1、1Treatment Related FactorsCatheter performance QB tends be roughly comparable for FE and R)sided SC and IJ lines Maximum achievable QB tends to be lower by 100 mL/min in L)sided SC and IJ lines AR tends to be highest in short FE lines,intermediate in long FE lines,and lowest in SC and IJ lines Dialy
2、zer and filter performanceOliver et al,Semin Dial,Vol 14,pp 432-435,2001Little et al,AJKD,Vol 36,pp 1135-1139,2000Margetts et al,JASN,Vol 10,pp 211A,19992Little et al,AJKD,Vol 36,pp 1135-1139,20003A-IJ catheter with no recirculation;B-20 cm FE catheter assumed to haveAR of 0%at 150 mL/min,8.5%at 250
3、 mL/min and 17%at 350 mL/min;C-15 cm FE catheter assumed to have AR of 5%at 150 mL/min,20%at 250mL/min and 30%at 350 mL/min(iHD treatments are modelled under the following conditions;duration 240 mins,dialysate flow 500 mL/min,hemodialyzer mass transfer coefficient 911 mL/min,V 40 L,nPCR 0.8 g/kg/da
4、y)6Treatment Related FactorsCatheter performanceFilter(CRRT)performance Down time due to filter clotting is the major reason for reduced CRRT dose78Treatment Related Factors Catheter performance Filter(CRRT)performance Down time due to filter clotting is the major reason for reduced CRRT dose Concen
5、tration polarization reduces filtration rate and the filtrate concentrations of various medium/large sized proteins High filtration fraction(high UF+low QB or post dilution)is associated with both of above Pre-dilution versus post-dilution9Treatment Related Factors10Treatment Related Factors For iHD
6、,long catheters should be used for femoral angioaccess,and adjust dose prescription in anticipation of increased AR For iHD,can adjust for solute compartmentalization using the Daugirdas,Garred,or Tattersall rate equations For both iHD and CRRT,optimize anticoagulation and adjust dose prescription i
7、n the advent of dialyzer and filter clotting11Treatment Related Factors For CRRT,avoid high filtration fraction by higher blood flow rates and pre-dilution to minimize concentration polarization and hemoconcentration Except using Regional Citrate Anticoagulation with post-dilution replacement For CR
8、RT,adjust prescription for predilution with either a FUN/BUN ratio or an empirical 15%for lower-dose prescriptions(2L/hr)and 30-40%for higher-dose prescriptions(4L/hr)12Overview Revisiting of dose and outcomes Patient and treatment related factors affecting dose prescription and delivery Therapy-spe
9、cific dose-outcome data Approach to prescription and quantification of acute RRT dose13Dose-Outcome DataCRRT1415Table I Clinical Diagnosis of study patientsNo of PatientsMultiple injury12Aortic rupture2Osteomyelitis1Abdominal aortic aneurysm repair22*Thoracic aortic aneurysm repair4Other vascular pr
10、ocedures11Bronchial carcinoma3Other thoracic procedures4Necrotising pancreatitis10Gastric cancer9Peritonitis/intestinal perforation7Diseases of gallbladder6Ileus5Perforated ulcer3Other abdominal operations17*Emergency in 18,elective in 416*Not Randomized1718192021222324Dose-Outcome Data(CRRT)Dose is
11、 quantified as effluent(filtration)rate indexed to body size A dose of 35 mL/kg/hr in post-dilution mode is reported as giving the best results Starting acute RRT earlier rather than later is suggested as giving the best results25Dose-Outcome DataiHD26272829303132333435363738Dose-Outcome Data(iHD)Do
12、se is quantified as clearance indexed to solute pool size(single pool Kt/V)A dose of 1.0 is reported as giving the best results Daily iHD is reported as giving better results that alternate day iHD3940Phu et al.70 patients with sepsis randomized to CVVH or CAPD Average weight 53 kg Most common diagn
13、osis falciparum malaria CVVH 25L/day pre-dilution lactate based substitution fluid rate,Ku 25L/day CAPD 70L/day dialysate exchanged,Ku 28L/day41CAPD provided unsatisfactory control of cidosis,longer duration of ARF,poorer survival42Overview Revisiting of dose and outcomes Patient and treatment relat
