桃红四物汤早期干预对大鼠骨折愈合中间充质干细胞归巢的影响

目的: 观察桃红四物汤对骨折大鼠的早期愈合过程中间充质干细胞(mesenchymal stem cells,MSCs)迁移能力、归巢数目及骨痂内细胞因子表达的影响,探讨桃红四物汤通过调控间充质干细胞归巢加速骨折愈合的作用机制。方法: 建立右侧股骨干开放性骨折大鼠模型。将5周龄雄性Sprague-Dawley(SD)大鼠32只,体重110~130(120±10) g,采用随机数字表法分为对照组,桃红四物汤低、中、高剂量组。对照组予蒸馏水,其他组予以不同剂量的桃红四物汤。术后第1天灌胃,每天2次,连续5 d。术后21 d,采用微型计算机断层扫描技术(micro-computed tomography,Micro-CT)观察骨体积分数即骨体积(bone volume)/组织体积(tissue volume)(BV/TV)和骨密度(bone mineral density,BMD)。术后5 d,体外培养对照组和药物组大鼠外周血MSCs,采用细胞迁移实验检测其迁移能力。免疫组化(immunohistochemistry,IHC)检测骨痂处MSCs的数目。蛋白芯片技术检测骨痂内细胞因子的表达。结果: Micro-CT结果显示,高剂量组BV/TV高于中剂量组(P=0.032),中剂量组高于低剂量组(P=0.041),对照组和低剂量组无差异性(P=0.651);此外,对照组BMD和低剂量组无差异(P=0.671),低剂量组低于中剂量组(P=0.018),中剂量组低于高剂量组(P=0.008)。细胞迁移实验表明,桃红四物汤能增强外周血MSCs的迁移能力;IHC检测发现,骨痂内CD45^-、CD90⁺、CD29⁺间充质干细胞较对照组明显增多;蛋白芯片显示,桃红四物汤能促进骨折大鼠骨痂内CINC-1(2.91倍)、CINC-3(1.59倍)、LIX (1.5倍)、Thymus Chemokine(2.55倍)、VEGF(1.22倍)表达,抑制TIMP-1(2.98倍)表达。结论: 骨折早期予活血化瘀代表方桃红四物汤能明显加速骨折愈合,其作用机制可能与增强外周血MSCs迁移能力和上调骨痂中CINC-1、CINC-3、LIX、Thymus Chemokine、VEGF,下调TIMP-1表达,进而促进外周血MSCs归巢有关。     

大鼠股骨干开放骨折愈合模型的建立及生物力学性能评价

目的: 比较闭合骨折髓内钉固定和开放骨折钢板固定大鼠股骨干骨折愈合模型的建立及生物力学性能。方法: 将40只8周龄SD雄性大鼠通过随机数字表法分为两组,分别建立左侧股骨干闭合骨折髓内钉内固定模型和开放骨折钢板内固定模型,每组20只。建立骨折模型后,分别于术后4、6、8、12周4个时间点对两组大鼠进行分批次处死后取材,测量骨折处骨痂的最大横截面积、体积,计算骨痂的最大载荷、最大载荷恢复率。比较两种不同骨折愈合模型的力学性能。结果: 两种骨折模型的平均手术时间比较,差异有统计学意义(P<0.001).两种骨折模型组术后各时间点的平均骨痂最大横截面积和平均骨痂体积差异具有统计学意义(P<0.05).两种骨折固定模型组术后各时间点的平均最大载荷以及平均最大载荷恢复率,差异均具有统计学意义(P<0.05).结论: 骨折愈合过程中,闭合骨折髓内钉固定模型的力学性能优于开放骨折钢板内固定模型,提示轴向的力学刺激在骨折愈合过程中起重要作用。     

高脂血症病人股骨颈骨折分型的临床研究

目的 探究高脂血症病人股骨颈骨折的分型特点。方法 将2012年8月至2017年11月在湖北省宜昌市第二人民医院骨外科和云南省中医医院骨科诊断为股骨近端骨折并符合纳入标准的196例病人作为研究对象,分为高血脂组（97例）和血脂正常组（99例）。根据股骨颈骨折部位及股骨转子间Evans骨折分型判断各例病人的骨折类型。入院及出院时分别检测各例病人的总胆固醇及低密度脂蛋白胆固醇（low density lipoprotein cholesterol, LDL-C）水平,将高血脂组按照高血脂病程分为短期组（≤1年）、中期组（＞1年,≤3年）和长期组（＞3年）。探究血脂水平与股骨颈骨折分型之间的潜在规律。结果 高血脂组股骨颈骨折者81例（83.5%）,显著高于血脂正常组的67例（67.7%）,差异有统计学意义（χ²=6.638,P=0.010）;长期组以颈中型骨折（19例,61.3%）最为多见,与短期组（1例,6.7%）、中期组（12例,23.5%）相比,差异有统计学意义（χ²=12.973,P=0.004;χ²=16.413,P均＜0.001）。高血脂组中,中、长期组血脂水平（总胆固醇、LDL-C）均高于短期组,差异均有统计学意义（P均＜0.05）。结论 合并长期（＞3年）高脂血症的股骨颈骨折病人中,以股骨颈颈中型骨折较为多见。     

