颈后路椎弓根钉棒短节段内固定治疗寰枢椎骨折脱位

目的:探讨颈后路椎弓根钉棒短节段内固定治疗寰枢椎骨折脱位的临床疗效。方法:对2015年1月至2018年1月手术治疗的60例寰枢椎骨折脱位患者进行回顾性分析,根据手术方法的不同分为研究组和对照组,其中研究组30例,男13例,女17例;年龄(39.32±2.85)岁;行颈后路椎弓根钉棒短节段内固定术。对照组30例,男12例,女18例;年龄(39.57±2.90)岁;行寰椎后路椎板夹内固定。记录两组患者手术时间、术中出血量、术后下床活动时间和住院时间以及并发症,观察两组患者疼痛视觉模拟评分(visual analogue scale,VAS),神经功能日本骨科协会(Japanese Orthopedic Association,JOA)评分及融合情况。结果:两组患者均获得至少12个月随访。研究组手术时间、术中出血量、术后下床活动时间及住院时间均优于对照组(P=0.000)。研究组发生呼吸道损伤1例;对照组发生切口感染2例,呼吸道损伤3例,相邻节段关节退变3例;研究组并发症发生率低于对照组(χ²=4.705,P=0.030)。术后1、3、7 d,研究组VAS低于对照组(P=0.000);术后1、3个月时,研究组JOA评分高于对照组(P=0.000)。术后12个月研究组患者均获得骨性融合;对照组出现3例骨性融合不佳,3例内固定断裂,发生率为20.00%(6/30);两组差异有统计学意义(χ²=4.629,P=0.031)。结论:颈后路椎弓根钉棒短节段内固定治疗寰枢椎骨折脱位具有创伤小、手术时间短、并发症少、疼痛程度轻等优势,且可促使神经功能尽快恢复。     

损伤控制技术诊断急性肢体骨筋膜室综合征

目的 研究损伤控制技术（damage control techniques, DCTs）在急性肢体骨筋膜室综合征（acute extremity compartment syndrome, AECS）诊断中的作用。方法 回顾性分析2012年6月至2018年6月我科收治的66例AECS病人的临床资料。其中男42例（63.64%）、女24例（36.36%）,年龄为（35.42±14.16）岁（16~67岁）。根据AECS病人诊断过程中是否采用DCTs将病人分为非DCTs诊断组（常规组15例+DCTs治疗组13例）和DCTs诊疗组（38例）,对比分析组间诊断指标的差异。结果 ①AECS早、中期确诊率：DCTs诊疗组显著高于非DCTs诊断组（χ²=10.866,P=0.001）;②晚期6“P”临床表现：非DCTs诊断组显著高于DCTs诊疗组（χ²=13.630,P＜0.001）;③检验结果：非DCTs诊断组的血钾、肌酐、尿素氮和pH值异常率均显著高于DCTs诊疗组（χ²=5.332,P=0.021;χ²=10.739,P=0.001;χ²=5.992,P=0.014和χ²=4.962,P=0.026）;④并发症：非DCTs诊断组急性肾功能不全（acute renal failure, ARF）和多器官功能障碍综合征（multiple organ dysfunction syndrome, MODS）发生率显著高于DCTs诊疗组（χ²=5.120,P=0.024和χ²=4.189,P=0.041）。结论 DCTs优于传统方式,通过早期精准诊断AECS,及时开展损伤控制性治疗,可预防AECS进展为缺血晚期,有利于后续确定性治疗的开展。     

