血细胞自动化分析后血涂片复审标准制定的原则与步骤

根据血细胞分析方法的变迁和仪器法血细胞检测后血涂片复审的现状,结合血涂片复审41条国际规则,介绍临床实验室制定血涂片复审标准的原则和步骤,以及值得注意的问题.     

ABX PENTRA DF 120血液分析仪复检规则建立和评估

目的建立并评价ABX PENTRA DF 120血液分析仪复检规则。方法参考国际血液学复检专家组推荐的"41条"复检规则,结合仪器报警系统,制订暂定复检规则。对本院1 500例标本进行仪器检测和镜检,对暂定规则和仪器提示细胞数量和形态异常报警分别进行统计学评估,制订最终规则;通过分析300例标本,评价最终规则有效性。结果假阳性率最高的前3项暂定规则为未成熟粒细胞、不典型淋巴细胞和血小板聚集。暂定规则形态学评估真阳性率17.47%、假阳性率10.00%、真阴性率69.93%、假阴性率2.6%、复检率27.47%。制订最终规则后,其临床应用复检率为22.00%,经验证未发现血液病理细胞漏检现象。结论本研究制订的ABX PEN-TRA DF 120血液分析仪复检规则具有临床可操作性和有效性。     

全自动血液分析流水线血片复检规则的设置及临床应用探讨

目的探讨通过软件设置合理的血液分析仪复检规则，对血液分析仪检测结果异常的标本进行自动筛选和标记，并用自动推片染色仪进行推片和染色以观察细胞形态学异常，用显微镜计数方法证实血细胞计数的异常，从而达到提高工作效率保证血液分析结果的准确性。方法利用Sysmex XE-2100血液分析仪的报警系统，结合国际实验血液学学会（ISLH）推荐的41条复检规则，并结合本科室实际检测患者的特点，制定出了适合我科的复检规则。并根据美国临床和实验室标准化委员会（CLSI）推荐的白细胞（WBC）分类方法和ISLH推荐血涂片阳性标准，并参照《全国临床检验操作规程》推荐的血细胞计数方法，对1300份标本中符合复检标准的“阳性”样本进行对应的复检，对不符合复检标准的“阴性”样本仅进行形态学检查。结果该套规则的阳性预示值为76．63％，阴性预示值为98．50％，该规则的复检率为28．3l％，诊断特异性为89．34％，诊断灵敏度为96．25％，总有效率为77．15％。结论我室制定的针对XE-2100血液分析仪的复检规则，能够有效地筛选出真正异常样本，使操作人员在有限的时间内对真正异常的标本进行复检，达到提高工作效率，保证血液分析结果准确性的目的。     

Establishment of improved review criteria for hematology analyzers in cancer hospitals

BackgroundAlthough hematologic review criteria for general hospitals have been established, they may be insufficient for cancer hospitals. This study aimed to establish the appropriate review criteria for hematology analyzers in cancer hospitals.MethodsA total of 1003 samples from our hospital were randomly selected for blood smear preparation and microscopic review. The review criteria of the International Consensus Group for Hematology Review (ICGH) and Chinese consensus group were used to obtain the review, true‐negative (TN), true‐positive (TP), false‐negative (FN), and false‐positive (FP) rates, as well as the triggered rules. Our review criteria were established by comparing flag or numeric value information of TP and FP samples, adjusting rules to obtain better efficiency, a low slide review rate, and an acceptable FN rate.ResultsOverall, 197 (19.64%) samples showed positive smear findings. Compared to the ICGH criteria, the slide review rate of the newly established criteria declined from 51.25% to 39.28%, and the TP and TN rates increased from 17.85% and 46.06% to 23.13% and 55.83%, respectively. The FN rate of the newly established criteria was 3.69%. Another set of samples used to validate the newly established criteria yielded the review, FN, and FP rates as 33.49%, 1.86%, and 25.58%, respectively.ConclusionThe newly established review criteria for hematology analyzers enabled the prompt identification, smear, and further verification of doubtful specimens, without a significant increase in the workload, thus improving the efficiency of the review process. This study provided data support for other cancer hospitals to establish review criteria.     

