低钙透析液对血液透析患者钙磷代谢的长期影响

目的 观察长期应用钙离子浓度为1.25 mmol/L的低钙透析液(LCaD)对血液透析患者钙磷代谢的影响.方法 本研究共纳入38例稳定透析患者,以1.25 mmol/L钙浓度透析液替换原使用的1.75mmol/L钙浓度透析液(HCaD),回顾性观察使用低钙透析液2年后患者血清钙、磷、钙磷乘积、全段甲状旁腺素(iPTH)等指标的变化.结果 与高钙透析液相比,整体观察,采用低钙透析液后患者血钙水平降低[HCaD(2.32±0.23)mmol/L,LCaD(2.21±0.24)mmoI/L;t=2.286,P=0.028],iPTH水平明显升高[HCaD(20.92±16.04)pmoL/L,LCaD(40.02±30.55)pmoL/L;t=-4.029,P=0.000],血磷及钙磷乘积变化不明显.按照基点处iPTH水平分组观察,低iPTH组(iPTH＜11.0 pmol/L)患者的血钙水平较前下降[HCaD(2.46±0.19)mmoL/L,LCaD(2.11±0.23)mmol/L;t=4.047,P=0.002],钙磷乘积下降[HCaD(4.75±1.66)mmol2/L2,LCaD(3.54±0.77)mmol2/L2;t=3.784,P=0.004],血磷保持稳定,iPTH水平中度升高[HCaD(5.67±2.84)pmol/L;LCaD(27.72±27.79)pmol/L;t=-2.490,P:0.032].高iPTH组(iPTH≥11.0 pmol/L)患者的血钙、血磷及钙磷乘积未见显著差异,iPTH水平显著升高[HCaD(27.15±15.43)pmol/L,LCaD(45.03±30.68)pmol/L;t=-3.138,P=0.004].按照基点处血钙水平分组观察,低血钙组(Ca＜2.10 mmol/L)和正常血钙组(ca 2.10-2.37 mmol/L)患者的钙、磷、钙磷乘积基本保持相对稳定.高血钙组(ca＞2.37 mmol/L)患者的血钙水平下降[HCaD(2.52±0.12)mmol/L,LCaD(2.25±0.20)mmol/L;t=4.153,P=0.001],血磷水平保持稳定,钙磷乘积下降[HCaD(4.94±1.19)mmol2/L2,LCaD(4.10±0.80)mmol2/L2;t=2.587,P=0.012].iPTH水平于低血钙组保持相对稳定,于正常血钙组[HCaD(20.18±11.00)pmol/L;LCaD(37.45±32.61)pmol/L;t=-2.351,P=0.032]和高血钙组[HCaD(14.68±12.98)pmol/L,LCaD(40.19±33.20)pmol/L;t=-3.432,P=0.004]均有升高.结论 1.25 mmoL/L钙浓度透析液可应用于多数不同血钙浓度的患者,长期应用低钙透析液可以降低血钙,促进PTH分泌,有利于减少转移性钙化和动力缺失性骨病的发生,但同时增加了继发性甲状旁腺功能亢进的风险.     

不同钙浓度透析液对维持性血液透析患者影响的对照研究

目的观察不同钙浓度(1.25mmol/L和1.75mmol/L)透析液治疗6个月对患者血压、钙、磷和甲状旁腺素影响。方法选择中山大学附属第三医院肾内科维持性血液透析患者20例,首先接受钙离子1.75mmol/L(高钙)透析液治疗6个月,而后接受钙离子1.25mmol/L(低钙)透析液治疗6个月,其它治疗不变。检测两种治疗组入组时、后3个月和6个月患者透析前后血压、血清钙、磷、甲状旁腺素、碱性磷酸酶的水平。结果使用低钙透析液单次治疗4h后血压下降(P<0.05),血钙下降7.5%(P>0.05),甲状旁腺素升高(P<0.05);而高钙透析液治疗后血压和血钙均升高(P<0.05),甲状旁腺素有所下降(P>0.05);治疗6个月后,使用低钙透析液,患者血压下降(P>0.05),血钙下降(P>0.05),血磷和钙磷乘积显著下降(P<0.05),甲状旁腺素升高(P>0.05),碱性磷酸酶升高(P<0.05);两种钙离子浓度透析液应用后收缩压、甲状旁腺素和碱性磷酸酶的变化相比差异有显著性(P<0.05)。结论单次应用低钙透析液进行透析,透析后甲状旁腺素升高,血压下降;与使用高钙透析液相比,长期应用(6个月)低钙透析液进行透析,钙负荷减轻,血钙磷乘积和收缩压下降,血清甲状旁腺素和碱性磷酸酶升高。     

