脊柱骨盆内固定系统治疗骶髂关节骨折脱位

[目的]探讨脊柱骨盆内固定系统治疗骶髂关节骨折脱位的疗效。[方法]2007年8月²011年11月共收治骶髂关节骨折脱位患者14例,其中男12例,女2例;年龄222011年11月共收治骶髂关节骨折脱位患者14例,其中男12例,女2例;年龄22⁵7岁,平均42.3岁;交通事故伤11例,高处坠落伤3例。合并骨盆前环骨折9例,骶丛神经损伤4例,四肢骨折6例,尿道断裂1例。根据骨盆环损伤的Tile分型法,该组病例均为骶髂关节复合体旋转垂直不稳定,C1型5例,C2型9例。14例患者均行脊柱骨盆内固定系统治疗。受伤至手术时间757岁,平均42.3岁;交通事故伤11例,高处坠落伤3例。合并骨盆前环骨折9例,骶丛神经损伤4例,四肢骨折6例,尿道断裂1例。根据骨盆环损伤的Tile分型法,该组病例均为骶髂关节复合体旋转垂直不稳定,C1型5例,C2型9例。14例患者均行脊柱骨盆内固定系统治疗。受伤至手术时间7¹4 d。术前经骨牵引,使骶髂关节骨折脱位基本复位后,采用Colorado2TM脊柱内固定系统和髂骨螺钉固定骶髂关节。应用Majeed评分标准评价患者功能恢复情况。应用PACS软件系统测量患者术后即刻及术后1年骶髂关节中部间隙变化,评价内固定的有效性。[结果]14例患者均获随访,随访时间1614 d。术前经骨牵引,使骶髂关节骨折脱位基本复位后,采用Colorado2TM脊柱内固定系统和髂骨螺钉固定骶髂关节。应用Majeed评分标准评价患者功能恢复情况。应用PACS软件系统测量患者术后即刻及术后1年骶髂关节中部间隙变化,评价内固定的有效性。[结果]14例患者均获随访,随访时间16²4个月,平均21.3个月。术后X线片复查示骶髂关节垂直和旋转移位均获满意复位,骶髂关节得到有效固定,未发生严重的血管、神经损伤等并发症。未发现内固定松动、断裂,骶髂关节无再移位情况发生。Majeed评分获优6例,良4例,一般3例,差1例。[结论]脊柱骨盆内固定系统可使骨折脱位的骶髂关节获得有效的即刻稳定性并维持至骨折愈合,是治疗骶髂关节骨折脱位的有效方法之一。     

髂腰重建术治疗不稳定性骶骨骨折并神经损伤的临床疗效

目的探讨髂腰重建术治疗不稳定性骶骨骨折并神经损伤的临床疗效。方法选取2008年1月~2013年6月我院收治的不稳定性骶骨骨折合并神经损伤患者12例,其中男性9例,女性3例,年龄22~50岁,平均年龄为(33.6±0.2)岁;Denis分型:Ⅱ区6例,Ⅲ区4例,Ⅱ区合并Ⅲ区2例;患者均有明显的骶神经根损伤症状。Gibbons神经损伤评分:8例3分,4例4分。所有患者均行后路骶管减压、神经松解、髂腰固定重建、后外侧植骨融合术,采用X线片或CT观察骨折复位及愈合情况,应用Majeed功能评分评价患者临床功能恢复情况,应用Gibbons标准评分评定患者神经功能改善情况,并观察并发症情况。结果本组手术时间130~200 min,平均时间(159.3±0.9)min,术中出血量750~1 200 ml,平均(854.5±2.1)ml。所有患者随访8~16个月,平均(12.9±0.8)个月。术后6个月骨折均骨性愈合,无骨折移位、残留骨盆畸形、假关节形成及深部感染等并发症;9例患者神经功能完全恢复;2例明显改善,但遗留不同程度的足下垂和下肢感觉障碍;1例下肢功能及膀胱、直肠功能均无明显改善。Majeed评分评定:优8例,良2例,可1例,差1例,优良率为83.3%;Gibbons评分由术前平均(3.4±0.2)分恢复至末次随访时的(1.4±0.5)分。结论髂腰重建术可恢复腰-骶-髂的解剖关系,重建腰骶复合体的稳定性,对治疗不稳定性骶骨骨折并神经损伤疗效确切。     

