脑脊液乳酸含量联合细胞学指标对神经外科手术后细菌性脑膜炎的早期诊断价值

目的 探索脑脊液乳酸含量(cerebrospinal fluid lactate,CSF-Lac)联合细胞学指标所建之模型对于神经外科手术后的细菌性脑膜炎(post-neurosurgical bacterial meningitis,PNBM)早期诊断的价值.方法 选取2019年1—12月于神经外科有创操作术后连续转...     

超高效液相色谱快速检测万古霉素浓度方法的建立和性能评价

目的建立一种基于超高效液相色谱(UPLC)技术快速测定血清万古霉素浓度的方法并评价其性能。方法以去甲万古霉素为内标,以0.3 mol/L硫酸锌水溶液为蛋白沉淀剂,对血清样本进行前处理。色谱柱为Phenomenex Kinetex C18柱(100 mm×2.1 mm,2.6μm),流速为0.5 mL/min,检测波长为220 nm,柱温40℃。流动相A为25 mmol/L磷酸二氢钾缓冲液(pH值为2.5),流动相B为乙腈,进行梯度洗脱,并对方法的线性、准确度(加标回收率)、精密度、携带污染率、定量限和检测限等分析性能进行评价。分别采用UPLC和高效液相色谱(HPLC)测定50例患者血清万古霉素浓度,并对测定结果进行方法学比对和评价。结果UPLC测定万古霉素的线性范围为2.0~99.6μg/mL,定量限和检测限分别为1.0和0.1μg/mL。低、中、高浓度样本的平均批内变异系数(CV)分别为3.28%、2.21%、2.59%,批间CV分别为5.73%、2.75%、0.82%。低浓度(2.0μg/mL)、中浓度(19.9μg/mL)、高浓度(79.6μg/mL)加标样本的平均加标回收率分别为104.06%、99.80%、100.19%。中浓度样本的携带污染率为0.57%,高浓度样本的携带污染率为0.19%。UPLC和HPLC测定患者血清万古霉素浓度具有良好的相关性(r=0.9919)。结论建立了基于UPLC技术的万古霉素血药浓度监测方法,该方法的重现性好、快速、简便、灵敏度高、准确度高,适用于临床常规万古霉素药物浓度监测。     

Clinical significance of cerebrospinal fluid inhibitory titers of antibiotics, based on pharmacokinetic/pharmacodynamic parameters, in the treatment of bacterial meningitis

The cerebrospinal fluid (CSF) inhibitory titer (CSF-IT) of an antibiotic, which can be used to estimate the duration of time above the agent’s MIC in the CSF, was introduced as one of the indices to evaluate the effectiveness of antibiotic selection in treating bacterial meningitis. The CSF-IT was determined via a microdilution method. A suspension of the causative organism was added to a tube containing twofold diluted CSF and double-concentrated Mueller-Hinton broth with supplement. The CSF-IT was determined by the maximum point without turbidity of medium after overnight incubation at 37°C. Concerning the strain of β-lactamase-negative ampicillin-resistant Haemophilus influenzae (BLNAR), the killing rates of both meropenem and piperacillin were compared in an in vitro pharmacokinetic (PK) model, in which human pharmacokinetics in CSF were simulated. Organisms recovered from the CSF in 37 treated clinical cases of bacterial meningitis were H. influenzae, Streptococcus agalactiae, Streptococcus pneumoniae, Escherichia coli, and Neisseria meningitidis; in these cases, the CSF-IT ranged from 1: 8 to as high as 1: 4 096. In the in vitro PK model, the concentrations of both drugs were higher than the MICs over a period of 24 h; however, the killing rate of piperacillin was higher than that of meropenem, and bacterial regrowth was observed after the administration of meropenem. A CSF-IT value higher than 1: 32 indicates that the antibiotic concentration in the CSF exceeds the MIC for 24 h. The effect of piperacillin on BLNAR depends not only on the time above MIC of 24 h but also on the maximum concentration in the CSF.     

Usefulness of interleukin 6 levels in the cerebrospinal fluid for the diagnosis of bacterial meningitis

Purpose

Interleukin 6 (IL-6) is a proinflammatory cytokine produced during infections. We hypothesized that IL-6 levels in the cerebrospinal fluid (CSF) would be elevated in bacterial meningitis and useful for diagnosing and predicting neurologic outcomes.

Materials and methods

For the differentiation of bacterial meningitis, serum and CSF samples were obtained from patients with an altered level of consciousness. Patients were classified into 3 groups: bacterial meningitis, nonbacterial central nervous system disease, and other site sepsis.

