危重症患儿连续性血液净化治疗中血磷水平的变化

Changes of serum phosphorus level during continuous blood purification therapy in critically ill children

目的观察危重症患儿连续性血液净化治疗（CRRT）过程中血磷水平的变化，以期指导危重症患儿CRRT时血磷水平的监测和补磷治疗方案的制定。方法以2017年1－6月于首都医科大学附属北京儿童医院重症监护病房住院并接受CRRT的患儿为研究对象，分别于CRRT治疗前、治疗第24、48、72小时监测患儿血磷水平。结果共纳入患儿32例，CRRT治疗前及治疗开始后第24、48、72小时血磷水平分别为（0.91±0.50） mmol/L、（0.54±0.20） mmol/L、（0.39±0.18） mmol/L、（0.36±0.19） mmol/L，治疗24 h后患儿均出现低磷血症，治疗前与治疗第24、48、72小时血磷水平比较差异均有统计学意义（t＝3.310、4.602、4.399，均P〈0.01）；血磷水平降低绝对值（△P）分别为（0.40±0.39） mmol/L、（0.15±0.05） mmol/L、（0.09±0.02） mmol/L，治疗开始的第24小时是血磷水平降低最快的时相，与第48小时、第72小时的△P比较差异均有统计学意义（t＝2.598、3.278，均P〈0.05）；CRRT治疗前基础血磷正常的患儿于治疗第24小时内血磷水平即显著降低，治疗前与治疗后各时段的血磷水平差异均有统计学意义（均P〈0.01）；但治疗开始前即已存在低磷血症的患儿，CRRT治疗前、后血磷水平差异无统计学意义。CRRT治疗24 h后初始血磷正常组与降低组血磷水平差异无统计学意义（均P〉0.05）。结论CRRT治疗过程中血磷水平的变化可能存在剂量依赖性，且与CRRT治疗时相密切相关，可能需要滴定式补磷的营养支持策略。

ObjectiveTo observe the changes of serum phosphorus level in critically ill children during continuous blood purification therapy （CRRT） in order to improve the monitoring of serum phosphorus and guide the supplementation of phosphorus during CRRT in critically ill children.MethodsThe patients who received CRRT from January to June 2017 in Pediatric Intensive Care Unit of Beijing Children′s Hospital Affiliated to Capital Medical University were selected as subjects.The changes of serum phosphorus before and 24 h, 48 h, 72 h after treatment of CRRT in the patients were observed and recorded respectively.ResultsThirty-two patients were enrolled in this study.The serum phosphorus were （0.91±0.50） mmol/L, （0.54±0.20） mmol/L, （0.39±0.18） mmol/L, （0.36±0.19） mmol/L before and 24 h, 48 h, 72 h after treatment of CRRT.There were significant differences of serum phosphorus in the critically ill children before and after CRRT （t=3.310, 4.602, 4.399, all P〈0.01）. All patients were accompanied with hypophosphatemia after 24 h treatment, and the absolute values of serum phosphorus reduction（△P） were （0.40±0.39） mmol/L, （0.15±0.05） mmol/L, （0.09±0.02） mmol/L in every 24 hours during CRRT.The first 24 h was the fastest changing phase for serum phosphorus, and the differences of △P between the 24 h and the 48 h, the 72 h after CRRT were statistically significant respectively （t=2.598, 3.278, all P〈0.05）. The serum phosphorus was sharply decreased in the 24 h of CRRT in patients with normal serum phosphorus before CRRT, and the differences were statistically significant （all P〈0.01）; but this phenomenon was not seen in hypophosphatemia group（all P〉0.05）.ConclusionIn the process of CRRT, the change of serum phosphorous may be dose-dependent and closely related to the treatment phase of CRRT.So a titration of phosphorus supplementation as a nutritional support strategy should be considered.