Sysmex XE-2100自动血细胞分析和白细胞分类的复检规则探讨

目的 采用Sysmex XE-2100血细胞分析仪评估国际血液学复检专家组推荐的血细胞复检规则,通过对实验数据进行分析,提出适合于中国人群使用的血细胞复检规则.方法 3家医院均采用日本希森美康公司生产的XE-2100五分群(类)全自动血细胞分析仪,随机检测患者标本共3 594份,同时涂片做显微镜检查,包括细胞形态观察和人工白细胞分类.按照国际血细胞复检规则、自行拟定的筛选方案和涂片镜检阳性标准进行评估,计算出真阳性、假阳性、真阴性、假阴性和涂片复检的比率,并筛选出最佳方案.结果 根据国际血液学复检专家组推荐的41条复检规则和涂片镜检阳性规则对检测结果进行统计学分析,真阳性率为14.02%(504/3 594),假阳性率为32.67%(1 174/3 594),真阴性率为51.47%(1 850/3 594),假阴性率为1.84%(66/3 594).由于中国人群血细胞参考范围不同于西方人群,我们采用修改后的复检规则(方案8)和镜检规则对3 594份标本的数据进行分析,结果显示,真阳性率为12.33%(443/3 594),假阳性率为21.01%(755/3 594),真阴性率为63.44%(2 280/3 594),假阴性率为3.23%(116/3 594).在此基础上,参考"国际血液学41条复检规则"、XE-2100的性能特点和我国的常规工作情况,提出了中国人群应用XE-2100的血细胞计数和白细胞分类的涂片复检规则,验证试验结果显示,血液病细胞无漏检情况.结论 制定合理适用的血细胞计数和白细胞分类的涂片复检规则非常重要,既可保证检测结果质量,又可提高工作效率.血细胞复检规则应该在工作中不断地改进完善.     

机测后显微镜复检的标准和应用

目的寻求保证白细胞分类准确性的方法,以利临床诊断和治疗。方法根据医院具体情况依据多项病人指标制定白细胞分类显微镜检查标准,通过标准实行后两组共1128份标本结果的数据分析,评价标准的可行性和可靠性。结果标准实行后有31%的仪器血常规CBC结果需要复检,其中33%存在杆状细胞增多、异型淋巴细胞增多或其它种异常细胞。结论制定血细胞显微镜复检标准非常重要,可以加强血细胞检查准确性,为临床提供更有价值的信息,有利诊断和治疗。     

Siemens Advia 2120血细胞分析仪复检规则的制定及应用

目的 建立Siemens Advia 2120血细胞分析仪的复检规则,并详细分析规则建立的必要环节,以期对其他医院建立合理的复检规则提供依据.方法 采集北京协和医院30个临床科室的1223份血标本,通过血细胞分析仪检测血常规,通过人工镜检法进行血细胞计数和形态学检查,参考国际血液学复检专家组制定的"41条"规则,通过调整规则降低假阳性率,控制漏诊率,建立适合本医院的血细胞分析的复检规则,并通过301例血液病、肿瘤放化疗及感染等有阳性或假阳性倾向的病例验证规则的有效性.结果 根据"41条"规则,复检率高达37.9%(464/1223),假阳性率为23.3%(285/1223),漏诊率为1.9%(23/1223),无血液恶性肿瘤漏诊.假阳性病例中占据前8位的单条触发规则依次为:小红细胞、大红细胞、不均一性红细胞、核左移、WBC<4.0×109/L或>30.0×109/L、未成熟细胞、原始细胞和PLT<100.0×109/L或>1000.0×109/L.未成熟细胞和原始细胞是血液恶性肿瘤容易出现的提示,不能被删除;核左移与重度细菌性感染密切相关,与WBC具有部分相同的意义,不被首先考虑改变;删除小红细胞(+)、大红细胞(+)和不均一性细胞(+);WBC由<4.0×109/L降至<3.0×109/L;PLT由<100.0×109/L降至<80.0×109/L,由此,假阳性率降至17.5%(214/1223),复检率降至31.1%(380/1223),漏诊率略上升为2.9%(36/1223),无血液恶性肿瘤漏诊,从而形成本医院Siemens Advia 2120血细胞分析仪的复检规则,有效性验证的漏诊率为0.结论 "41条"规则适用于Siemens Advia 2120血细胞分析仪,但复检率过高不被大型医院采用,优化后,规则的复检率和漏诊率具有临床可操作性和有效性.     

