高效液相色谱法检测血红蛋白A2诊断β-地中海贫血携带者的最佳阈值

目的确定高效液相色谱法（HPLC）检测血红蛋白A2（HbA2）诊断β-地中海贫血（β地贫）携带者的最佳阈值,以提高HbA2作为β地贫携带者诊断指标的应用价值,减少漏诊与误诊。方法以反向点杂交技术（RDB）为金标准方法,将近两年来已确诊的1007例β地贫携带者和606例正常对照采用HPLC检测HbA2的结果按不同阈值界定的范围分为真阳性、假阳性、真阴性和假阴性,并评估出敏感度、特异度、阳性似然比、阴性似然比、尤登（Youden脂数等评价指标,同时绘制受试者工作特征曲线（ROC）,确定HPLC诊断β地贫携带者HbA2的最佳阈值。结果以HbA2≥4．0％作为HPLC诊断β地贫携带者的阈值时,其敏感度为99．21％,特异度为99．34％,阳性似然比为150．30,阴性似然比为0．008,尤登指数为0．99,其中尤登指数优于其它阈值,且对应的切点在ROC曲线上最靠近左上方。结论HbA：≥4．0％为HPLC诊断D地贫携带者的最佳阈值,其敏感度与特异度的综合评价陛能最理想,诊断试验的真实性最好。     

Low-complexity R-peak detection for ambulatory fetal monitoring

Non-invasive fetal health monitoring during pregnancy is becoming increasingly important because of the increasing number of high-risk pregnancies. Despite recent advances in signal-processing technology, which have enabled fetal monitoring during pregnancy using abdominal electrocardiogram (ECG) recordings, ubiquitous fetal health monitoring is still unfeasible due to the computational complexity of noise-robust solutions. In this paper, an ECG R-peak detection algorithm for ambulatory R-peak detection is proposed, as part of a fetal ECG detection algorithm. The proposed algorithm is optimized to reduce computational complexity, without reducing the R-peak detection performance compared to the existing R-peak detection schemes. Validation of the algorithm is performed on three manually annotated datasets. With a detection error rate of 0.23%, 1.32% and 9.42% on the MIT/BIH Arrhythmia and in-house maternal and fetal databases, respectively, the detection rate of the proposed algorithm is comparable to the best state-of-the-art algorithms, at a reduced computational complexity.     

ECG-based gating in ultra high field cardiovascular magnetic resonance using an independent component analysis approach

Background

In Cardiovascular Magnetic Resonance (CMR), the synchronization of image acquisition with heart motion is performed in clinical practice by processing the electrocardiogram (ECG). The ECG-based synchronization is well established for MR scanners with magnetic fields up to 3 T. However, this technique is prone to errors in ultra high field environments, e.g. in 7 T MR scanners as used in research applications. The high magnetic fields cause severe magnetohydrodynamic (MHD) effects which disturb the ECG signal. Image synchronization is thus less reliable and yields artefacts in CMR images.

Methods

A strategy based on Independent Component Analysis (ICA) was pursued in this work to enhance the ECG contribution and attenuate the MHD effect. ICA was applied to 12-lead ECG signals recorded inside a 7 T MR scanner. An automatic source identification procedure was proposed to identify an independent component (IC) dominated by the ECG signal. The identified IC was then used for detecting the R-peaks. The presented ICA-based method was compared to other R-peak detection methods using 1) the raw ECG signal, 2) the raw vectorcardiogram (VCG), 3) the state-of-the-art gating technique based on the VCG, 4) an updated version of the VCG-based approach and 5) the ICA of the VCG.