Colorado 2TM骶髂板治疗Tile C型骨盆骨折中骶髂关节骨折脱位的临床研究

目的探讨Colorado 2TM骶髂板在治疗Tile C型骨盆骨折中对骶髂关节骨折脱位稳定性重建的作用。方法 2009年2月-2011年1月,收治8例Tile C型骨盆骨折患者。男3例,女5例;年龄22～52岁,平均34.4岁。交通事故伤3例,高处坠落伤3例,重物挤压伤2例。按照Tile分型,C1-2型5例,C1-3型2例,C2型1例。受伤至手术时间5～10 d,平均7 d。经股骨髁上牵引,使骶髂关节骨折脱位复位后,采用Colorado 2TM骶髂板固定骶髂关节,选择性加用骨盆前环重建钢板或外固定支架固定。结果术后X线片复查示骶髂关节垂直和旋转移位均获满意复位,骶髂关节得到有效固定,骨盆后环获得即刻稳定性。术后切口均Ⅰ期愈合,未发生血管、神经损伤等严重并发症。8例均获随访,随访时间6～24个月,平均12个月。骶髂关节无再移位,螺钉无松动。骨折愈合时间6～12个月,平均9个月。末次随访时采用Majeed功能评价标准,获优5例,良2例,一般1例。结论 Colorado 2TM骶髂板固定可使骨盆后环获得有效的即刻稳定性并维持至骨折愈合,是治疗Tile C型骨盆骨折中骶髂关节骨折脱位的有效方法之一。     

Colorado 2~(TM)骶髂板治疗Tile C型骨盆骨折中骶髂关节骨折脱位的临床研究

目的探讨Colorado 2TM骶髂板在治疗Tile C型骨盆骨折中对骶髂关节骨折脱位稳定性重建的作用。方法 2009年2月-2011年1月,收治8例Tile C型骨盆骨折患者。男3例,女5例;年龄22～52岁,平均34.4岁。交通事故伤3例,高处坠落伤3例,重物挤压伤2例。按照Tile分型,C1-2型5例,C1-3型2例,C2型1例。受伤至手术时间5～10 d,平均7 d。经股骨髁上牵引,使骶髂关节骨折脱位复位后,采用Colorado 2TM骶髂板固定骶髂关节,选择性加用骨盆前环重建钢板或外固定支架固定。结果术后X线片复查示骶髂关节垂直和旋转移位均获满意复位,骶髂关节得到有效固定,骨盆后环获得即刻稳定性。术后切口均Ⅰ期愈合,未发生血管、神经损伤等严重并发症。8例均获随访,随访时间6～24个月,平均12个月。骶髂关节无再移位,螺钉无松动。骨折愈合时间6～12个月,平均9个月。末次随访时采用Majeed功能评价标准,获优5例,良2例,一般1例。结论 Colorado 2TM骶髂板固定可使骨盆后环获得有效的即刻稳定性并维持至骨折愈合,是治疗Tile C型骨盆骨折中骶髂关节骨折脱位的有效方法之一。     

经皮微创螺钉内固定治疗骨盆环骨折脱位的临床疗效

目的探讨经皮微创螺钉内固定治疗骨盆环骨折脱位的临床疗效。方法笔者自2013-01—2016-04诊治45例(113处)骨盆环骨折脱位;均于伤后3~10 d行经皮微创技术置入骶髂关节螺钉,评价其术后疗效。结果所有患者均获得随访3~24个月,平均9个月。随访期间未发现复位丢失情况,骨折均一期愈合,愈合时间2~4个月,平均3.3个月。1例术后出现骶神经损伤症状,经取出内固定后症状消失。末次随访疗效按照Majeed功能评定标准评定:优35例,良7例,可3例,优良率93.3%。所有患者均无内固定脱落及折断。结论经皮微创螺钉内固定治疗骨盆环骨折脱位较传统切开复位钢板内固定,具有骨折愈合时间短、功能优良、切口美观、术中出血量少、住院时间短、术后卧床时间短、功能复恢情况良好等优点,能有效降低术后并发症的发生率。     

前路双钢板内固定治疗骶髂关节骨折脱位

目的探讨前路双钢板内固定治疗骶髂关节骨折脱位的临床疗效。方法12例骶髂关节骨折脱位患者术前行肠道准备,术中采用骶髂关节前路切开复位加双钢板内固定治疗,术后行功能煅练。结果术后随访5～18个月,12例患者术后无一例感染,无周围神经损伤,2例骶髂关节处轻度疼痛,术后3个月复查见骶髂关节分离约1．0cm。根据Matta功能评定标准,优7例,良3例,一般2例。结论骶髂关节前路双钢板内固定术有直视复位、固定可靠、有效避免神经损伤的优点。且操作简单,临床疗效好,适合基层医院开展。     

