与正常人群比较2型糖尿病患者骨转换标志物特点及分析

目的研究2型糖尿病患者骨转换标志物的变化情况。方法选取2型糖尿病患者(822例)为T2DM组;健康人群(821例)为对照组。比较两组间的骨转换标志物【血钙,血磷(P),血磷碱性磷酸酶(ALP),总Ⅰ型前胶原氨基端延长肽(tP1NP),Ⅰ型胶原羧基端肽β特殊序列(β-CTX),骨钙素(OC),25羟维生素D(25OHD),甲状旁腺素(PTH)】;并分析T2DM组上述指标与糖化血红蛋(HbA1c),空腹血糖(FPG)、糖尿病病程、年龄等指标的关系。同时根据《维生素D与成年人骨骼健康应用指南(2014年标准版)》将T2DM组患者按25OHD的水平分为维生素D(VitD)充足(≥20 ng/mL)、VitD不足(12～20ng/mL)和VitD缺乏(12 ng/mL)3个亚组,比较分析T2DM患者不同维生素D水平的3个亚组各参数的差别。结果 T2DM组的β-CTX、OC、25OHD水平均低于对照组(P0.05),PTH水平高于对照组(P0.05)。T2DM组中OC的主要影响因素有tP1NP、β-CTX、PTH、HbA1c(标准β=0.533、0.256、0.163、-0.127,P0.05);β-CTX的主要影响因素有OC、tP1NP、HbA1c、年龄(标准β=0.415、0.215、-0.149、-0.077,P0.05),25OHD的主要影响因素有Ca、HbA1c、PTH、P(标准β=0.250、-0.149、-0.155、-0.130,P0.05)。2型糖尿病患者VitD充足组、VitD不足组的FPG、HbA1c水平均低于VitD缺乏组(P0.05),血钙水平均高于VitD缺乏组(P0.05)。VitD充足组、VitD不足组的PTH水平均低于VitD缺乏组(P0.05);三组间tP1NP、β-CTX、OC无明显差异(P0.05)。结论 2型糖尿病患者较正常人群β-CTX、OC、25OHD减低,PTH升高;其改变独立于25OHD的变化;受到血糖代谢的影响。     

股骨粗隆间骨折骨代谢生化指标测定

目的测定股骨粗隆间骨折患者的血骨代谢生化指标以期预测骨折发生的危险性。方法对142例60岁以上老年股骨粗隆间骨折（骨折组）和141例老年骨质疏松但非骨折患者（对照组）进行血骨代谢测定,测定指标包括I型前胶原氨基端延长肽（P1NP）、I型胶原羧基端β特殊序列（β-CTX）、骨钙素（OC）、甲状旁腺素（PTH）、25（OH）D3。结果骨折组P1NP、β-CTX、OC和PTH高于对照组,组间差异有统计学意义（P〈0．05）;两组25（OH）D3差异无统计学意义（P〉0,05）。结论老年骨质疏松患者血骨代谢测定中PINP、PTH、B—CTX和OC增高,可能预测股骨粗隆间骨折风险增高,由此可以识别股骨粗隆间骨折高风险人群并给予及时的抗骨质疏松治疗。     

2型糖尿病合并微血管病变与骨转换标志物的相关性

目的探讨2型糖尿病合并微量白蛋白尿、视网膜病变患者骨转换标志物的变化。方法选取301名成人2型糖尿病患者,将合并微量白蛋白尿和(或)视网膜病变患者作为试验组,无微量白蛋白尿和视网膜病变患者作为对照组,运用统计学分析比较两组间I型原胶原N-端前肽(procollagentype I N-terminal propeptide,PINP)、β-异构C-端肽(beta-isomerized Ctelopeptide,β-CTX)以及相关资料的差异,并对两组骨转换标志物进行相关性分析。结果两组间血清PINP的比较,差异无统计学意义(P0.05);试验组β-CTX明显高于对照组(P=0.001);相关分析显示β-CTX与BUN(γ=-0.431,P=0.013)、Cr(γ=-0.602,P=0.013)、UA(γ=-0.538,P=0.012)、25(OH)D3(γ=-0.703,P=0.036)呈负相关,与HbA1c(γ=0.235,P=0.030)、PTH(γ=0.652,P=0.000)呈正相关。结论 2型糖尿病合并微量白蛋白尿和视网膜病变时,β-CTX明显增高,认为β-CTX可能成为监测2型糖尿病微血管病变患者骨代谢变化的特异性指标。     