Results

Of the 70 patients included in this study, there were 13 in the bacterial meningitis group, 21 in the nonbacterial central nervous system disease group, and 36 in the other site sepsis group. The CSF IL-6 level was significantly higher in the bacterial meningitis group than in the other 2 groups (P < .0001). Of the 5 CSF parameters assessed, CSF IL-6 level exhibited the largest area under the receiver operating characteristic curve (0.962), with a cut-off value of 644 pg/mL (sensitivity, 92.3%; specificity, 89.5%). To examine a potential association between a high CSF level and neurologic outcome, CSF IL-6 levels were divided into 4 quartiles, and each level was compared with the frequency of a good neurologic outcome. The frequency of a good neurologic outcome was significantly lower in the highest CSF IL-6 quartile than in the other 3 quartiles (odds ratio, 0.18; 95% confidence interval, 0.05-0.69; P = .013).

Conclusions

Measurement of the CSF IL-6 level is useful for diagnosing bacterial meningitis.     

Evaluation for optimal dosing of vancomycin in patients with different physical types

The sufficient dose to obtain an optimal trough concentration of vancomycin (VCM) in patients with non-standard physical types remains controversial. In this study, we examined the relationship between the dose and physical type in patients in whom an optimal trough concentration was obtained among VCM-treated patients. We retrospectively investigated the dose of VCM and physical type in patients treated with VCM between January 2012 and January 2017 at two medical institutions (n = 272). The physical type was classified using the body mass index (BMI). Patients with a BMI of <18.5 kg/m² were assigned to the lean group, those with a BMI of 18.5–24.9 kg/m² were assigned to the standard group, and those with a BMI of ≥25 kg/m² were assigned to the obesity group. The mean doses of VCM per time (mg/kg) to achieve the target trough concentration of VCM, 15–20 μg/mL, were 19.8 ± 4.3, 16.5 ± 3.7, and 13.7 ± 2.7 mg/kg in the lean, standard, and obesity groups, respectively. The dose per time to achieve the target trough concentration decreased significantly in association with an increase of BMI. The upper limit of the recommended dose (15–20 mg/kg) or higher in lean patients, and the lower dose in obese patients than the recommended dose might be appropriate to achieve the target trough concentration when we calculated the dose per time based on actual body weight.     

Semi-quantitative analysis of cytokine gene expression in blood and cerebrospinal fluid cells by reverse transcriptase polymerase chain reaction

An easy, reproducible and semi-quantitative, non-radioactive method for the analysis of mRNA expression for various cytokines, (i.e., Interleukin (IL)-1β, IL-4, IL-6, tumor necrosis factor (TNF)-α, lymphotoxin (LT), transforming growth factor (TGF)-β, interferon (IFN)-γ and endothelin-1 (ET-1)) in cells from cerebrospinal fluid (CSF) and peripheral blood mononuclear cells (PBMC) has been established. By means of polymerase chain reaction primers that cover a splice junction, amplification of contaminating DNA was omitted. Densitometric scanning of ethidium bromide-stained agarose gels proved to be very sensitive for semiquantitative analysis of PCR products. Serial tenfold dilutions of cDNA revealed a log-linear regression from 10⁶ to 10² cells under optimal cycle conditions. The intra- and inter-assay variability of the method was below 10%. With this assay, the cytokine expression pattern of as few as 10⁴ mononuclear cells from blood or CSF was determined. This method made it possible to detect differences in the cytokine gene expression pattern of mononuclear cells from patients with different neurological diseases. CSF cells from 43 patients with various neurological diseases were analyzed. TNF-α, LT, and IL-1 mRNA were prominent in the CSF cells of most patients with bacterial meningitis. TNF-α, LT, IFN-γ and IL-6 mRNAs were detected in patients with active multiple sclerosis, whereas TNF-α, IL-6, and endothelin-1 mRNA expression was found frequently in patients with HIV encephalitis. Pro-inflammatory cytokines were rarely detected in CSF cells from patients with non-inflammatory diseases of the central nervous system. In blood mononuclear cells from patients with multiple sclerosis, TNF-α mRNA expression was associated with disease activity. The sensitivity, specificity, velocity and reliability of this assay considerably facilitates the analysis of cytokine production in mononuclear cells even in conditions where only a limited number of cells is available for analysis.     

Importance of vancomycin loading doses in intermittent infusion regimens

Purpose

Delayed achievement of target vancomycin serum concentrations may adversely affect clinical outcomes. The objective of this retrospective study was to explore the real frequency of loading dose use and to evaluate the impact of loading dose for the achievement of vancomycin PK/PD target in adult patients treated with intermittent vancomycin. As a secondary aim we determined optimal vancomycin loading dose based on individual pharmacokinetic calculations.

