Abstract: Hyperkalemia is a rare but serious complication of urinary tract infection（UTI）in infants.Its common causes include secondary pseudohypoaldosteronism（PHA）and medication（such as sulfamethoxazole）.Secondary PHA（sPHA）is a complication of UTI which is most often overlooked， and it is more common in children under 6 months old with urinary tract infections or（and）urinary tract malformations. sPHA is more common in boys than in girls.The clinical manifestations are non-specific，including difficulty in feeding，decreased water intake，vomiting，diarrhea and growth retardation，and hypovolemia，seizures and even cardiac arrest may occur in some patients. Laboratory tests reveal hyponatremia，hyperkalemia，metabolic acidosis，reduced urinary potassium，increased urinary sodium，hyperaldosterone and renin activity. sPHA should be differentiated from congenital and acquired aldosteronism（such as congenital adrenal hyperplasia）in clinical practice.Children with PHA secondary to urinary tract infection or（and）malformation have good prognosis if they can be diagnosed early and treated in time with sodium supplementation，antibiotic treatment or surgical intervention.

Key words: hyperkalemia, hyponatremia, urinary tract infection, pseudohypoaldosteronism

摘要： 高钾血症是婴儿泌尿系感染（UTI）少见但严重的并发症，其病因包括继发性假性醛固酮减少症（PHA）、药物（如磺胺甲[口][恶]唑）等。其中，继发性PHA是UTI最易被忽视的一类并发症，多见于6月龄以下的UTI或（和）泌尿系畸形患儿，男多于女，临床表现为非特异性，包括喂养困难、饮水量下降、呕吐、腹泻和生长发育迟缓等，少数患儿甚至出现血容量不足、抽搐发作，甚至心脏骤停。实验室检查可见高钾血症、低钠血症、代谢性酸中毒、尿钾排泄减少、尿钠排泄增多、高醛固酮和高肾素活性等。在临床中，应与各类先天性、获得性醛固酮减少症（如先天性肾上腺皮质增生症）等疾病进行鉴别。继发于UTI或（和）泌尿系畸形的PHA患儿，若能早期识别，积极给予补钠、抗感染或外科手术等治疗措施，临床预后较好。

关键词: 高钾血症, 低钠血症, 泌尿系感染, 假性醛固酮减少症