基于Caprini风险评估模型的干预策略对全膝关节置换术后静脉血栓栓塞症的预防效果观察

目的：探讨基于Caprini血栓风险评估模型的干预策略对全膝关节置换术（total knee replacement,TKA）后静脉血栓栓塞症（venous thromboembolism,VTE）的预防效果。方法：自2017年5月至2021年12月收治257例TKA患者,以2019年5月是否引进Caprini血栓风险评估模型为界分为传统常规干预策略（对照组121例）和基于Caprini血栓风险评估模型的干预策略（观察组136例）。对照组男79例,女42例;年龄50~78（63.10±11.86）岁;体质量指数（body mass index,BMI）19~32（25.21±4.95） kg/m²;左侧55例,右侧66例。观察组男81例,女55例;年龄50~78（64.35±10.54）岁;BMI 19~32（24.43±5.18） kg/m²;左侧87例,右侧49例。比较两组患者术后VTE发生率,疼痛视觉模拟评分（visual analogue scale,VAS）,美国特种外科医院（Hospital for Special Surgery,HSS）膝关节评分,患肢肿胀情况,血流平均速度（mean velocity,Vm）,峰值速度（peak velocity,PV）,D-二聚体（D-dimer,D-D）及凝血酶原时间（prothrombin time,PT）和并发症发生率。结果：观察组VTE发生率为1.47%（2/136）,对照组VTE发生率为9.09%（11/121）,两组比较差异有统计意义（χ²=6.976,P=0.008）。术后7 d,观察组VAS、HSS评分及患肢周径差值均明显优于对照组（P<0.05）。术后7 d,两组血流Vm和PV水平均明显升高（P<0.001）,且观察组血流Vm、PV水平高于对照组（P<0.001）。术后7 d,观察组血清D-D水平明显低于对照组,PT水平明显高于对照组（P<0.05）。两组并发症发生率比较,差异有统计意义（χ²=4.488,P=0.034）。结论：基于Caprini血栓风险评估模型的干预策略可有效降低TKA患者VTE发生率及并发症发生率,改善患肢肿胀、血流动力学及凝血功能状态,有助于膝关节功能恢复。     

股骨闭合复位器辅助复位股骨交锁髓内钉固定治疗股骨干骨折的临床疗效分析

目的 探讨股骨闭合复位器辅助复位股骨交锁髓内钉固定治疗股骨干骨折的临床疗效。方法 回顾性分析手术治疗股骨干骨折的100例病人,其中股骨闭合复位器辅助复位股骨交锁髓内钉固定50例（复位器辅助组）,单纯牵引架牵引复位股骨髓内钉固定50例（牵引架辅助组）,比较两组的手术时间、出血量、导针反复进针次数、骨折愈合时间、需要骨折断端切开辅助复位例数及术后并发症发生率。结果 随访时间为12~18个月。复位器辅助组：骨折均愈合,愈合时间为4~8个月,无感染、内外翻、短缩畸形发生,术后Harris髋关节评分及美国特种外科医院（Hospital for Special Surgery, HSS）膝关节评分优良率均达92.0%。牵引架辅助组：发生骨不连1例,余病人骨折均愈合,愈合时间为4~9个月,无感染发生,无内外翻、短缩畸形发生,Harris及HSS评定标准优良率均达88.0%。两组手术时间、出血量、导针反复进针次数、骨折断端切开辅助复位例数比较,差异均有统计学意义（t=10.699,P＜0.001;t=22.517,P＜0.001;t=3.010,P=0.003;χ²=6.383,P=0.012）。骨折愈合时间、并发症发生率、髋膝关节功能优良率比较,差异均无统计学意义（t=0.646,P=0.520;χ²=1.010,P=0.315;χ²=0.444,P=0.505）。结论 股骨闭合复位器辅助复位股骨交锁髓内钉固定治疗股骨干骨折,操作简便、创伤小、效果可靠。     

预成型肋骨锁定钛板联合超声引导下胸椎旁神经阻滞治疗老年多发性肋骨骨折

目的:探讨预成型肋骨锁定钛板内固定手术与超声引导下胸椎旁神经阻滞联合应用对于老年多发性肋骨骨折患者的疗效。方法:回顾性分析2016年2月至2020年11月收治的221例老年多发性肋骨骨折患者,根据是否手术治疗,分为预成型肋骨锁定钛板联合超声引导下胸椎旁神经阻滞组(手术组)102例,保守治疗组(非手术组)119 例。手术组中男58 例,女44 例;年龄60~85(67.2±3.6)岁;肋骨骨折3~12(5.3±2.1)处。非手术组中男66 例,女53 例;年龄60~84 (66.8±3.2)岁;肋骨骨折2~11 (6.1±2.3)处。比较分析两组患者的临床资料、治疗效果及并发症情况。结果:两组患者术前临床资料比较,差异无统计学意义(P>0.05),所有患者顺利出院。手术组患者肺部感染(P=0.028),肺不张(P=0.032),呼吸衰竭(P=0.026),主动下床时间(P=0.040),骨折愈合时间(P=0.035),住院时间(P=0.043),治疗后3 d疼痛视觉模拟评分(visual analogue scale,VAS)(P=0.028),治疗后5 d VAS (P=0.032),治疗后7 d VAS (P=0.019),术后3个月最大自主通气量(maximal voluntary ventilation,MVV)(P=0.042),1 s用力呼气容积(forced expiratory volume in one second,FEV1)(P=0.035)以及术后6个月MVV(P=0.021),FEV1(P=0.026)均优于非手术治疗组。结论:对于老年严重多发肋骨骨折的患者,预成型肋骨锁定钛板与超声引导下胸椎旁神经阻滞的联合应用与非手术治疗相比较,能够及时有效镇痛,恢复胸廓稳定性,缩短住院时间,减少肺部感染及急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS) 等并发症的发生率。预成型肋骨锁定钛板治疗老年多发性肋骨骨折具有较好的临床效果。     