脑脊液与血清利奈唑胺浓度监测指导颅内感染临床治疗的价值

目的监测神经外科手术后颅内感染患者应用利奈唑胺抗感染治疗时脑脊液利奈唑胺药物浓度及血脑屏障通透率,指导利奈唑胺临床应用。 方法选取2019年6月至2019年11月入住青岛大学附属医院神经外科监护室的颅脑术后感染患者6例,静脉应用利奈唑胺抗感染治疗。连续监测患者脑脊液及血液利奈唑胺浓度、脑脊液常规、脑脊液生化及一般生命体征,分析利奈唑胺血脑屏障通透率。 结果利奈唑胺给药前0.5 h的血清和脑脊液药物谷浓度分别为（4.65±2.72）μg/ml和（3.78±1.53）μg/ml。在开始用药后2 h,血清中利奈唑胺的最大平均浓度为（12.53±3.79）μg/ml,而脑脊液中最大平均浓度为（5.55±2.00）μg/ml。脑脊液利奈唑胺曲线下面积/血清曲线下面积约为45%。所有患者应用利奈唑胺抗感染治疗后,颅内感染均得到治愈。 结论利奈唑胺具有满意的血脑屏障通透率,临床治疗效果良好。静脉应用利奈唑胺脑脊液浓度个体间差异大,推荐临床监测脑脊液浓度指导应用。     

脑脊液/血清苯妥英钠浓度比值与ABCB1基因多态性的相关性研究

目的研究ATP结合盒B亚家族成员1转运蛋白(ABCB1)基因的遗传多态性与脑脊液、血苯妥英钠浓度及其比值的关联性。方法依赖高效液相色谱法(HPLC)测定200例癫痫患者的脑脊液、血苯妥英钠浓度以及依靠PCR-RFLR法分析患者的ABCB1 C1236T、ABCB1 C3435T和ABCB1 G2677T/A三个单碱基突变位点。多组间统计数据比较采用单因素方差分析。结果在ABCB1基因三个突变位点的各自基因型中,均未发现血浆苯妥英钠浓度、脑脊液苯妥英钠浓度以及两者比值具有统计学差异(P>0.05)。结论脑脊液、血清苯妥英钠浓度及其比值未发现与ABCB1基因的多态性相关。     

脑脊液和血清白蛋白比值在中枢神经系统疾病中的诊断价值

本文测定了80例中枢神经系统疾病患者和30例对照组的脑脊液(CSF)总蛋白(CTP)、CSF白蛋白(CAlb)与血清白蛋白(SAlb)的比值(CAlb/SAlb).结果显示,各组脑膜炎CAlb/SAlb都大于10×10-3,且化脓性脑膜炎与结核性脑膜炎组增加更明显,而实质性病变的多发性硬化CAlb/SAlb小于10×10-3.病毒性脑膜炎与多发性硬化组CTP无显著性差异(P＞0.05),而CAlb/SAlb差异非常显著(P＜0.001).提示测定CAlb/SAlb对判断血脑屏障损伤程度以及CSF蛋白质来源具有重要参考价值.CAlb/SAlb比值越大,血脑屏障损害越重,化脓性脑膜炎、结核性脑膜炎为重度损害,病毒性脑膜炎为中度损害,多发性硬化为轻度损害.     

神经梅毒患者血清及脑脊液免疫学指标诊断特征分析

目的探讨神经梅毒患者血清及脑脊液免疫学诊断特点。 方法选取2013年6月至2016年7月首都医科大学附属宣武医院收治的35例神经梅毒患者,其中32例患者行血清与脑脊液免疫学指标检测,回顾性分析35例患者的检查结果,应用Fisher精确检验比较血清组与脑脊液组IgA、IgM的差异,应用卡方检验比较血清组与脑脊液组IgG的差异,并对脑脊液寡克隆条带阳性检出率和脑脊液24 h IgG合成率进行分析。 结果32例神经梅毒患者检测血清免疫球蛋白,有53.13%(17/32)的患者IgG升高,6.25%(2/32)的患者IgA升高,0%(0/32)的患者IgM升高;脑脊液中,有84.38%(27/32)的患者IgG升高,100.00%(32/32)的患者IgA升高,90.63%(29/32)的患者IgM升高;血清与脑脊液IgA、IgM升高率比较,差异有统计学意义(P<0.01),IgG升高率比较,差异无统计学意义(χ²＝7.27,P>0.05)。25例神经梅毒患者行CSF寡克隆电泳,IgG寡克隆条带阳性率为100.00%(25/25),96.00%(24/25)患者脑脊液24 h IgG合成率升高。 结论神经梅毒临床表现多样,是易误诊的可治性疾病。血清及脑脊液IgG多表现为升高,脑脊液IgA、IgM多表现为升高而血清IgA、IgM多表现为正常,脑脊液寡克隆条带阳性,脑脊液24 h IgG合成率升高等免疫学特点对神经梅毒诊断有意义。     

