Vascular Access for CRRT Timothy E Bunchman Professor & Director Helen DeVos Children’s Hospital Grand Rapids, MI (Thanks to Rick Hackbarth MD for his help and slides)

Access n If you don’t have it you might as well go home. n This is the most important aspect of CRRT therapy. n Adequacy. n Filter life. n Increased blood loss. n Staff satisfaction.

Vascular Access n Ideal Catheter Characteristics n Easy Insertion n Permits Adequate Blood Flow without Vessel Damage n Minimal Technical Flaws n High Recirculation Rate n Kinking n Shorter and Larger Catheters SIZE DOES MATTER n Lower Resistance n Improved Bloodflow

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

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

Vascular Access Two questions to be answered- n What size catheter to use? n Where to put it?

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

Femoral vs IJ catheter performance Type Number Qb (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

Vascular Access ppCRRT Registry Access Study n 13 Pediatric Institutions n 376 patients n 1574 circuits n Circuit survival by Catheter size, site, and modality Hackbarth R et al: IJAIO 30: , 2007

Vascular Access Hackbarth R et al: IJAIO 30: , 2007

Vascular Access Hackbarth R et al: IJAIO 30: , 2007 Shorter life span for 7 and 9 French catheters (p< 0.002) 1st 72 hrs of circuit life only

Hackbarth R et al: IJAIO 30: , 2007

Vascular Access “Location, location, location!” Femoral Vein Pros: n Accessible under almost any conditions n Easier to maintain hemostasis Cons: n Potential for kinking n More recirculation n Thrombosis n Problematic flow with increased abdominal pressures

Vascular Access “Location, location, location!” Subclavian Vein Pros: n Shorter catheter/better flow n Less recirculation Cons: n Potential for kinking n Difficult hemostasis n Potential for venous narrowing n Less accessible with cervical trauma

Vascular Access “Location, location, location!” Internal Jugular Vein Pros: n Shorter catheter/better flow n Less recirculation Cons: n Difficult hemostasis n Less accessible with cervical trauma n Catheter length problematic in small infants

Hackbarth R et al: IJAIO 30: , 2007

Vascular Access Hackbarth R et al: IJAIO 30: , 2007 Survival favors IJ Location (p< 0.05)

Vascular Access Catheter proximity n Inadvertent removal of infusions n Circuit clotting with platelet transfusions n Entraining calcium into the circuit

Vascular Access Note the relationship of the line tips.

Vascular Access for Pediatric CRRT (Hackbarth et al, CRRT 2005) n Children on CRRT/24 months n Age range 2 days – 18 yrs n Wt range Kg n Citrate anticoagulation n Avg circuit life 3.1 days ( days) n Access was size dependent

n 7 Fr dual lumen with clot in 50% n Avg BFR 27 mls/min n 8 Fr dual lumen with clot in 20% n Avg BFR 73 mls/min n 12 Fr triple lumen with no clot in any n Avg BFR 127 mls/min n This was used in in all children > 35 kg Vascular Access for Pediatric CRRT (Hackbarth et al, CRRT 2005)

Triple vs Dual in Peds RRT n 5 year experience with Pediatric CRRT using the “pigtail” as the CaCL replacement n If not for citrate CRRT also serves as an added central line for other med/TPN infusion n What staff at bedside ever has sufficient central access?

Vascular Access What size catheter should we use? n Don’t use a 5 French catheter. n Choose the largest diameter that is safe for the child. n Choose the smallest catheter that will achieve the necessary flow easily. n Choose the the minimum length to position the tip for optimal flow. n In the femoral position, longer catheters will minimize recirculation

Vascular Access Where should the catheter go? n What sites are available? n Are there anatomic or physiologic constraints? n Which vessel is optimal for the catheter size? n Is the patient coagulopathic? n Consider patient mobility and risk of kinking. n Is there elevated intra-abdominal pressure?

Vascular Access Where should the catheter go? Answer: Internal Jugular vein if possible