cvvh時(shí)治療劑量的計(jì)算

1、CVVH時(shí)治療劑量的計(jì)算,北京協(xié)和醫(yī)院杜斌,內(nèi)容,腎臟的生理功能,腎臟替代治療 vs. 腎臟,,,heparin,,,V,,V,PV,PA,,,,high-flux,腎小球,原尿,腎小管,濾器剖面圖,濾器清除物質(zhì)的原理,超濾(ultrafiltration)對(duì)流(convection)彌散(diffusion)吸附(adsorption),超濾作用的原理: 跨膜壓,跨膜壓(TMP): 半透膜兩側(cè)的壓力差溶劑的移動(dòng)從壓力高的

2、一側(cè)向壓力低的一側(cè)增加壓力差可以增加溶劑的超濾,,,,,,,超濾作用的原理: 跨膜壓,跨膜壓(TMP): 半透膜兩側(cè)的壓力差溶劑的移動(dòng)從壓力高的一側(cè)向壓力低的一側(cè)增加壓力差可以增加溶劑的超濾壓力差消失時(shí)超濾作用終止,,,,,,,UFR = BFRin – BFRout,超濾作用的原理: 超濾率,通過(guò)超濾作用清除的溶劑量(UFR),,BFRin,,BFRout= BFRin – UFR,UFR = Lp.A.?P = Kuf.

3、?P,超濾率的影響因素,Lp: 膜超濾系數(shù)[ml/(hr.mmHg.m2)]Kuf: 濾器超濾系數(shù)[ml/(hr.mmHg)],?P: TMP,高通量濾器,低通量濾器,超濾率的影響因素: 膜超濾系數(shù),,Lp (ml/(hr.mmHg.m2),10,20,膜對(duì)溶劑(水)的通透性,超濾率的影響因素: 跨膜壓,超濾率的影響因素: 濾過(guò)分?jǐn)?shù),,BFR血細(xì)胞 BFR x Hct血漿 BFR x (1 – Hct),BFR血細(xì)胞

4、 BFR x Hct血漿 BFR x (1 – Hct) - UFR,UFR,超濾率的影響因素: 濾過(guò)分?jǐn)?shù),FF% = UFR x 100 / QpQp = BFR x (1 – Hct),FF% < 30%以防止血液濾器凝血,超濾率的影響因素: 濾過(guò)分?jǐn)?shù),,BFR血細(xì)胞 BFR x Hct血漿 BFR x (1 – Hct),BFR血細(xì)胞 BFR x Hct血漿 BFR x (1 – Hct) - UFR

5、,UFR,,100 ml/minHct 30%血細(xì)胞 30 ml/min血漿 70 ml/min,BFR血細(xì)胞 30 ml/min血漿 70 - UFR,UFR,超濾率的影響因素: 濾過(guò)分?jǐn)?shù),BFR = 100 ml/min, Hct = 0.30Qp = BFR x (1 – Hct) = 70 ml/minFF ? 30%,UFR ? FF x Qp = 21 ml/min,血流量是影響超濾率的最主要因

6、素**后稀釋,對(duì)流作用的原理,跨膜壓(TMP): 半透膜兩側(cè)的壓力差溶質(zhì)的移動(dòng)隨溶劑移動(dòng)從壓力高的一側(cè)向壓力低的一側(cè),,,,,,,,,,,,,,,,,,,,對(duì)流作用的原理,對(duì)流清除溶質(zhì)的效率,腎臟CrCl = Ucr x UO / Scr,CVVHC = Ufcr x UFR / Scr,,BFR,BFR,UFR,對(duì)流作用的原理: 篩選系數(shù),篩選系數(shù)(S, sieving coefficient)S = [UF] / [p

7、lasma],,,,,,,,,,,,,,,,,,,[plasma],[UF],對(duì)流作用的原理: 對(duì)流清除率,C = S.UFR,Kuf.?P = Lp.A.?P,,,篩選系數(shù): [UF] / [plasma],對(duì)流作用的原理: 篩選系數(shù),對(duì)流作用的應(yīng)用: 持續(xù)血液濾過(guò)(CVVH),,,heparin,,,V,,V,PV,PA,,,,high-flux,內(nèi)容,腎臟替代治療的劑量: Ronco,篩選患者(n = 492),隨機(jī)分組(n =

