Substituting whole blood for urine in a bedside pregnancy test

Background

Point-of-care testing for rapid detection of pregnancy in women of reproductive age is common practice in the emergency department. Commercially available rapid human chorionic gonadotropin (hCG) immunoassays are validated for use with urine and serum, but not whole blood.

Study Objectives

We assessed the validity of using whole blood to detect pregnancy using a point-of-care hCG assay by comparing it to a laboratory quantitative serum hCG assay as the criterion standard.

Methods

A convenience sample of female patients of reproductive age (18–51 years) submitted 5 mL of whole blood, from which two drops were immediately applied to a point-of-care hCG kit, with results recorded at 10 min. The remainder of each whole blood specimen was sent to the hospital laboratory for the criterion-standard quantitative serum hCG assay. The criterion standard for a positive pregnancy test was defined as quantitative serum hCG ≥ 5 mIU/mL. Investigators performing the whole blood test and laboratory technicians performing the quantitative serum assay were blinded to one another’s results.

Results

There were 633 patients enrolled, with a mean age of 30 years (± 7.7 years); 34% of the patients were pregnant. Overall, the whole blood pregnancy test was 95.8% sensitive (negative predictive value 97.9%), whereas the urine test was 95.3% sensitive (negative predictive value 97.6%); the specificity and positive predictive value of both tests was 100%.

Conclusion

Using a standard point-of-care qualitative hCG immunoassay kit, whole blood may be used for rapid detection of pregnancy with similar, or greater, accuracy than urine.     

Procedure for pregnancy testing

This article summarises the procedure for assessing and undertaking a test to determine if a woman is pregnant.     

UF-100在尿液检测中的应用价值

目的 评价UF-100全自动尿液细胞分析仪在实际工作中的应用。方法 对474例尿液标本同时进行干化学分析、尿沉渣镜检和UF-100检查,对比分析。结果 在尿液有形成分的检测方面,UF-100法与手工镜检法结果相近,符合性好,UF-100法与干化学检验结果存在差异。结论 UF-100在一定范围内能对尿液中的有形成分进行准确计数,定量报告,并能提示RBC的相关信息,有效地提高了尿常规的检验质量。     

阴道超声联合尿HCG检查对不典型异位妊娠的诊断价值

目的：探讨阴道超声联合尿HCG检查诊断不典型异位妊娠的应用价值。方法：对经手术及病理证实的135例异位妊娠患者进行回顾性分析,术前行阴道超声及尿HCG检查,对宫内无孕囊且尿HCG检查阳性者,观察卵巢旁有无肿块及其血流表现。结果：阴道超声直接确诊异位妊娠9例,阴道超声联合尿HCG检查阳性诊断异位妊娠122例,符合率97.04%（131/135）,灵敏度97.04%,漏诊4例,漏诊率2.96%（4/135）。结论：单独应用某项检查并不能准确鉴别诊断不典型异位妊娠,阴道超声联合尿HCG检查能有效提高不典型异位妊娠的诊断准确率,降低误诊及漏诊率。     

溴酚蓝简易快速筛选尿中微量清蛋白

目的探讨溴酚蓝染料结合法筛选尿中极微量清蛋白。方法用0.231mmol/L的溴酚蓝试剂与尿中清蛋白显色,肉眼与标准色度杯比较定性或分光光度计比色定量测定尿中极微量清蛋白。结果最低检出线为5mg/L。定量法的线性范围5～500mg/L,批内CV为0.42%～2.12%,批间CV为0.84%～3.9%。回收率96.7%～104.8%。与免疫透射比浊法的相关系数r=0.962,y=0.98x+0.097。尿中常见的物质及临床常用的药物均无明显干扰。正常参考范围5～45mg/L。结论本法不需特殊仪器和试剂,简易快速、灵敏度高、特异性强、重复性好。