Effects Of Different Calcium Supplementation Pathways On Calcium Ion Concentration In Calcium-free Regional Citrate Anticoagulation-Continuous Renal Replacement Therapy

Objectives This study investigated the differences between different calcium supplementation pathways during the clinical application in calcium-free regional citrate anticoagulation-continuous renal replacement therapy（RCA-CRRT）.By two different calcium supplementation sites,to explore whether there is difference between the venous line of the blood filter and subclavian vein in arterial iCa²⁺concentration and post-filtration iCa²⁺concentration,and to increase evidence for individualized calcium supplementation.Methods This was a prospective,single-center,randomized cross-over trial.From December 2018 to December 2019,22 patients with RCA-CRRT at the Department of Intensive Care Unit of the First Hospital of Lanzhou University were selected,whose hemofiltration catheters were catheterized at the femoral vein.According to the different calcium sites,the patients were randomly divided into two groups.The calcium supplementation order of Group A（n=11）was the venous line of the blood filter catheter-subclavian vein;Group B（n=11）was supplemented with subclavian vein-the venous line.Blood gas analysis results were compared using blood gas analyzers before and after replacement of the calcium supplementation route in all cases.The primary measurement outcome was the differences between arterial iCa²⁺concentration and post-filtration iCa²⁺concentration with different calcium supplementation pathways.The secondary outcomes were the incidences of catheter dysfunction,hypocalcemia and bleeding and hematoma at puncture points during the intervention.Minitab 17.0 software was used to analyze the data.Results⑴A total of 23 patients were enrolled in this study,11 in group A and 12 in group⑵Compared to the venous line of the blood filter,when calcium was infused through the subclavian vein with the same calcium supplement dose,the arterial iCa²⁺concentration was higher,and the difference between the two was statistically significant.⑶Compared to the venous line of the blood filter,when calcium was infused through the subclavian vein with the same calcium supplement dose,the post-filtration iCa²⁺concentration was lower.However,there was no significant difference between the two.Conclusions For patients with calcium-free regional citrate anticoagulation-continuous renal replacement therapy（RCA-CRRT）,when the calcium supplementation site is different,the level of iCa²⁺concentration in peripheral blood is also different.Compared to the venous line of the blood filter,when calcium was infused through the subclavian vein with the same calcium supplement dose,the arterial iCa²⁺concentration may be higher.