血液透析中应用低钙透析液的临床观察

目的探讨低钙透析透液用于血液透析的有效性及安全性。方法采用稀解释后浓度为1.25 mmol/L碳酸低钙透析液,常规透析治疗20例高钙血症血液透析患者的规律。观察高钙血症血液透析患者在应用碳酸低钙透析液3个月和6个月后,血钙、钙磷乘积、甲状旁腺激素(iPTH)的指标变化及不良反应。结果发现血钙下降水平与低钙透析液使用前比较有明显差异(P<0.05)乘积也有显著性差异(P<0.05)血磷无显著性差异(P>0.05);iPTH无显著性差异(P>0.05)。结论高钙血症的血液透析患者在使用低钙透析液后,血钙下降明显,可有效降低钙磷乘积,可能有益于减轻血液透板患者骨外转移性钙化的发生。     

比较血液透析患者在不同PTH状态下低钙透析液的疗效

目的通过观察不同甲状旁腺激素(PTH)状态下合并高钙血症的血液透析患者应用低钙透析液的疗效,以肯定其实用性。方法选择27例维持性血液透析合并高钙血症患者,根据iPTH水平分为三组:I组血iPTH<120pg/ml,考虑低转运骨病(lowturnoverbonediease,LTBD),共6例;II组血iPTH不相识120～600pg/ml,即PTH合适或轻度甲状旁腺功能亢进组,共13例;III组血iPTH600～1000pg/ml,重度继发甲旁亢需活性维生素D冲击治疗组,共8例;三组患者应用低钙透析液(1.25mmol/L)三个月后比较血清钙、磷、钙磷乘积及血iPTH的变化。结果应用低钙透析液后,三组患者透析前、后血钙都有明显下降(P<0.05),尤其透析后血钙下降更明显(P<0.01);透析前、后血磷变化不大;透析前、后钙磷乘积全部下降(P<0.05);LTBD组iPTH明显升高(P<0.05),其余二组iPTH虽有所升高,但无显著性差异(P>0.05)。观察中不良反应的发生率为6/27(22.2%),主要有肌痉挛、低血压和心律失常,除1例肌痉挛不能耐受而退出以外,余5例经对症处理后尚能坚持完成3个月的观察。结论对不同原因导致的血液透析患者高钙血症,包括活性维生素D冲击治疗及LTBD患者,都适宜个体化的低钙透析液进行透析,可以降低高钙血症及钙磷乘积,但要定期监测血清钙、磷及PTH的变化。     

调整透析液钙浓度对血液透析患者血钙和甲状旁腺激素的影响

目的了解调整透析液钙浓度对血液透析患者血钙和甲状旁腺激素(PTH)的影响.方法选择北京大学第三医院肾脏内科23例血液透析患者,血PTH＞300pg/ml,调整其透析液钙浓度,以观察其血钙和PTH变化.结果按入选时的血钙水平将这些患者分成低血钙组和正常血钙组.将透析液钙浓度从1.25 mmol/L提高到1.5mmol/L后一个月,低血钙组患者的血钙水平显著升高[从(1.92±0.15)到(2.06±0.12)mmol/L,P＜0.001)],同时血PTH水平明显下降[从(615±305)到(306±180)pg/ml,P＜0.001),而正常血钙组患者的血钙和PTH水平变化不大.结论如果同时有低血钙和高PTH血症,提高透析液钙浓度可以使这些血液透析患者的血钙正常并使其血PTH水平下降.     

