目的 探讨早产儿出生后1周内局部脑氧饱和度（regional cerebral oxygen saturation, rScO₂）变异性的动态变化规律及其与不同类型脑损伤的关系。 方法 回顾性选取2021年8月—2025年6月沧州市人民医院收治的70例胎龄28~32周、出生后7 d内连续接受近红外光谱技术（near‑infrared spectroscopy, NIRS）监测rScO₂的早产儿为研究对象。根据颅脑超声和磁共振成像结果分为脑室内出血（intraventricular hemorrhage, IVH）组（n=23）、脑室周围白质软化（periventricular leukomalacia, PVL）组（n=18）、缺氧缺血性脑病（hypoxic‑ischemic encephalopathy, HIE）组（n=11）及对照组（n=18）。计算不同时间点的rScO₂变异系数（coefficient of variation, CV）、变化斜率、峰值CV及谷值CV，分析其与脑损伤类型及严重程度的相关性。 结果 出生后7 d内rScO₂ CV呈先升后降、再升再降的“双相变化”特征，第一个高变异期出现于0~<24 h，第二个高变异期出现于72~<120 h。出生后6 h rScO₂ CV与脑损伤严重程度呈正相关（r_s =0.72，P<0.001），诊断脑损伤的曲线下面积为0.862（P<0.05）。联合6 h、24 h、72 h rScO₂ CV预测脑损伤的曲线下面积达0.924（P<0.05）。 结论 早产儿出生后7 d内rScO₂变异性呈双相波动，不同脑损伤类型具有特征性变异模式，早期rScO₂ CV可作为脑损伤早期识别的敏感指标。

Objective To investigate the dynamic changes in regional cerebral oxygen saturation (rScO₂) variability within the first week after birth in preterm infants and its relationship with different types of brain injury. Methods A retrospective study included 70 preterm infants with a gestational age of 28-32 weeks admitted to Cangzhou People's Hospital from August 2021 to June 2025. All infants underwent continuous near-infrared spectroscopy (NIRS) monitoring of rScO₂ within the first 7 days after birth. Based on cranial ultrasonography and magnetic resonance imaging findings, infants were divided into intraventricular hemorrhage (IVH) group (n=23), periventricular leukomalacia (PVL) group (n=18), hypoxic-ischemic encephalopathy (HIE) group (n=11), and control group (n=18). The coefficient of variation (CV), slope, peak, and trough values of rScO₂ were calculated across different time windows, and their correlations with brain injury type and severity were analyzed. Results Within the first 7 days after birth, rScO₂ CV showed a biphasic pattern characterized by an initial increase, followed by a decrease, then a second increase and decrease. The first high-variability period occurred at 0 to <24 hours, and the second at 72 to <120 hours. The CV at 6 hours after birth was positively correlated with brain injury severity (r_s =0.72, P<0.001). The area under the receiver operating characteristic curve (AUC) for diagnosing brain injury using 6-hour CV was 0.862 (P<0.05). A combined predictive model incorporating CV values at 6, 24, and 72 hours achieved an AUC of 0.924 (P<0.05). Conclusions The variability of rScO₂ within the first week after birth in preterm infants exhibits a biphasic fluctuation pattern. Different brain injury types show characteristic variability patterns, and early CV values can serve as sensitive indicators for early identification of brain injury.