Clinical applicability of urinary creatinine clearance for determining the initial dose of vancomycin in critically ill patients

IntroductionThe purpose of this study was to evaluate the clinical applicability of urinary creatinine clearance (CrCl) for determining the initial dose of vancomycin (VCM) in critically ill patients and to assess VCM trough plasma concentration/maintenance daily dose (C/D) ratio in patients with augmented renal clearance (ARC).MethodsAs the primary outcome measure, correlations between estimated renal function and the VCM C/D ratio were compared using the following formulas: CrCl, Cockcroft-Gault equation (eCrCl_C-G) and KineticGFR equation (KeGFR). Patients were divided into those with or without changes in renal function. The patients were further classified based on the presence or absence of ARC. The secondary outcome was the comparison of VCM C/D ratio between ARC and Non-ARC patients.ResultsA total of 65 patients were enrolled for analysis. In all groups, CrCl tended to correlate better with the VCM C/D ratio than eCrCl_C-G and KeGFR. A significantly lower VCM C/D ratio was observed in patients with persistent ARC than in the Non-ARC group (0.24 versus 0.52 kg/L).ConclusionsThe clinical applicability of CrCl for the initial dosing design of VCM in critically ill patients was shown. Furthermore, the results indicated that patients with persistent ARC required a higher VCM dose than Non-ARC patients. Although our findings are limited, they have a value for further verification.     

脑脊液中肝素结合蛋白、总蛋白、降钙素原检测在鉴别细菌性与非细菌性颅内感染疾病中的临床应用

目的探讨脑脊液中肝素结合蛋白(HBP)、总蛋白、降钙素原(PCT)检测在鉴别细菌性与非细菌性颅内感染疾病中的临床应用价值。方法我院收治的颅内感染患者248例,分为细菌性颅内感染142例(细菌组)和非细菌性颅内感染106例(非细菌组),选取同期无颅内感染住院患者85例为对照组。比较三组血白细胞计数(WBC)、血清PCT以及脑脊液WBC、HBP、总蛋白、PCT水平。绘制ROC曲线计算灵敏度、特异度。结果细菌组血WBC、血清PCT及脑脊液WBC、HBP、总蛋白、PCT水平均高于非细菌组与对照组(P<0.05)。各指标鉴别细菌性与非细菌性颅内感染脑脊液HBP的截断值为21.30 ng/ml,灵敏度为75.35%,特异度为79.25%。脑脊液总蛋白的截断值为1054.50 mg/L,灵敏度为83.10%,特异度为70.75%。脑脊液PCT的截断值为0.16 ng/ml,灵敏度为88.03%,特异度为89.62%。结论脑脊液中HBP、总蛋白、PCT检测在鉴别细菌性与非细菌性颅内感染具有较高的价值,可与传统指标血WBC、脑脊液WBC以及血清PCT等联合应用,辅助临床诊断。     

巢式聚合酶链式反应检测脑脊液标本中病原体的方法评价

目的探讨巢式聚合酶链式反应(PCR)检测脑脊液标本中病原体的可行性,为疾病的快速临床诊断提供参考。方法源自细菌16S rRNA基因序列设计的巢式PCR技术方法,包括2对引物,2次PCR扩增,第1对引物首次PCR扩增脑脊液标本提取的核酸DNA,第2对引物再次PCR扩增,其DNA模板为第1轮PCR扩增产物。将第2轮PCR扩增产物进行测序,对序列进行比对分析,从而确定感染的病原体。使用DNA微量分光光度测定布鲁氏菌纯菌核酸DNA,将DNA进行倍比稀释,用于巢式PCR敏感性测试。结果巢式PCR能够检测的最低限约为1个核酸DNA拷贝数。应用巢式PCR检测40份临床患者的脑脊液标本,扩增结果表明有37份标本获得约1 460 bp的预期扩增条带(不同细菌扩增片段有差异),测序比对结果显示,检出脑膜炎奈瑟菌7份、产碱假单胞菌1份、草假单胞菌22份、嗜麦芽窄食单胞菌2份、肺炎链球菌1份、未知细菌性病原体4份、未检出3份。结论巢式PCR能够快速检测与鉴定脑脊液标本中的细菌性病原体。     