探讨糖尿病患者的骨转换标志物的变化与骨质疏松的关系

目的探讨不同血糖控制水平糖尿病患者的骨转换情况与骨质疏松的关系,为控制患者骨折风险提供参考依据。方法将2017年1月至2018年9月于北京大学国际医院内分泌科就诊的患者494例纳入研究,分别测定糖化血红蛋白(glycosylated hemoglobin,HbA1c)与25羟维生素D(25-hydroxyvitamin D,25-VD),I型胶原氨基延长肽(type I collagen amino-lengthening peptide,P1NP),β胶原降解产物(β-crosslaps,β-Cross),骨钙素(osteocalcin,OC)。按糖化血红蛋白水平将糖尿病患者分为A组(HbA1c7.0%)、B组(7.0%≤HbA1c9.0%)、C组(HbA1c≥9.0%),同期非糖尿病体检人群45例作为对照组。对不同分组的测定结果进行统计分析。结果糖化血红蛋白与25羟维生素D、I型胶原氨基延长肽、β胶原降解产物、骨钙素均存在负相关关系(P0.05),相关系数分别为-0.11、-0.10、-0.10、-0.19.对照组4项骨代谢标志物均高于A、B、C 3个糖尿病患者组(P0.05),糖尿病患者A组的骨钙素水平高于B组和C组(P0.05)。结论糖尿病患者血糖控制情况影响骨转换标志物水平。骨钙素在骨转换标志物中是更为敏感的实验室检测指标,可能在糖尿病患者骨质疏松的诊断和治疗监测中更值得关注。     

绝经后女性骨密度与骨代谢生化指标的相关性分析

目的分析绝经后女性骨密度(bone mineral density,BMD)与骨代谢生化指标的相关性。方法选取西南医科大学附属医院2017年1月至2018年12月收治的绝经后女性患者151例。根据骨密度T值将患者分为骨质疏松组(83例)、骨量低下组(47例)和骨量正常组(21例),比较三组患者骨代谢生化指标的差异,并对各项指标与BMD进行相关性分析。结果骨质疏松组甲状旁腺素(PTH)、Ⅰ型前胶原氨基末端前肽(P1NP)、Ⅰ型胶原羧基端肽β特殊序列(β-CTX)显著高于骨量低下组和骨量正常组(P0. 05),骨量低下组显著高于骨量正常组(P0. 05)。骨质疏松组体质量指数(bone mass index,BMI)、25(OH) D_3显著低于骨量低下组和骨量正常组(P0. 05),骨量低下组显著低于骨量正常组(P0. 05)。血钙、血磷、骨钙素(BGP)、血清的骨特异性碱性磷酸酶(BALP)在三组之间比较,差异无明显统计学意义(P0. 05)。Spearman相关分析显示,PTH、P1NP、β-CTX与骨密度呈负相关(r=-0. 538,-0. 520,-0. 462,P 0. 05),25(OH) D_3与骨密度呈正相关(r=0. 517,P0. 05),血钙、血磷、BALP、BGP与骨密度无相关性(P0. 05)。结论血清25(OH) D_3、PTH、P1NP、β-CTX与骨密度存在显著相关性,骨代谢生化指标监测有助于绝经后女性骨质疏松的早期诊断。     