活性维生素D和低钙透析液治疗血液透析患者继发性甲状旁腺功能亢进的疗效观察

目的探讨新进入血液透析的13例患者使用活性维生素D和低钙透析液（含钙1.25mmol/L）治疗继发性甲状旁腺功能亢进的疗效及不良反应.方法选择北京医院肾内科13例患者首先使用低钙透析液透析,根据继发性甲状旁腺功能亢进的程度给予活性维生素D治疗;观察7～18个月,记录血钙、磷、钙磷乘积和iPTH的变化及其它不良反应.结果治疗2个月时,13例患者血钙明显升高,iPTH水平显著降低（P＜0.05）;钙磷乘积和血磷有所增高（P＞0.05）;在结束观察时,钙磷乘积和血磷较治疗前显著增高（P＜0.05）,血钙、磷和钙磷乘积较治疗2个月时增高（P＞0.05）;11例患者的iPTH在150～320pg/ml范围波动,2例患者iPTH出现反弹.13例患者对低钙透析液的耐受性良好.结论活性维生素D和低钙透析液对新进入血液透析患者的继发性甲状旁腺功能亢进治疗效果良好,对于透析前磷高而钙不低的患者,推荐使用低钙透析液,可减少因服用含钙的磷结合剂所致体内钙负荷增加的危险,达到降低血钙磷乘积和减少心血管钙化的目的.     

低钙透析液用于血液透析的临床观察

目的探讨低钙透析液用于血液透析的有效性及安全性.方法采用稀释后浓度为1.25mmol/L碳酸低钙透析液,常规透析治疗24例高钙血症血液透析患者的规律.结果观察高钙血症血液透析患者在应用碳酸低钙透析液3个月和6个月后,血钙、钙磷乘积、iPTH的指标变化及不良反应.结果发现血钙下降水平与低钙透析液使用前比较有明显差异(P＜0.05);钙磷乘积也有显著性差异(P＜0.05);血磷无显著性差异(P＞0.05);iPTH无显著性差异(P＞0.05).结论高钙血症的血液透析患者在使用低钙透析液后,血钙下降明显、可有效降低钙磷乘积,可能有益于减轻血液透析患者骨外转移性钙化的发生.     

低钙透析液在无动力性骨病中的应用

目的观察低钙透析液对维持性血液透析患者无动力性骨病的临床效果。方法选择该院治疗的24例无动力性骨病血液透析患者,在血液透析过程中采用低钙透析液(钙离子浓度为1.25mmol/L),疗程为6个月,对比观察在低钙透析前后血钙、磷、钙磷乘积、全段甲状旁腺激素(iPTH)等指标的变化、达标率及不良反应发生情况。结果观察结束时,患者血钙、钙磷乘积降低,iPTH升高,差异有统计学意义(P0.05);血磷较低钙透析前有所下降,但差异无统计学意义(P0.05)。结论低钙透析液能改善无动力性骨病被过度抑制的甲状旁腺功能,降低血清高钙负荷。     