14、ed factors affecting dose prescription and delivery Therapy-specific dose-outcome data Approach to prescription and quantification of acute RRT dose43CRRT Prescription For all CRRT,aim for 85%delivery of prescribed dose For all CRRT,aim for effluent rate of 35 mL/kg/hr,with appropriate adjustments f
15、or the effect of pre-dilution,and accounting for patient and treatment related barriers44CRRT Prescription It is unlikely CVVH can achieve an effluent rate of 35mL/kg/hr without high blood flow rate+/-pre-dilution Except the patient is small/pediatric,or not particularly sick or Using Regional Citra
16、te Anticoagulation+post-dilution The adequacy of an effluent rate of 35mL/kg/hr is unclear for CVVHD(F)since this dose applies to dialysate generated by diffusion rather than filtrate generated by convection45iHD Prescription It is unlikely that iHD can deliver an adequate dose outside of a daily or
17、 near daily regimen unless the patient is unless the patient is small/pediatric,or not particularly sick For daily iHD,aim for a delivered single pool Kt/V of at least 1.0,accounting for patient and treatment related barriers(?prescribe 1.3)46iHD Prescription The most practical expression of iHD dos
18、e is single pool Kt/V,and is most accurately achieved by formal UKM The most realistic expression iHD dose is equilibrated Kt/V,and is most accurately achieved by adjusting single pool Kt/V using the Daugirdas,Garred,or Tattersall rate equations47PD Prescription It is even less likely that PD can de
19、liver an adequate dose outside of continuous flow PD unless the patient is small/pediatric,or not particularly sick48Dose and Therapy Choice If iHD is not delivering adequate dose despite optimizing all factors,try Hybrid Therapy or CRRT If CRRT is not delivering adequate dose despite optimizing all
20、 factors,try Hybrid Therapy or iHD There are increasing data suggesting that delaying acute renal replacement therapy in critically ill patients is unwise49Is there an expression of acuteRRT dose that will allow us toreconcile these differentrecommendations for iHD andCRRT?50Standard Kt/V(stdKt/V)Un
21、its:week-1515253stdKt/V Requires a solute steady state for calculation Expresses acute RRT dose as a new less intuitive parameter Based on peak-concentration hypothesis,which can reconcile Kt/V standards forCAPD and iHD dose in the outpatient setting,but is arbitrary and difficult to define in the c
22、ritically ill54Corrected Equivalent RenalUrea Clearance(EKRc)Units:mL/min55=G/TAC or J/TAC56A comparison of BUN time-concentration profiles between twointermittent hemodialysis regimens delivering a cEKR of 24 ml/min.Thesolid line reflects solute removal over 3 treatments per week,the dottedsolute r
23、emoval over 7 treatments per week.57EKRc(1st Generation)Analogous to GFR,conceptually simple since it expresses acute RRT dose as mL/min Is corrected for body size(a 70 kg person with a V of 40L or BSA of 1.73m2)Is based on time-averaged BUN,which is easier to define and less arbitrary than peak BUN
24、5859606162EKRjc(2nd Generation)63EKRjc(2nd Generation)Is valid during solute non-steady state,and is insensitive to variation in V and G Does not require precise knowledge of V,G of Kd Can be calculated on a simple Excel spreadsheet with input of patients estimated V and BUN both pre and post iHD fo
25、r sequential dialysis cycles Can use post-iHD Ceq(Tattersall)64656667Dialysis Dose and Prescription68http:/www.atnstudy.org/697071http:/www.clinicaltrials.gov/ct/show/NCT00221013Augmented vs Normal Renal Replacement Therapy in Acute Renal Failure7273How should one prescribe and dose acute RRT to optimize patient outcomes?Individually,according to the requirements of the patient
