绝经后女性骨质疏松性椎体压缩骨折腰椎椎旁肌肉的质与量：基于MRI的病例对照研究

目的 基于MRI探讨绝经后女性腰椎椎旁肌肉的质量与骨质疏松性椎体压缩骨折（osteoporotic vertebral compression fractures，OVCF）的关系。方法 收集我院2014年8月至2018年10月收治的绝经后女性单节段OVCF病例，按1∶1年龄配对选择同时期收治的腰椎退变病例，分别纳入观察组和对照组。最终两组各纳入48例。基于两组病人的腰椎MRI，测量L_3/4、L_4/5椎间盘水平横断面的椎间盘面积和椎旁肌（竖脊肌、多裂肌、腰大肌）面积，计算腰肌性和脂肪退变比率，并比较两组间上述指标的差异。结果 观察组病人L_3/4、L_4/5椎间盘水平的腰肌性分别为241.6%±85.4%、269.8%±78.3%，明显低于对照组的275.6%±92.7%、314.8%±85.3%；脂肪退变比率分别为13.6%±5.4%、15.9%±6.5%，明显高于对照组的9.7%±2.5%、9.4%±2.6%；组间比较，差异均有统计学意义（P均＜0.05）。结论 绝经后女性OVCF病人的肌肉净含量减少，肌肉的脂肪浸润程度增加，需要进一步研究证实椎旁肌质量与OVCF的关系以及改善肌肉质量对OVCF发生率的影响。     

慢性腰痛对脊旁多裂肌萎缩影响的临床研究

目的：明确慢性腰痛对脊旁多裂肌净横截面积大小及脂肪化程度的影响。方法：2010年3月至2013年8月对门诊治疗的腰痛患者进行回顾性分析,最终筛选出31例符合非特异性慢性腰痛患者,其中男19例,女12例;年龄23～55岁,平均36.4岁。主要症状是反复腰痛,病程大于1年,X线、CT、MRI均未见明显异常。采用MRI成像测量同一病例先后不同时间点多裂肌净横截面积及T2信号比率的变化,再获取2次MRI检查时VAS和Oswestry功能障碍评分,分析先后2次测量多裂肌净面积及T2信号比率的变化与腰痛的病程、VAS、Oswestry功能障碍评分的相关性,从而得出腰痛对脊旁多裂肌的影响。结果：同一病例第2次MRI检查多裂肌净横截面积明显小于第1次MRI检查,T2信号比率则明显高于第1次MRI检查（P<0.05）.多裂肌净横截面积减小率与VAS评分、病程和Oswestry功能障碍评分均呈正相关（P<0.001）,而T2信号比率增加率与VAS评分、病程和Oswestry功能障碍评分均无相关性（P>0.05）.结论：慢性腰痛是脊旁多裂肌萎缩和脂肪化的重要原因,腰痛时间、程度和功能障碍程度均与多裂肌萎缩呈正相关。     

单侧双通道内镜单纯髓核摘除术对椎旁肌肉的影响

目的 研究单侧双通道内镜单纯髓核摘除术（unilateral biportal endoscopic discectomy，UBED）对于椎旁肌肉的影响，并评估椎旁肌肉改变与随访时间的相关性。方法 回顾性分析2020年3月至2021年12月就诊于我院脊柱外科并接受UBED手术治疗的42例病人的临床资料。所有病人在术前、术后、末次随访时均行MRI检查。收集病人基本信息、末次随访时间、MRI图像、腰部和腿部的疼痛视觉模拟量表（visual analogue scale，VAS）评分及Oswestry功能障碍指数（Oswestry disability index，ODI）。结果 与术前相比，手术侧多裂肌术后信号强度、水肿面积均明显上升［41.02±14.40 vs. 19.14±10.11，（26.95±14.70） cm² vs. （10.17±5.41） cm²］；与非手术侧相比，术后手术侧多裂肌信号强度、横截面积、水肿面积占比明显升高［41.02±14.40 vs. 21.92±11.07，（39.27±12.82）cm² vs. （33.66±11.79）cm²，26.95%±14.70% vs. 11.53%±7.06%］；上述指标比较，差异有统计学意义（P＜0.05）。手术对于竖脊肌上述指标的改变未见统计学意义（P＞0.05）。手术侧多裂肌信号强度、水肿面积占比均与随访时间存在显著负相关（r=-0.53、r=-0.47）。结论 UBED对于椎旁肌肉的影响集中于手术侧多裂肌，但其损伤是可逆的。     