醋酸钙联合低钙透析液治疗透析患者高磷血症及对冠状动脉钙化的影响

目的:观察应用口服醋酸钙联合低钙透析液对维持性血液透析患者高磷血症的治疗及对冠状动脉钙化的影响。方法:选择2013年10月~2014年10月本院血液净化中心90例有高磷血症、血钙正常伴不同程度冠状动脉钙化的维持性血液透析(MHD)患者,随机分成治疗组和对照组,治疗组采用低钙透析液(钙浓度为1.25 mmol/L,透析期间口服醋酸钙),对照组采用常规透析液(钙浓度为1.75 mmol/L,透析期间口服醋酸钙),所有患者透析12个月。在透析初始、3个月、6个月、12个月时检测患者血钙、血磷、血清全段甲状旁腺激素(iPTH)、观察前后血压及不良反应,同时用64层MSCT检查患者冠状动脉钙化积分。结果:透析12个月后,治疗组患者血钙水平有所下降,血磷及钙磷乘积显著下降(P0.05),血清全段甲状旁腺激素(iPTH)有所上升(P0.05);对照组血钙、钙磷乘积和iPTH均不同程度上升(P0.05)。全部患者低钙透析不良反应的发生率为7/90(7.8%),主要为肌痉挛、低血压。治疗组在透析3个月、6个月、12个月冠脉钙化积分(CACS)轻微增高,而对照组患者冠脉钙化积分随透析时间延长持续增高。结论:对有高磷血症合并冠状动脉钙化的MHD患者,阶段性采用低钙透析液联合口服醋酸钙的方法,可以有效降低血磷、钙磷乘积,延缓冠状动脉钙化进展速度,值得临床广泛使用。     

醋酸钙联合低钙透析治疗透析患者高磷血症及对冠状动脉钙化的影响

【】目的 观察应用口服醋酸钙联合低钙透析液对维持性血液透析患者高磷血症的治疗及对冠状动脉钙化的影响。方法 选择本院血液净化中心90例有高磷血症、血钙正常伴不同程度冠状动脉钙化的维持性血液透析(MHD)患者,随机分成治疗组和对照组,治疗组采用低钙透析液(钙浓度为1.25mmol/L,透析期间口服醋酸钙),对照组采用常规透析液(钙浓度为1.75mmol/L,透析期间口服醋酸钙),所有患者透析12个月。在透析初始、3个月、6个月、12个月时检测患者血钙、血磷、血清全段甲状旁腺激素(iPTH)、观察前后血压及不良反应,同时用64层MSCT检查患者冠状动脉钙化积分。结果 透析12个月后,治疗组患者血钙水平有所下降,血磷及钙磷乘积显著下降(P＜0.05),iPTH有所上升(P＞0.05);对照组血钙、钙磷乘积和血清全段甲状旁腺激素(iPTH)均不同程度上升(P＞0.05),观察低钙透析不良反应的发生率为7/90(7.8%),主要为肌痉挛、低血压。治疗组在透析3个月、6个月、12个月冠脉钙化积分(CACS)轻微增高,而对照组患者冠脉钙化积分随透析时间延长持续增高。结论 对有高磷血症合并冠状动脉钙化的MHD患者,阶段性采用低钙透析液联合口服醋酸钙的方法,可以有效降低血磷、钙磷乘积,延缓冠状动脉钙化进展速度,值得临床广泛使用。     

Determination of creatine kinase isoenzyme MB activity in serum using immunological inhibition of creatine kinase M subunit activity. Activity kinetics and diagnostic significance in myocardial infarction.

This is a new method for the determination of creatine kinase isoenzyme MB activity in serum. The method uses direct activity measurement of creatine kinase B subunit activity after blocking of CK-M subunit activity by inhibiting antibodies. The test takes no longer than 15 min. The method yields an intra-serial C.V. of 2.0-12.9%, and a C.V. from day to day of 5.5%. The detection limit is 3.4 U/l creatine kinase MB. In the 95 cases with proven myocardial infarction several types of creatine kinase MB activity kinetics could be determined. The percentage of creatine kinase MB of peak CK-total is 6-25%, with a mean of 11.1%. The amount of creatine kinase MB with respect to total CK activity after reinfarction is higher than the amount after initial infarction.     