Results

ECG signals from eight volunteers were recorded inside the MR scanner. Recordings with an overall length of 87 min accounting for 5457 QRS complexes were available for the analysis. The records were divided into a training and a test dataset. In terms of R-peak detection within the test dataset, the proposed ICA-based algorithm achieved a detection performance with an average sensitivity (Se) of 99.2%, a positive predictive value (+P) of 99.1%, with an average trigger delay and jitter of 5.8 ms and 5.0 ms, respectively. Long term stability of the demixing matrix was shown based on two measurements of the same subject, each being separated by one year, whereas an averaged detection performance of Se = 99.4% and +P = 99.7% was achieved.Compared to the state-of-the-art VCG-based gating technique at 7 T, the proposed method increased the sensitivity and positive predictive value within the test dataset by 27.1% and 42.7%, respectively.

Conclusions

The presented ICA-based method allows the estimation and identification of an IC dominated by the ECG signal. R-peak detection based on this IC outperforms the state-of-the-art VCG-based technique in a 7 T MR scanner environment.     

Prediction of Hyperkalemia in Dogs from Electrocardiographic Parameters Using an Artificial Neural Network

OBJECTIVE: To predict severe hyperkalemia from single electrocardiogram (ECG) tracings. METHODS: Ten conditioned dogs each underwent this protocol three times: Under isoflurane anesthesia, 2 mEq/kg/hr of potassium chloride was given intravenously until P-waves were absent from the ECG and ventricular rates decreased > or =20% in < or =5 minutes. Serum potassium levels (K(+)) were measured at regular intervals with concurrent digital storage of lead II of the surface ECG. A three-layer artificial neural network with four hidden nodes was trained to predict K(+) from 15 separate elements of corresponding ECG data. Data were divided into a training set and a test set. Sensitivity, specificity, and diagnostic accuracy for recognizing hyperkalemia were calculated for the test set based on a prospectively defined K(+) = 7.5. RESULTS: The model produced data for 189 events; 139 were placed in the training set and 50 in the test set. The test set had 37 potassium levels at or above 7.5 mmol/L. The neural network had a sensitivity of 89% (95% CI = 75% to 97%) and a specificity of 77% (95% CI = 46% to 95%) in recognizing these. The positive likelihood ratio was 3.87. Overall accuracy of this model was 86% (95% CI = 73% to 94%). Mean (+/-SD) difference between predicted and actual K(+) values was 0.4 +/- 2.0 (95% CI = -0.2 to 1.0). CONCLUSIONS: An artificial neural network can accurately diagnose experimental hyperkalemia using ECG parameters. Further work could potentially demonstrate its usefulness in bedside diagnosis of human subjects.     

Use of baseline ST-vector magnitude to identify electrocardiographic injury in patients with suspected acute myocardial infarction

No information is currently available regarding optimal cut-off values of the ST-vector magnitude (ST-VM) for predicting acute myocardial infarction (AMI) in emergency department (ED) chest pain patients undergoing vectorcardiographic (VCG) monitoring. A prospective observational study was performed in 1,722 chest pain patients with suspected acute coronary syndrome and absence of bundle branch block (BBB) and left ventricular hypertrophy (LVH) on initial ECG who underwent continuous VCG ST-segment monitoring during the initial ED evaluation. Three cut-off values for baseline ST-VM are reported and represent the smallest values in which the positive likelihood ratio (+LR) for AMI is greater than 5, 10, and 20, respectively. AMI occurred in 158 of 1,722 patients (9.2%) without BBB or LVH on initial ECG. Optimal cut-off values at the predetermined +LR values of 5, 10, and 20, were 121 microV (sensitivity, 41.8%; specificity, 92.0%), 151 microV (sensitivity, 29.1%; specificity, 97.1%), and 175 microV (sensitivity, 25.9%; specificity, 98.7%), respectively. Combining the earlier-mentioned cut-off values with physician judgment of initial pretest probability (high, intermediate, or low, respectively) resulted in a relative increase in identification of injury of 37.5% as compared with the ED physician's interpretation of initial ECG (41.8% v 30.4%; P <.0001), and 65.2% as compared with the official ECG interpretation (41.8% v 25.3%; P <.0001). Increasing ST-VM results in increasing likelihood of AMI. Clinical studies need to be performed to determine if ST-VM cut-off values of 121, 151, and 175 microV in conjunction with physician pretest probability of AMI can be used as criterion for emergent reperfusion therapy in patients without LVH or BBB on the initial ECG.     