不稳定型骶骨骨折手术治疗方式选择

[目的]探讨骶骨骨折的临床特点,手术内固定方式的选择及后方张力带钢板、髂腰固定的临床疗效。[方法]2010年1月~2016年6月本科住院行手术治疗并获得随访的19例患者,其中行后方张力带钢板固定8例,髂腰固定11例,采用Majeed评分和X线片检查评估疗效。[结果]所有患者随访时间8~20个月,平均13个月,术后随访X线片提示骨折均获骨性愈合,平均愈合时间8个月,5例神经功能完全恢复;1例明显改善,仅遗留轻微感觉运动功能障碍;1例略有改善,遗留足下垂和下肢感觉障碍。末次随访临床功能依据Majeed评分评定:优11例,良6例,可1例,差1例,优良率89.5%。[结论]对于不稳定的骶骨骨折,需充分了解其损伤类型,关注腰骶结合部损伤,重视创伤性脊柱骨盆分离,有的放矢,个性化地选择骶骨骨折的手术方式,才能提高手术治疗的效果。     

不稳定骶骨骨折手术治疗体会

目的探讨不稳定骶骨骨折的手术治疗方法及临床体会。方法回顾性分析自2012-01—2018-12采用腰髂椎弓根钉内固定治疗的35例不稳定骶骨骨折(DenisⅡ型24例,DenisⅢ型11例),23例合并神经损伤症状(其中14例存在神经根管压迫需进行骶神经根管减压)。结果 35例均获得随访,随访时间平均24.1(10～36)个月。2例切口延迟愈合。1例切口深层感染,经二次清创并灌洗引流2周后愈合。骶骨骨折均愈合,未出现内固定松动、断裂。术后平均13.1(10～18)个月取出内固定物,内固定物与周围组织无粘连。末次随访时Majeed评分平均85.1(62～94)分,其中优24例,良8例,可3例。23例神经损伤者末次随访时神经功能较术前明显改善,Gibbons评分:Ⅰ级17例,Ⅱ级4例,Ⅲ级1例,Ⅳ级1例。结论不稳定骶骨骨折需积极手术治疗,腰髂椎弓根钉内固定可以早期稳定骨折端,同时需对合并骶神经损伤者进行综合评价,存在神经压迫者要早期减压,如此才能获得满意疗效。     

骶管减压腰髂固定后外侧植骨融合治疗Denis Ⅲ型骶骨骨折伴腰盆分离

目的:探讨Denis Ⅲ型骶骨骨折伴腰盆分离的外科治疗方法。方法:2009年1月～2011年1月,我院共收治骶骨骨折患者87例,其中Denis Ⅲ型骶骨骨折伴腰盆分离患者15例,男9例,女6例,年龄18～51岁,平均32.7岁。致伤原因:坠落伤8例,车祸伤5例,挤压伤2例。患者均有明显的骶神经根损伤症状,依据Gibbons标准:3型6例,4型9例。均行后路手术复位、骶管减压、探查松解神经、腰髂固定、后外侧植骨融合术。记录围手术期并发症,观察骨折复位情况和植骨愈合情况,应用Gibbons标准评分评定患者神经功能改善情况。结果:手术时间120～190min,平均160min;术中出血量780～1200ml,平均840ml。术中无相关并发症。术后1例患者出现创面浅表感染,给予及时清创及敏感抗生素治疗后治愈。所有患者均获得随访,随访时间8～24个月,平均16个月,术后6个月骨折均获得骨性愈合,无残留骨盆畸形及假关节形成。无骨折再移位、深部感染等并发症。11例神经功能完全恢复;3例明显改善,但遗留足下垂及下肢感觉减退;1例略有改善,除遗留下肢功能障碍外,尚有膀胱、直肠功能障碍。Gibbons评分由术前的平均3.80±0.78分恢复至末次随访时的1.49±0.81分。1例术后9个月内固定断裂,患者无明显临床症状,复查X线片和三维CT提示植骨融合,取出内固定;1例术后1年复查X线片提示S1椎体螺钉松动,患者无临床症状,未予处理。结论:后路手术复位、骶管减压、腰髂固定、后外侧植骨融合可以恢复腰骶复合体的解剖关系,重建腰骶段稳定性,有利于神经损伤的恢复,是治疗DenisⅢ型骶骨骨折伴腰盆分离的有效方法。     

前路双重建钢板固定结合植骨治疗难复性TileC型骶髂关节骨折脱位

目的探讨采用前路双重建钢板固定植骨治疗难复性TileC型骶髂关节骨折脱位的临床疗效。方法对39例难复性TileC型骶髂关节骨折脱位采用前路双重建钢板进行固定,取髂骨松质骨植骨。结果所有患者获平均18（8—24）个月的随访,骶髂关节在解剖位或功能位融合。3例术前合并腰骶丛不完全损伤者,在3-4个月内完全恢复。按照Tornetta和Matta复位评定标准：优24例,良8例,可7例,优良率82．1％。根据Majeed功能评分系统：优22例,良9例,可8例。优良率79．5％。结论采用前路双重建钢板固定与植骨治疗难复性TileC型骶髂关节骨折脱位可获得满意复位、固定可靠、稳定性好。有利于骶髂关节融合、并发症少、可使患者早期康复。     

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.     

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.     

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.     

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.