Dissociable correlates of two classes of retrieval processing in prefrontal cortex

Although substantial evidence suggests that the prefrontal cortex (PFC) implements processes that are critical for accurate episodic memory judgments, the specific roles of different PFC subregions remain unclear. Here, we used event-related functional magnetic resonance imaging to distinguish between prefrontal activity related to operations that (1) influence processing of retrieval cues based on current task demands, or (2) are involved in monitoring the outputs of retrieval. Fourteen participants studied auditory words spoken by a male or female speaker and completed memory tests in which the stimuli were unstudied foil words and studied words spoken by either the same speaker at study, or the alternate speaker. On "general" test trials, participants were to determine whether each word was studied, regardless of the voice of the speaker, whereas on "specific" test trials, participants were to additionally distinguish between studied words that were spoken in the same voice or a different voice at study. Thus, on specific test trials, participants were explicitly required to attend to voice information in order to evaluate each test item. Anterior (right BA 10), dorsolateral prefrontal (right BA 46), and inferior frontal (bilateral BA 47/12) regions were more active during specific than during general trials. Activation in anterior and dorsolateral PFC was enhanced during specific test trials even in response to unstudied items, suggesting that activation in these regions was related to the differential processing of retrieval cues in the two tasks. In contrast, differences between specific and general test trials in inferior frontal regions (bilateral BA 47/12) were seen only for studied items, suggesting a role for these regions in post-retrieval monitoring processes. Results from this study are consistent with the idea that different PFC subregions implement distinct, but complementary processes that collectively support accurate episodic memory judgments.     

俯卧位通气对高海拔地区肺复张治疗无效急性呼吸窘迫综合征患者氧合的影响

目的 探讨俯卧位通气对高海拔地区肺复张术(RM)治疗无效急性呼吸窘迫综合征(ARDS)患者的治疗作用.方法 从海拔2260m的地区医院筛选RM治疗无效的41例ARDS患者[平均氧合指数( PaO2/FiO2)较RM前升高＜20％视为RM无效],依不同病因分为肺内源性ARDS组(ARDSp组)和肺外源性ARDS组(ARDSexp组),每组再按信封法随机分为俯卧位组和仰卧位组,即ARDSp俯卧位组(11例)、ARDSp仰卧位组(9例)、ARDSexp俯卧位组(10例)、ARDSexp仰卧位组(11例).在通气前及通气1、2、3、4h监测动脉血氧分压( PaO2)、PaO2/FiO2、静态顺应性(Cst)、气道阻力(Raw)的变化.结果 通气lh时,ARDSexp俯卧位组PaO2/FiO2( mm Hg,l mm Hg=0.133 kPa)即较通气前显著升高(157.4±40.6比129.3±48.7,P＜0.05),并随通气时间延长呈持续增高趋势,4h达峰值(219.1 ±41.1);且ARDSexp俯卧位组通气3h内PaO2/FiO2较其他3组显著增高,另3组间则差异无统计学意义.ARDSp俯卧位组、ARDSexp俯卧位组通气4h时PaO2/FiO2均较相应仰卧位组显著增高(208.8±39.7比127.4±47.1,219.1±41.1比124.9±50.8,均P＜0.05).4组通气前后Cst无显著改变,各组间差异也无统计学意义.ARDSp俯卧位组通气4h时Raw(cmH2O·L-1·s-1)较通气前显著降低(6.8±1.7比10.7±1.8,P＜0.05),且明显低于其他3组;其他3组各时间点Raw组内及组间比较差异均无统计学意义.结论 俯卧位通气作为ARDS机械通气重要策略之一,可以改善RM无效高原ARDS患者的氧合,为抢救患者赢得宝贵的时间.     