血清半乳甘露聚糖检测对器官移植术后侵袭性肺曲霉病的诊断价值

目的 前瞻性评价酶联免疫吸附试验（ELISA）检测曲霉半乳甘露聚糖（GM）抗原对器官移植术后侵袭性肺曲霉病的诊断价值。方法 采用ELISA连续检测62例器官移植术后患者血清中的GM，并根据欧洲癌症研究治疗组织及真菌研究组（EORTC／MSG）的标准将研究对象分类。分别计算各组的ELISA评价指标。结果 ELISA的敏感度为85．7％，特异度为95．7％。阳性预测值为75％，阴性预测值为97．8％，阳性似然比为19．7，阴性似然比为0．15。准确度为94．3％。结论 ELISA连续检测血清GM是一种可靠的早期诊断方法，高危人群中GM阳性的患者应采取先发积极的抗曲霉治疗。     

CT三维重建对孤立性肺结节良恶性诊断价值的Meta分析

目的：通过使用Meta分析法，综合评价CT 三维重建对孤立性肺结节（SPN）良恶性的诊断价值。方法：系统搜索万方医学网、CNKI、PubMed、Medline、VIP等数据库,检索使用CT三维重建技术对孤立性肺结节诊断的相关中外文献，检索时间截至2019年10月，严格遵从Cochrane 协作网推荐的与诊断试验相关的纳入标准以筛选相关文献,提取纳入研究文献的特征信息。Meta分析采用Stata15.1SE软件进行，文献评价采用诊断实验质量评价量表QUQDAS-2。结果:共纳入9篇研究文献[1-9],共计681例患者。汇总并计算灵敏度、特异度、诊断比值比、阳性似然比及阴性似然比，同时绘制汇总受试者工作特征(SROC)曲线并计算曲线下面积(AUC)，以及95%可信区间。得到的值分别为：0.97（0.92,0.99）、0.93（0.87,0.96）、431（96,1936）、14.0（7.4,26.7）、0.03（0.01,0.09）;0.98（0.97-0.99）。结论：CT三维重建应用于孤立性肺结节良恶性的诊断，具有较高的灵敏度、特异度及准确率，是诊断孤立性肺结节良恶性一项重要的影像学方法，具有较高的诊断效能及诊断价值。     

Automated detection of obstructive sleep apnoea at different time scales using the electrocardiogram

An automated classification algorithm is presented which processes short-duration epochs of surface electrocardiogram data derived from polysomnography studies, and determines whether an epoch is from a period of sleep disordered respiration (SDR) or normal respiration (NR). The epoch lengths considered were 15, 30, 45, 60, 75, and 90 s. Epochs were labeled as 'NR' or 'SDR' by a human expert, based on standard polysomnography interpretation rules. The automated classification algorithm was trained and tested on a database of 70 overnight ECG recordings from subjects with and without obstructive sleep apnoea syndrome (35 used for training, 35 for independent validation). Depending on the epoch length, the classifier correctly labeled between 87% (15 s epochs) and 91% (60 s epochs) of the epochs in the test set. Accuracy was lowest for the shortest (15 s) and longest (90 s) epoch lengths, but the analysis was relatively insensitive to choice of epoch length. The classifications from these epochs were combined to form an overall summary measure of minutes-of-SDR, allowing per-subject classification.     

Tc-99m HMPAO labelled WBCs in the detection of occult sepsis in the intensive care unit

In a retrospective study involving 25 patients with occult sepsis in the ICU of Taichung Veterans General Hospital, the sensitivity and specificity of the new diagnostic method, Tc-99m HMPAO labelled white blood cells (WBCs) scan, were compared with other evaluating methods including clinical information, radiograph, ultrasound, bacterial culture, operative findings and pathological report. It was found that Tc-99m HMPAO labelled WBCs scans gave a sensitivity of 96.0%, a specificity of 84.4% and an overall accuracy of 87.3%, as well as the probable causes of false positive and false negative diagnoses were discussed. In conclusion, Tc-99m HMPAO labelled WBCs scans provide a reliable method for imaging of occult sepsis in the ICU.     

