目的:关于是否常规使用分光光度法检测脑脊液(CSF)中的黄色症或目视检查是否足够,仍存在分歧。我们旨在评估这些方法在检测突发性严重头痛患者的动脉瘤性蛛网膜下腔出血中的诊断准确性。
背景:当患者出现怀疑蛛网膜下腔出血的头痛时,排除这一点的金标准是,如果入院时的头颅非对比计算机断层扫描(CT)检查结果为阴性,则在有或没有分光光度法的情况下对黄色症进行CSF分析.
方法:应用黄金标准后,我们回顾性纳入了2002-2020年期间在我院接受了CT扫描和CSF分光光度法测定的急性头痛患者.如果头颅CT被解释为阳性,则排除患者,有血淋淋的脑脊液,或无法获得CSF的视觉评估数据。我们仔细检查了患者的病历,并评估了分光光度法与目视检查相比的益处。支持蛛网膜下腔出血的净胆红素吸光度截止值设定为>0.007吸光度单位。如果净胆红素吸光度≤0.007并且净氧合血红蛋白吸光度≥0.1吸光度单位,则分光光度法也被认为是阳性。我们计算并比较了CSF分光光度法和目视检查CSF的敏感性和特异性。
结果:总计,769名患者,平均年龄为42.3±(标准偏差[SD]=17.3)岁,包括在内。41.5%的头痛发作被归类为雷击性头痛,4.7%的人突然失去知觉。15例患者(2%)最终被诊断为蛛网膜下腔出血,6人(0.8%)有动脉瘤性蛛网膜下腔出血,7人(0.9%)有中脑周围出血,一个(0.1%)有皮质脑静脉窦血栓形成,1人(0.1%)有脊髓硬膜外血肿。4例(0.5%)蛛网膜下腔出血,目测未检出,两个是动脉瘤破裂引起的.这两名患者中有一人在干预前死亡,另一个接受了前交通动脉瘤的盘绕。腰椎穿刺检测蛛网膜下腔出血所需的数量为51,但检测动脉瘤出血所需的数量为128。CSF分光光度分析所需的相应数字分别为192和385。31例患者(4.0%)分光光度法阳性,其中18人(2.3%)也目测黄色症(11人真阳性)。在视觉上清晰的CSF的13个样品中,平均净胆红素吸光度为0.0111±(SD=0.0103)吸光度单位,用阴性分光光度法与脑脊液中的0.0017±(SD=0.0013)进行比较。相应的氧合血红蛋白净吸光度为0.0391±(SD=0.0522)对0.0057±(SD=0.0081)。分光光度黄色症检测的灵敏度为100%(95%置信区间[CI],78-100),相比之下,视觉黄色症检测为73%(95%CI,45-92)。分光光度黄色症检测的特异性为98%(95%CI,97-99),而视觉黄色症检测的特异性为99%(95%CI,98-100)。两种方法均具有较高的阴性预测值:100%(95%CI,99.5-100)与99.5%(95%CI,98.6-99.9),分别。
结论:目测和分光光度法对脑脊液黄色症的检测都有很高的诊断准确性,但是较低的视觉评估灵敏度使其不可靠,我们建议在临床实践中使用分光光度法。
OBJECTIVE: There is still disagreement about whether to routinely use
spectrophotometry to detect xanthochromia in cerebrospinal fluid (CSF) or whether visual inspection is adequate. We aimed to evaluate the diagnostic accuracy of these methods in detecting an aneurysmal subarachnoid hemorrhage in patients with sudden onset severe headache.
BACKGROUND: When a patient presents to the emergency department with a headache for which there is suspicion of a subarachnoid hemorrhage, the gold standard to rule this out is to perform a CSF analysis for xanthochromia with or without spectrophotometry if the cranial non-contrast computed tomography (CT) upon admission is negative.
METHODS: Having applied the gold standard, we retrospectively included patients with acute headache who underwent both CT scan and CSF spectrophotometry at our hospital in the period 2002-2020. Patients were excluded if the cranial CT was interpreted as positive, there was a bloody CSF, or if visual assessment data of the CSF was unavailable. We scrutinized the patients\' medical records and evaluated the benefit of
spectrophotometry compared to visual inspection. The net bilirubin absorbance cut-off for support of subarachnoid hemorrhage was set at >0.007 absorbance units. The
spectrophotometry was also considered positive if the net bilirubin absorbance was ≤0.007 and net oxyhemoglobin absorbance was ≥0.1 absorbance units. We calculated and compared the sensitivity and specificity of CSF
spectrophotometry and visual inspection of the CSF.
RESULTS: In total, 769 patients, with a mean age of 42.3 ± (standard deviation [SD] = 17.3) years, were included. The headache onset was classified as a thunderclap headache in 41.5%, and 4.7% had a sudden loss of consciousness. Fifteen patients (2%) were finally diagnosed with a subarachnoid hemorrhage, six (0.8%) had an aneurysmal subarachnoid hemorrhage, seven (0.9%) had a perimesencephalic hemorrhage, one (0.1%) had a cortical cerebral sinus venous thrombosis, and one (0.1%) had a spinal epidural hematoma. Four patients (0.5%) had a subarachnoid hemorrhage that was not detected by visual inspection, and two were caused by an aneurysmal rupture. One of these two patients died just before intervention, and the other underwent coiling for an anterior communicating aneurysm. The number needed for lumbar puncture to detect a subarachnoid hemorrhage was 51, but 128 to detect an aneurysmal hemorrhage. The corresponding numbers needed for CSF spectrophotometric analysis were 192 and 385, respectively. Spectrophotometry was positive in 31 patients (4.0%), of whom 18 (2.3%) also had visually detected xanthochromia (11 true positive). The mean net bilirubin absorbance in the 13 samples with visually clear CSF was 0.0111 ± (SD = 0.0103) absorbance units, compared to 0.0017 ± (SD = 0.0013) in the CSF with negative spectrophotometry. The corresponding figures for net oxyhemoglobin absorbance were 0.0391 ± (SD = 0.0522) versus 0.0057 ± (SD = 0.0081). The sensitivity of spectrophotometric xanthochromia detection was 100% (95% confidence interval [CI], 78-100), compared to 73% (95% CI, 45-92) for visual xanthochromia detection. The specificity of spectrophotometric xanthochromia detection was 98% (95% CI, 97-99) compared to 99% (95% CI, 98-100) for visual xanthochromia detection. Both methods had high negative predictive values: 100% (95% CI, 99.5-100) versus 99.5% (95% CI, 98.6-99.9), respectively.
CONCLUSIONS: Both visual inspection and
spectrophotometry have high diagnostic accuracy for detecting CSF xanthochromia, but the lower sensitivity of visual assessment makes it unreliable, and we recommend the use of spectrophotometry in clinical practice.