RRT and Renal Transplant Flashcards
When should RRT planning begin in CKD?
When the risk of renal failure is 10-20% within a year.
Referral to nephrology less than 1 year before RRT is required is considered a late referral.
All suitable patients should be listed for a deceased donor transplantation 6 months before the anticipated start of RRT.
All suitable patients should also be informed about the advantages of a pre-emptive living kidney transplant and efftorts made to find a donor.
When should RRT be started?
When it is necessary to manage one or more symptoms of renal failure including:
Inability to control volume status, including pulmonary oedema.
Inability to control blood pressure
Serositis
Acid-base or electrolyte abnormalities
Pruritus
Nausea, vomiting, deterioration in nutritional status
Cognitive impairment
What are the two types of dialyses?
Haemodialysis (HD)
Peritoneal dialysis (PD)
Explain PD.
Uses the peritoneum of the patient as a semi-permeable membrane.
A catheter is inserted into the peritoneal cavity and fluid is infused.
Ultrafiltration is achieved by adding osmotic agents such as glucose to the dialysate fluid. This makes solutes such as electrolytes, urea and creatinine to move from the patient’s blood into the dialysate fluid as well as water.
Advantages of PD.
It can be performed at home!
Quality of life might be greater
It’s a good first choice for patients with some native renal function left.
The PD regimes are largely individualised to the patient’s own needs.
Not as heavy on dietary restrictions as HD
Disadvantages of PD.
Patients need to be able to manage technical aspects of dialysis themselves.
It is unsuitable for patients with stoma or previous surgery
Complications of PD.
Drainage problems
Risk of infection (peritonitis)
Catheter exit infection
Malposition
Leaks
Herniae
Hydrothorax
Constipation may impair flow of dialysate
Sclerosing peritonitis is a potentially fatal complication
What are the different types of PD?
Continuous ambulatory peritoneal dialysis (CAPD)
Automated peritoneal dialysis
Assisted Automated PD
Explain automated PD.
Also called nightly intermittent peritoneal dialysis.
It is carried out with an automated cycle machine performed at night.
10-12L usually exchanged over 8-10 hours.
This leaves daytime free.
Explain CAPD.
4-5 dialysis exchanges per day, usually 2 litres each.
They are performed at regular intervals throughout the day with a long overnight dwell.
What is haemodialysis?
Can be used as temporary dialysis or permanent.
The dialysis machine pumps blood from the patient through a disposable tubing, through a dialyser or artificial kidney and then back into the patient again.
Waste solute, salt and excess fluid is removed from the blood.
What is the (IV) access of haemodialysis?
Usually an arteriovenous fistula is surgically formed between radial/brachial artery and cephalic vein or a Tunnelled cuffed catheter.
Synthetic arteriovenous grafts can be used as an alternative.
If AVF is not appropriate or if the patient is in an acute setting a semi-permanent dual-lumen venous catheter (Tunnelled cuffed catheter) can be inserted under a skin tunnel into the jugular, subclavian or femoral vein.
For urgent dialysis or temporary an untunnelled large-bore double-lumen dialysis catheter can be inserted into a central vein.
Advantages of HD.
Efficient form of dialysis
Unit based with plenty support from staff
Removes the need for the patient to manage the dialysis themselves.
Disadvantages of HD.
Dialysis access needs to be secure.
Need access to hospital
Need to be close to hospital
Need to be able to travel to hospital
Complications of haemodialysis.
Infection/bacteraemia, septic arthritis, vertibritis, endocarditis
Haemodynamic instability
Haematomas and risk of bleed
Muscle cramps
Anaemia due to clotted lines/haemolysis
AVF steal syndrome
SVCO from central line
Malfunction, thrombosis or bleeding from access.
Cerebral oedema and fitting due to rapid urea removal
Give examples of types of haemodialysis.
Home HD
Nocturnal HD
CRRT (continuous renal replacement therapy) - mainly used in an acute setting.
Explain haemofiltration.
Water is cleared by +ve pressure, dragging solutes into the waste by convection.
The ultrafiltrate is replaced with a clean fluid.
This might be preferred in an acute setting where haemodynamic instability is common.
It is not used long term RRT unless in combination with HD (haemodiafiltration).
Complications of RRT.
Cardiovascular disease (BP up, calcium/phosphate dysregulation, vascular stiffness, inflammation)
Protein-calorie malnutrition.
Renal bone disease - High bone turnover, renal osteodystrophy, osteitis fibrosa
Infection - uraemia causes granulocyte and T cell dysfunction
When should renal transplant be considered?
Every patient with, or progressing towards stage G5 kidney disease.
It is the treatment of choice for kidney failure provided benefits outweigh the risk.
Advantages of transplantation.
Near normal lifestyle
Better mortality/morbidity
No need for dialysis
Disadvantages of renal transplant.
Criteria to meet suitability to safely undergo operation
Compliance with lifelong medication
Risk of rejection
Long waiting times for cadaveric organ.
Contraindications of renal transplant.