Lack of relationship between the true airway pressure and the pressure displayed with an infant ventilator.

OBJECTIVE: To establish if the pressure indicated in the manometer of an infant ventilator (IV 100B, Sechrist, Anaheim, CA) reflects the true pressure delivered to the proximal airway during mechanical ventilation in the neonatal ICU. DESIGN: With approval of our Institutional Research Board, data were collected prospectively. Peak inspiratory pressure and end-expiratory pressure were measured at the "Y" piece of the breathing tubing. Pressure readings from the conventional ventilator's manometer were compared with simultaneously obtained measurements using an electronic monitor. SETTING: This study was conducted in a 45-bed neonatal ICU, admitting 700 to 750 newborns per year. PATIENTS: Twelve neonates who required mechanical ventilation were included in the study. INTERVENTIONS: Specific interventions were not made by study design. Measurements routinely obtained were compared. MEASUREMENTS AND MAIN RESULTS: Two hundred seventy-five simultaneous measurements of peak inspiratory pressure and positive end-expiratory pressure were compared. Peak inspiratory pressure values were higher with the electronic monitor in 273 (99%) of 275 measurements and the mean of the differences between the electronic monitor and ventilator's manometer was statistically significant (p less than .001). For positive end-expiratory pressure measurements, values indicated by the electronic monitor were lower in 152 (55%) of 275 determinations, equal in 65 (23%), and higher in 58 (21%) determinations. Percent variations between methods ranged from 0% to 140% for peak inspiratory pressures and from 0% to 500% for positive end-expiratory pressure. CONCLUSIONS: These data demonstrate that it is impossible to know the true pressure delivered to the proximal airway of a neonate during mechanical ventilation by observing the ventilator pressure manometer. The manometer readings consistently underestimate the true peak inspiratory pressure values and are very unpredictable regarding positive end-expiratory pressure values. These findings support the use of other methods to monitor the proximal airway pressure besides the ventilator's manometer in the neonatal ICU. Furthermore, mean airway pressure should not be calculated from the pressure readings obtained from the tested ventilator's manometer.     

Quantitative111in antimyosin antibody imaging to predict the age of myocardial infarction

To establish whether quantitative¹¹¹In antimyosin uptake can be used to predict infarct age, we studied the heart-lung ratio in 107 images from 90 patients at various intervals following a Q-wave infarction. Imaging was performed 24 hours following¹¹¹In antimyosin injection. The HLR was measured as the ratio of the maximum counts in the infarcted myocardium to the adjacent lung background. The ratio ranged from 1.26 to 3.87, and declined with increasing infarct age. Infarcts were classified on the basis of age as type I (< 3 days old), type II (<14 days), and type III (<90 days). True positive and false positive rates (TPR and FPR), and test-likelihood ratio calculations were performed for HLR thresholds ranging from 1 to 4, for the three infarct types. A FPR of 0% and likelihood ratio of infinity was obtained at a HLR threshold of 2.3 for type I infarcts (TPR 40.8%); at a HLR threshold of 2 for type II infarcts (TPR 50.6%), and a threshold of 1.8 for type III infarcts (TPR 52.6%). The likelihood of each infarct type can be estimated directly from the HLR for values below the above thresholds. These results show that quantitative¹¹¹In-antimyosin imaging may be used to predict infarct age.     

