Learning Objectives: Dialysis

semipermeable

Hemodialysis uses a dialyzer with a ___________ membrane.

blood and dialysate flow

What 2 things countercurrent to maximize gradient in hemodialysis?

small solutes (urea, creatinine, K, phosphate, drugs)

What molecules diffuse in hemodialysis?

convection

What clears middle molecules (beta 2 microglobulin) in hemodialysis?

ultrafiltration

What removes water via transmembrane pressure in hemodialysis?

peritoneal

Peritoneal dialysis uses the _________ membrane.

diffusion

How does solute clearance occur into the dialysate in peritoneal dialysis?

dextrose or icodextrin

What provides the osmotic gradient for fluid removal in peritoneal dialysis?

CAPD

manual exchanges

APD

automated overnight cycling

90%

What % of patients are on hemodialysis in the US?

10%

What % of patients are on peritoneal dialysis in the US?

younger, motivated or vascularly challenged patients

Who is peritoneal dialysis better suited for?

older/comorbid pts or those preferring center based car

Who is hemodialysis better suited for?

20-50%

What % of people in hemodialysis sessions experience intradialytic hypotension?

-excessive ultrafiltration

-poor vascular response

-low cardiac reserve

What are the causes of intradialytic hypotension?

Trendelenburg, saline, cooling, dialysate, lowering UF rate

How can you manage intradialytic hypotension?

-adjust dry weight

-sodium modeling

-midodrine

How can you prevent intradialytic hypotension?

intradialytic hypertension

due to fluid overload, RAAS activation, or medication removal

chronic hypotension

SBP <100 mmHg post-dialysis, treated with midodrine

-AV fistula

-Catheter thrombosis

-Infections

What are the vascular access complications?

Heparin

How do you prevent catheter thrombosis?

rt-PA

How do you treat catheter thrombosis?

empiric Vacomycin + aminoglycoside

How do you treat Infections?

S. Aureus, Pseudomonas, Candida

When should you remove the catheter in infections?

0.5

How many episodes per patient per year are there of peritonitis?

symptoms of peritonitis

-abdominal pain

-N

-fever

-cloudy effluent

effluent WBC > 100; > 50% PMNs, positive culture

How do you diagnose peritonitis?

intraperitoneally

How is therapy for peritonitis administered?

gram neg and pos

What should empiric coverage for peritonitis cover?

-S. epidermidis

-S. aureus

-E. coli

-Pseudomonas

What are the common organisms causing peritonitis?

catheter removal + anti-fungal therapy

What should you do with fungal infections?

Mupirocin/polysporin

What is the prevention strategy that you can apply at the catheter exit site to prevent peritonitis and catheter infections?

nasal Mupirocin

reduces S. aureus carriage for the prevention of peritonitis and catheter infections

recurrence

Rifampin pulsed dosing reduces _________ for peritonitis and catheter infections.

reduce

Improved connectors and patient education __________ peritonitis rates.

CKD stage 4 (eGFR < 30)

When should you begin planning for dialysis in CKD pts?

-refractory volume overload

-hyperkalemia

-pericarditis

-encephalopathy

-bleeding

When should you initiate dialysis?

eGFR 5-10 with symptoms

When is the time for typical initiation of dialysis?

NO

Should you initiate dialysis solely on eGFR without symptoms?

-size

-solubility

-protein binding

-Vd

What does dialyzability depend on?

aminoglycosides and lithium

What drugs are readily removed by dialysis?

digoxin and warfarin

What drugs are poorly removed by dialysis?

larger

High-flux hemodialysis clears _______ molecules.

supplemental dosing

What is often required with hemodialysis?

intraperitoneal antibiotics and insulin

What is feasible with peritoneal dialysis?

product labeling, reputable drug references, case reports

What should you always consult when medication dosing in dialysis patients?

patient centered advantages in hemodialysis

rapid clearance, quick recognition of under-dialysis, but higher hemodynamic instability and time in-center

patient centered advantages in peritoneal dialysis

preserves residual kidney function, more independence, but higher infection/peritonitis risk and treatment burden

-lifestyle

-comorbidities

-support system

What should you use to individualize to chose HD or PD for a pt?

-FDA package insert

-KDIGO/KDOQI guidelines

-Lexicomp

-Micromedex

What are the primary sources you can use to determine drug specific adjustments?

you must give a supplemental post HD dose

For Levetiracetam (Keppra) what is the specific adjustment beyond general principles for dialysis patients?

give post HD supplemental dose

For Piperacillin-Tazobactam what is the specific adjustment beyond general principles for dialysis patients?