腰椎滑脱症患者椎旁肌入路术后采用近红外线局部照射的疗效观察

目的 分析探讨腰椎滑脱症椎旁肌入路术后结合近红外线局部照射的临床效果,为临床应用提供科学依据。方法 2011年3月至2012年3月因为腰椎滑脱症收住开封市中心医院骨科的患者,符合纳选条件的患者随机数字表分为手术组（39例）和近红外线组（33例）,手术组实施单纯的椎旁肌入路减压复位内固定手术,近红外线组实施椎旁肌入路减压复位内固定手术,切口拆线后开始实施近红外线局部照射,随访1.5年,记录比较术前及术后1.5年患者视觉模拟疼痛评分（visual analogue scale,VAS）、Oswestry功能障碍指数（Oswestry disability index,ODI）和椎旁肌CT冠状面面积（S值）并计算差值。结果 近红外线组患者术后1.5年VAS评分为（1.46±0.21）分、ODI为0.21±0.17、S值为（4.87±0.27） cm²,与手术组的VAS评分[（3.97±0.39）分]、ODI（0.30±0.24）、S值[（4.36±0.18） cm²]相比,差异均具有统计学意义（均P＜0.01）;近红外线组患者VAS评分、ODI评分、S值术前与术后1.5年的差值分别为（4.42±0.97）分、0.51±0.38、（0.45±0.57） cm²,手术组患者术前与术后1.5年的差值分别为（3.89±1.14）分、0.42±0.61、（1.25±0.40） cm²,两组比较差异均具有统计学意义（均P＜0.01）。结论 椎旁肌入路结合近红外线局部照射是治疗腰椎滑脱症的一种有效方法,值得在临床中推广应用。     

CT测量腹部脂肪相关参数诊断冠心病

目的 探讨CT测量腹部脂肪相关参数对诊断冠心病的价值。方法 对211例疑诊冠心病患者于30天内行冠状动脉造影及腹部CT平扫，分析冠心病发生危险因素，采用ROC曲线观察各危险因素单独及联合诊断冠心病的效能。结果 211例中，经冠状动脉造影明确诊断冠心病112例，非冠心病99例。单因素分析结果显示，冠心病与非冠心病患者间年龄、性别、吸烟、糖尿病、高血压、高密度脂蛋白胆固醇（HDL-C）、内脏脂肪（VAT）面积、皮下脂肪（SAT）面积及VAT面积/SAT面积（VAT/SAT）差异均有统计学意义（P均<0.05），体质量指数（BMI）、腹围（WC）及腹部总脂肪（TAT）面积差异均无统计学意义（P均>0.05）。多元Logistic回归分析结果显示，年龄、吸烟、糖尿病及VAT/SAT为冠心病独立危险因素（P均<0.01）。ROC曲线显示年龄、吸烟、糖尿病及VAT/SAT诊断冠心病的AUC分别为0.67、0.61、0.62及0.73，4者联合的AUC为0.80，高于各参数单独检测（P均<0.05）。结论 CT测量的腹部脂肪相关参数可用于诊断冠心病。     

对比冷冻消融与微波消融治疗兔VX2椎旁肿瘤的有效性及安全性

目的 对比冷冻消融（CA）与微波消融（MWA）治疗兔VX2椎旁肿瘤的有效性及安全性。方法 选取48只新西兰大白兔建立VX2椎旁肿瘤模型并随机分为CA组（n=24）及MWA组（n=24）,比较组间完全消融率、生存率、布里斯托尔兔疼痛量表（BRPS）评分及并发症发生率。结果 CA组完全消融率及治疗后21天生存率分别为91.67%（22/24）及33.33%（8/24）,均高于MWA组［66.67%（16/24）及16.67%（4/24）］（P均＜0.05）。CA组治疗后4 h、1天、4天、7天及14天BRPS评分均低于MWA组（P均＜0.001）;2组上述时间点BRPS评分均低于治疗前（P均＜0.05）。CA组并发症发生率（3/24,12.50%）低于MWA组（8/24,33.33%）（P＜0.05）。结论 CA治疗兔VX2椎旁肿瘤的安全性及有效性均优于MWA。     

