MSDN - Drug dosing in RRT and hemodialysis & peritoneal dialysis Exam 4 Questions with 100% Correct Answers

MSDN - Drug dosing in RRT and hemodialysis & peritoneal dialysis Exam 4 Questions with 100% Correct Answers what is diffusion? movement of solute down a concentration gradient through the pores of the dialysis membrane, i.e. from an area of higher concentration (blood) to one of lower concentration. Most efficient for removal of small molecular weight drugs. What is convection? removal of plasma water from the blood compartment by ultrafiltration due to a pressure difference across the membrane. Most efficient at removal of larger MW drugs drug specific factors affecting drug removal during dialysis molecular weight protein binding volume of distribution pore size membrane surface area ultrafiltration coefficient blood flow dialysate flow duration of dialysis how does MW affect drug removal during dialysis large molecules less likely to diffuse due to limitations of membrane pore size and less contact with membrane pores how does protein binding affect drug removal during dialysis highly protein bound drugs not substantially removed due to large size of protein relative to pores of the membrane how does volume of distribution affect drug removal during dialysis? relates to drug exposure to the dialyzer -larger Vd indicates extensive tissue binding and less free drug in the plasma compartment to be dialyzed how does membrane pore size affect drug removal during dialysis? large pore size more conducive to removal of larger MW solutes compared to conventional membranes how does membrane surface affect drug removal during dialysis? larger surface area provides more contact sites for solute removal and may lead to increased increase how does ultrafiltration coefficient effect drug removal during dialysis? KUF is the volume of fluid per hour transferred across the membrane per mm Hg of transmembrane pressure (TMP) how does blood flow affect drug removal during dialysis? increases in blood flow rates generally increase clearance of small molecules by maintaining the concentration gradient how does dialysate flow affect drug removal during dialysis? increases in dialysate flow increase diffusion by maintaining a concentration gradient between dialysate and blood. dialysate flow rates are typically between 500-800 mL/min for intermittent procedures how does duration of dialysis affect drug removal during dialysis? longer procedures allow more tim