Pupillary dilation reflex and behavioural pain scale: Study of diagnostic test

BackgroundThe objective of this study was to assess the value of the pupillary dilation reflex as an assessment pain tool in critically ill patients. It is important to continue working for the well-being and security of critically ill patients.MethodsWe studied the diagnostic accuracy of the pupillary dilation reflex against the Behavioral Pain Scale. Inclusion criteria were: age greater than 18, receiving mechanical ventilation, with a basal score of the Behavioural Pain Scale of three and a Richmond Agitation and Sedation score between −1 and −4. We studied the responses to a non-painful stimulus, four calibrated stimuli, after a tracheal aspiration and with and without pain. The receiver operating curve was plotted and we calculated the area under the curve. We identified the cut-off points showing the highest sensitivity and specificity and studied diagnostic performance based on negative predictive value, positive predictive value, and accuracy. These were reported with their 95% confidence intervals.Results183 measurements were performed. An AUC of 0.88(95% CI 0.83–0.94) was obtained. The pupillary dilation reflex of 11.5% had a sensitivity of 89.8%(95% CI 78.2–95.6) and a specificity of 78.4%(95% CI 70.6–84.5) with an accuracy of 81.4(75.2–86.4). The pupillary dilation reflex detected nociceptive pain response in 15.8% of the measurements that did not show pain according to the Behavioural Pain Scale.ConclusionsPupillometry may be a valid alternative for identifying pain in critically ill patients.     

Failure to normalize lymphopenia following trauma is associated with increased mortality, independent of the leukocytosis pattern

Introduction

Following trauma and systemic inflammatory response syndrome (SIRS), the typical response is an elevation of the total complete blood count (CBC) and a reduction of the lymphocyte count. This leukocytosis typically returns to normal within 48 hours. The persistence of a leukocytosis following trauma is associated with adverse outcomes. Although lymphocyte anergy and dysfunction following trauma is associated with increased risk for infection and sepsis, there is a paucity of data regarding the impact of a persistence of a low lymphocyte count in trauma patients.

Methods

This is a retrospective review of prospectively collected data from trauma patients collected over the 5 years of September 2003 to September 2008. Patients were included if the injury severity score (ISS) was >/=15, and they survived at least 3 days. Demographic data, mechanism and injury severity score, mortality, and length of stay were collected from the medical record. Laboratory values for the first 4 hospital days were collected. Leukocyte, neutrophil and lymphocyte counts were extracted from the daily complete blood count (CBC). Patients were then grouped based on response (elevation/depression) of each component of the CBC, and their return, or failure thereof, to normal. Proportional hazards regression with time-varying covariates as well as Kaplan-Meier curves were used to predict risk of death, time to death and time to healthy discharge based on fluctuations of the individual components of the CBC.

Results

There were 2448 patients admitted over the 5 years included in the analysis. When adjusting for age, gender and ISS the relative risk of death was elevated with a persistent leukocytosis (2.501 (95% CI = 1.477-4.235)) or failure to normalize lymphopenia (1.639 (95% CI = 10.17-2.643)) within the first 4 days following admission. Similar results were seen when Kaplan-Meier curves were created. Persistent lymphopenia was associated with shortest time to death. Paradoxically in survivors persistent lymphopenia was associated with the shortest time to discharge.

Conclusions

Persistently abnormal CBC responses are associated with a higher mortality following trauma. This is the first report noting that a failure to normalize lymphopenia in severely injured patients is associated with significantly higher mortality.     

