WordNet

of a function or curve; extending without break or irregularity
continuing in time or space without interruption; "a continuous rearrangement of electrons in the solar atoms results in the emission of light"- James Jeans; "a continuous bout of illness lasting six months"; "lived in continuous fear"; "a continuous row of warehouses"; "a continuous line has no gaps or breaks in it"; "moving midweek holidays to the nearest Monday or Friday allows uninterrupted work weeks" (同)uninterrupted
the act of furnishing an equivalent person or thing in the place of another; "replacing the star will not be easy" (同)replacing
(medicine) the act of caring for someone (as by medication or remedial training etc.); "the quarterback is undergoing treatment for a knee injury"; "he tried every treatment the doctors suggested"; "heat therapy gave the best relief"

PrepTutorEJDIC

(時間的・空間的に)『切り目なく続く』;続けざまの,途切れない
置き換わること,取り替えること,元へ戻すこと;返済・置き換わる物(人),代理;補充員補充物
(病気の)治療,療法 / =psychotherapy
腎臓の
(17,8世紀音楽での)通奏低音

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2015/05/07 02:24:00」(JST)

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In medicine, hemofiltration, also haemofiltration, is a renal replacement therapy which is used in the intensive care setting. It is usually used to treat acute kidney injury (AKI), but may be of benefit in multiple organ dysfunction syndrome or sepsis.^[1] During hemofiltration, a patient's blood is passed through a set of tubing (a filtration circuit) via a machine to a semipermeable membrane (the filter) where waste products and water (collectively called ultrafiltrate) are removed by convection. Replacement fluid is added and the blood is returned to the patient.^[2]

1 Principle
2 Replacement fluid composition
3 Hemodiafiltration
4 Intermittent vs. continuous modes of therapy
- 4.1 On-line intermittent hemofiltration (IHF) or hemodiafiltration (IHDF)
- 4.2 Continuous hemofiltration (CHF) or hemodiafiltration (CHDF)
5 Is on-line intermittent hemodiafiltration (IHDF) better than regular hemodialysis?
6 See also
7 References

Principle

As in dialysis, in hemofiltration one achieves movement of solutes across a semi-permeable membrane. However, solute movement with hemofiltration is governed by convection rather than by diffusion. With haemofiltrate, dialysate is not used. Instead, a positive hydrostatic pressure drives water and solutes across the filter membrane from the blood compartment to the filtrate compartment, from which it is drained. Solutes, both small and large, get dragged through the membrane at a similar rate by the flow of water that has been engendered by the hydrostatic pressure. Thus convection overcomes the reduced removal rate of larger solutes (due to their slow speed of diffusion) seen in hemodialysis.

Replacement fluid composition

An isotonic replacement fluid is added to the blood to replace fluid volume and electrolytes. The replacement fluid must be of high purity, because it is infused directly into the blood line of the extracorporeal circuit. The replacement hemofiltration fluid usually contains lactate or acetate as a bicarbonate-generating base, or bicarbonate itself. Use of lactate can occasionally be troublesome in patients with lactic acidosis or with severe liver disease, because in such cases the conversion of lactate to bicarbonate can be impaired. In such patients use of bicarbonate as a base is preferred.

Hemodiafiltration

Hemofiltration is sometimes used in combination with hemodialysis, when it is termed hemodiafiltration. Blood is pumped through the blood compartment of a high flux dialyzer, and a high rate of ultrafiltration is used, so there is a high rate of movement of water and solutes from blood to dialysate that must be replaced by substitution fluid that is infused directly into the blood line. However, dialysis solution is also run through the dialysate compartment of the dialyzer. The combination is theoretically useful because it results in good removal of both large and small molecular weight solutes.

Intermittent vs. continuous modes of therapy

These treatments can be given intermittently, or continuously. The latter is usually done in an intensive care unit setting. There may be little difference in outcome between the two in the context of acute renal failure.^[3]

On-line intermittent hemofiltration (IHF) or hemodiafiltration (IHDF)

Either of these treatments can be given in outpatient dialysis units, three or more times a week, usually 3–5 hours per treatment. IHDF is used almost exclusively, with only a few centers using IHF. With both IHF or IHDF, the substitution fluid is prepared on-line from dialysis solution by running dialysis solution through a set of two membranes to purify it before infusing it directly into the blood line. In the United States, regulatory agencies have not yet approved on-line creation of substitution fluid because of concerns about its purity. For this reason, hemodiafiltration, had historically never been used in an outpatient setting in the United States.

Continuous hemofiltration (CHF) or hemodiafiltration (CHDF)

Continuous hemofiltration was first described in a 1977 paper by Kramer et al as a treatment for fluid overload.^[4] Hemofiltration is most commonly used in an intensive care unit setting, where it is either given as 8–12 hour treatments, so called SLEF (slow extended hemofiltration), or as CHF (continuous hemofiltration), also sometimes called continuous veno-venous hemofiltration (CVVH) or continuous renal replacement therapy (CRRT).^[5]^[6] Hemodiafiltration (SLED-F or CHDF or CVVHDF) also is widely used in this fashion. In the United States, the substitution fluid used in CHF or CHDF is commercially prepared, prepackaged, and sterile (or sometimes is prepared in the local hospital pharmacy), avoiding regulatory issues of on-line creation of replacement fluid from dialysis solution.