绝经后女性2型糖尿病伴骨质疏松患者骨密度与骨代谢指标的相关性分析

目的分析研究绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标的相关性。方法选取2013年10月至2017年05月于重庆医科大学附属第一医院内分泌内科住院的绝经后女性2型糖尿病患者385名。搜集其基本资料、骨代谢指标及骨密度等。根据T值将这些患者分为骨质疏松组(233例)、骨量减少组(101例)和骨量正常组(51例),比较三组间骨代谢指标的变化,并对骨密度(bone mineral density,BMD)与各项骨代谢指标进行相关性分析。结果 1型前胶原氨基末端前肽(Type I procollagen N-terminal propeptide,P1NP)、骨钙素(bone Gla protein,BGP)在骨质疏松组显著高于骨量减少组、骨量正常组(P0.05);随着骨密度的降低,1型胶原羧基端肽β特殊序列(β-Carboxyl terminal peptide,β-CTX)逐渐升高,骨质疏松组、骨量减少组与骨量正常组相比较差异有统计学意义(P0.05);Spearman等级相关分析示P1NP、BGP、β-CTX与骨密度呈负相关,25(OH)D_3与骨密度呈现正相关。结论绝经后女性2型糖尿病伴骨质疏松症患者骨密度与骨代谢指标有一定的相关性,有助于预测骨折风险并及时抗骨质疏松治疗。     

老年2型糖尿病患者血尿酸水平与骨代谢、骨密度及骨质疏松的关系

目的探讨老年2型糖尿病患者血尿酸水平与骨代谢标志物、骨密度及骨质疏松的相关关系。方法选取2018-2019年于北京大学国际医院内分泌科门诊就诊及住院的年龄60岁以上的老年2型糖尿病患者,共计577人,其中男性289人,女性288人(均为绝经后女性)。对所有研究对象进行一般临床资料调查、生化指标及甲状旁腺素(PTH)、25羟维生素D[25(OH)D]、骨钙素(OC)、血清I型前胶原N-末端前肽(P1NP)、I型胶原交联C-末端肽(β-CTX)测定,计算估算肾小球滤过率(eGFR),双能X线吸收法(DXA)测定股骨颈(FN)及腰椎(L1~4)骨密度(bone mineral density,BMD)。将血尿酸(SUA)四分位法分层比较分析股骨颈及腰椎总BMD变化趋势,Pearson和Spearman相关分析SUA与血钙(Ca)、PTH及OC、P1NP、CTX、25(OH)D、腰椎及股骨颈BMD的关系,多因素Logistic回归分析SUA与骨质疏松的关系。结果SUA第4分组BMI、肌酐(Cr)、股骨颈及总腰椎BMD水平明显高于第1分位组,SUA第4分组eGFR水平明显低于第1分位组,差异具有统计学意义(P<0.05);Pearson相关分析显示SUA与股骨颈BMD(r=0.082,P=0.002)、糖尿病病程(r=0.129,P=0.005)、BMI(r=0.201,P=0.000)正相关,与eGFR负相关(r=-0.434,P=0.000),Spearman相关分析显示SUA与腰椎总BMD(r=0.168,P=0.003)、Ca(r=0.147,P=0.001)正相关,与β-CTX负相关(r=-0.157,P=0.001),与PTH、25(OH)D、OC、P1NP无相关性(P>0.05)。以老年2型糖尿病合并骨质疏松为因变量,多因素Logistic回归显示,调整年龄、eGFR、BMI、HbA1c后,SUA是老年2型糖尿病患者发生骨质疏松的保护因素(P=0.039,OR=0.452,95%CI:0.212~0.962)。结论在老年2型糖尿病患者中,正常偏高的血尿酸水平可能减少骨质疏松的发生风险。     

