妇科择期手术与血清钾离子浓度变化的关系

目的探讨妇科择期手术患者血清钾离子浓度(血钾)的变化。方法前瞻性测定75例妇科择期手术患者手术前后的血钾及术前血红蛋白、血清白蛋白、肌酐水平;记录术前禁食时间、手术时间和术中补液量、输血量、出血量及尿量,比较手术前后血钾差异,分析术后影响血钾的相关因素。结果妇科择期手术患者术后当日血钾低于术前[(3.60±0.38)mmol/L与(3.86±0.32)mmol/L,t=5.763,P<0.01],术后次日血钾亦低于术前[(3.58±0.34)mmol/L与(3.86±0.32)mmol/L,t=5.518,P<0.01]。术后低钾血症组其术前血钾低于非低钾血症组[(3.79±0.32)mmol/L与(3.94±0.30)mmol/L,t=-2.043,P<0.05]。相关分析显示术后当日血钾与术前血钾正相关(r=0.293,P<0.05),与术前禁食时间负相关(r=-0.237,P<0.05)。术后次日血钾与术前血钾、术中输血量及手术当日血钾正相关(r值分别为0.255、0.268及0.404,P<0.05或P<0.01)。结论妇科择期手术患者术后血钾低于术前。术后血钾与术前血钾正相关,与术前禁食时间负相关。为避免术后低钾血症的发生,妇科择期手术患者应将术前血钾提高到3.95 mmol/L左右,术前禁食时间较长的患者可适当予以静脉补钾。术后当日应及时补钾,避免血钾进一步降低。     

高浓度静脉补钾治疗低钾血症的临床研究

目的：探讨高浓度静脉补钾治疗低钾血症的有效性和安全性。方法：70例低钾血症随机分为慢速组和快速组,根据公式[钾剂量(mmol)=(4．5-血钾浓度)×公斤体重×0．2]计算需要的补钾量,注射氯化钾的浓度均为200mmol/L,两组的速度分别为10mmol／h和20mmol／h。测定补钾前后的血钾浓度、尿量和尿钾浓度。计算细胞外液钾含量、尿排钾量、净补钾量和钾跨细胞转移量等指标。结果：两组补钾前血钾浓度、需要的补钾量和尿钾浓度相似。但慢速组与快速组相比,钾注射时间长[(2．10±0．18)h比(0．97±0．21)h,P<0．01],补钾后血钾浓度较低[(3．44±0．62)mmol／L比(3．94±1．22)mmol/L,P<0．05],尿排钾量较多(7．13±1．47)mmol／L比[(3．67±0．75)mmol,P<0．01],钾跨细胞转移量较多[(5．16±1．31)mmol／L比(3．35±2．73)mmol,P<0．05]。两组中均未见高钾血症及与之相关的一过性心律失常。结论：本研究中设定的补钾方法是安全的。快速组更有效,可能与肾排钾和钾跨细胞转移较少有关。     

心脏瓣膜置换术后低血钾的监护

目的：通过43例心脏瓣膜置换术后血清钾的动态监测，维持血清钾浓度在4．5-5．0mmol／L，防治心律失常。方法：密切观察有无低血钾症状，动态监测血气分析、电解质等结果，以作为补钾依据。每500ml尿补钾1．0g，每小时补钾量≤3．0g。结果：低血钾引起的心律失常得到了纠正。单瓣膜置换术后病人血清钾为4．0-4．5mmol／L，双瓣膜置换术病人血清钾为4．5—5．0mmol/L。结论：维持血清钾的正常浓度，减少低钾血症的发生，对于瓣膜置换术后安全渡过危险期(术后72h)有重要意义。     

心脏疾病术后高浓度静脉补钾的观察与护理

正常人血清钾浓度为3.5～5.5mmol/L,当血清钾的浓度低于3.5mmol/L,时,称为低血钾症.低血钾时,易引起多个系统功能紊乱,易发生恶性心律失常甚至危及生命.心脏疾病术后要求严格控制入量,常规浓度补钾由于入液量的控制,往往不能纠正低血钾.目前临床常用高浓度静脉补钾.补钾浓度大于0.4%即称为高浓度补钾[1].2003年2月～2006年2月我们对心脏疾病术后出现低血钾症的55例患者进行高浓度静脉补钾治疗,效果良好,现就高浓度静脉补钾的护理总结报告如下.     

1例低钾危象病人行超高钾浓度置换液CVVH救治的护理

钾是人体内重要的电解质之一,对维持细胞的正常代谢与酸碱平衡、细胞膜的应激性和心肌的正常功能有重要作用.正常血钾浓度为3.5 mmol/L～5.5 mmol/L,当血清钾低于3.5mmol/L时称为低钾血症,当血清钾低于2.0 mmol/L时称为严重低钾血症[1].病人可突然出现难以解释的面色苍白或灰暗、软弱无力、意识变化、抽搐、昏迷、呼吸困难、心音低钝或心律失常、腹胀明显等情况,容易并发呼吸衰竭[2].因此,快速准确判断低钾血症,并给予及时有效的治疗和护理至关重要.通常所用的静脉输液补钾、口服补钾、超声雾化补钾、灌肠补钾以及食物补钾在剂量、速度、安全性等方面存在一定不足.我院采用超高钾浓度置换液配方行持续静脉-静脉血液滤过(CVVH)方式成功救治1例代谢性酸中毒合并重度低钾血症的病人.现将护理报告如下.     

