AKI, CKD & RRT

Rutendo Ganyani & Sarah Folkerts

• Patricia, a 72-yr old lady, has been admitted with collapse. She was found at home by her carer, and was responsive, but confused. You dip her urine which shows markers of a UTI, and take some blood.

• Her blood tests come back showing her inflammatory markers are raised. You also sent a sample for U+E, which shows she is in renal failure, with her U+E from 2 weeks ago being normal.

What is the definition of AKI?

A significant deterioration in renal function, which is potentially reversible, over a period of hours or days.

an abrupt (within 48h) absolute increase in the SCr of ≥ 0.3 mg/dL (26.4 micromol/L) from baseline, a percentage increase in the SCr of ≥ 50%, or oliguria of < 0.5 mL/kg/h for > 6h

Give two features of the U+Es that indicate renal failure!

• Raised urea• High potassium• Raised creatinine• Low eGFR

Name 3 symptoms of AKI• Peripheral oedema• Shortness of breath

– pulmonary oedema– metaolic acidosis

• Anorexia• Oliguria• Confusion• N&V• Hiccups• Hypertension• Hyperkalaemia• Encephalopathy

What are the 3 categories of AKI?Give 2 examples for each!

• Pre-renal (inadequate perfusion): – Hypotension (Shock, Sepsis, Anaphylaxis)– Hypovolaemia (Haemorrhage, severe vomiting/diarrhoea,

burns)– Renal artery stenosis/renal vein obstruction– Drugs altering renal haemodynamics

• NSAIDs• ACEi

• Renal (instrinsic)- Acute Tubular Necrosis (‘Muddy brown casts’ in urinalysis)- Glomerulonephritis- Interstitial nephritis (usually drug induced e.g NSAIDs, ABx)- Rhabdomyolysis- Vasculitis, emboli, Malignant HTN, DIC...- Malaria, Legionnaires’ disease, Leptospirosis- Multiple Myeloma

• Post-renal (obstruction)- Intrinsic: renal calculi- Malignancy- Extrinsic: - Pelvic tumours (prostate, cervix, bladder, ureters)- BPH- Retroperitoneal fibrosis

How do you manage Patricia?

• ABCDE approach• Find & Treat underlying cause• Stop nephrotoxic drugs• Generic AKI management:

– pre-renal – IV-fluids– Intrinsic – treat medically– Post-renal – relieve obstruction

• monitor vitals, daily U+Es, fluid balance• If not improving - Get specialist help! (eg ITU, renal

specialist)

One of the key complications in AKI is hyperkalaemia. Patricia’s potassium level has risen to 7.0 mmol/L. Name 2 features you might expect to find on her ECG!How would you manage her?

• ECG changes:– Tall tented T-waves– Small p waves– Prolonged PR interval– Wide QRS complex– Ventricular fibrillations

• Treatment (at once!)– Stabilise myocardium: Ca Gluconate– Shift K+ into cells: IV Insulin+Dextrose– Diuresis, Ca Resonium (Resin binds K+), – (RRT/Dialysis)

• Paul, a 55-year-old man with a history of hypertension is reviewed. As part of routine blood tests to monitor his renal function whilst taking ramipril the following blood tests are received

• A urine dipstick is subsequently performed which is normal and a renal ultrasound sound shows normal sized kidneys with no abnormality detected. What stage of chronic kidney disease does this patient have?

a) No chronic kidney diseaseb) Chronic kidney disease stage 4c) Chronic kidney disease stage 3d) Chronic kidney disease stage 2e) Chronic kidney disease stage 1

• A 55-year-old man with a history of hypertension is reviewed. As part of routine blood tests to monitor his renal function whilst taking ramipril the following blood tests are received

• A urine dipstick is subsequently performed which is normal and a renal ultrasound sound shows normal sized kidneys with no abnormality detected. What stage of chronic kidney disease does this patient have?

a) No chronic kidney diseaseb) Chronic kidney disease stage 4c) Chronic kidney disease stage 3d) Chronic kidney disease stage 2e) Chronic kidney disease stage 1

Chronic kidney disease is only diagnosed in this situation if supporting tests such as urinalysis or renal ultrasound are abnormal

Definition:CKD = Progressive, irreversible decline in kidney function over months or years

a GFR < 60 mL/min/1.73 m2 or a GFR> 60 mL/min/1.73 m2 together with the presence of kidney damage, present for 3 months.