性激素及甲状旁腺激素与老年男性骨转换生化指标的相关性分析

目的:探讨老年男性血清性激素及甲状旁腺激素与骨转换生化指标的相关性。方法:收集2011年5~6月在我院常规年度体检年龄≥60岁的老年男性465例,年龄60~93岁。测定血清卵泡刺激素(FSH)、黄体生成素(LH)、雌二醇(E2)、睾酮(T)、性激素结合球蛋白(SHBG);血清甲状旁腺激素(PTH)、25-羟化维生素D3(25(OH)D3);骨转换生化指标(I型胶原羧基末端肽:CTX;骨钙素:OC;Ⅰ型前胶原氨基末端前肽:PINP);并计算游离睾酮(FT)、生物可利用睾酮(BT)、睾酮分泌指数(TSI)和游离睾酮指数(FTI);分析各指标与老年男性骨转换生化指标的相关性。结果:老年男性血清FSH、LH、SHBG水平随年龄增加而升高,而FT、BT、TSI、FTI、PTH及CTX、OC和PINP随增龄呈下降趋势,80岁以后下降较为显著(P0.05)。PTH与CTX、OC和PINP均呈正相关(r=0.227,0.269,0.162;P0.01),校正年龄因素后,相关性仍然存在;SHBG与OC负相关(r=-0.100,P0.05)。各骨转换指标随PTH四分位水平升高而增加,第一分位与第四分位之间均存在显著差异(P0.01)。多元逐步回归结果显示,年龄与CTX、OC和PINP负相关(β=-0.126,-0.141,-0.122;P0.05),PTH与CTX、OC和PINP正相关(β=0.196,0.279,0.189;P0.001),SHBG与OC负相关(β=-0.100,P0.05)。结论:增龄是老年男性骨转换减低的根本原因,血清PTH和SHBG水平与骨转换生化指标相关。     

中老年2型糖尿病周围神经病变患者骨代谢指标变化研究

目的探讨中老年2型糖尿病合并周围神经病变与骨代谢指标β-CTX、PINP之间的相关性。方法选取遵义医科大学附属医院内分泌科2017年10月至2018年8月的2型糖尿病患者189例,基于患者有无合并周围神经病变进行分组,将患者划分为合并病变组(DPN组)和未合并病变组(NDPN组),两组分别为97例和92例。测定各组FPG、HbA1c、C肽、FIns、HOMA-IR、TG、TC、LDL-C、HDL-C、Ca、P、BMD(L2-L4、Neck、Troch、Ward’s三角)、β-CTX、PINP水平。结果与NDPN组比较,DPN组FPG、HbA1c、FIns、HOMA-IR、TG均高于NDPN组,而P、HDL-C、腰椎L2-L4、股骨颈Neck、Troch处BMD、β-CTX、PINP低于NDPN组(P<0.05);Pearson相关性分析显示,β-CTX与FPG呈负相关(r=0.484,P<0.05);PINP与HDLC、P呈正相关(r分别为0.242、0.309,P<0.05),与HbA1c、HOMA-IR、股骨颈Neck呈负相关(r分别为-0.173、-1.460、-0.237,P<0.05)。结论DPN患者血清β-CTX、PINP水平降低,骨转换指标异常,可能具有更高的骨折风险。     

女性护骨素和转化生长因子-β水平对骨转换率的影响

目的了解女性护骨素(OPG)和转化生长因子-β(TGF-β)与骨转换指标的关系及其对骨转换指标的影响。方法研究长沙地区691名健康女性(年龄20~80岁)的血清OPG、TGF-β1和TGF-β2,以及血清骨特异性碱性磷酸酶(BAP)、骨钙素(OC)、血清I型胶原N-末端肽(sNTX)、血清I型胶原C-末端肽(sCTX)、尿NTX(uNTX)、尿CTX(uCTX)和尿脱氧吡啶酚(uDPD),并分析这些细胞因子与各种骨转换指标之间的关系。结果血清OPG和TGF-β2与血清BAP、OC、uNTX、uCTX和uDPD呈显著正相关(r=0.145~0.397,P均=0.000),血清TGF-β1与BAP、OC、sCTX、uNTX和uCTX呈显著负相关(r=-0.114~-0.286,P均=0.004~0.000)。调整年龄和BMI之后,它们之间的偏相关系数多数仍然有意义。多元线性回归分析显示,OPG和TGF-β2对BAP、uNTX和uCTX是一个正性决定因素,可分别解释这些指标0.6%~16.6%的变异。TGF-β1对BAP、OC、和uCTX是一个负性决定因素,可以分别解释这些指标变异的0.7%~7.3%。结论本研究揭示了女性OPG和TGF-β与骨转换指标的关系,提示循环中的OPG和TGF-β是骨转换速率的重要决定因素。     

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.     

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.     

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.     

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.