全髋关节置换术后假体周围发生骨折的列线图预测模型构建和评估

目的:构建评估行全髋关节置换术(total hip arthroplasty,THA)患者术后假体周围发生骨折的列线图预测模型。方法:选取2013年4月至2019年2月行THA患者538例为研究对象,男318例,女220例,年龄40~60(50.79±6.37)岁。根据对所有行THA患者跟踪随访3年的结果,将其分为无骨折组506例和骨折组32例。单因素和多因素Logistic回归分析行THA患者术后假体周围发生骨折的影响因素;构建行THA患者术后假体周围发生骨折的列线图预测模型,评估该预测模型的有效性、区分度。结果:骨折组行THA患者中存在骨质疏松状态、有外伤史、有髋关节翻修占比高于无骨折组(P<0.05),骨水泥型假体占比低于无骨折组(P<0.05)。骨质疏松状态[OR=4.177,95%CI(1.815,9.617),P<0.05],外伤史[OR=7.481,95%CI(3.104,18.031),P<0.05],髋关节翻修[OR=11.371,95%CI(3.220,40.153),P<0.05]是影响行THA患者术后假体周围发生骨折的独立危险因素,骨水泥型假体[OR=0.067,95%CI(0.019,0.236),P<0.05]是影响行THA患者术后假体周围发生骨折的独立保护因素。Hosmer-Lemeshow拟合优度检验显示, χ²=7.864,P=0.325。受试者工作特征(receiver operating characteristic curve,ROC)曲线评估行THA患者术后假体周围发生骨折的曲线下面积(area under curve,AUC)为0.892,敏感度为87.5%,特异性为77.7%。结论:本研究构建的行THA患者术后假体周围发生骨折的列线图预测模型区分度较好,有益于临床预测行THA患者假体周围是否发生骨折,为进行个体化预防骨折提供便利。     

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。     

区域CT值在预测股骨近端骨折中的价值

目的:探讨60岁以上成人发生股骨近端骨折的股骨颈部松质骨CT值。方法:自2020年1月至2020年12月,回顾性分析行双髋关节CT检查的年龄＞60岁的280例研究对象,男85例,女195例;年龄75(66,82)岁;左侧120例,右侧160例。其中136例股骨近端骨折患者为研究组,144例无骨折者为对照组。采用GEOptima CT机扫描并分别重建出股骨近端水平位、冠状位和矢状位层面。测量并比较两组股骨颈部松质骨的CT值;采用Logistic回归分析股骨颈松质骨CT值与股骨颈骨折间的关系。结果:骨折组年龄79(73.3,85.0)岁,无骨折组年龄69.5(64.0,78.8)岁,两组年龄比较,差异有统计学意义(P＜0.05)。骨折组区域CT值8.62(-3.62,27.15) HU低于无骨折组34.31(-5.93,71.74) HU(P＜0.05)。冠状位平面内骨折组的区域CT值-8.48(-30.96,17.46) HU低于无骨折组40.49(5.55,80.71) HU(P＜0.05);矢状位平面内骨折组区域CT值-31.28(-54.91,-5.11) HU低于无骨折组7.74(-20.12,44.54) HU(P＜0.05);水平位平面内骨折组区域CT值0.17(-23.13,24.60) HU低于无骨折组46.40(10.42,85.18) HU(P＜0.05);骨折组股骨颈部区域CT值低于无骨折组(P＜0.05)。经Logistic回归分析,冠状位区域CT值是股骨近端骨折的影响因素,可以写入预测骨折概率的回归方程。结论:在60岁以上成人,随着年龄的不断增大,股骨颈部松质骨CT值呈下降趋势。股骨颈部松质骨CT值越小发生股骨近端骨折的风险越大。     

术中滑轨CT辅助在经皮骶髂关节螺钉治疗骨盆后环损伤中的应用

目的：比较术中滑轨CT联合C形臂X线机辅助与单纯使用C形臂X线机辅助透视下经皮骶髂关节螺钉治疗骨盆后环损伤临床疗效。方法：自2018年12月至2022年2月收治76例骨盆后环损伤患者,其中,C形臂联合滑轨CT辅助下行内固定治疗39例为CT组,男23例,女16例,年龄(44.98±7.33)岁;仅在C形臂透视下行内固定治疗37例为C形臂组,男24例,女13例,年龄(44.37±10.82)岁。合并有前环骨折患者42例,均采用经皮髂前下棘内置外固定架(internal fixation,INFIX)或耻骨上支螺钉固定骨盆前环。术后比较两组随访时间、置钉时间、并发症。比较两组Matta复位评价、Majeed疗效评价、CT分级及二次手术翻修率。结果：CT组置钉时间(32.63±7.33) min,短于C形臂组(52.95±10.64) min(t=-9.739,P＜0.05)。CT组随访时间(11.97±1.86)个月,C形臂组(12.03±1.71)个月,两组比较差异无统计学意义(P＞0.05)。两组术后并发症发生比较,差异无统计学意义(χ²=0.159,P＞0.05)。CT组Matta复位评价结果(Z=2.79,P＜0.05)、Majeed疗效评价结果(Z=2.79,P＜0.05)、CT分级(Z=2.83,P＜0.05)均优于C形臂组。CT组二次手术翻修率低于C形臂组(χ²=5.641,P＜0.05)。结论：术中滑轨CT联合C形臂辅助下经皮骶髂关节螺钉置入手术与传统C形臂透视相比,具有手术时间短、准确度及安全性高、术后二次翻修率显著下降等特点,是重建骨盆骨折后环稳定性的有效方法之一。     

