Vascular Access Considerations and Options for Pediatric CRRT Stuart L. Goldstein, MD

Vascular Access: Overview Required performance characteristics Size and site options –Pros and cons of femoral vs IJ –Recirculation issues Special situations –LVAD/ECMO –Citrate anticoagulation

Pediatric CRRT Vascular Access: Performance = Blood Flow Minimum 30 to 50 ml/min to minimize access and filter clotting Maximum rate of 400 ml/min/1.73m 2 or –10-12 ml/kg/min in neonates and infants –4-6 ml/kg/min in children –2-4 ml/kg/min in adolescents

Venous Access for CRRT Match catheter size to patient size and anatomical site One dual- or triple-lumen or two single lumen uncuffed catheters Sites –femoral –internal jugular –avoid sub-clavian vein if possible

Vascular Access for Pediatric CRRT: Pros and Cons of Femoral Site Relatively larger vessel may allow for –larger catheter –higher flows Ease of placement No risk of pneumothorax Preserve potential future vessels for chronic HD Shorter femoral catheters with increased % recirculation Poor performance in patients with ascites/increased abdominal pressure Trauma to venous anastamosis site for future transplant PROS CONS

Vascular Access for Pediatric CRRT: Pros and Cons of IJ/SCV Site Tip placement in right atrium decreases recirculation Not affected by ascites Preserve potential vein needed for transplant SCV stenosis (SCV) Superior vena cava syndrome Risk of pneumothorax in patients with high PEEP Trauma to veins needed potentially for future HD access PROS CONS

Femoral versus IJ catheter performance 26 femoral –19 > 20 cm –7 < 20cm 13 IJ Qb 250 ml/min (ultrasound dilution) Recirculation measurement by ultrasound dilution method Little et al: AJKD 36:1135-9, 2000

Femoral versus IJ catheter performance Type NumberQb (ml/min)Recirculation(%)95% CI Femoral *7.6 to 18.6 > 20cm **2.9 to 13.7 < 20cm **17.1 to 35.5 Jugular *-0.1 to 1.0 Little et al: AJKD 36:1135-9, 2000 * p<0.001 ** p<0.007

Femoral versus IJ catheter performance : Pediatrics P value NS NS NS NS (Gardner et al, CRRT 1997 Quinton 8 Fr; n = 20; 120 Treatments)

Venous Access for CRRT: Special Situation/LVAD-ECMO Parallel to other extra-corporeal circuit –ECMO –LVAD Blood prime High ECMO/LVAD flows can cause minimal negative “arterial” pressure –access disconnect alarms –arterial screw clamp to cause negative pressure

CRRT in LVAD circuit LVAD CRRT

Vascular Access for Pediatric CRRT: Some Final Thoughts Catheters with poor function will function poorly… over and over and over and over Balance between surgical/ICU expertise (preference?) and the necessary evils dictated by the patient –high PEEP… femoral catheter? –massive ascites… IJ catheter? –available sites… are there any? Which vessel are you willing to traumatize?