A new method to estimate the amplitude spectrum analysis of ventricular fibrillation during cardiopulmonary resuscitation

AIMS

Accurate ventricular fibrillation (VF) waveform analysis usually requires rescuers to discontinue cardiopulmonary resuscitation (CPR). However, prolonged “hands-off” time has a deleterious impact on the outcome. We developed a new filter technique that could clean the CPR artifacts and help preserve the shockability index of VF

METHODS

We analyzed corrupted ECGs, which were constructed by randomly adding different scaled CPR artifacts to the VF waveforms. A newly developed algorithm was used to identify the CPR fluctuations. The algorithm contained two steps. First, decomposing the raw data by empirical mode decomposition (EMD) into several intrinsic mode fluctuations (IMFs) and combining the dominant IMFs to reconstruct a new signal. Second, calculating each CPR cycle frequency from the new signal and fitting the new signal to the original corrupted ECG by least square mean (LSM) method to derive the CPR artifacts. The estimated VF waveform was derived by subtraction of the CPR artifacts from the corrupted ECG. We then performed amplitude spectrum analysis (AMSA) for original VF, corrupted ECG and estimated VF.

RESULTS

A total of 150 OHCA subjects with initial VF rhythm were included for analysis. Ten CPR artifacts signals were used to construct corrupted ECG. Even though the correlations of AMSA between the corrupted ECG vs. the original VF and the estimated VF vs. the original VF are all high (all p < 0.001), the values of AMSA were obviously biased in corrupted ECG with wide limits of agreement in Bland–Altman mean-difference plot. ROC analysis of the AMSA in the prediction of defibrillation success showed that the new algorithm could preserve the cut-off AMSA value for CPR artifacts with power ratio to VF from 0 to 6 dB.

CONCLUSION

The new algorithm could efficiently filter the CPR-related artifacts of the VF ECG and preserve the shockability index of the original VF waveform.     

Validity of the Waterlow scale for pressure ulcer risk assessment in the intensive care unit: a prospective analysis of 698 patients

Critically ill patients are at a particular risk for developing pressure ulcers. Yet until now, no sufficiently specific, validated pressure ulcer risk assessment instruments exist for critically ill patients. In a prospective study of 698 patients of medical intensive care unit (ICU), we therefore analyzed if the Waterlow scale is suitable for pressure ulcer risk assessment in the ICU. Only patients with no pressure ulcer on admission to the ICU were included. The Waterlow scale was used to assess pressure ulcer risk on admission to the ICU, and the number of points on the scale were analyzed with regard to pressure ulcers development in the course of the ICU stay (121 patients). Our results show that adequate pressure ulcer risk assessment on admission to the ICU is not possible with the Waterlow scale. Sensitivity and specificity reached their maximal values of 64.6% and 48.8%, respectively, at a comparably high cut-off of 30 points on the Waterlow scale (positive and negative likelihood ratio being 1.26 and 0.73, respectively). The area under the curve (AUC) was 0.59 in the receiver-operator-characteristic curve. Adding intensive care related parameters to the scale yielded some degree of improvement (AUC 0.69), but the development of ICU specific pressure ulcer risk scales still seems to be necessary to allow reliable pressure ulcer risk assessment in the ICU.     

结核分枝杆菌耐乙胺丁醇诊断试验的系统评价

目的系统评价各种检测结核分枝杆菌耐乙胺丁醇诊断试验方法的准确性。方法计算机检索PubMed、EMbase等数据库,并手工检索相关期刊,全面收集结核分枝杆菌耐乙胺丁醇诊断试验的研究,依据QUADAS评价纳入诊断试验的质量,并对结果进行Meta分析。结果最终纳入9个研究。Meta分析结果显示：硝酸盐还原法与比例法相比,以及BACTEC MGIT 960与BACTEC 460 TB相比,其敏感度、特异度、阳性似然比、阴性似然比及SROC曲线下面积分别为92%、99%、30.50、0.13、0.9752和93%、92%、6.27、0.11、0.9;MB/BacT,噬菌体生物扩增法亦显示了较好的检验效能。结论硝酸盐还原试验可代替比例法作为结核分枝杆菌耐乙胺丁醇的筛查试验;BACTEC MGIT 960可代替BACTEC 460检测系统作为结核分枝杆菌耐乙胺丁醇的确诊试验。     

Algorithm to identify components of arterial blood pressure signals during use of an intra-aortic balloon pump

