月诊治的79例退变性脊柱侧凸患者(病例组)的影像学资料,选取41例诊断为特发性脊柱侧凸患者(对照组)的影像学资料做为对照.所有患者以主弯内的椎体及附件为观测对象,分别测量椎体和椎间两侧高度及两侧关节突关节面矢状角角度,分别计算椎体和椎间两侧平均高度及两侧关节突关节面平均矢状角作为骨性结构参数.采用分级评分法对各个椎间盘及邻近终板退变程度进行量化,其分值代表椎间盘-终板退变的程度.组内比较各骨性结构参数,分析骨性结构参数的特点及其与椎间盘-终板退变和侧凸Cobb角的关系.结果 经配对t检验比较,病例组的椎间高度、椎体高度及关节面矢状角凸凹侧差异有统计学意义(t=3.411,2.623和2.085,P＜0.05);对照组的椎间高度凸凹侧差异有统计学意义(t =3.276,P＜0.01),椎体高度及关节面矢状角差异无统计学意义(t=1.572和1.493,P＞0.05).直线相关和多元回归分析显示,各骨性结构参数不对称度与椎间盘-终板退变有显著相关性(-1 ＜r＜1,P ＜0.05),与腰椎侧凸Cobb角呈正相关(0＜r＜1,P＜0.05),且存在直线回归关系(F=427.342,P＜0.01),其回归方程为Cobb角=-8.904+8.136×椎间不对称度+3.274×椎体不对称度-0.713×关节突不对称度.结论 退变性脊柱侧凸两侧骨性结构呈不对称改变,其不对称性与椎间盘-终板退变和脊柱侧凸相互关联;不对称骨性结构改变可能是侧凸渐进性发展的生物力学动力因素,而椎间盘-终板不对称退变可能有病因学意义.     

退变性脊柱侧凸长节段融合远端融合椎应选择L5还是S1?

<正>对退变性脊柱侧凸(degenerative scolliosis,DS)患者远端融合椎(lower instrumented vertebra,LIV)应选择L5还是S1的问题,目前仍存在较大争议。多数学者认为,当L5/S1节段无明显退变(包括椎间盘及关节突两部分),无椎管狭窄、腰椎峡部裂性滑脱、椎间滑移等病变,L5椎体冠状面上倾斜15°时,并且在整体上无矢状面及冠状面失平衡的条件下,可考虑融合至L5以保留活动节段~([1、2])。然而,L5/S1节段     

局部冠状面失平衡在退变性腰椎滑脱中的临床意义

[目的]探讨伴局部冠状面失平衡(local coronal imbalance,LCI)的退变性腰椎滑脱症影像学特征及对手术疗效的影响。[方法]回顾性分析2010年1月~2015年3月在本院行经椎间孔椎体间融合手术(TLIF)治疗且随访2年的114例L4/5退变性滑脱患者,其中男21例、女93例;年龄39~73岁(平均50.50岁)。根据在术前腰椎X线片上是否伴LCI现象将患者分为非LCI组和LCI组。于术前、术后和末次随访时测量矢状面和冠状面参数。矢状面参数包括滑脱率、滑脱角、椎间隙相对高度和腰椎前凸角;冠状面参数包括冠状面侧凸角、L4倾斜角、椎间隙楔变角、冠状面失平衡。采用t检验比较两组间影像学的差异。[结果]本组患者15例(13.16%)伴有LCI现象。术前LCI组和非LCI组滑脱率分别为(21.35±4.12)%和(24.27±4.70)%、椎间隙相对高度分别为(0.27±0.03)和(0.23±0.09)、腰椎前凸角分别为(47.39±10.54)°和(42.11±11.60)°,两组比较差异均有统计学意义(P0.05);术前LCI组冠状面侧凸角、冠状面失平衡、L4倾斜角和椎间隙楔变角均显著高于非LCI组(P0.05)。经TLIF术后,两组患者术后及末次随访时各影像学指标较术前均明显改善。但术后和末次随访时LCI组滑脱率改善显著低于非LCI组(P0.05),滑脱角、椎间隙高度、腰椎前凸角比较未见差异(P0.05);术后LCI组冠状面失平衡显著高于非LCI组,冠状面侧凸角、L4倾斜角和椎间隙楔变角差异均无统计学意义(P0.05),而末次随访时冠状面参数组间比较差异均无统计学意义(P0.05)。[结论]伴有LCI的DS患者伴有腰椎侧凸和椎间隙塌陷,TLIF术式可有效矫正伴LCI患者冠状面侧凸和失衡,但其滑脱改善率低于非LCI组。     