组配式假体在Crowe Ⅰ、Ⅱ型发育性髋关节发育不良全髋关节置换术中的应用

目的 探讨应用组配式假体行全髋关节置换术（total hip arthroplasty, THA）治疗CroweⅠ、Ⅱ型发育性髋关节发育不良（developmental dysplasia of the hip, DDH）的短期临床疗效。方法 回顾性分析2016年10月至2017年10月,中国人民解放军总医院骨关节科收治的40例单侧Crowe Ⅰ、Ⅱ型DDH病人的临床资料,其中男5例,女35例;年龄为（36.90±10.30）岁（19~51岁）,股骨选用组配式假体,全部纳入组配式假体组。另选择既往40例术前设计采用普通锥形假体的单侧Crowe Ⅰ、Ⅱ型DDH病人作为对照组。比较两组病人的基本信息,术中及术后并发症发生情况,术前及术后6个月髋关节Harris功能评分,术后双下肢长度及偏心距差异等指标。结果 组配式假体组与对照组病人的术中股骨假体周围骨折发生率（5.0%比10.8%）、术后脱位率（2.5%比8.1%）、偏心距差异发生率（20.0%比37.8%）比较,差异均无统计学意义（χ²=0.276,P=0.600;χ²=0.353,P=0.553;χ²=2.997,P=0.083）。术后,组配式假体组的髋关节Harris功能评分较对照组高[（89.45±9.22）分比（84.69±8.77）分;t=2.077,P=0.041],双下肢不等长发生率低（17.5%比43.2%;χ²=6.081,P=0.014）。结论 在Crowe Ⅰ、Ⅱ型DDH中,组配式假体比普通假体更易获得双下肢等长及更佳的关节功能。     

自制多功能组合式复位固定钳在股骨、胫骨骨干骨折的初步应用

目的 总结自制多功能组合式复位固定钳治疗股骨、胫骨骨干骨折的临床效果。方法 回顾性分析2019年1月至2020年5月我院收治的86例股骨干骨折、胫骨干骨折病人的临床资料,根据治疗方式不同分为观察组和对照组,每组各43例。观察组采用多功能组合式复位固定钳治疗,对照组采用传统持骨钳把持。比较两组病人切口长度、术中出血量、手术时间、骨折愈合时间、并发症发生等情况。结果 对照组切口大小、术中出血量、手术时间、愈合时间均高于观察组,差异均有统计学意义（P均＜0.05）;观察组优良率为97.67%,高于对照组的83.72%,差异无统计学意义（χ²=3.445,P=0.063）;对照组（16.28%）并发症发生率高于观察组（2.33%）,差异无统计学意义（χ²=3.445,P=0.063）。结论 自制多功能组合式复位固定钳在实际操作过程中使用灵活,有利于减少创伤,方便了手术操作,缩短了手术时间,有其临床应用价值。     

C臂CT辅助数字减影血管造影引导肾上腺静脉取血

目的 观察C臂CT辅助数字减影血管造影(DSA)引导肾上腺静脉取血(AVS)的价值。方法 回顾性分析57例原发性醛固酮增多症(PA)患者,其中25例接受DSA引导AVS(DSA-AVS组)、32例接受C臂CT辅助DSA引导AVS(C臂CT-AVS组),比较组间插管总成功率(双侧AVS均插管取血成功为总成功)、曝光时间及辐射剂量面积乘积(DAP)。结果 C臂CT-AVS组AVS插管总成功率为84.38%(27/32),DSA-AVS组为52.00%(13/25),组间差异有统计学意义(χ²=7.00,P=0.01);组间曝光时间及DAP差异均无统计学意义(P均＞0.05)。DSA-AVS组1例右肾上腺静脉(RAV)破裂出血,出血较少,后自行缓解;2组均未见肾上腺危象、严重出血、下腔静脉穿孔等严重并发症。结论 C臂CT辅助DSA引导可在不增加曝光时间和辐射剂量的前提下提高AVS技术成功率。     