> 80 yo
WHO performance score of 3 or more
Cancer with metastases
Active infection, HIV with viral replication, unstable CVD (all temporary, not absolute)
Congestive heart failure
CVD
Severe lung disease
Reversible renal disease
Uncontrolled substance abuse or psychiatric illness
Short life expectancy
Types of graft.
Living donor (preferred)
Deceased donor
Types of living donor.
Living related donor
Living unrelated donor
Explain living related donor.
Best possible transplant.
An elective procedure with a selected donor that might have good compatibility.
Time to transplantation usually within months.
Explain living unrelated donor.
4 types:
Live-donor paired exchange
Live-donor/deceased-donor exchange
Live-donor chain
Altruistic donation
Usually comparable outcomes to live-related
Time to transplantation usually within months
Types of deceased donor.
Donor after brain death also called heart-beating donor
Expanded criteria donor
Donor after cardiac death
Explain expanded criteria donor.
From an older kidney or from a patient with a history of CVA, BP, or CKD.
This impacst on the long-term prognosis of the transplant, however offers a better outcome than remaining on dialysis.
Risks of donor after cardiac death.
Delayed graft function
Why is it important to keep transplant protocols up to date in deceased donor transplantation?
Because patients who will receive this type of transplantation usually have little time to prepare because of availability.
Time to transplantation in deceased donor.
Years
What is best, living or deceased donor?
Living gives a much better prognosis.
Even if the living-donor is completely unrelated in both blood group and HLA the prognosis can still be better than deceased donor.
Which patients are more difficult to cross-match for transplant?
Patients who have been on episodes of immunisation such as blood transfusion, pregnancies and prior transplants.
Induction treatment for the transplant.
Immunosupp are used to create tolerance of the graft.
Methylprednisolone in combination with;
Basiliximab and thymoglobulin.
Sometimes alentuzumab and rituximab is used.
This is to prevent acute rejection and graft loss.
Treatment will be needed long term as well to prevent acute or chronic rejection of the graft.
What medications are used as maintenance treatment?
Prednisolone
Calcineurin inhibitors such as tacrolimus, ciclosporine and voclosporin
Antimetabolites - mycophenolate acid and azathioprine
Rapamycin inhibitors - sirolimus, everolimus
T-cell regulation - belatacept and belimumab
Long term care of transplant patient.
Follow up several times a month, after 6 months it’s less.
Monitor GFR, CNI levels, proteinuria, calcium, phosphate, PTH, lipis and glucose.
Vaccinate
Monitor and control CVS disease, bone and mineral metabolism disease
Screen for malignancies - annual skin check e.g.
Contraception is obligatory first year
Complications of renal transplant.
Infection
Surgical
Delayed graft function
Rejection
New-onset diabetes after transplant
Malignancy
CVD
Explain infection-related complications in renal transplant in terms of time frame.
< 4 weeks = nosocomial infections or related to donor
1-12 months = activation of latent infections, relapse, residual, opportunistic infections or community.
> 12 months = community acquired.
Important pathogens to consider in renal transplant infection.
CMV
Hep B
HSV
VZ
EBV
BK (polyomavirus infection)
Aspergillus
P. jirovecii
Listeria
M. tuberculosis
Toxoplasma gondii
Why might NODAT (diabetes) happen?
Because you give them a new gluconeogenic kidney.
There is a risk of malignancy, due to the transplant but mainly due to immunosuppression.
What are important to screen for?
Skin
Cervix
Breast
Prostate
Renal
Urothelial
Liver
Colorectal
Lymphoproliferative disease (EBV)
Explain rejection of kidney.
Can be acute or chronic.
Acute can be antibody mediated or cellular (most common).
Treatment for acute is high dose steroids and immunosuppression.
Acute tubular necrosis in graft.
Delayed graft function can result from ATN.
Hypotension or loss of cardiac output will have an impact.
Prolonged “cold ischaemia time” also leads to delayed graft function due to ATN. Cold ischaemia time means the period during which the retrieved organ is cooled on ice in transit and awaits implantation.
Prognosis of renal transplant.
Acute rejection < 15%
1 year graft survival > 90%
The most common outcome is death with a functioning transplant meaning that the transplant outlives the patient.
Give examples of simultaneous kidney transplantations.
Liver-kidney
Pancreas-kidney
Kidney on kidney. Patients who goes into ESRF again can have a kidney re-transplanted.
Examination of an AV fistula
Skin integrity
Aneurysm
Palpable thrill
Machinery murmur on auscultation
Explain STEAL syndrome in AV fistula
STEAL syndrome is where there is inadequate blood flow to the limb distal to the AV fistula.
The AV fistula “steals” blood from the distal limb. The blood is diverted away from where is was supposed to supply and flows straight into the venous system. This causes distal ischaemia.
Why might high output heart failure happen in RRT with an AV fistula?
Where there is an A-V fistula blood is flowing very quickly from the arterial to the venous system through the fistula.
This means there is rapid return of blood to the heart. This increases the pre-load in the heart (how full the heart is before it pumps). This leads to hypertrophy of the heart muscle and heart failure.
