混合推拉法经中心静脉导管与外周静脉采血在肾移植患儿他克莫司监测中的自身对照试验OA

Background Tacrolimus(FK506)is a key immunosuppressant in children after kidney transplantation.Clinicians need to monitor its blood concentration on a regular basis.However,peripheral venipuncture(VP)is often difficult in pediatric patients.Repeated VP may increase the risk of tissue injury,hematoma,and infection.For this challenge,utilizing central venous catheter(CVC)for blood sampling has become an important clinical need.Objective To compare the correlation and agreement of Tacrolimus blood concentrations measured via two collection methods—CVC vs.VP—in pediatric kidney transplant recipients,and to provide evidence-based support for optimizing clinical sampling practices.Design Self-controlled study.Methods Pediatric kidney transplant recipients(aged≤18 years)receiving FK506 therapy were recruited.All patients were admitted to the Nephrology Department of Children's Hospital of Fudan University between December 2024 and June 2025.Participants with missing data resulting from procedural issues or voluntary withdrawal were excluded.During the first 7 days after surgery,trained nurses collected paired blood samples each day.All participating nurses completed standardized procedural training and passed a competency assessment before the study began.For each sampling session,the nurse collected blood through VP and obtained a second sample from the CVC using the mixed push-pull method.The nurse recorded the time interval between the two sampling procedures.Staff transported all samples to the laboratory within 2 hours after collection and maintained a cold-chain temperature of 2 to 8℃during transport.The laboratory measured whole-blood FK506 concentrations using a Siemens therapeutic drug monitoring analyzer(Viva-E,Germany).The laboratory used a homogeneous enzyme multiplied immunoassay technique for the measurement.The Pearson correlation analysis was used to examine the relationship between FK506 concentrations obtained from the two sampling methods,the Bland-Altman analysis was used to assess the agreement between the two methods.The linear mixed-effects model was used to evaluate the association of sampling method and sampling time point with FK506 blood concentration.Main Outcome Measures Correlation and agreement evaluation parameters between the two blood collection methods.Results The study included 15 pediatric kidney transplant recipients(7.87±4.60)years and collected 105 paired blood samples.Eight patients were male(53.3%)and 7 were female(46.7%).Renal dysplasia was the most common primary disease(40.0%).Tubulointerstitial disease was the second most common cause(33.3%).Most central venous catheters were placed in the right internal jugular vein.Nine patients received FK506 by intravenous infusion(60.0%).Six patients received oral FK506(40.0%).The median time interval between the two blood samples was 3(2,3)minutes.No statistically significant differences in FK506 concentrations between the two methods over seven consecutive postoperative days were observed(P>0.05).Pearson correlation analysis showed a strong positive linear relationship between the two methods(r=0.969,P<0.001).The Bland-Altman analysis showed a mean difference of 0.276(95%CI:-2.637 to 3.189)and indicated good agreement between the two sampling methods.Additionally,the linear mixed-effects model treated each child as a random effect,and sampling method(VP vs.CVC)and sampling time point as fixed effects.The test of fixed effects showed that the main effect of sampling method was not significant(F=1.396,P=0.241),while the main effect of sampling time point was significant(F=5.417,P<0.001).Conclusion In pediatric kidney transplant recipients who receive FK506 therapy,blood sampling through CVC using the mixed push-pull method yields FK506 concentrations that are highly agreement with those obtained through VP.Consequently,this method represents a safe,reliable,and clinically feasible alternative for Tacrolimus monitoring.