Hemodialysis 서울병원 신장내과 R3. 서 대 철

Case Nausea Onset ) 내원 1주일전 Admission date) 2013.01.17 71세 여자환자 2011년 edema로 인근 병원 방문하여 Cr 상승 및proteinuria 있다고 들음 2011년 4월 선린병원에 거품뇨, 전신 부종, 소변량 감소로 내원하여 Nephrotic syndrome 의심되어 2011년 4월 21일 본원에서 우측 신장 조직 검사 시행 nephrotic syndrome, diabetic nephropathy 소견 관찰됨. Diabetic nephropathy에 의한 CKD 로 외래 f/u 중 1달전부터 Generalized edema, frequency, dysuria, 2주전부터 Dyspnea, 1주일전부터 General weakness, dizziness, nausea/vomiting 있고 혈액검사에서 Cr 상승 보여 입원

Past history DM (+) : 12yr Glipizide 5mg 1T HTN (+) : 30yr Losartan potassium 50mg 1T Nephrotic syndrome(+) : 2011/4(d/t DM nephropathy) Hypothyroidism(+) : 15yr Synthyroid 0.1mg 1T Social History Alcohol drinking : (-) Cigarette smoking : (-) Hospitalization / Op. History 9년전 L-spine HIVD 수술 2006.03.31 PD & PLIF c instrumentation 2년전 양안 백내장 수술

Abdomen USG

Hospital course 입원 당시 몸무게 56.4kg로 Generalized edema 심하였고 Nausea/Vomitting, General weakness,Dyspnea 등 Uremic symptom 호소 입원 당일 Perm catheter insertion 후 HD 시행 지속적인 투석위해 GS 전과되어 1/26 New AVBG, Rt. forearm (loop type) 수술시행 받음 현재 몸무게 50kg(화,목,토 Dry weight 49kg으로 HD 유지중)

Hemodialysis

Hemodialysis Renal replacement therapies Peritoneal dialysis Kidney transplantation A method for removing waste products in renal failure. Creatinine and urea, Free water from the blood

Principle of hemodialysis Diffusion of solutes across a semipermeable membrane Counter-current flow maintains the concentration gradient across the membrane at a maximum and increases the efficiency of the dialysis. 300-500 mL/min 500-800 mL/min

Principle of hemodialysis Fluid removal (ultrafiltration) is achieved by altering the hydrostatic pressure of the dialysate compartment, causing free water and some dissolved solutes to move across the membrane along a created pressure gradient.

Principle of hemodialysis Solute제거; 1) diffusion(diffusie transport)- 농도차, membrane surface area, coefficient of the membrane 2) ultrafiltration(convective clearance) – solvent drag; memb 구멍크기 이하의 모든 용질들이 같은 속도로 제거, 물을 따라 휩쓸려 거의 원래 농도의 용질들이 따름. Solvent drag

Hemodialysis circuit

Type of hemodialysis Conventional HD 3-4 hour treatments given 3 times a week Blood is drawn out through a tube at a rate of 300~500cc/min The tube is connected to a 15, 16, or 17 gauge needle inserted in the dialysis fistula or graft, or connected to one port of a dialysis catheter. The blood is then pumped through the dialyzer, and then the processed blood is pumped back into the patient's bloodstream through another tube During the procedure, the patient's blood pressure is closely monitored. The patient's entire blood volume (about 5000 cc) circulates through the machine every 15 minutes.

Type of hemodialysis Short daily HD Nocturnal HD 1.5-4hr sessions given 5-7times per week Nocturnal HD 6-10 hours per night, 6 nights per week

Hemodialysis components Vascular access Dialyzer Dialysate Tubing for transport of blood and dialysis solution Machine to power and mechanically monitor the procedure

Vascular access Arteriovenous fistula Thrill, bruit Nondominant arm Forearm (radiocephalic fistula) Elbow (brachiocephalic fistula) 4-6weeks mature time Advantage lower infection rates lower incidence of thrombosis, higher blood flow rates (more effective dialysis) Blood flow rate; 250-500ml/min, depending largely on the type and integrity of the vascular access Anastomosis of an artery to a vein, results in arterialization of the vein