腰椎侧方不稳在退变性腰椎滑脱中的临床相关研究

目的 探讨腰椎侧方不稳在退变性腰椎滑脱中的影像学特征及其对手术疗效的影响。方法 回顾性分析2019年2月～2022年5月在本院接受手术治疗且随访>2年的97例退变性腰椎滑脱(degenerative lumbar spondylolisthesis, DLS)患者。根据在术前腰椎X线片上是否伴有腰椎侧方不稳(lumbar lateral instability, LLI)现象,将被纳入的患者分为侧方不稳定组(L组)和非侧方不稳定组(NL组)。记录两组患者术前、术后以及末次随访时的生活质量评估结果及矢状面和冠状面影像学参数。结果 本研究有22例(22.7%)患者伴有LLI现象。L组患者术前滑脱角、腰椎冠状面平衡距离、L₄倾斜角和椎间隙楔变角均显著高于NL组,且L组患者腰椎前凸角度丢失更为严重(P<0.05)。术后及末次随访时,两组患者矢状面和冠状面参数无显著差异,且两组患者术后的生活质量均得到了显著提高。结论 伴有LLI的DLS患者是一个与腰椎不稳定相关的独特亚群,手术治疗可有效改善伴LLI患者的冠状面形态。     

椎体终板的凹陷角与腰椎间盘退变的相关性

目的研究下腰椎椎体终板的凹陷角以及它在腰椎间盘退变时的变化规律.方法129例研究对象依据椎间盘退变情况分成3组对照组27例,共54个椎间盘(L4,5、L5S1椎间盘各27个);腰椎间盘退变102例,共158个椎间盘(L4,5椎间盘84个,L5S1椎间盘74个),按退变程度分为2组腰椎间盘轻度退变组,共99个椎间盘(L4,5椎间盘53个,L5S1椎间盘46个);腰椎间盘重度退变组,共59个椎间盘(L4,5椎间盘31个,L5S1椎间盘28个).所有病例摄腰椎正侧位X线片及腰椎MR检查,将X线片及MR图像输入计算机.在MRI正中矢状面T2加权像上测量终板凹陷角,并观察退变椎间盘相邻椎体骨髓的MRI信号改变;在X线片上测量椎体的相对前高、后高和矢状径.结果①终板凹陷角在男女两性间差异无显著性(P＞0.05);②终板的凹陷角在对照组、腰椎间盘轻度和重度退变组逐渐增大,两两间差异有显著性(P＜0.05);③退变椎间盘的上下位椎体的相对前高、后高在对照组、腰椎间盘轻度和重度退变组逐渐减小,而相对矢状径逐渐增大,两两间比较差异均有显著性(P＜0.05);④椎间盘轻度、重度退变组的相邻椎体骨髓的MRI信号改变率分别为24%和44%,差异有显著性(P＜0.05).结论腰椎间盘退变时,病变间隙椎体终板凹陷角增大、终板倾向平坦化,其平坦化程度与退变的严重程度有关.终板的平坦化是椎间盘退变时椎体骨重建结果,可能是对椎间盘退变时生物力学变化的一种自我保护机制.     

合并椎间盘突出的退变性腰椎滑脱椎间盘形态改变及其意义

【摘要】 目的：观察合并椎间盘突出的退变性腰椎滑脱（lumbar degenerative spondylo-listhesis,LDS）患者的椎间盘影像学特点,探讨椎间盘退变程度、椎间隙角度及高度与退变性腰椎滑脱间的关系。方法：以2009年10月～2011年11月我院和石景山医院收治的合并L4/5椎间盘突出的退变性腰椎滑脱患者37例作为观察组,另选同期单纯L4/5椎间盘突出症患者38例作为对照组,对L4/5椎间盘退变程度按照Pfirrmann法分级,CT测定L4/5椎间盘正中矢状面的椎间隙角度和椎间隙高度,对所得数据进行统计分析。结果：观察组L4/5椎间盘MRI退变程度B、C、D、E级分别为1、25、8及1例,对照组分别为2、21、13及2例,两组椎间盘退变程度间差异没有显著性（P>0.05）;CT测量L4/5椎间隙角度观察组和对照组分别为3.08°±1.87°和6.48°±2.92°,对照组椎间隙角度明显大于观察组（P<0.05）;椎间隙高度观察组和对照组分别为8.46±1.81mm和9.38±2.46mm,两组间比较差异没有显著性（P>0.05）。结论：椎间隙角度减小,可能是退变性腰椎滑脱发病的重要因素之一。     

腰椎矢状面不平衡与关节突关节形态的相关性研究

目的探讨腰椎矢状面不平衡与关节突关节形态的相关性。方法纳入自2016-01—2018-12经CT检查确诊为L4椎体假性滑脱的30例作为滑脱组,纳入同期经CT检查无腰椎滑脱的30例作为对照组。比较滑脱组与对照组椎体小关节角与椎弓根角。结果滑脱组与对照组左侧与右侧椎体小关节角差异无统计学意义(P0.05);但滑脱组双侧椎体小关节角差值与对照组比较差异有统计学意义(P 0.05)。滑脱组左侧与右侧椎弓根角与对照组比较差异有统计学意义(P 0.05)。结论腰椎小关节角与腰椎矢状面不平衡无明显相关性,但双侧椎体小关节角差异与关节面前倾是腰椎矢状面不平衡的影响因素。椎体小关节的三维结构失衡是导致椎体矢状面不平衡的重要诱因,但不是唯一因素。     

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.     

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.     

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.     

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.