8、425),排除患者(n = 67),UFR 35 ml/kg/hr(n = 139),UFR 20 ml/kg/hr(n = 146),UFR 45 ml/kg/hr(n = 140),,Ronco C, Bellomo R, Homel P, et al. Effects of different doses in continuous veno-venous haemofiltration on outcomes of acu

9、te renal failure: A prospective randomised trial. Lancet 2000; 356: 26-30,腎臟替代治療的劑量: Ronco,Ronco C, Bellomo R, Homel P, et al. Effects of different doses in continuous veno-venous haemofiltration on outcomes of acute ren

10、al failure: A prospective randomised trial. Lancet 2000; 356: 26-30,腎臟替代治療的劑量: Ronco,Ronco C, Bellomo R, Homel P, et al. Effects of different doses in continuous veno-venous haemofiltration on outcomes of acute renal fai

11、lure: A prospective randomised trial. Lancet 2000; 356: 26-30,腎臟替代治療的劑量: Ronco,Ronco C, Bellomo R, Homel P, et al. Effects of different doses in continuous veno-venous haemofiltration on outcomes of acute renal failure:

12、A prospective randomised trial. Lancet 2000; 356: 26-30,ARF的治療劑量: Kellum,“Patients with ARF should be treated with at least 35 mL/kg/h of hemofiltration/ hemodiafiltration or daily hemodialysis until or unless ongoing mu

13、lti-center clinical trials show otherwise.”,CVVH的參數(shù)設(shè)置,,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,BWt 60 kgHct 30%后稀釋BFR = 150 ml/minRFR = 2000 ml/hr平衡 = -100 ml/hr,流出液 = 2100 ml/hr交換量 35 ml/kg/hr但是FF%

14、= 35 / (150 x 70%) = 33%,CVVH的參數(shù)設(shè)置,,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,BWt 60 kg后稀釋交換量 35 ml/kg/hrBFR應(yīng)當(dāng)設(shè)置為多少?,FF% < 30%以防止血液濃縮,流出液 35 x 60 = 2100 ml/hr流出液 35 ml/min血漿流量(Qp) 35 / 30% = 117 ml/min

15、BFR = 117 / 70% = 167 ml/min,CVVH的參數(shù)設(shè)置,如果BFR只能維持150 ml/min如何達(dá)到35 ml/kg/hr的交換量?,內(nèi)容,增加對(duì)流清除溶質(zhì)能力的方法,增加UFR提高跨膜壓(TMP)超濾液一側(cè)的負(fù)壓血液一側(cè)的正壓增加膜超濾系數(shù)(Lp)增加濾器膜面積(A)提高血流量(BFR)采用前稀釋方式增加彌散清除,C = S.UFR = S.Lp.A.?P,C = S.UFR.BFR / (

16、BFR + RFR),KT = KD + UFR.S.(1 – KD/BFR),對(duì)流清除能力的影響因素: 濾過(guò)分?jǐn)?shù),,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,FF% = UFR x 100 / QpQp = BFR x (1 – Hct),FF% < 30%以防止血液濃縮,后稀釋時(shí), BFR是影響UFR的主要因素,增加對(duì)流清除能力: 前稀釋 vs. 后稀釋,,,

17、R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,,,前稀釋的優(yōu)點(diǎn)與缺點(diǎn),,BFR,BFR,UFR,,BFR,BFR,UFR,RFR,RFR,后稀釋,前稀釋,有血液濃縮過(guò)程UFR受到濾過(guò)分?jǐn)?shù)的限制,沒(méi)有血液濃縮過(guò)程UFR不受濾過(guò)分?jǐn)?shù)的限制,前稀釋的優(yōu)點(diǎn)與缺點(diǎn),,BFR,BFR,UFR,,BFR,BFR,UFR,RFR,RFR,后稀釋,前稀釋,血液沒(méi)有被稀釋UF中溶質(zhì)濃度與血漿濃

