Dialysis Flashcards
Clinical features of EPS
> 4yrs on dialysis, weight loss, ascites, low albumin
How do you clear more phosphate
Increase length of dialysis / number of sessions
Cleared most effectively with nocturnal dialysis
Max UF
13 ml/kg/hr
Reasons for Home HD patients to have an acidosis
Lactate is used as a buffer in HHD in place of HCO3
Just after HHD patients will be acidotic
What is a low urea pre dialysis suggestive of?
Malnutrition - Protein catabolic rate can be determined by urea excretion and residual renal function
Causes of raised arterial pressure and venous pressure
Arterial pressure (becomes more negative) = needle issues / kink in the line / hypotension
Venous pressure = central stenosis
Anticoagulation for CVVH
Regional citrate = unless contraindicated in which cause use unfractionated or LMWH
Note - citrate can accumulate in liver disease = causes metabolic acidosis and low ionised calcium - this is an indication to stop
Anticoagulation options for HIT
Results in thrombocytopenia, thrombosis and infarction
Use instead Argatroban or Fondaparinux (= which can be used during CRRT)
What is meant by the ‘conductivity measure’
Composition of the dialysate / acid base balance in the machine
Reducing toxins on dialysis and key things
RO - removes infections / endotoxins
Carbon filter - if defective can lead to cyanosis in patients and methemoglobinaemia
High TMPT = dialysate pressure to high and suggests leak in the system
Water levels for HDF - ultrapure
Bacterial level <0.1
Endotoxin level <0.03
Average AVF fistula blood flow
Approx 1L/min
If >1L - may need echo ? steal syndrome causing ccf
If <1L - then poor AVF and needs intervention
HHD versus PD
Similar outcomes
PD has higher risk of hospitalizations in the first year
What is the recommended Dialysis catheter
Straight, double cuff
PD peritonitis
Culture negative - think fungal PD
Multiple organisms - ? colonic malignancy
WCC >1000 on day 3 - Treatment failure and needs removal
Icodextrin and raised BMs
Icodextrin can cross react with glucose readers - causes falsely high BMs
It can also cause falsely low serum amylase so if acute pancreatitis is considered then do serum lipase test
Treatment of PD infusion pain
Switch to neutral / lactate and buffered solution
PD Dialysis prescription if patient has inguinal hernia
Switch to APD - laying flat at night, small volume, dry days - this will reduce intra abdominal pressures
Key things for MDT discussion in PD
PROMS / Fluid status / Nutrition / Removal toxins (Kt/v)
Treatment of dialysis disequilibrium syndrome
Mainly supportive
Can give mannitol, hypertonic dextrose, oxygenation, intravenous phenytoin for fits, and in severe cases intubation and ventilation.
Types of dialysis reactions
Type A - acute, instant, anaphylactic like reaction
Often secondary to medications e.g heparin.
Type B - Non specific, occurs 15-30mins into dialysis
Symptoms of nausea and vomiting.
Indications for TNL removal
Staph aureus bacteremia / line culture
Infected tunnelling
Commonest cause of PD peritonitis
1) Coagulase neg staph
2) Staph aureus
2) Enterococcus or pseudomonas
10% will be culture negative
What is Ultrafiltration coefficient (KUK)
Ultrafiltration coefficient / KUF - determines the ultrafiltration rate
It indicates the volume of ultrafiltration expected per hour for each 1 mmHg of transmembrane pressure. For example KUF of 3 ml/hour/mmHg, = 3 ml of ultrafiltrate per hour, In order to achieve 1 L of ultrafiltrate per hour, the transmembrane pressure would be 333 mmHg (3ml/hr/mmHg X 330 mmHg=1000 ml/hour).
Transmembrane pressures that exceed 250 mmHg are dangerous because they can result in membrane rupture and blood leak to the dialysate compartment. By increasing the KUF, you can take off the same 1L per hour with a lower transmembrane pressure e.g (8 ml/hr/mmHg X 125 mmHg =1000 ml/ hour).
Features and how to deliver Intradialytic parenteral nutrition
Intradialytic parenteral nutrition to boost protein/ energy intake, although the evidence is weak.
Nutrition is given during dialysis, starting with slow infusion and increasing progressively and continued as long as the patient needs it. It has the advantages of utilizing the dialysis time for the infusion and ability to UF extra fluid.
Key dialysis trials: FHN, HEMO, Evolve
FHN Trial: compared 3x a week dialysis with short daily dialysis and found that daily dialysis has favourable outcomes but more access issues.
The HEMO study = no mortality difference between Kt/v of 1.2 vs Kt/v of 1.7. and no difference in the high flux vs low flux dialyzer.
NCDS = showed that the KT/V > 1 was associated with a significant mortality benefit.
MPO trial =looked at the high flux dialyzers vs low flux dialyzer and found no overall mortality benefits.
EVOLVE = the effect of cinacalcet on cardiovascular outcomes in haemodialysis patients - cinacalcet did not significantly reduce the risk of death or major cardiovascular events
Vitamin A in dialysis patients
Vitamin A accumulates in chronic kidney disease and it is not removed by dialysis.
It can build up with chronic use to toxic levels.
Causes Hypercalcaemia, deranged liver enzymes, and pseudotumour cerebri
Patients complain of loss of appetite, generalized joint and bone pain, and weight loss. dryness of his skin and lips, and hair loss. recurrent morning headaches and papilloedema
Intradialytic hypertension
Often due to clinically undetectable fluid overload
Patients tend to have too high target weights and fail to achieve enough UF.
tX = Reduce target weight, reduce Na dialysate and carvediolol
Advantages / disadvantages of button hole technique
Advantages = reducing pain, unsuccessful attempts, bleeding, hematoma, and aneurysm formation.
Disadvantages = Increased infection risk
Complications from first dialysis session
Dialysis disequilirbrium syndrome
In cases of acidosis - rapid correction using dialysis can cause reduction in ionised calcium - leading hypocalcemia = seizures etc. Can give IV calcium
