Catéteres venosos centrales permanentes tunelizados para hemodiálisis: estudio de recirculación y dosis de diálisis con líneas normales e invertidas

introduction: permanent tunnelled central venous catheters for haemodialysis frequently present a complication called the section effect, where the arterial branch collapses in the aspiration manoeuvres without offering resistance when pressed, making it necessary to invert the lines in order to carry out the treatment. the study focuses on the relationship between the anatomical position of the catheter tips using a chest x-ray and recirculation measured by ultrasound dilution, the urea reduction ratio and kt/v, determined both with lines in normal and inverted position and at pump flow rates of 250 and 300 ml/min. material and method: quasi-experimental intrasubject study with a duration of 18 months on n=28 catheters implanted in 25 patients undergoing haemodialysis. results: ？ recirculation: ？ normal lines at 250 and 300 ml/min: 0.85 ± 2.41% and 1.23 ± 3.14%. ？ inverted lines at 250 and 300 ml/min; 22.41 ± 12.12% and 24.93 ± 12.09%. ？ urea reduction ratio: ？ normal lines at 250 and 300 ml/min; 66.49 ± 8.62% and 70.55 ± 5.30%. ？ inverted lines at 250 and 300 ml/min; 61.05 ± 8.34% and 62.34 ± 8.68%. ？ kt/v: ？ normal lines at 250 and 300 ml/min: 1.31 ± 0.30 and 1.46 ± 0.23%. ？ inverted lines at 250 and 300 ml/min: 1.10 ± 0.21% and 1.19 ± 0.30%. discussion: the urea reduction ratios and kt/v with inverted lines at both flow rates studied show suitable dialysis doses assuming recirculation of around 20%.