With slow continuous therapies, the blood flow rates are usually in the range of 100-200 ml/min, and access is usually achieved through a central venous catheter placed in one of the large central veins. In such cases a blood pump is used to drive blood flow through the filter. Native access for hemodialysis (e.g. AV fistulas or grafts) are unsuitable for CHF because the prolonged residence of the access needles required might damage such accesses.

The length of time before the circuit clots and becomes unusable, often referred to as circuit life, can vary depending on the medication used to keep blood from clotting. Heparin and regional citrate are often used, though heparin carries a higher risk of bleeding.^[7]

Is on-line intermittent hemodiafiltration (IHDF) better than regular hemodialysis?

There is controversy about whether intermittent on-line hemodiafiltration (IHDF) gives better results than hemodialysis in an outpatient setting. In Europe, several observational studies have compared outcomes in patients getting dialysis with those getting IHDF.

A recent study assesses the better outcome of patients treated with OL-HDF rather than standard HD.^[8]

References

^ Cruz D, Bellomo R, Kellum J, de Cal M, Ronco C. The future of extracorporeal support. Critical Care Medicine. 2008;36(Suppl):S243–S252. doi:10.1097/CCM.0b013e318168e4f6.
^ Hoffmann JN, Faist E. Removal of mediators by continuous hemofiltration in septic patients. World Journal of Surgery. 2001;25(5):651–659. doi:10.1007/s002680020027.
^ Pannu N, Klarenbach S, Wiebe N, Manns B, Tonelli M. Renal replacement therapy in patients with acute renal failure. JAMA. 2008;299(7):793. doi:10.1001/jama.299.7.793. PMID 18285591.
^ Kramer P, Wigger W, Rieger J, Matthaei D, Scheler F. Arteriovenous haemofiltration: a new and simple method for treatment of over-hydrated patients resistant to diuretics. Klinische Wochenschrift. 1977;55(22):1121–1122. doi:10.1007/BF01477940.
^ Bellomo R, Ronco C. Continuous renal replacement therapy in the intensive care unit. Intensive Care Medicine. 1999;25(8):781–789. doi:10.1007/s001340050953.
^ Abdeen O, Mehta RL. Dialysis modalities in the intensive care unit. Critical Care Clinics. 2002 Apr;18(2):223–247. doi:10.1016/s0749-0704(01)00007-0.
^ Wu M, Hsu Y, Bai, C, Lin Y, Wu C, Tam K (2012). "Regional citrate versus heparin anticoagulation for continuous renal replacement therapy: a meta-analysis of randomized controlled trials". American Journal of Kidney Diseases 59 (6): 810–818. doi:10.1053/j.ajkd.2011.11.030.
^ Maduell F, Moreso F, Pons M, Ramos R, Mora-Macia J, Carreras J et al. High-efficiency postdilution online hemodiafiltration reduces all-cause mortality in hemodialysis patients. J Am Soc Nephrol. 2013 [Retrieved 2 November 2014];24(3):487–497. doi:10.1681/ASN.2012080875.

UpToDate Contents

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1. 持続的腎代替療法：概要 continuous renal replacement therapies overview
2. 急性腎障害（急性腎不全）における持続的腎代替療法 continuous renal replacement therapy in acute kidney injury acute renal failure
3. 持続的腎代替療法中の抗凝固療法 anticoagulation for continuous renal replacement therapy
4. 持続的腎代替療法中の薬物除去 drug removal during continuous renal replacement therapy
5. 持続的静静脈血液濾過透析：技術的な懸念 continuous venovenous hemodiafiltration technical considerations

English Journal

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Zhu JM1, Qi RD1, Liu YM1, Zheng J1, Xing XY1, Sun LZ2.
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery.Eur J Cardiothorac Surg.2016 Mar;49(3):778-82. doi: 10.1093/ejcts/ezv242. Epub 2015 Jul 11.
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Nehus EJ1,2, Mizuno T3, Cox S3, Goldstein SL1,2, Vinks AA3,2.
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Meropenem is frequently prescribed in critically ill children receiving continuous renal replacement therapy (CRRT). We previously used clinical trial simulations to evaluate dosing regimens of meropenem in this population and reported that a dose of 20 mg/kg every 12 hours optimizes target attain
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Duration of anuria predicts recovery of renal function after acute kidney injury requiring continuous renal replacement therapy.

Jung HY, Lee JH, Park YJ, Kim SU, Lee KH, Choi JY, Park SH, Kim CD, Kim YL, Cho JH.
The Korean journal of internal medicine.Korean J Intern Med.2016 Feb 12. doi: 10.3904/kjim.2014.290. [Epub ahead of print]
Background/Aims: Little is known regarding the incidence rate of and factors associated with developing chronic kidney disease after continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. We investigated renal outcomes and the factors associated with incomplete renal reco
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