该文报道了5例有机酸血症伴严重高氨血症的新生儿，包括异戊酸血症（isovaleric acidemia, IVA）1例、甲基丙二酸血症（methylmalonic acidemia, MMA）3例、丙酸血症（propionic acidemia, PA）1例。患儿日龄3~19 d，均以吃奶差、精神反应差等非特异性症状起病，部分伴呕吐；所有患儿均存在呼吸困难，1例合并惊厥。所有患儿均经基因检测确诊，1例IVA为IVD基因纯合变异，3例MMA均为MMUT基因复合杂合变异，1例PA为PCCA基因纯合变异。5例患儿在高氨血症急性期均接受卡谷氨酸（N⁃carbamylglutamate, NCG）治疗，其中2例血氨峰值>1 500.0 μmol/L的重症患儿先行连续性静脉-静脉血液透析治疗，待血氨降至200 μmol/L以下后，予NCG口服；3例直接予以NCG口服治疗。所有患儿血氨水平均显著下降，均顺利恢复喂养并逐步增加蛋白质摄入。慢性期均维持NCG口服治疗。除1例MMA患儿因家属放弃治疗，于生后6 d死亡外，其余4例血氨均保持低于80 μmol/L。经12个月以上的随访，4例患儿各项生长发育指标（包括身长、体重、头围等）均在正常范围，其中2例粗大运动、语言理解能力轻度落后。NCG用于有机酸血症相关高氨血症的急性期救治及长期管理具有较好的安全性和有效性，可为该类疾病的临床治疗提供新的参考策略。

Five neonates with organic acidemia complicated by severe hyperammonemia were reported, including one case of isovaleric acidemia (IVA), three cases of methylmalonic acidemia (MMA), and one case of propionic acidemia (PA). The neonates were 3 to 19 days old. All presented with nonspecific symptoms such as poor feeding and decreased responsiveness, some with vomiting. All had dyspnea, and one had seizures. All cases were genetically confirmed: the IVA case carried a homozygous IVD variant, the three MMA cases carried compound heterozygous MMUT variants, and the PA case carried a homozygous PCCA variant. During the acute hyperammonemic phase, all five received N-carbamylglutamate (NCG). Two critically ill infants with peak ammonia >1 500 μmol/L underwent continuous veno-venous hemodialysis first and were started on oral NCG after ammonia fell below 200 μmol/L; the other three received oral NCG directly. Blood ammonia levels declined markedly in all cases, feeding was resumed successfully, and protein intake was gradually increased. In the chronic phase, all were maintained on oral NCG. One MMA infant died at 6 days of age due to treatment withdrawal by the family; the remaining four maintained ammonia <80 μmol/L. Over more than 12 months of follow-up, all four survivors had growth parameters (length, weight, and head circumference) within normal ranges, with two exhibiting mild delays in gross motor and language comprehension. NCG shows good safety and effectiveness for both acute rescue and long-term management of organic-acidemia-related hyperammonemia, and provides a reference strategy for clinical care.