Usefulness of thresholds for smear review of neutropenic samples analyzed with a Sysmex XN-10 analyzer

Neutropenia is one of the main criteria for a blood smear review. The objective of this study was to compare the thresholds proposed by the international consensus group for hematology review (1.0 10⁹/L) and the French speaking Group for Cellular Haematology (1.5 10⁹/L) in terms of the number of useless smears. We collected 112,097 analyzed samples from four laboratories equipped with XN instruments (Sysmex, Kobe, Japan) during early 2016. The only exclusion criterion was a leucocyte count below 0.5 10⁹/L. In the absence of abnormal cells and/or morphology suggesting haematological disease, samples were classified as ‘negative for morphology’ and the differential from the XN-10 was reported. These smear procedures were considered as uninformative. Some 2202 samples met the criterion for neutropenia (<1.5 10⁹/L) for slide review representing 1.96% of the total. These included 1031 with neutropenia alone and 1171 neutropenia plus other abnormalities. Of the 1031 with neutropenia alone, 886 had a neutrophil count between 1.0 10⁹/L and 1.5 10⁹/L. The smear was uninformative for all of these samples. In conclusion, microscopic examination of a blood smear provided very limited information in cases of neutropenia without other abnormalities.     

血细胞分析仪筛选建立显微镜复检标准及临床价值

目的根据对血细胞分析仪检测结果的分析及细胞形态学的鉴别，建立显微镜复检标准，保证血细胞分析结果的准确性。方法根据本院门诊病人的具体情况应用血细胞分析仪检测结果筛选制定出显微镜复检标准，通过对1683例标本仪器结果的数据分析，对标准的可行性和实用性进行探讨与分析。结果仪器检测的标本有16．1％的血液分析标本需要复查，其中18．5％存在中性杆状粒细胞增多、异型淋巴增多、幼稚细胞、中晚幼粒细胞、靶形红细胞等其他类型的异常，所制定的标准经临床验证有重要价值和意义。结论血细胞分析仪不能完全代替显微镜涂片检查，制定血细胞显微镜复检标准非常必要，保证血细胞检查的准确性，为临床诊断、治疗提供有价值的信息。     

The effects of low‐dose epinephrine infusion on spleen size,central and hepatic circulation and circulating platelets

In several conditions associated with adrenergic stimulation, an increase in peripheral count of larger platelets has been observed, but the mechanism remained elusive. Larger platelets have greater prothrombotic potential and increase the risk of acute thrombotic events. The human spleen retains one‐third of total body platelets, with mean volume (MPV) about 20% greater than that of circulating platelets. We aimed to answer whether low‐dose epinephrine infusion results in spleen contraction and MPV increase. We undertook the continuous ultrasonic measurements of spleen volume, hepatic and central circulation with concurrent blood sampling in response to intravenous infusion of epinephrine (6 min of 0·06 µg kg^?1 per min, followed by 3 min of 0·12 µg kg^?1 per min) in nine healthy young subjects. The spleen volume started to decrease immediately after the onset of infusion, in the presence of substantial decreases in peripheral resistance and mean blood pressure and increases in heart rate and cardiac output. The majority of spleen emptying, approximately 25%, (95% CI 71·3–299·7) was observed 1 min after infusion onset, the hepatic vein flow peaked at the end of infusion for 28·4% (95% CI 1074·6–407·9), while increases in platelet count for approximately 31% (95% CI 187·8–314·8) and MPV for 4·4% (95% CI 7·3–10·9) lagged until 1 min after infusion cessation. We suggest that spleen is a dynamic reservoir of large platelets, which are mobilized even by low‐dose epinephrine infusion in conditions of decreased blood pressure.     

Access to elective vascular surgery within the recommended time according to emergency referrals

