早产儿缺氧缺血性脑损伤的诊断与分度探讨

A preliminary study on diagnosis and grading of hypoxic-ischemic brain damage of premature infants

目的随着围产医学的进步,足月儿缺氧缺血性脑损伤(HIBD)已显著减少,而早产儿HIBD成为临床关注的重点。但临床医生对早产儿HIBD诊断与治疗尚存在困惑与混乱,该文旨在探讨早产儿HIBD的诊断与分度标准,为规范早产儿HIBD的诊断与治疗提供临床参考。方法对该院2001年4月至2005年10月间按足月儿缺氧缺血性脑病标准诊断为HIBD的453例早产儿的病史、临床表现、实验室检查和影像学检查结果等进行回顾性分析,结合早产儿脑损伤的病理特点,提出早产儿HIBD诊断和分度参考标准。结果按足月儿缺氧缺血性脑病标准诊断为HIBD的453例早产儿中,符合本研究制定的早产儿HIBD诊断标准者346例,占76%。其中208例动脉血PaO2或/和SaO2降低,分别为42.21±8.33mmHg和(68.49±5.19)%;138例BE值显著降低,为(-10.86±3.41)mmol/L。所有患儿均有一定的临床表现和影像学改变。诊断早产儿HIBD头颅CT的敏感度为100%,特异度为17.8%;头颅超声的敏感度为87.9%,特异度为100%。结论用足月儿缺氧缺血性脑病标准诊断早产儿HIBD,会导致诊断扩大化,本组为24%。根据研究结果,提出早产儿HIBD的诊断参考标准为:①有缺氧的证据;②相关的临床表现;③影像学检查存在脑损伤的改变;④除外感染、电解质紊乱及先天性代谢缺陷等疾病引起的脑损伤。并建议结合头颅超声检查,临床上分为轻度和重度脑损伤。

Objective Hypoxic-ischemic brain damage （HIBD） occurs frequently in premature infants, resulting death or neurological sequela in some survivors. Up to now, however, there are no diagnostic criteria for this disease. The aim of this study was to explore the diagnostic criteria and the grading principle for HIBD of premature infants. Methods The clinical data of 453 premature infants who were diagnosed with HIBD based on the diagnostic criteria for HIBD of term infants, including medical history, clinical manifestations, laboratory results and imaging findings, were studied retrospectively. Results A preliminary diagnostic criteria for HIBD of premature infants was propounded based on clinical and pathologic features of brain damage of premature infants. Of the 453 premature infants, 346 （76%） matched the diagnostic criteria. Of the 346 cases, PaO2 （42. 21±8.33 mmHg） and /or SaO2 （68.49 ± 5. 19% ） decreased in 208 patients and the BE value （ - 10.86±3.41 mmol/L） decreased in 138 patients. The sensitivity and specificity of cranial computer tomography for the diagnosis of HIBD in premature infants was 100% and 17.8%, respectively. Cranial ultrasound displayed a sensitivity of 87.9% and specificity of 100% for the diagnosis of HIBD in premature infants. Condusions The diagnostic criteria used for HIBD for term infants is not suitable for premature infants. This study puts forward the reference diagnostic criteria of premature HIBD as following： （1） evidence of hypoxia; （2） neurological symptoms and signs; （3） imaging findings： severe brain edema, germinal matrix-intraventricular hemorrhage （GMH-IVH）, periventricular leukomalacia （PVL）, or brain infarction, and/or the resistance index （RI） 〉0.75 or 〈0.55 showed by cranial ultrasound; （4）Brain damage caused by infection, electrolyte disturbance and congenital metabolic disease was excluded. The grading principle of premature HIBD is proposed as follows： MILD HIBD when cranial ultrasound shows grade I-II of GMH-IVH or PVL, and SEVERE HIBD when cranial ultrasound shows grade Ill-IV of GMH-IVH or PVL.