Vascular access Arteriovenous graft Artificial vessel is used to join the artery and vein Thromosis, graft failure (intimal hyperplasia at anastomosis) Smaller vein, damaged vain by repeated venipuncture/after prolonged hospitalization

Vascular access Catheter Non-tunnelled temporary Tunnelled : reduce bacterial translocation from skin, infection↓ Smaller vein, damaged vain by repeated venipuncture/after prolonged hospitalization

Dialyzer Hollow fiber dialyzers m/c They contain thousands of hollow fibers similar in structure to a human capillary

Dialyzer Dialyzer component Type of membrane Blood volume capacity Surface area Ultrafiltration coefficient Clearance of various substances Capacity for reuse Sterilization requirements

Dialyzer Type of membrane Bioincompatible, no hydroxyl groups Cellulose membranes (cuprophan) Substituted cellulose membranes(cellulose acetate..) Cellulosynthetic membranes Synthetic membranes(polyacrylonitrile, polysulfone, polycarbonate, polyamide,PMMA); m/c Bioincompatible, no hydroxyl groups Complement activation↓

Dialyzer Ultrafiltration coefficient Clearance Correlates directly with its permeability. The volume of fluid (in mL/h) that is transferred across the membrane per mmHg of pressure gradient is called the ultrafiltration coefficient (Kuf). Clearance  Clearance of various solutes from blood is a function of dialyzer efficiency. Dialyzer clearances are routinely reported as urea or creatinine clearances (small solutes) as well as vitamin B12 (large solute) clearances. KoA, the quantitative measure of a particular dialyzer's efficiency of clearance, is defined by membrane porosity and thickness, solute size, and flow rate of blood and dialysate.

Dialysate Dialysis machines mix different components with water to produce the final solution of dialysate. Na↓ ; low osmol > intravascular volume감소 > hypotension Na↑ ; Wt, BP ↑ Intradialytic hypotension > higher dialysate sodium/ sodium modeling

Measurement of dialysis dose Kt/V K : urea clearance rate(L/hr) t : dialysis time(hr) V : urea distribution volume(L) Acceptable : > 1.2 Target dose: 1.4 Urea reduction ratio The fractional decrease in blood urea nitrogen during a single HD 100 x ((1ㅡ(postdialysis BUN/predialysis BUN)) K/DOQI guidelines > at least 65% target dose: 70% 0.08x HD time

CRRT Continuous renal replacement therapy Vascular access Mode Arterio-venous; arterial pr(>80mmHg시 90~150ml/min) large hematoma, pph a embolism Veno-venous; double-lumen, pump Mode CVVHD (Continuous venovenous hemodialysis) CVVH (Continuous venovenous hemofiltration) CVVHDF(continuous veno-venous hemodiafiltration)

CRRT Vascular access Mode Arterio-venous; arterial pr(>80mmHg시 90~150ml/min) large hematoma, pph a embolism Veno-venous; double-lumen, pump Mode CVVHD (Continuous venovenous hemodialysis) CVVH (Continuous venovenous hemofiltration) CVVHDF(continuous veno-venous hemodiafiltration) solute제거의 중요한 부가방법으로 ultrafiltration이 사용되는 방법을 hemofiltration이라 한다. HD와 hemofiltration은 흔히 urea(분자량 60)같은 작은 용질의 제거는 비슷하지만 inulin(분자량 5200)같이 더 크고 잘 확산되지 않는 solute의 제거에는 hemofiltration이 훨씬 더 효과적이다.

CRRT 투석액 대신 대용량(25-50L/d)의 replacement fluid가 주입됨. Membrane을 통해 UF되어야 하는 액체의 양이 많음(보충액 + 과잉용액 제거량) ; 역시 UF되는 수분량은 약 3-6L/d

CRRT ICU에서 slow continuous therapy의 장점 혈류역학적으로 잘 견딤; 혈장 삼투압이 최소한의 변화 Uremia와 electrolyte-acid balance조절이 우수 경과에 따라 생기는 불균형들이 교정됨; steady state laboratory levels 수분 제거에 매우 효과적(수술후, 폐부종, ARDS) 비경구 영양공급 및 필수 비경구 약제(ex. Inotropics)의 투여가 용이