18、度相似SC = 1,血液被稀釋UF中溶質(zhì)濃度低于血漿濃度SC < 1,前稀釋CVVH時(shí)交換量的計(jì)算,BWt 60 kgHct 30%BFR 150 ml/min全部前稀釋RFR 2000 ml/hr平衡-100 ml/hr,,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,BFR 150 ml/min,RFR 2000 ml/hr,UFR2100 ml/h

19、r,前稀釋CVVH時(shí)交換量的計(jì)算,首先按照完全后稀釋方式計(jì)算交換量UFR 2100 ml/hr = 35 ml/kg/hrC = SC x UFR = 35 ml/kg/hr其次計(jì)算稀釋比例BFR = 150 ml/min, Hct = 30%Qp = 150 x (1 – 30%) = 105 ml/min前稀釋RFR = 2000 ml/hr = 33 ml/min稀釋比例 = Qp / (Qp + RFR) = 10

20、5 / (105 + 33) = 76%最后計(jì)算校正后交換量C = 35 x 76% = 26.6 ml/kg/hr,流出液量相同的情況下溶質(zhì)清除效率前稀釋 < 后稀釋,前稀釋CVVH時(shí)交換量的計(jì)算,BWt 60 kgHct 30%BFR 150 ml/min全部前稀釋平衡-100 ml/hrRFR x ml/hr才能保證交換量35 ml/kg/hr,,,R,heater,,heparin,,,V,,V,,PV

21、,PA,,,,UF,,,,BLD,,SAD,,,BFR 150 ml/min,RFR x ml/hr,UFRX+100 ml/hr,前稀釋CVVH時(shí)交換量的計(jì)算,首先按照完全后稀釋方式計(jì)算交換量UFR x + 100 ml/hr = (x + 100) / 60 ml/kg/hrC = SC x UFR = (x + 100) / 60 ml/kg/hr其次計(jì)算稀釋比例BFR = 150 ml/min, Hct = 30%Q

22、p = 150 x (1 – 30%) = 105 ml/min前稀釋RFR = x ml/hr = x / 60 ml/min稀釋比例 = Qp / (Qp + x / 60) = 105 / (105 + x / 60)最后計(jì)算校正后交換量C = (x + 100) / 60 . 105 / (105 + x / 60) = 35 ml/kg/hr,RFR = x = 3000 ml/hr,CVVH時(shí)交換量的計(jì)算,BWt 6

23、0 kgHct 30%BFR 150 ml/min平衡-100 ml/hrRFR 3000 ml/hr如何保證交換量40 ml/kg/hr,,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,,,CVVH時(shí)交換量的計(jì)算,全部前稀釋RFR 3000 ml/hrUFR 3100 ml/hrC 35 ml/kg/hr,全部后稀釋RFR 3000 ml/hrUFR 3

24、100 ml/hrC 51.7 ml/kg/hrFF% 50%,滿足C 40 ml/kg/hr部分前稀釋+部分后稀釋?,CVVH時(shí)交換量的計(jì)算,BWt 60 kgHct 30%BFR 150 ml/min平衡-100 ml/hrRFR 3000 ml/hr如何保證交換量40 ml/kg/hr,,,R,heater,,heparin,,,V,,V,,PV,PA,,,,UF,,,,BLD,,SAD,,,,,preRFR 3

25、000 x pre% ml/hr,postRFR 3000 x (1 - pre%) ml/hr,BFR 150 ml/min,UFR3100 ml/hr,前稀釋+后稀釋交換量的計(jì)算,首先按照完全后稀釋方式計(jì)算交換量UFR 3100 ml/hr = 51.7 ml/kg/hrC’ = SC x UFR = 51.7 ml/kg/hr其次計(jì)算稀釋比例BFR = 150 ml/min, Hct = 30%Qp = 150 x (

26、1 – 30%) = 105 ml/min前稀釋RFR = 3000 x pre% ml/hr = 50 x pre% ml/min稀釋比例 = Qp / (Qp + 50 x pre%) = 105 / (105 + 50 x pre%)最后計(jì)算校正后交換量C = 51.7 x 105 / (105 + 50 x pre%) = 40 ml/kg/hr,Pre% = 60%前稀釋RFR = 1800 ml/hr后稀釋RFR