Dialysis/transplant/renal function Flashcards
types of donor 2
living
cadaveric
living include
related
directed
altruistic
cadaveric
DCD
DBD
DCD can further be categorised via Maastricht classification which describes mode cardiac arrest
extended criteria donors
DBD donars more than 60 and 50-59 with 2 of hypertension terminal creatinine >133 cerebrovascular cause of death
extended criteria to increase pool for recipients
contraindications to being a living renal donor 7 absolute
absolute pregnancy single kidneys sig below age related gfr cut off active untreated malignancy morbid obesity >40 uncontrolled disease process that will impact renal fuction under 18
how are organs preserved
cooling by perfusion cold perfusate
ice
perservation fluid
aim reduce risk cellular degradation due to low oxygen situation
soltran
soltran solution 4 MMCC
pot citrate
mannitol
mag sulphate
sod citrate
other perfusates
UW Belzer
collins
marshalls
why use right iliac fossa
vessels more superficial than left rutherford morrison incision ep approach do vein first may use internal iliac or common RA end to side to EIA or end to end to IIA RV end to side to EIV, CIV
ureterocystostomy
can be onlay or tunnelled
donor ureter kept as short as possible with periureteric fat preserved
what is GFR
describes flow rate of fluid through the nephrons and is one of the ways to measure kidney function
how can gfr be measured
using clearance of a substance from plasma or estimate from plasma creatinine using formula
creatinine overestimation gfr
as 10% secreted by kidney
formula to calculate gfr
cockcroft gault and MDRD
Cockcroft-Gault CrCl, mL/min = (140 – age) × (weight, kg) × (0.85 if female) / (72 × Cr)
formal measurement GFR
Cr 51 EDTA most accurate
DPTA can be used but slightly secreted
single infection Cr51 EDTA given
then measure blood levels at specified intervals 2-5 hours after injection to demonstrate decay curve
slope intercept method to calculate clearance
GFR normalised to BSA
MDRD vs cockcroft gault
CG estimates creatinine clearance, used for drug dosing
MDRD for those with impaired function, calulates GFR per BSA, not creatinine clearance
classification CKD
based on GFR into five main groups >90 = 1 60-90 = 2 45-60 = 3a 30-45 =3b 15-30 =4 less than 15 = 5
options for patient with ESRD 3
peritoneal dialysis /haemodialysis
transplant
no RRT
leading to certain death average 10-90 days
dialysis options
Continuous renal replacement thearpy
haemodialysis
peritoneal dialysis
options continuous RRT
CVVH CVVHD CVVHDF SCUF - slow continuous ultrafiltration CAVHD
haemodialysis options
in centre HD 3 x a week
home HD short daily nocturnal
peritoneal dialysis options
manual CAPD
cycler APD
peritoneal dialysis options
manual CAPD
cycler APD
indications acute dialysis 5
fluid overload unresponsive diuretics severe hyperkalaemia more than 6.5 severe met acidosis less than 7.1 uraemic symptoms >30 mmol/l drug overdose dialysable toxin
what is difference between HD and CVVH
Haemodilaysis is diffusive process using a semi-permeable membrane and a counter current flow (contraflow) system to maintain a waste solute concentration which is always lower on the dialysate side of the membrane. The gradient persists along the entire length of the membrane.
second principle ultrafiltration caused by convective flow of solutes and liquids
CVVH is continuous veno-venous haemofiltration. This involves Filtration and fluid replacement. Runs continuously. Takes much longer than HD, but better tolerated cardiovascularly. Therefore useful in ITU and in CVS patients”.
no dialysate
relies on hydrostatic pressure alone to produce ultrafilatration
fluid replaced either before or after ultrafiltration
more haemodynamic stability
diffusion vs convection in HD vs HF
HD there is concentration gradient between blood and dialysate which allows diffusion of waste production
the driving force is the concetration gradient
haemofiltration
the driving force is the transmembrane pressure
movement due to convection between blood and fitlrate