Existing bedside cardiovascular monitors often inaccurately measure arterial blood pressure during intra-aortic balloon pump (IABP) assist. We have developed an algorithm that correctly identifies features of arterial pressure waveforms in the presence of IABP. The algorithm is adaptive, functions in real-time, and uses information from the electrocardiographic (ECG) and arterial blood pressure signals to extract features and numeric values from the arterial blood pressure waveform. In its current form, it requires reliable ECG beat detection and was not intended to operate under conditions of extremely poor balloon timing. The algorithm was evaluated by an expert (P.F-C.) on a limited data set, which consisted of 12 1-minute epochs of data recorded from 6 intensive care unit patients. A criterion for selection of patients was that the ECG beat detector could detect ECG beats correctly from the waveforms. The overall sensitivity and positive predictivity for beat detection were 94.04% and 100%, respectively. For feature identification, the overall sensitivity was greater than 89%, positive predictivity was 100%, and the false-positive rate was 0%. The performance measures may be biased by the criteria for patient selection. This approach to identifying waveform features during IABP improves the accuracy of measurements. The utility of using 2 sources of information to improve measurement accuracy has been demonstrated and should be applicable to other physiologic signal-processing applications.     

A multitest regimen of pain provocation tests as an aid to reduce unnecessary minimally invasive sacroiliac joint procedures

OBJECTIVE: To compare the diagnostic accuracy of a multitest regimen of 5 sacroiliac joint (SIJ) pain provocation tests with fluoroscopically controlled double SIJ blocks using a short- and long-acting local anesthetic in order to reduce the exposure of patients to unnecessary invasive SIJ procedures. DESIGN: Prospective, observational study. SETTING: Hospital setting. PARTICIPANTS: Sixty patients with chronic low back pain. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Visual analog scale score and receiver operating characteristic (ROC) curve. RESULTS: Twenty-seven patients responded positively to the blocks, of whom 23 were found positive after the multitest regimen and 4 were negative. For the nonresponders (n=33), these figures were 7 positive and 26 negative. The calculated sensitivity and specificity were .85 (95% confidence interval [CI], .72-.99) and .79 (95% CI, .65-.93), respectively. Positive and negative predictive values were .77 (95% CI, .62-.92) and .87 (95% CI, .74-.99), respectively. The positive likelihood ratio was 4.02 (95% CI, 2.04-7.89); the negative likelihood ratio was .19 (95% CI, .07-.47). The area under the ROC curve was .799. CONCLUSIONS: The test regimen with 3 or more positive tests is indicative of SIJ pain. It can be used in early clinical decision making to reduce the number of unnecessary minimally invasive diagnostic SIJ procedures.     

磁共振成像对前交叉韧带损伤诊断价值的系统评价

目的系统评价磁共振成像与关节镜法成像相比诊断前交叉韧带损伤的临床价值。方法计算机检索PubMed（1966～2008．8）、EMbase（1974～2008．8）、Cochrane图书馆（2008年第3期）、中国生物医学文献数据库（1978～2008．8）、中国科技期刊全文数据库（1994～2008．8）、中国期刊全文数据库（1994～2008．8）,并手工检索相关期刊,全面收集磁共振成像诊断前交叉韧带损伤的研究,按QUADAS条目评价纳入研究质量,并对结果进行Meta分析。结果最终纳入29个研究：结果显示：磁共振成像与关节镜相比,其敏感度、特异度、阳性似然比、阴性似然比以及SROC曲线下面积分别为：93％、93％、9．85、126．39和0．9714。结论磁共振成像可作为临床上诊断前交叉韧带损伤有效可行的方法。     

Influence of the skeletal muscle activity on time and frequency domain properties of the body surface ECG during evolving ventricular fibrillation in the pig

