Dialysis

Question 1

Discussion bullet points when “should this patient be offered dialysis?” (5)

Answer 1

Key points:

1. Is the patient symptomatic? - IDEAL study shows no difference in outcome between early vs late. Stronger argument if symptomatic
2. Age >75 + ≥2 comorbidities (one being CCF or PVD) - there is no survival advantage of dialysis over non-dialysis pathway
   - Also consider physical disability, cognition, social circumstances
3. Life-expectancy (more towards dialysis if reasonable long, e.g. 5-years)
4. Regardless all should be offered NDP information
5. Would discuss advanced care planning early

When life expectancy is reasonably long (e.g. 5-years)

Question 2

What are the comorbidities to consider when you are thinking of dialysis on this ESRF patient? (6)

Answer 2

1. Cognition
2. Fine-motor skills / Physical disability (e.g. arthritis + vision + mobility!) - problem with home HD or PD
3. Social issues: work, family & home support, compliance
4. NYHA III-IV: with HD, due to sudden drop in PVR with AVF.
5. Pulmonary HTN: with HD
6. Abdominal: hernia, obesity, previous abdominal surgery
   - In 3&4, options are dialysis through vascath or PD if possible.

What is the most important for patient?

Question 3

Cut-off for dialysis?

Answer 3

about eGFR 15.

Have discussion early (e.g. eGFR 30)

Refer to renal and consider access ~eGFR 20 (e.g. vascular mapping, assessing home situation, medical vs. surgical insertion of PD catheter)

Question 4

Why should you vaccination is so important prior to commencing on dialysis?

Answer 4

During dialysis vaccinations do not work - despite multiple vaccinations you often find that they are still -ve for e.g. Hep B.

Question 5

So when would you consider this patient for dialysis? (5)

Answer 5

1. eGFR <15
2. Uraemic symptoms (if not tolerable, patients have varying levels of tolerance)
3. Fluid overload (resistant to medical tx)
4. Hyperkalaemia (resistant to medical tx)
5. Pericarditis (rare)

Question 6

What are contraindications to haemodialysis? (5)

Answer 6

Hypotensive HF

Severe angina (poorly tolerates dialysis)

Severe PVD (AVF → vascular steal syndrome → decreased supply to extremities and ischaemia)

Limited prognosis

Comorbidities: mobility, cognition, manual dexterity, home situation

Question 7

What are the contraindications of peritoneal dialysis? (3)

Answer 7

Intra-abdominal surgery + Adhesions

Morbid obesity

Comorbidities: physical, cognitive, manual dexterity, poor personal hygiene

Question 8

What are indications for acute dialysis? (4)

Answer 8

Hyperkalaemia

Fluid overload

Acidosis

• that are refractory to medical Mx

Uraemic symptoms

Question 9

Difference between dialysis and ultrafiltration?

Answer 9

Dialysis = solute clearance

Ultrafiltration = water removal

Question 10

What is the most effective way of increasing the dialysis efficacy in patient with high weight gain in between dialysis?

Answer 10

Increasing Time is the key.

Time

Time

Yes… blood flow rate, dialysate flow rate…matter but minor.

Time!

Did I mention time?

Question 11

What are the complications of Vascular access (AVF or AV graft [synthetic]? (6)

Answer 11

Stenosis

Ischaemia + steal syndrome

Aneurysm & pseudoaneurysm

Infection

Thrombosis

High-output cardiac failure

Question 12

What are complications of haemodialysis? (5)

Answer 12

Hypotension

Angina/Chest pain/Arrythmia

Bleeding

Infection

Thrombosis

Headache, nausea, vomiting

Question 13

What are the advantages of PD over HD?

Answer 13

Does not require access/surgery & it’s complications

Much greater flexibility, can be done at home

Kinder to haemodynamics

Question 14

Difference between CAPD, IPD, APD.

Answer 14

CAPD (continuous ambulatory PD): 2-3L of infusion of dialysate 4-5 times/day. Dwell 4h.

IPD (intermittent PD): 2-3L over 15 minutes, dwell 30 minutes, drained in 15 minutes. Primarily used for AKI.

APD (automated): long day time dwell and 3-6 night time exchanges (CCPD; continuous cyclic, NIPD - nocturnal intermittent exchange, no dialysate during the day). Some may require both to achieve adequate clearance.

Question 15

What are the complications of PD? (5)

Answer 15

1. Peritonitis
2. Infection around exit site
3. Protein loss**
4. Catheter migration
5. Sclerosing Peritonitis

Question 16

What are the common organisms in Peritonitis?

Answer 16

Staph (skin) = commoest

Gram-negatives (translocation from bowel)

Fungal (recent ABx use)

Mycobacteria

Question 17

What are the indications of Tenchoff catheter removal? (5)

Answer 17

Refractory peritonitis or exit-site/tunnel infection

Relapsing peritonitis

Fungal

Mycobacterial

Multiple-enteric.

Must wait for 2-3 weeks before re-insertion, longer for fungal.

Question 18

How would you assess the adequacy of dialysis? (3)

Answer 18

Patient’s symptoms: physical, mental, social well being

Weight & nutritional status

Ultrafiltration adequacy

BP

Complications - are they stable or not (e.g. anaemia, acidosis, MBD)

Question 19

What is your approach to preparing this dialysis patient for operation? (3)

Answer 19

1. HD patient: organize HD a day prior to surgery if possible.

Remember that HD is usually delivered with Heparin/LMWH to prevent clots in the blood circuit: minimise prolonged anticoagulation - speak to renal re: no heparin dialysis

• Check CMPs and adjust dialysate K/Ca/Bicarb aiming for normal levels for OT
  2. PD patient: increase the dialysis time a week before surgery (to prevent under-dialysis in post-op period e.g. due to a delay form ileus). If CAPD - additional exchange each day.
  3. Cease ACE/ARB/Diuretics 2 days prior (reduces the haemodynamic stability ass with anaesthetic agents)
  4. Aim K <5.5 prior to OT
  5. Aim close to dry weight
  6. examine dialysis access site carefully

Question 20

How would you distinguish between CKD-MBD (mineral and bone disorder) from osteoporosis?

Answer 20

Osteoporosis: Ca, Phos, PTH, 25-Hydroxy Vit D, ALP should all be normal. If these patients have DEXA T-score <-2.5, then you have OP.

If eGFR <30 (e.g. dialysis patient) - you need hx of fragility #, also as well as above, you need to have normal bone-specific ALP (used to predict underlying bone turn over - may indicate dynamic bone disease)

Bone biopsy is the gold standard.

Question 21

How can PTH be used as surrogate marker for the bone turn over?

Answer 21

High PTH (>X9 normal i.e. >585 pg/mL) indicate osteitis fibrosa cystica (e.g. severe PTH-bone disease)

Very low PTH <100 pg/mL - usually associated with dynamic bone disease (will also have low level of other bone turn over markers - bone-specific ALP)

Question 22

What is the agent of choice in patient with fragility # and T<-2.5 in ESRF patient with eGFR <15

Answer 22

Oral bisphosphonate: Risedronate 35mg every other week (i.e. half of usual dose) - but should not be used routinely without consulting MBD experts - as one must exclude renal osteodystrophy.

Denosumab is option, but in it has been associated with clinically significant hypocalcemia in Dialysis patients

Patient with dynamic bone disease should never be treated with OP drug as it will further reduce bone turn over

CKD-MBD - OP drug has no efficacy.