Symptoms & Signs of CKD?

You review Paul who is now 65 and his renal function has declined over the years after he has also developed DM. He is now stage 5 chronic kidney disease in the renal outpatient clinic. He has recently been started on erythropoietin injections. Which one of the following is the main benefit this treatment?

a) Reduced proteinuriab) Improved exercise tolerancec) Reduced blood pressured) Improved renal functione) Reduced long-term all-cause mortality

You review Paul who is now 65 and his renal function has declined over the years after he has also developed DM. He is now stage 5 chronic kidney disease in the renal outpatient clinic. He has recently been started on erythropoietin injections. Which one of the following is the main benefit this treatment?

a) Reduced proteinuriab) Improved exercise tolerancec) Reduced blood pressured) Improved renal functione) Reduced long-term all-cause mortality

Erythropoietin treats CKD associated anaemia which in turn would improve exercise tolerance.

If his kidney function further declines, he will have to decide if he wants to have renal replacement therapy (RRT).What are his options?

• Haemodialysis• Peritoneal dialysis• Kidney transplant• Palliative care

Peritoneal dialysis

Transplantation

Haemodialysis

Supportive Care

(Haemofiltration)

What are the aims of dialysis ?

mimics the excretory homeostatic functions of the normal kidney:

• Fluid removal• Removal of toxins• Correction of electrolytes• Correction of pH• Adjustment of calcium

You need to advise him on dialysis. He asks you to explain the difference between peritoneal dialysis and haemodialysis.

Haemodialysis • Blood from patient pumped through the

dialyser (array of semipermeable membranes)

• which bring the blood into close contact with dialysate, flowing countercurrent to the blood.

• The plasma biochemistry changes towards that of the dialysate owing to diffusion of molecules down their concentration gradients

Needs the creation of an arterio-venous fistula to ensure proper flow velocity

• Peritoneal dialysis:• Peritoneum acts as semipermeable membrane• A tube is placed into the peritoneal cavity through the anterior

abdominal wall• Dialysate is run into the peritoneal cavity• Urea, creatinine, phosphate and other uraemic toxins pass into the

dialysate down their concentration gradients. • Water (with solutes) is attracted into the peritoneal cavity by osmosis,

depending on the osmolarity of the dialysate. This is determined by the glucose or polymer content of the dialysate.

• The fluid is changed regularly to repeat the process.

Advantages & Disadvantages of HD and PD

HD PD• Requires hospital visit each time• Requires trained staff • Less frequent (3x week)• Need strict diet and fluid intake

• More flexible• Patient is able to be home based• Less dietary restrictions • Body image problems • More prone to infection • Frequent (1x at least per day)• Associated with DM - glucose absorbed

from dialysate

You are reviewing a 66-year-old in the renal clinic. He has been on haemodialysis for chronic kidney disease for the past 6 years. What is he most likely to die from?

a) Hyperkalaemiab) Malignancyc) Dilated cardiomyopathyd) Dialysis related sepsise) Ischaemic heart disease

• You are reviewing a 66-year-old in the renal clinic. He has been on haemodialysis for chronic kidney disease for the past 6 years. What is he most likely to die from?

a) Hyperkalaemiab) Malignancyc) Dilated cardiomyopathyd) Dialysis related sepsise) Ischaemic heart disease

50 % of deaths due to IHD – previous morbidity + vascular remodelling due to ESRD