病原治疗前脑脊液隐球菌负荷量在新生隐球菌性脑膜炎临床转归中的意义

目的:探讨新生隐球菌性脑膜炎患者病原治疗前脑脊液隐球菌负荷量与治疗效果及临床转归的关系.方法:收集52例新生隐球菌性脑膜炎患者的临床资料,以治疗前脑脊液隐球菌计数与临床转归关系的特异度及灵敏度之和的最大值所对应的脑脊液隐球菌计数2 125个/ml为分界点,分为脑脊液隐球菌计数＜2 125个/ml(低量)组31例和脑脊液隐球菌计数≥2 125个/ml(高量)组21例,比较抗真菌治疗后两组患者的阴转率和临床疗效.结果:抗真菌治疗后低量组的脑脊液隐球菌阴转率为52％,高量组的脑脊液隐球菌阴转率为14％,两组比较差异有统计学意义(P＜0.01);低量组治愈率48％,好转率23％,总有效率71％:高量组治愈率14％,好转率14％,总有效率29％,两组的治愈率及总有效率比较差异均有统计学意义(P＜0.01).结论:在新生隐球菌性脑膜炎患者中,病原治疗前脑脊液隐球菌计数＜2 125个/ml者相比于≥2125个/ml者,抗真菌治疗后脑脊液隐球菌阴转率高,临床转归好,脑脊液隐球菌负荷量是评估治疗效果和临床转归的一个实用、便捷的参数.     

Normal cerebrospinal fluid protein and associated clinical characteristics in children with tuberculous meningitis

BackgroundAlthough abnormal cerebrospinal fluid (CSF) protein can be used to predict the outcome of tuberculous meningitis (TBM) and diagnose TBM, normal CSF protein remains a concern in patients with TBM. This retrospective study aimed to assess the clinical characteristics associated with normal CSF protein, to resolve the dilemma of CSF protein in the management of childhood TBM.MethodsBetween January 2006 and December 2019, consecutive child patients (≤15 years old, a diagnosis of TBM, and tested for CSF protein) were included for analysis. CSF protein was tested on a chemistry analyzer using the pyrogallol red-molybdate method. Abnormal CSF protein was defined as >450 mg/L. Patient characteristics were collected from the electronic medical records. Then, characteristics associated with normal CSF protein were estimated in the study, using univariate and multivariate logistic regression analysis.ResultsA total of 125 children who met the criteria were enrolled during the study period. Twenty-nine patients had a normal CSF protein and 96 had an abnormal CSF protein. Multivariate analysis (Hosmer–Lemeshow goodness-of-fit test: χ²=2.486, df = 8, p = .962) revealed that vomiting (age- and sex-adjusted OR = 0.253, 95% CI: 0.091, 0.701; p = .008) and serum glucose (>5.08 mmol/L; age- and sex-adjusted OR = 0.119, 95% CI: 0.032, 0.443; p = .002) were associated with the normal CSF protein in childhood TBM.ConclusionIn suspected childhood TBM, patients without vomiting or having low serum glucose are easy to present with normal CSF protein. Hence, when interpreting the level of CSF protein in children with such characteristics, a careful clinical assessment is required.

KEY MESSAGES

• In suspected childhood tuberculous meningitis, patients without vomiting or having low serum glucose are easy to present with normal CSF protein. Hence, when interpreting the level of CSF protein in children with such characteristics, a careful clinical assessment is required.

     

Continuous intravenous administration of vancomycin in medical intensive care unit patients

Purpose

The aim of this study was to evaluate continuous vancomycin infusion (contV) in intensive care unit patients.

Materials and Methods

A retrospective study in 164 patients treated with contV was conducted. They were compared with 75 patients treated with intermittent vancomycin infusion.

Results

The median duration of vancomycin therapy in the contV group was 6 (5%-95% percentile range, 2-21) days. The median daily vancomycin dose in the contV group was 960 (526-1723) mg, resulting in a median serum vancomycin plateau concentration of 19.8 (9.8-29.4) mg/L (target: 15-25 mg/L). The contV administration regime was sufficient regarding achievement of the target serum vancomycin concentration. However, in the contV group, serum vancomycin levels were frequently in a subtherapeutic range on treatment days 1 (44%), 2 (29%), and 3 (23%). In the contV group, serum vancomycin concentration determinations per treatment day were performed significantly less often compared with the intermittent vancomycin infusion group (0.38 [0.15-0.75] vs 0.43 [0.22-1.00], P = .041).

Conclusions

In medical intensive care unit patients, contV is sufficient to achieve target serum vancomycin concentrations. Because contV frequently resulted in subtherapeutic drug levels on the first days of therapy, a higher loading or starting dose might be necessary.