BACKGROUND: Referral pattern is a potential confounding factor when waiting-list performance is reported across hospitals or periods. A common concern is the ability to accurately estimate proportions of patients undergoing surgery in the recommended time without considering emergency caseload. In this study, the relation between emergency referrals and the rate of elective admissions to hospital within the recommended time was estimated. DESIGN: A prospective cohort study. SETTING: An acute care hospital in Kingston, Ont. PATIENTS: Between 1994 and 1999, 1,173 consecutive patients accepted for elective vascular surgery. MAIN OUTCOME MEASURES: The proportion of patients who underwent surgery within the recommended time, and time to surgery. STUDY VARIABLES: The weekly number of emergency cases, enrolment periods, urgency and type of surgery. RESULTS: Overall, the proportion of patients who underwent surgery within recommended time was 0.45, (95% confidence interval [CI], 0.42-0.48). Adjusted for enrolment period, urgency and type of surgery, the estimated proportion was 0.57, (95% CI, 0.49-0.64). Compared with surgery for peripheral vascular disease, the odds of the procedure being done within the recommended time were 34% lower for aortic abdominal aneurysm repair and 41% lower for carotid endarterectomy. After adjustment for the case-mix and access attributes, the rate of elective admission within recommended time was on average 30% lower for weeks in which there were 1 to 2 emergency cases (rate ratio [RR] = 0.70, [95% CI, 0.53- 0.93]), and 39% lower for weeks with 3 or more emergency cases (RR = 0.61 [95% CI, 0.53-0.83]), relative to weeks with no emergency cases. CONCLUSIONS: When there is an increase in the number of emergency cases, a lower proportion of patients undergo elective surgery within the recommended time. Thus, when performance of surgical servces is evaluated, the probability of patients undergoing elective surgery on time should be adjusted relative to the number of emergency referrals.     

Trends in opioid analgesic use for headaches in US emergency departments

Objective

Although not recommended as first line therapy by consensus guidelines, opioid analgesics are commonly used to treat headaches. This study evaluates trends in opioid use for headaches in US emergency departments (EDs).

Methods

We performed a retrospective review of the National Hospital Ambulatory Medical Care Survey, 2001 through 2010. Adult headache-related visits were identified. Medications (opioid and nonopioid) used for the treatment of headache were categorized based on medication class. Trends in ED use of the most common opioids (codeine, hydrocodone, hydromorphone, morphine, and oxycodone) were explored. The proportion of visits for which each medication was used was tabulated, and trends were analyzed using survey-weighted logistic regression.

Results

Headache visits during which any opioid was used increased between 2001 (20.6%; 95% confidence interval [CI], 18.1-23.4) and 2010 (35.0%; 95% CI, 31.8-38.4; P < .001). Prescribing of hydromorphone, morphine, and oxycodone increased, with the largest relative increase (461.1%) in hydromorphone (2001, 1.8% [95% CI, 1.2-2.6]; 2010, 10.1% [95% CI, 8.2-12.4]). Codeine use declined, and hydrocodone use remained stable. Use of opioid alternatives, including acetaminophen, butalbital, and triptans did not change over the study period, whereas use of nonsteroidal anti-inflammatory drugs increased from 26.2% (95% CI, 23.0-29.7) to 31.4% (95% CI, 28.6-34.3). Prescribing of antiemetic agents decreased from 24.1% (95% CI, 19.6-29.2) to 23.5% (95% CI, 21.1-26.0). Intravenous fluid use increased from 20.0% (95% CI, 17.0-23.4) to 34.5% (95% CI, 31.0-38.2) of visits.

Conclusions

Despite limited endorsement by consensus guidelines, there was increased use of opioid analgesics to treat headaches in US EDs over the past decade.     

Ketamine for emergency sedation of agitated patients: A systematic review and meta-analysis

Prior studies suggest that ketamine is effective for acute agitation in the emergency department (ED) and prehospital settings. This systematic review and meta-analysis aims to evaluate the rate of sedation and need for airway management in patients given ketamine for management of acute agitation. Methods: We performed a systematic review of publications describing the use of ketamine to control agitation in the ED and prehospital settings. Studies were included if they included agitated patients, used ketamine to control agitation, occurred in the ED and prehospital setting and measured sedation status or need for airway management. Following data abstraction, a meta-analysis was performed to synthesize the rate of effective sedation and the need for airway management. Result: 13 studies met the inclusion criteria. 10 studies were conducted in the prehospital setting and 3 in the ED setting. The overall proportion of subjects receiving airway management across all 13 studies was 20% (95% CI = 0.0489–1.6505). The estimate of the proportion of subjects that achieved sedation was 85% (95% CI = 0.71–0.93). After synthesizing data from the four studies that compared ketamine to controls, ketamine was associated with increased rates of sedation (RR, 1.95 [CI, 0.47–8.1]) and increased need for intubation (RR, 2.44 [CI, 0.75–7.91]). The differences were not significant by random effects model.     