Digital imaging among medical facilities

The Department of Veterans Affairs (VA) in the USA operates a network of 172 medical centres which all utilize a hospital information system (HIS) which has been developed and is currently maintained by the VA. During the past several years, an image management and communication module has been developed, installed and clinically utilized at the Washington DC and Maryland VA Medical Centres. This image management and communication system, referred to as the decentralized hospital computer program (DHCP) imaging system, is fully integrated with a commercial picture archiving and communication system (PACS). The system is utilized to capture, archive, and display all images generated within the hospital including radiology, nuclear medicine, pathology, endoscopy, bronchoscopy, and dermatology, intraoperative photographs, ECG data, and a limited number of paper documents. The ultimate goal of the project is to have all patient text and image data available at any clinical workstation to any authorized user anywhere within the network of medical centres. Clinical requirements for an imaging workstation include ease of use, rapid and reliable access to the complete set of patient information, and images which are of acceptable quality to meet the requirements of the user and the subspecialty. Patient confidentiality and data security must be safeguarded at all times. Integration of the images with the remainder of the patient's database was found to be critical to the success of the project. The experience at the Washington and Maryland facilities suggests that an imaging system that is successfully integrated with a hospital information system can provide substantial clinical and economic benefits both within and among medical centres. Clinical acceptance and utilization of the system has been excellent, particularly in diagnostic radiology where DHCP Imaging has been interfaced to a commercial PAC system. Based upon this initial experience, the VA has begun to deploy the system throughout its large network of medical centres.     

Myocardial elastography at both high temporal and spatial resolution for the detection of infarcts

Myocardial elastography is a novel method for noninvasively assessing regional myocardial function, with the advantages of high spatial and temporal resolution and high signal-to-noise ratio (SNR). In this paper, in-vivo experiments were performed in anesthetized normal and infarcted mice (one day after left anterior descending coronary artery [LAD] ligation) using a high-resolution (30 MHz) ultrasound system (Vevo 770, VisualSonics Inc., Toronto, ON, Canada). Radiofrequency (RF) signals of the left ventricle (LV) in longitudinal (long-axis) view and the associated electrocardiogram (ECG) were simultaneously acquired. Using a retrospective ECG gating technique, 2-D full field-of-view RF frames were acquired at an extremely high frame rate (8 kHz) that resulted in high-quality incremental displacement and strain estimation of the myocardium. The incremental results were further accumulated to obtain the cumulative displacements and strains. Two-dimensional and M-mode displacement images and strain images (elastograms), as well as displacement and strain profiles as a function of time, were compared between normal and infarcted mice. Incremental results clearly depicted cardiac events including LV contraction, LV relaxation and isovolumetric phases in both normal and infarcted mice, and also evidently indicated reduced motion and deformation in the infarcted myocardium. The elastograms indicated that the infarcted regions underwent thinning during systole rather than thickening, as in the normal case. The cumulative elastograms were found to have higher elastographic SNR (SNR(e)) than the incremental elastograms (e.g., 10.6 vs. 4.7 in a normal myocardium, and 6.0 vs. 2.4 in an infarcted myocardium). Finally, preliminary statistical results from nine normal (m = 9) and seven infarcted (n = 7) mice indicated the capability of the cumulative strain in differentiating infracted from normal myocardia. In conclusion, myocardial elastography could provide regional strain information at simultaneously high temporal (>/=0.125 ms) and spatial ( approximately 55 microm) resolution as well as high precision ( approximately 0.05 microm displacement). This technique was thus capable of accurately characterizing normal myocardial function throughout an entire cardiac cycle, at the same high resolution, and detecting and localizing myocardial infarction in vivo.     

Clinical Pharmacokinetics of Morphine

Morphine, the most widely used mu-opioid analgesic for acute and chronic pain, is the standard against which new analgesics are measured. A thorough understanding of the pharmacokinetics of morphine is required in order to safely and effectively use this analgesic in a wide variety of patients with different levels of organ function. A MEDLINE search was conducted to identify literature published between 1966 and January 2002 relevant to the pharmacokinetics of morphine. These publications were reviewed and the literature summarized regarding unique and clinically important elements of morphine disposition relative to its parenteral administration (including intravenous, intramuscular, subcutaneous, epidural and intrathecal administration), absorption profile (immediate release, controlled release, and sublingual/buccal, and rectal administration), distribution, and its metabolism/ excretion. Special populations, including infants, elderly, and those with renal/liver failure, have a unique morphine pharmacokinetic profile that must be taken into account in order to maximize analgesic efficacy and reduce the risk of adverse events.