冠状动脉介入治疗术后电解质紊乱观察

目的:观察冠状动脉介入治疗(percutaneous coronary intervention,PCI)后患者血清钾、钠、氯离子浓度变化并进行初步分析.方法:接受PCI治疗患者58例,其中男38例,平均年龄(57.5±9.70)岁;女20例,平均年龄(63.45±6.74)岁.入选患者均为冠心病、不稳定型心绞痛,符合2007年12月ACC/AHA发布的PCI治疗指南中规定的不稳定型心绞痛PCI治疗指征.所有患者PCI治疗前1 d静脉取血查血清钾、钠、氯离子浓度,术后6 h复查血清钾、钠、氯离子浓度,对比术前、术后血清钾、钠、氯离子浓度变化.结果:58例接受PCI治疗患者,术后血钾、钠离子浓度变化差异具有统计学意义(P<0.05).14例患者术后发生低钾血症.所有患者术后无低钠血症发生.术前血钾3.5～4.0 mmol/L者23例,术后12例发生低钾血症;血钾≥4.0 mmol/L者35例.术后2例发生低钾血症;比较两组术后低钾血症发生率,两者差异具有统计学意义(P<0.05).术后低钾血症发生率为24.1%,估测总体低钾血症发病率的95%可信区间为13.12%～35.16%.结论:PCI治疗后电解质紊乱并不少见,术后应常规进行血电解质检测.     

高浓度静脉补钾治疗危重患者低钾血症33例疗效观察与监测

目的:探讨中心静脉微量泵入高浓度钾治疗危重患者低钾血症的疗效与监测.方法:将66例合并低钾血症的危重患者随机分为治疗组和对照组各33例,治疗组补钾速度为6.66～13.32 mmol/h,对照组为4 mmol/h,两组均进行严密监护与血钾浓度监测,血钾正常时停止补钾. 结果:补钾24 h后,血钾浓度治疗组(4.73±0.40)mmol/L、对照组(3.76±0.35)mmol/L,补钾液体量治疗组(240.00±49.77)ml/d,对照组(2400.00±834.39) ml/d,两组比较差异有统计学意义(P<0.01).结论:微量泵入高浓度钾治疗危重患者低钾血症可以在短时间内纠正低钾血症,是安全有效的.     

低血钾症流行病学特征及血清钾检测值与心电图改变的相关性

目的探讨东莞常安镇低钾血症流行病学特征及血清钾检测水平与心电图改变的相关性。方法收治的700例低钾血症患者,总结流行病学特点,并分析患者血清钾测定值与心电图改变的关系。结果本组低钾血症男性占58.00%,年龄为21～30岁(50.00%),职业多为个体户(11.71%),病史以甲状腺功能亢进为主(8.86%),发病诱因主要为上呼吸道感染(21.43%),发病至就诊的时间多为6～12h(41.57%),临床表现以四肢肌肉酸痛、肌无力为主(100.0%);其中轻度低钾(血清钾水平为3.0～3.5mmol/L)占17.71%,中度低钾(血清钾水平为2.5～3.0mmol/L)占28.57%,重度低钾(血清钾水平2.5mmol/L)占53.71%,患者细胞计数增高比例为56.71%,心电图异常比例为94.14%,住院时间以3d为主(89.57%);重度低钾患者心电图异常比例高于重度和轻度低钾患者;患者血钾浓度与心电图异常发生率呈负相关(P0.05)。结论东莞常安镇低钾血症发病群体以男性、工人、青壮年为主,诱因主要为上呼吸道感染,患者常伴心电图异常改变且患者血清钾水平与心电图异常改变发生率呈负相关。     

原发性醛固酮增多症患者肾丢钾的标准

原发性醛固酮增多症是少数几个可以治愈的高血压疾患之一,临床表现:高血压、低血钾、肾功能正常的肾丢钾、低肾素高醛固酮血症。当血清钾<3.5mmol/L时,肾丢钾的标准在权威书刊各不相同,有>25mmol/d,>25mmol/L,>30mmol/L,>40mmol/d,给临床应用带来困惑。本文收集近年来我院经手术证实的16例原发性醛固酮增多症患者尿钾排泄量,结合文献提出原发性醛固酮增多症肾丢钾的标准。 1 临床资料 住院患者16例,年龄24～45岁,病程2个月～20年。血清钾及尿钾测定用自动生化仪(Beckman,ELISE)。患者均正常饮食,未用任何影响血钾及尿钾排泄     

16例抗精神病药物致低血钾的心电图分析

回顾性分析我院2000年1月～2012年6月期间16例抗精神病药物致低血钾患者的临床资料。结果 (1)所有患者均有房室传导阻滞,其中Ⅲ度3例,Ⅱ度7例,Ⅰ度6例,心室率平均79.5次/min;(2)Ⅰ、Ⅱ度房室传导阻滞血清钾分别是1.99±0.77mmol/L、2.06±0.48mmol/L,2组数据的差异不显著,没有统计学意义(P>0.05);Ⅲ度房室传导阻滞血清钾为2.02±0.84mmol/L,对于Ⅰ、Ⅱ度房室传导阻滞血清钾,其差异不显著,无统计学意义(P>0.05)。抗精神病药物致低血钾症房室传导阻滞在采取积极有效补钾后具有较快的恢复速度,预后良好,不需立刻使用抗心律失常药物防止因此出现更加严重的心律失常。     

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.