CT肝-膈肌间脂肪疝入征及右膈肌增厚征诊断早期肝硬化

目的 观察CT所见肝-膈肌间脂肪疝入征及右膈肌增厚征用于诊断早期肝硬化的价值。方法 对47例临床诊断早期肝硬化患者(肝硬化组)及45名健康体检者(对照组)行上腹部CT,于门静脉期薄层CT图像显示右侧肾上腺层面测量肝-膈肌间脂肪面积、肝-膈肌脂肪横径(F)、肝右叶横径(D)及双侧膈肌厚度,以F/D值≥0.5为肝-膈肌间脂肪疝入征阳性,以右膈肌与左膈肌厚度之差＞2 mm为右侧膈肌增厚征阳性。比较组间相关CT参数差异,绘制受试者工作特征(ROC)曲线,计算曲线下面积(AUC),评估CT所见肝-膈肌间脂肪面积、肝-膈肌间脂肪疝入征阳性及右侧膈肌增厚征阳性诊断早期肝硬化的效能。结果 组间肝-膈肌间脂肪面积、F/D值、肝-膈肌间脂肪疝入征阳性率、双侧膈肌厚度之差及右膈肌增厚征阳性率差异均有统计学意义(P均＜0.01)。根据肝-膈肌间脂肪面积、肝-膈肌间脂肪疝入征阳性及右膈肌增厚征阳性诊断早期肝硬化的AUC分别为0.67、0.78及0.79,敏感度分别为57.40%、85.10%及72.30%,特异度分别为80.00%、66.70%及82.20%。结论 CT所见肝-膈肌间脂肪疝入征及右膈肌增厚征有助于诊断早期肝硬化。     

微创经椎间孔入路腰椎椎间融合术治疗单节段腰椎退行性疾病对椎旁肌的影响

目的 对比微创经椎间孔入路腰椎椎间融合术（MIS-TLIF）与传统开放TLIF治疗单节段腰椎退行性疾病的临床疗效及椎旁肌损伤变化。方法 2017年1月—2020年1月收治单节段腰椎退行性疾病患者41例,其中18例采用MIS-TLIF治疗（MIS-TLIF组）,23例采用TLIF治疗（对照组）。记录2组患者卧床时间、住院时间,术前和术后1、3、5 d血清肌酸激酶（CK）、白介素-6（IL-6）水平;术前及术后6、12个月采用疼痛视觉模拟量表（VAS）评分和Oswestry功能障碍指数（ODI）评估患者腰腿痛程度和腰椎功能状况。在术前、术后12个月MRI上测量手术节段及邻近节段多裂肌横截面积（MCSA）,并计算其变化率。结果 所有手术顺利完成,患者随访（12.40±0.35）个月。MIS-TLIF组术后卧床时间、住院时间均短于对照组,差异有统计学意义（P < 0.05）。2组CK、IL-6血清浓度在术后呈显著升高趋势,其峰值均出现在术后1 d,术后3、5 d逐渐下降;MIS-TLIF组术后1 d的CK、IL-6血清浓度显著低于对照组,差异有统计学意义（P < 0.05）。2组术后6、12个月的VAS评分、ODI较术前显著改善,MIS-TLIF组术后6个月的ODI较对照组更低,差异均有统计学意义（P < 0.05）。2组中各10例患者末次随访时复查腰椎MRI,MIS-TLIF组术后12个月责任节段MCSA显著大于对照组,MCSA减少率显著低于对照组,差异均有统计学意义（P < 0.05）。而MIS-TLIF组术后12个月邻近节段MCSA与对照组相比,差异无统计学意义（P > 0.05）;但邻近节段MCSA减少率显著低于对照组,差异有统计学意义（P < 0.05）。结论 MIS-TLIF较传统开放手术具有切口小、组织损伤少、功能康复快等特点,且在术后早期患者全身炎性反应更轻,术后中期对多裂肌的干扰更小。     