AIM OF THE STUDY: To evaluate influence of the skeletal muscle activity (SMA) on time and frequency domain properties of ECG during VF. MATERIALS AND METHODS: We studied the first 9min of electrically induced VF (N=7). We recorded Lead II ECG, 247 unipolar epicardial ventricular electrograms (UEGs) and 3 bipolar skeletal electromyograms (EMGs) near the positions of the ECG electrodes (sampling rate, 500Hz). We reconstructed ECG (RECG) from UEGs using forward-solution transformation matrix. Spectral properties of ECG, RECG, UEGs and MEGs were assessed in the range 2-250Hz by the median frequency (MF) and the upper limit of frequency range containing 99% of spectral energy (Flim(99)). Scaling exponent of ECG, RECG and EMGs was calculated in the ranges of 1-8 and 5-20 sampling intervals (ScE1-8 and ScE5-20, respectively). RESULTS: We observed non-monotonic increases in MF and Flim(99) of the ECG, but not UEGs and RECG, at 1-5min of VF. Maximum values of MF and Flim(99) in ECG, UEGs and RECG were (in Hz): 32+/-29 and 166+/-67; 11+/-2 and 36+/-7; 10+/-2 and 32+/-6, respectively. The transient increases in the high-frequency content of the ECG were correlated with enhanced activity in EMGs, characterized by an almost uniform spectrum in the range 2-250Hz (MF=92+/-29; Flim(99)=245+/-4Hz). Peak values of ScE(1-8) were the highest in EMGs (1.95+/-0.04), intermediate in the ECG (1.59+/-0.26), and the lowest in RECG (1.088+/-0.007). CONCLUSION: SMA significantly contributes to ECG during VF and can bias metrics used for assessment of VF organization.     

比较四种实验室辅助检查方法在肺结核诊断中的应用价值

目的 评价结核感染T淋巴细胞斑点试验(T-SPOT)、荧光PCR、抗结核抗体试验、抗酸染色四种辅助检查方法对于肺结核诊断的应用价值。方法 回顾性分析2012年1月～2014年12月期间530例同时进行上述四项检查的病例,以临床诊断为金标准,计算四种方法的敏感度、特异度、阳性预测值、阴性预测值、Kappa值、约登指数、阳性似然比、阴性似然比等指标,进行四种检测方法之间的配对χ²检验。结果 T-SPOT敏感度95.90%,误诊率14.33%,阴性预测值97.29%,约登指数0.82,均为最高,阴性似然比0.05为最低; PCR漏诊率87.18%为最高; 抗结核抗体阳性似然比6.48为最低; 抗酸染色特异度99.70%,阳性预测值98.90%,阳性似然比153.83均为最高。四种方法间两两比较差异均有统计学意义。结论T-SPOT和抗酸染色可作为重要的辅助检查,抗结核抗体具有高时效的特点,而PCR方法更适用于无菌部位体液的检查。     

Wells评分联合D-二聚体检测在诊断创伤后下肢深静脉血栓形成中的似然比分析

目的 评价Wells评分联合D-二聚体检测在诊断创伤后下肢深静脉血栓形成(DVT)中的应用价值.方法 回顾性分析59例确诊为创伤后DVT的临床资料以及60例无DVT的同期住院患者的临床资料,分别以Wells评分、D-二聚体以及二者联合与有无DVT的诊断结果 进行似然比等分析.结果 Wells评分在诊断创伤后DVT中灵敏度为91.53%、阴性预测值为91.07%;D-二聚体检测在诊断创伤后DVT中灵敏度为93.22%、阴性预测值为92.59%,阴性似然比为0.08;Wells评分结合D-二聚体检测在诊断创伤后DVT中的特异度为91.67%、灵敏度为94.91%、阳性预测值为91.80%、阴性预测值为94.83%、阳性似然比为11.30、阴性似然比为0.06.结论 Wells评分结合D-二聚体检测可以确定创伤后DVT诊断.如果Wells评分<2而且D-二聚体检测结果 为阴性就可以基本排除DVT诊断;如果Wells评分≥2而且D-二聚体检测结果 为阳性就应该考虑DVT诊断.两项指标联合评估可以避免一些不必要的搬动创伤患者,减少检查,降低费用.