Performance evaluation of the white cell precursor channel on the Sysmex XN hematology analyzer in HIV specimens

Background

Automated hematology analyzers generate white blood cell (WBC) suspect flags to indicate smears requiring manual review. In a human immunodeficiency virus (HIV) patient population with a high frequency of abnormal specimens, the usefulness of these flags depends on their sensitivity and specificity. The white cell precursor (WPC) channel on the Sysmex XN‐9000 analyzer (Sysmex Corporation, Kobe, Japan) has recently been introduced in order to distinguish immature cells such as blasts and abnormal lymphocytes.

Methods

The efficiency of the flags generated by WPC reflex testing was compared to the white cell differential (WDF) on the Sysmex XN‐9000 in 400 routine HIV samples.

Results

A flag was generated by the WDF channel in 346 (86.50%) samples. Addition of the WPC to the WDF resulted in a 20.99% reduction in the smear review rate. WPC analysis correctly identified the initial WDF flag in 59 (60.82%) samples with ‘blasts?’ or ‘abnormal lympho?’ flags. WPC showed an excellent sensitivity of 100%. However, the specificity remained poor. On investigation, samples with chronic infection/inflammation (35.00%) and lymphopenia (63.25%) were associated with a high false positive rate of 76.32% and 55.56%, respectively. WPC analysis removed 45 (51.72%) coexisting ‘atypical lympho?’ false positive WDF flags. The ‘atypical lympho?’ flag showed an increased sensitivity and specificity of 88.46% and 74.67%, respectively.

Conclusion

White cell precursor reflex testing showed improved flagging efficiency for the ‘atypical lympho?’ flag, which was a good indicator of reactive lymphocytes during chronic infection/inflammation. Nevertheless, the false positive rate for ‘abnormal lympho/blasts?’ was high in the presence of lymphopenia and infection.

     

Prevalence of blood donation eligibility in Australia: A population survey

Background

Reliable estimates of the population proportion eligible to donate blood are needed by blood collection agencies to model the likely impact of changes in eligibility criteria and inform targeted population-level education, recruitment, and retention strategies. In Australia, the sole estimate was calculated 10+ years ago. With several subsequent changes to the eligibility criteria, an updated estimate is required.

Study Design and Methods

We conducted a cross-sectional national population survey to estimate eligibility for blood donation. Respondents were aged 18+ and resident in Australia. Results were weighted to obtain a representative sample of the population.

Results

Estimated population prevalence of blood donation eligibility for those aged 18–74 was 57.3% (95% CI 55.3–59.3). The remaining 42.7% (95% CI 40.7–44.7) were either temporarily (25.3%, 95% CI 23.5–27.2) or permanently ineligible (17.4%, 95% CI 16.1–18.9). Of those eligible at the time of the survey, that is, with the UK geographic deferral for variant Creutzfeldt-Jakob disease included, (52.9%, 95% CI 50.8–54.9), 14.2% (95% CI 12.3–16.3) reported donating blood within the previous 2 years. Eligibility was higher among men (62.6%, 95% CI 59.6–65.6) than women (52.8%, 95% CI 50.1–55.6). The most common exclusion factor was iron deficiency/anemia within the last 6 months; 3.8% (95% CI 3.2–4.6) of the sample were ineligible due to this factor alone.

Discussion

We estimate that approximately 10.5 million people (57.3% of 18–74-year-olds) are eligible to donate blood in Australia. Only 14.2% of those eligible at the time of survey reported donating blood within the previous 2 years, indicating a large untapped pool of potentially eligible blood donors.     

Puzzles in practice. Platelet satellitism

A 68-year-old woman underwent a right total hip arthroplasty for severe osteoarthritis. The surgery was uneventful without excessive blood loss, but she was found to have a platelet count of 62 000 per cm on a routine postoperative complete blood count (CBC). There was no preoperative CBC available for comparison. Other than mild anemia (Hb, 11.2 g/dL), there were no abnormalities in the automated CBC. The patient had did not have a history of easy bruisability, abnormal mucosal bleeding, gastrointestinal bleeding, or genitourinary bleeding. Her family history was negative for any bleeding disorders. The patient's only medication was acetaminophen for hip pain. The peripheral smear was reviewed and showed rosetting of platelets about polymorphonuclear leukocytes. What is your diagnosis?     

