case 20 kg child with sepsis and oliguria on norepinephrine with a BP of 95/45 Vent at 70% FIO2 and a PEEP of 8 FO at 15% K of 6 meq/dl and a BUN of 100 mg/dl

What is your prescription Access, size and location BFR if applicable What is your solution (bicarb, lactate, etc) What is your dialysate/convection flow rate Anticoagulation Over what period of time do you remove fluid How do you dose medications and nutrition

CRRT Case Prescription Timothy E Bunchman MD Professor & Director Pediatric Nephrology Timothy.bunchman@vcuhealth.org pedscrrt@gmail.com www.pcrrt.com

Access, size and location and BFR Proper location BFR Access dependent with a beginning rate of ~ 5 mls/kg/min BFR may increase unless risk of osmolar shift

Solutions components Historical solutions were lactate based This will result in plasma lactate levels being detected making the question of sepsis or tissue damage a concern All present commercially made solutions are bicarbonate based Physiologic components of Na, K, Ca (if heparin based), HCO3 as well as phosphorous as needed

Convective Clearance To increase clearance by convection, increase ultrafiltration rate (will require more replacement fluids)

Sieving Coefficients Solute (MW) Convective Coefficient Diffusion Coefficient Urea (60) 1.01 ± 0.05 1.01 ± 0.07 Creatinine (113) 1.00 ± 0.09 1.01 ± 0.06 Uric Acid (168) 1.01 ± 0.04 0.97 ± 0.04* Vancomycin (1448) 0.84 ± 0.10 0.74 ± 0.04** Calcium (protein bound) 0.67 + 0.1 0.61 + 0.07 Cytokines (large) adsorbed minimal clearance *P<0.05 **P<0.01

ppCRRT [Cytokine] % Change: Convection vs. Diffusion TNF-alpha -3.7 + 9.6 3.9 + 9.1 0.08 IL-1 beta -2.8 + 14.8 1.4 + 12.9 0.46 IL-6 32.7 + 102.8 -2.6 + 18.4 0.21 IL-8 -29.1 + 26.0 - 8.3 + 17.2 0.018 IL-10 -44.6 + 29.0 3.1 + 45.0 0.007 IL-18 -13.6 + 17.9 16.9 + 24.7 0.002 PELOD -22 + 34 -6 + 30 0.26

How aggressive do you UF? Net UF is often targeted to ~ 0.5-2 mls/kg/hr but is dependent upon hemodynamics Rule of thumb Take off the fluid at about the same rate as it was required

pH correction upon Epi effect (mic/kg/min) MAP Time

Comparison of Total Amino Acid losses: CVVH vs CVVHD (Maxvold et al, Crit Care Med 2000 Apr;28(4):1161-5 ) NS Amino Acid Losses (g/day/1.73 m2)

Medication dosing If possible make continuous If possible use medications that can be measured (e.g Vancomycin) Knowing Vanco in s~ 1500 Kda and ~ 75% protein bound will add it deciding dosing and frequency on other medications Vaso pressor agents are often small molecular weight and non protein bound so the clearance will be immediate

So my prescription would be IJ triple lumen 12 Fr catheter BFR ~ 150 mls/min Convection clearance at ~ 2-2.5 liters/m2/hr or ~ 40 mls/kg/hr Citrate anticoagulation Net UF initially zero then once stable will target ~ 1-2 mls/kg/hr net UF TPN/enteral nutrition ~ 3 gms/kg/day Meds Vanc and a cephalosporin with vasopressors adjusted for MAP

Comparison of RRT modalities Modality CRRT SLED HD (standard or HF) PD CFPD BFR 3-5 mls/kg/min access dependent 10-20 mls/kg/pass 20-40 mls/kg/pass Dialysis Flow Rate 0-4 liters/hr 6 liters /hr 30-50 liters/hr 0.5-2 liters/hr Convective Flow Rate Systemic Anticoagulation Heparin or citrate Heparin or none none Thermic control Yes yes partial Ultrafiltration control Solutions Industry made On Line production Drug clearance Continuous Intermittent Nutritional clearance Hemodynamic stability (1 best; 4 least) 1 4 5 3 2 Solute clearance