Abstract: Objective　To compare the efficacy of routine-dose and high-dose continuous blood purification （CBP）on the treatment of acute respiratory distress syndrome （ARDS） in children.Methods　31 patients were enrolled who met the criteria for ARDS and were treated at the Pediatric Intensive Care Unit（PICU） of Chongqing Three Gorges Central Hospital from 2012 to 2015.All the patients were assigned to the routine-dose treatment（n=15） and the high-dose treatment（n=16） by a random number table.The two groups were treated with CBP using the continuous veno-venous hemodiafiltration （CVVHDF） mode on the basis of mechanical ventilation.The routine-dose group received routine replacement liquid dose （20-35 ml·kg-1·h-1） treatment,and the high-dose group received high replacement liquid dose （50-70 ml·kg-1·h-1） treatment.End points included the death of patients and the discharge from PICU.Observed the treatment outcomes of the two groups.The oxygenation index（PaO2/FiO2）,pH values,arterial blood oxygen tension（PaO2）,partial pressure of carbon dioxide（PaCO2）,base excess （BE）,inspiratory oxygen concentration （FiO2）,respiratory rate,peak airway pressure（PIP）,positive end-expiratory pressure （PEEP） and tidal volume（Vt）were compared between the two groups before（0 h） and during（24,48,96,144 h） treatment.And pediatric critical illness score （PCIS） and the pediatric risk of mortality （PRISM Ⅲ） scores after OBP for treating 120 hours,the duration of CBP therapy,mechanical ventilation time,the length of stay in PICU and the adverse events（including chills/hypothermic,hypotension,hypertension,filters clotting and local and/or systemic hemorrhage） during CBP treatment were also compared between the two groups.Results　There was no significant difference in the improvement between the two groups（P=0.121）.There was no interaction effect between dose and time on PaO2/FiO2,pH,PaO2,PaCO2,BE,FiO2,respiratory rate,PIP,PEEP,and Vt（P>0.05）.The interaction effect of dose on PaO2/FiO2,PaO2 was significant（P<0.05）.There was no significant main effect of dose on pH,PaCO2,BE,FiO2,respiratory rate,PIP,PEEP and Vt（P>0.05）.The main effect of time on PaO2/FiO2,pH,PaO2,PaCO2,BE,FiO2,respiratory rate,PIP,PEEP and Vt was significant（P<0.05）.The PaO2/FiO2 and PaO2 of high-dose group were higher than those of routine-dose group,while the PEEP of high-dose group was lower than that of routine-dose group after CBP for treating 24 hours（P<0.05）.The PaO2/FiO2 and PaO2 of high-dose group were higher than those of routine-dose group,while the PaCO2,FiO2 and PIP of high-dose group were lower than those of routine-dose group after CBP for treating 48 hours（P<0.05）.The PCIS of high-dose group was higher than that of routine-dose group after CBP for treating 120 hours,while the mechanical ventilation time of high-dose group was shorter than that of routine-dose group（P<0.05）.There were no significant differences in PRISM Ⅲ scores,the duration of CBP therapy and the length of stay in PICU between the two groups（P>0.05）.The patients of routine-dose group accepted 65 sessions of CBP treatment,and high-dose group accepted 72 sessions.The incidence of chills/hypothermic,hypotension and hypertension in high-dose group was higher than in routine-dose group，however,the incidence of filters clotting in high-dose group was lower than that in routine-dose group（P<0.05）.There was no significant difference in the incidence of local and/or systemic hemorrhage between the two groups（P>0.05）.Conclusion　The high-dose CBP had superiority of improving oxygenation over the routine-dose CBP in the early stage of the management of ARDS in children.However,considering clinical outcomes,the length of stay in PICU and the adverese events during CBP-associated complications,the mode of CBP should depend on patients’ conditions.

Key words: Respiratory distress syndrome, Hemodiafiltration, Dose-response relationship, Comparative effectiveness research

摘要： 目的　比较常规剂量置换液与高剂量置换液连续性血液净化（CBP）治疗小儿呼吸窘迫综合征（ARDS）的临床疗效。方法　选取2012—2015年重庆三峡中心医院儿童重症医学科（PICU）收治的符合纳入标准的ARDS患儿31例，按照随机数字表法分为常规剂量组15例及高剂量组16例。两组患儿均在常规机械通气等疗法基础上，采用连续性静-静脉血液透析滤过（CVVHDF）模式进行CBP治疗，常规剂量组给予常规剂量置换液（20~35 ml·kg-1·h-1）治疗，高剂量组给予高剂量置换液（50~70 ml·kg-1·h-1）治疗。以患儿死亡或转出PICU作为研究终点，观察两组患儿的治疗结果；比较两组患儿治疗前（治疗0 h）及治疗中（24、48、96、144 h）氧合指数（PaO2/FiO2）、pH值、动脉血氧分压（PaO2）、动脉血二氧化碳分压（PaCO2）、碱剩余（BE）、吸入氧浓度（FiO2）、呼吸频率、吸气峰压（PIP）、呼气末正压（PEEP）、潮气量（Vt），治疗120 h时小儿危重病例评分（PCIS）、第三代小儿死亡风险（PRISM Ⅲ）评分，CBP治疗时间、机械通气时间、入住PICU时间以及CBP治疗期间不良事件（包括寒战/低体温、低血压、高血压、滤器凝血、局部和/或全身出血）发生情况。结果　两组患儿治疗好转率比较，差异无统计学意义（P=0.121）。剂量与时间在PaO2/FiO2、pH值、PaO2、PaCO2、BE、FiO2、呼吸频率、PIP、PEEP、Vt上不存在交互作用（P>0.05）；剂量对PaO2/FiO2、PaO2的主效应显著（P<0.05）；剂量对pH值、PaCO2、BE、FiO2、呼吸频率、PIP、PEEP、Vt的主效应不显著（P>0.05）；时间对PaO2/FiO2、pH值、PaO2、PaCO2、BE、FiO2、呼吸频率、PIP、PEEP、Vt的主效应显著（P<0.05）。高剂量组患儿治疗24 h时PaO2/FiO2、PaO2高于常规剂量组，PEEP低于常规剂量组（P<0.05）；高剂量组患儿治疗48 h时PaO2/FiO2、PaO2高于常规剂量组，PaCO2、FiO2、PIP低于常规剂量组（P<0.05）。高剂量组患儿治疗120 h时PCIS高于常规剂量组，机械通气时间短于常规剂量组（P<0.05）；两组患儿治疗120 h时PRISM Ⅲ评分、CBP治疗时间及入住PICU时间比较，差异无统计学意义（P>0.05）。常规剂量组患儿共进行65例次CBP治疗，高剂量组患儿共进行72例次CBP治疗；高剂量组患儿寒战/低体温、低血压、高血压发生率高于常规剂量组，滤器凝血率低于常规剂量组（P<0.05）；两组患儿局部和/或全身出血发生率比较，差异无统计意义（P>0.05）。结论　在CBP治疗早期，高剂量置换液较常规剂量置换液改善ARDS患儿氧合情况存在一定优越性，但综合患儿临床结果、入住PICU时间及CBP治疗期间不良事件等因素，临床选择尚需根据患儿实际情况而定。

关键词: 呼吸窘迫综合征, 血液透析滤过, 剂量效应关系, 疗效比较研究