椎间孔镜下经椎板间入路髓核摘除术与开窗髓核摘除术治疗L5S1椎间盘突出的疗效分析

目的：探讨椎间孔镜下经椎板间入路髓核摘除术与开窗髓核摘除术治疗L₅S₁椎间盘突出的临床疗效。方法：回顾性分析2014年1月至2017后3月收治的L₅S₁椎间盘突出并获得随访患者86例,依据手术方法不同分成椎间孔镜组（43例）及开窗组（43例）。所有手术在全身麻醉下进行,椎间孔镜组采用全脊柱内镜经椎板间入路髓核摘除术（percuteneous endoscopic interlaminar discectomy,PEID）,开窗组采用经典开窗髓核摘除术（fenestration discectomy,FD）。比较两组患者的切口长度、手术时间、出血量、住院时间、术后卧床时间、并发症等一般情况,记录手术前后患肢疼痛及腰部疼痛的VAS评分,观察两组患者术后血清肌酸激酶的变化,采用改良的Macnab标准评定疗效,并通过MRI观察术后椎旁肌残存率。结果：PEID组及FD组皮肤切口长度分别为（0.7±0.1）cm和（5.0±1.8）cm,出血量分别为（8.0±3.0）ml和（62.0±50.5）ml,住院时间分别为（3.0±1.5）d和（11.0±2.5）d,术后卧床时间分别为（1.0±0.5）d和（3.0±0.8）d,两组比较差异有统计学意义（P<0.05）。术后24 h及术后1年两组患肢疼痛VAS评分较术前均明显降低（P<0.05）,但组间比较差异无统计学意义（P>0.05）。PEID及FD组术后24 h腰痛VAS评分分别为2.99±0.32和5.44±1.31,术后1年分别为1.56±0.60和3.05±0.24,两组比较差异有统计学意义（P<0.05）。FD组肌酸激酶术后24、48 h较PEID组明显升高（P<0,05）。术后1年,PEID及FD组Macnab优良率分别93%和95%。通过MRI观察,PEID组术后1年椎旁多裂肌残存率明显高于开窗组（P<0.05）。两组患者均未发生硬脊膜撕裂、神经根损伤、血管损伤、椎间隙感染等并发症。结论：两种方法在治疗L₅S₁椎间盘突出患者均安全可靠,可取得满意效果,但在椎旁肌保护、手术切口、出血量、住院时间及术后卧床时间等指标上,椎间孔镜更具优势,更符合微创理理念。     

椎管扩大椎板成形术联合MRI T2加权像髓内高信号节段单侧侧块螺钉内固定治疗多节段脊髓型颈椎病

目的 探讨椎管扩大椎板成形术联合MRI T2加权像髓内高信号（ISI）节段单侧侧块螺钉内固定治疗多节段脊髓型颈椎病（MCSM）的临床疗效。方法 2015年1月—2019年1月收治伴MRI T2加权像髓内ISI的MCSM患者59例，其中26例采用椎管扩大椎板成形术联合MRI T2加权像髓内ISI节段单侧侧块螺钉内固定治疗（A组），33例采用单纯椎管扩大椎板成形术治疗（B组）。记录2组手术时间、术中出血量及并发症发生情况。采用日本骨科学会（JOA）评分及其改善率评价神经功能状态。在颈椎X线片上测量C_2~7 Cobb角，计算颈椎整体活动度（ROM）。测量髓内信号改变比值（SCR=ISI区域光密度值/C₇ ~ T₁正常区域光密度值），定量评估髓内ISI程度，并进一步分析SCR变化值对JOA评分及其改善率的影响。结果 所有手术顺利完成。2组手术时间、术中出血量差异无统计学意义（P > 0.05）。A组术后JOA评分及其改善率、术后SCR及其变化值明显高于B组，差异均有统计学意义（P < 0.05）。2组术后C_2~7 Cobb角、颈椎整体ROM及其保留率差异无统计学意义（P > 0.05）。2组并发症发生率差异无统计学意义（P > 0.05）。SCR变化值显著改变组的JOA评分改善率最高，中度改变组次之，轻度改变组最低，3组间两两相比，JOA评分改善率差异均有统计学意义（P < 0.05）。结论 对于伴MRI T2加权像髓内 ISI的MCSM患者，椎管扩大椎板成形术联合MRI T2加权像髓内ISI节段单侧侧块螺钉内固定具有较好的临床和影像学结果，尤其在术后髓内ISI的改善方面具有一定优势。     

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.     

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.