【持续性肾脏替代治疗crrt英文精品课件】pediatriccrrttheprescription

Pediatric CRRT: The Prescription,Stuart L. Goldstein, MD Professor of Pediatrics Baylor College of Medicine,Whats in a CRRT Prescription?,Indication (Why? Who? When?) Technical Aspects (What?) Nutrition (Maxvold) Anticoagulation (Brophy) Access (Bunchman) CRRT Delivery (How?) Blood pump flow rates Modality Priming Dose,Why CRRT in AKI?,Critically ill patient Advantages Slower blood flows Slower UF rates UF rates can be prescriptive (versus PD) Adjust UF rates with hourly patient intake Increased cytokine (bad humors) removal? Disadvantages Increased cytokine (good humors) removal? Non-dialysis personnel with many other bedside responsibilities required to monitor circuit,When Should CRRT Be Started?,Standard AKI criteria not responsive to medical therapy OR only preventable with limiting adequate nutrition Uremia Hyperkalemia Acidosis Fluid Overload Prevention of worsening fluid overload?,Timing of Pediatric RRT,No adequate definition for “timing of initiation” Absence of a generally accepted, validated and applied AKI definition has impeded the adequate investigation of this question The decision to initiate RRT affected by Strongly held physician beliefs Patient characteristics Organizational characteristics,Retrospective evaluation of 226 children who received RRT for AKI from 1992-1998 Pressor use surrogate marker for patient severity of illness Survival defined at PICU discharge,Percent Fluid Overload Calculation,% FO at CVVH initiation =,Fluid In - Fluid Out ICU Admit Weight,* 100%,Fluid In = Total Input from ICU admit to CRRT initiation Fluid Out = Total Output from ICU admit to CRRT initiation,Lesser % FO at CVVH (D) initiation was associated with improved outcome (p=0.03) Lesser % FO at CVVH (D) initiation was also associated with improved outcome when sample was adjusted for severity of illness (p=0.03; multiple regression analysis),Fluid Overload Thresholds at CRRT Initiation and Mortality,The Evolution of Idea to Practice Paradigm,Single center study,Registry,Randomized Trial,Prospective Pediatric CRRT (ppCRRT ) Registry: Phase 1 Design,Collect prospective data from 10 pediatric centers treating 15 to 20 patients annually (376 patients over 5 years) Each center follows own institutional practice Patient selection Initiation and termination Anti-coagulation protocols Convection versus diffusion versus hemodiafiltration Fluid composition,ppCRRT FO Threshold,Sutherland S. for the ppCRRT: AJKD 2010,Pediatric CRRT Circuit Priming,Heparinized (5000 units/L) for most patients Smaller patients require blood priming to prevent hypotension/hemodilution Circuit volume 10-15% patient blood volume Packed RBCs Citrated low ionized calcium Acid load Potassium load,Bradykinin Release Syndrome,Mucosal congestion, bronchospasm, hypotension at start of CRRT Resolves with discontinuation of CRRT Thought to be related to bradykinin release when patients blood contacts hemofilter Most common with AN-69 membranes Exquisitely pH sensitive,Technique Modifications to Prevent Bradykinin Release Syndrome,Buffered system THAM, CaCl, NaBicarb to PRBCs Bypass system prime circuit with saline, run PRBCs into patient on venous return line Recirculation system recirculate blood prime against dialysate,Recirculation Plan: Qb 200ml/min Qd 40ml/min Time 7.5 min,Does Modality Make A Difference?,Equal clearance of smaller molecules Middle and large molecule clearance enhanced by convection,Membrane Selectivity,Courtesy of J. Symons,Clearance: Convection vs. Diffusion,Solute Molecular Weight and Clearance,Solute (MW) Sieving 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* *P0.05 vs sieving coefficient *P0.01 vs sieving coefficient,Flores FX et al: CRRT 2006 abstract,ppCRRT Pediatric Sepsis Outcome Data,57/102 (56%) pts survived. Ventilated pts had similar survival rate as non-ventilated pts (53% vs. 68%, p=0.1). There was no significant difference in the survival rate among CRRT modalities. Tendency toward better survival with convective therapies,Flores FX et al: CRRT 2006 abstract,Survival Based on CRRT Modality?,Confounded Center Timing of initiation Sepsis definition not standardized Suggestive If all else equal, why not convect?,Flores FX et al: CRRT 2006 abstract,Dialysate/ Ultrafiltration Rates,The UF rate/plasma flow rate =BFRx(1-HCT) ratio should 0.35-0.4 in order to avoid filter clotting (Golper AJKD 6: 373-386,1985) Dialysate or effluent flow rates ranging from 20-30 ml/min/m2 (2000ml/1.72m2/hr) are usually adequate (experiential but consistent with adult data),Dose: Pediatric CRR