术后延长吸氧时间对老年全膝关节置换术病人术后疼痛、炎症因子及免疫功能的影响

目的 探讨术后延长吸氧时间对老年全膝关节置换术（TKA）病人术后疼痛、炎症因子及免疫功能的影响。方法 选取2022年1月至2023年1月西安交通大学第二附属医院收治的拟行TKA治疗的病人142例,男65例,女77例;年龄（73.35±7.30）岁。采用随机数字表法将病人分为观察组和对照组,每组71例。对照组病人术后给予8 h的常规鼻导管低流量（3 L/min）吸氧,观察组在对照组的基础上延长吸氧时间至术后48 h。观察两组术前和术后8、24、48 h简易精神状态检查量表（MMSE）评分和疼痛视觉模拟量表（VAS）评分,术前和术后8、48 h血清炎症因子和免疫功能指标水平;术前和术后24、48 h脉搏血氧饱和度（SpO₂）、心率和呼吸频率情况。结果 观察组术后24、48 h MMSE评分显著高于对照组（P＜0.05）,VAS评分显著低于对照组（P＜0.05）。两组术后24、48 h VAS评分较术前均显著降低（P＜0.05）。对照组术后各时点MMSE评分较术前均显著降低（P＜0.05）,观察组术后8、24 h MMSE评分显著降低（P＜0.05）。观察组术后24、48 h SpO2显著高于对照组（P＜0.05）,心率、呼吸频率显著低于对照组（P＜0.05）。观察组术后48 h白介素-10（IL-10）、CD³⁺、CD⁴⁺、CD⁸⁺、CD⁴⁺/CD⁸⁺水平显著高于对照组（P＜0.05）,白介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）水平显著低于对照组（P＜0.05）。与术前比较,两组术后8、48 h血清IL-6、TNF-α水平均显著升高（P＜0.05）,CD³⁺、CD⁴⁺、CD⁸⁺、CD⁴⁺/CD⁸⁺水平均显著降低（P＜0.05）。结论 术后延长吸氧时间可降低老年TKA病人疼痛,提高病人术后免疫功能,改善炎症因子水平。     

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。     

抗骨质疏松药物对急性骨质疏松性脊柱骨折后放射学特征和临床结果的影响

目的 探讨不同抗骨质疏松药物治疗对急性骨质疏松性脊柱骨折（osteoporotic spinal fracture, OSF）后放射学特征和临床结果的影响。方法 前瞻性纳入120例拟接受保守治疗的老年OSF病人,根据随机数字表将病人分为对照组（40例）、骨吸收抑制剂组（40例）和甲状旁腺激素（parathyroid hormone, PTH）组（40例）,分别在保守治疗的基础上接受安慰剂、双膦酸盐、特立帕肽治疗3个月。比较三组病人治疗前后的数字分级法（numerical rating scale, NRS）疼痛评分、Oswestry功能障碍指数（Oswestry disability index, ODI）、骨折椎体高度丢失比、后凸角和椎骨隐裂（intravertebral cleft, IVC）发生情况。结果 经过3个月治疗,PTH组的NRS评分、ODI均明显低于对照组和骨吸收抑制剂组,骨吸收抑制剂组的上述指标也显著低于对照组,差异均有统计学意义（P均＜0.05）。PTH组和骨吸收抑制剂组的椎体高度丢失比均低于对照组,差异均有统计学意义（P均＜0.05）;但骨吸收抑制剂组和PTH组比较,差异无统计学意义（P＞0.05）。三组病人治疗后的后凸角比较,差异无统计学意义（P＞0.05）。PTH组的IVC发生率显著低于对照组（P＜0.05）,但骨吸收抑制剂组和对照组比较,差异无统计学意义（P＞0.05）。单因素及多因素Logistic回归分析显示MRI Ⅱ型［OR=3.531,95% CI（2.300,5.628）,P＜0.001］是导致骨折愈合不良的独立危险因素,PTH［OR=0.826,95% CI（0.703,0.966）,P=0.018］和骨吸收抑制剂［OR=0.853,95% CI（0.768,0.962）,P=0.006］是预防骨折愈合不良的独立保护性因素。结论 PTH类合成代谢药物可以有效促进骨折愈合、减少椎体塌陷,并显著减轻病人疼痛和促进脊柱功能恢复。     

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.     

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.