国际血细胞复检规则在贝克曼-库尔特系列血细胞分析仪上的应用及改进方案

目的 采用贝克曼.库尔特系列血细胞分析仪评估国际血液学复检专家组推荐的血细胞复检规则,通过对实验数据进行分析建立适合于中国人群使用的血细胞复检规则.方法 3家医院分别采用美国贝克曼.库尔特公司生产的MAXM、GENS和LH750五分群(类)全自动血细胞分析仪随机检测患者标本共3 600份,同时涂片做显微镜检查,包括人工白细胞分类和细胞形态观察.按照国际血细胞复检规则和涂片镜检阳性规则进行评估,计算出真阳性、真阴性、假阳性和假阴性的比率.通过分析假阳性和假阴性的原因,并结合中国人群和临床检验的实际情况,对国际复检规则进行修改,制定出适合于中国人群使用的血细胞复检规则.然后检测240份患者标本对新规则进行验证.结果 根据国际血液学复检专家组推荐的41条复检规则和涂片镜检阳性规则对检测结果进行统计学分析,真阳性率为4.9%(177/3 600);假阳性率为24.2%(870/3 600);假阴性率为0.5%(19/3 600);真阴性率为70.4%(2 534/3 600).由于中国人群血细胞正常参考范围不同于西方人群,通过对数据进行分析,并根据我国的常规工作情况,将国际复检规则修改为23条;将镜检阳性规则中添加了白细胞分类比率4条规则.采用修改后的复检规则和镜检阳性规则评估结果,真阳性率为9.9%(355/3 600);假阳性率为17.1%(617/3 600);假阴性率为1.8%(65/3 600);真阴性率为71.2%(2 563/3 600).采用前后两个复检规则均未漏检原幼细胞,修改后假阴性率略高,是由于镜检阳性规则中增加了白细胞分类比率所致.验证实验结果表明:真阳性率为13.7%(33/240);假阳性率为15.8%(38/240);假阴性率为2.5%(6/240);真阴性率为68.0%(163/240).结论 国际血液学复检专家组推荐的血细胞复检规则虽有重要临床参考价值,但在中国人群中使用却增加了假阳性率.本研究制定出的贝克曼-库尔特系列血细胞分析仪的血细胞复检规则更符合中国人群特征.     

Occupational Injuries among Emergency Medical Services Personnel

Background. Emergency medical services (EMS) personnel treat 22 million patients a year in the United States, yet little is known of their injury risks. Objectives. To describe the epidemiology of occupational injuries among EMS personnel, calculate injury rates, andcompare the findings with those for other occupational groups. Methods. This was a retrospective review of injury records kept by two urban agencies. The agencies submitted all 617 case reports for three periods between January 1, 1998, andJuly 15, 2002. The agency personnel worked an estimated 2,829,906 hours during the study periods. Cases were coded according to U.S. Department of Labor (DOL) criteria. Results. Four hundred eighty-nine cases met the DOL inclusion criteria. The overall injury rate was 34.6 per 100 full-time (FT) workers per year (95% confidence interval [CI] 31.5–37.6). “Sprains, strains, andtears” was the leading category of injury; the back was the body part most often injured. Of the 489 cases, 277 (57%) resulted in lost workdays, resulting in a rate of 19.6 (95% CI 17.3–21.9) per 100 FT workers; in comparison, the relative risks for EMS workers were 1.5 (95% CI 1.35–1.72) compared with firefighters, 5.8 (95% CI 5.12–6.49) compared with health services personnel, and7.0 (95% CI 6.22–7.87) compared with the national average. Conclusions. The injury rates for EMS workers are higher than rates reported by DOL for any industry in 2000. Funding andadditional research are critical to further defining the high risks to EMS workers anddeveloping interventions to mitigate this serious problem.