儿童肱骨髁上骨折保守治疗旋前或旋后固定后肘内翻畸形的病例对照研究

目的: 通过回顾性分析比较手法复位后旋前或旋后位石膏固定的儿童肱骨髁上骨折肘内翻畸形发生情况,从而指导临床治疗.方法: 收集2009年6月至2011年12月在我院急诊骨科行手法复位石膏固定的儿童肱骨髁上骨折病例,经筛选排除后共64例.按手法复位后固定位置不同分为两组：A组采用手法复位并旋前位石膏固定,B组采用手法复位并旋后位石膏固定.A组30例,男18 例,女12例;平均年龄(7.5±3.5) 岁;B组34例,男23 例,女11 例,平均年龄(7.0±2.6)岁.比较两组组间及组内的肘内翻发生率及提携角减小角度.结果: A组出现13例肘内翻,B组出现16例,两组差异无统计学意义(χ²=0.089,P=0.765).A组提携角减小角度(8±4)°,B组提携角减小角度(9±5)°,两组差异无统计学意义(t=0.584,P=0.564).A组组内桡偏型与尺偏型的肘内翻发生率与提携角减小角度差异均有统计学意义(χ²=6.160,P=0.013;t=-2.409,P=0.035);B组组内桡偏型与尺偏型的肘内翻发生率与提携角减小角度差异均有统计学意义(χ²=5.120,P=0.024;t=-2.250,P=0.041).两组肘关节功能Flynn评价差异无统计学意义(P=0.822).结论: 儿童肱骨髁上骨折旋前位固定和旋后位固定肘内翻发生率和提携角减小角度均无明显差异.而尺偏型儿童肱骨髁上骨折,旋前位固定有利于降低肘内翻率及其程度;桡偏型儿童肱骨髁上骨折,旋后位固定有利于降低肘内翻率及其程度.     

抗血栓治疗对大结肠息肉患者内镜下黏膜切除术后迟发性出血的影响

背景与目的 抗血栓治疗被认为是结肠息肉切除术后出血的危险因素。然而,抗血栓治疗对大结肠息肉患者术后迟发性出血的影响尚未完全明确。因此,本研究探讨抗血栓治疗及其相关因素对大结肠息肉患者行内镜下黏膜切除术（EMR）后迟发性出血的影响,以期提高医生对该类患者围手术期管理的认识。方法 回顾性收集2019年1月—2022年12月因大结肠息肉（>10~20 mm）行EMR的157例患者资料,根据EMR期间是否接受抗血栓治疗、使用抗血栓药物类型、术前是否停用抗血栓药物,分别将患者分为抗血栓组（n=51）与非抗血栓组（n=106）、抗凝组（n=33）与抗血小板组（n=36）、停药组（n=35）与未停药组（n=41）。比较各组间术后迟发性（24 h至30 d内）出血发生率及出血时间点的差异,并通过Kaplan-Meier曲线分析各组间术后30 d累积出血发生率。结果 抗血栓组与非抗血栓组迟发性出血发生率差异有统计学意义（19.61% vs. 5.66%,χ²=7.32,P=0.01）;抗血栓组的出血时间点明显早于非抗血栓组（t=2.17,P=0.047）;抗血栓组术后30 d累积出血发生率明显高于非抗血栓组（χ²=6.18,P=0.01）。抗凝组与抗血小板组迟发性出血发生率差异无统计学意义（24.24% vs. 27.78%,χ²=0.11,P=0.74）,两组在出血时间点、术后30 d累积出血发生率方面差异均无统计学意义（t=0.25,P=0.80;χ²=0.13,P=0.72）。停药组与未停药组迟发性出血发生率差异有统计学意义（14.29% vs. 29.27%,χ²=3.97,P=0.046）,未停药组在出血时间点方面明显早于停药组（t=3.03,P=0.01）;停药组术后30 d累积出血发生率明显低于未停药组（χ²=4.36,P=0.04）。结论 抗血栓治疗可能导致大结肠息肉EMR后迟发性出血发生率升高,但术后迟发性出血发生率与抗血栓药物类型无明显关系。术前适当停药可能是降低患者术后出血的有效策略。     

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.