Acute Kidney Injury, Chronic Kidney Disease And Renal Replacement Therapy Flashcards
What are the patterns of renal disease?
Nephrotic syndrome Nephritic syndrome Haematuria Proteinuria AKI CKD
What are the 2 subcategories of renal disease?
- Renal e.g. IgA nephropathy, minimal change disease + membranous nephropathy
- Systemic e.g. diabetes, Wegeners + systemic lupus erythematosus (SLE)
What are the 3 functions of the kidneys?
- Homeostasis: fluid, electrolytes + acid-base balance
- Hormone production: renin/angiotensin, vitamin D metabolites + erythropoietin (EPO)
- Excretion of metabolites: organic acids, phosphates + urea/creatinine
What is the definition of AKI?
A significant deterioration in renal function, which is potentially reversible, over a period of hours or days.
(mostly inpatient cases)
What would you expect to see creatinine, GFR + urine output do in AKI?
Creatinine would increase
GFR would decrease
Urine output would decrease
When can you work out a patients urine output?
If they are already in hospital
What are the 3 main causes of AKI? How common is each one?
- Pre-renal failure - 85%
- Intrinsic renal failure - 5%
- Post-renal failure - 10%
What causes pre-renal failure?
Renal hypoperfusion in e.g.
- Systemic hypotension: hypovolaemia (bleeding, dehydration) or sepsis
- Local: renal artery stenosis or drugs (ACE inhibitors, NSAIDs)
What causes intrinsic renal failure?
Primary renal disease - glomerulonephritis
Secondary renal disease - diabetes, SLE, myeloma etc.
Interstitial nephritis - usually drug induced
Secondary acute tubular necrosis (ATN) - established after pre-renal failure
What causes post-renal failure?
Obstruction/blockage of drainage from kidneys
Why do the relation of a obstruction/blockage in relation to the bladder matter in post-renal failure?
If its below the bladder, you can feel/percuss the bladder to feel if it is distended (easier situation as if the bladder is full you can just catheterise)
However, if its above the bladder you need to do a diagnostic ultrasound
What are the 3 anatomical locations of where blockages can occur in the lumen of the tubes in post-renal failure? What type of blockage is usually found in each location?
In lumen - stones
In wall - tumour
Outside wall - anything swollen enough in the abdomen to compress the tubes i.e. lots of things
What would you want to find out in the history?
Rate of onset
Precipitating factors
Urinary symptoms
Chronic symptoms
Systemic features of autoimmune disease e.g. myalgias, rash, ENT symptoms, haemoptysis
Relevant PMH/PFH e.g. CKD, DM, vascular disease, polycystic kidney disease etc.
Drug history
When examining a patients fluid status, what would you look at?
Tissue turgor Mucous membranes/tongue Pule rate, rhythm + volume Lying + standing BP Jugular venous pressure (JVP) Peripheral perfusion Peripheral oedema
What signs of sepsis would you look for?
Fever Tachycardia/bounding pule Tachypnoea Warm peripheries (or cold in extreme cases) Local signs of sepsis
What would you look for when examining the other parts of the body?
Cardiac - pericardial rub Respiratory - pulmonary oedema/effusion Abdominal - ascites/masses/bladder CNS - drowsiness/confusion Skin - rashes
What 3 tests would you do for renal dysfunction?
Bloods
Urine tests
Radiological tests
Why would you look for pericarditis + drowsiness/confusion in a patient with renal problems?
Because they would get these symptoms if their urea levels have rose so they have become uraemic
What 3 types of tests would you run for a renal dysfunction blood test?
Biochemistry
Haematology
Immunology
What would you test for in a biochemistry blood test?
Creatinine eGFR NA/K Bicarbonate Ca/Phosphate/Parathyroid hormone (PTH) CRP/creatinine kinase (CK)
What 2 components of a biochemistry blood test would you look at in order to stage kidney disease?
Creatinine
eGFR
What would you test for in a haematology blood test?
Hb
What would you test for in a immunology blood test?
Antinuclear antibodies (ANA) Anti-neutrophil cytoplasmic antibody (ANCA) Anti-GBM Complement (C3, C4) Electrophoresis (IgA/G/M) Serum free light chains
What urine tests could you run on a patient with kidneys problems?
Urine dipstick Albumin creatinine ratio (ACR)/protein creatinine ratio (PCR) 24h creatinine clearance Urine output MSU (looks for infection) Urine creatinine/electrolytes/calcium
What are the 4 most important urine tests you would run on a patient with kidney problems?/
Urine dipstick
ACR
Urine output
MSU (looks for infection)
What would you test for in a urine dipstick?
Microscopic haematuria
Leucocytes/nitrites
Proteinuria
What radiological test would you run for renal dysfunction?
Renal tract USS CT renal angiogram CT KUB Renogram (to see if blood vessels are narrowed) CXR (to look for buildup of fluid)
What is the initial management of an AKI?
Keep the patient alive Generic management of AKI including: - Review medication - Close observation - Fluid management Diagnose cause + treat (often requires specialist input so know your limitations)
What would you deal with to keep an AKI patient alive?
Hyperkalaemia
Fluid overload
Hypotension
(Acidosis, Uraemia)
How would you detect a hyperkalaemic patient?
Blood tests
ECG changes - peaked “tented” T waves, prolonged P-R interval, prolonged QRS duration, loss of P waves + ventricular defibrillation/asystole
What is in the incidence of AKI?
5-20% of all critically ill patients suffer AKI
4.9% of all ICU admissions
What is the mortality rate of AKI?
10% in uncomplicated AKI
> 50% in AKI with multi-organ failure
Independent risk factor for mortality
AKI has a high mortality and it is thought that AKI is not handled the best even though it is often predictable and preventable. Although the situation has got better, it is still not ideal. What are the top ten risk predictable/preventable risk factors for AKI that could help this?
Age (elderly most at risk) Co-morbidity Medication (polypharmacy e.g. ACE inhibitors, diuretics) Previous CKD Hypovolaemia Sepsis Biochemistry Urinalysis (blood + protein in urine) Extremes of weight Nutritional status
What is CKD?
Kidney injury has to go on for over 90 days (months-years) and is mostly irreversible
(mostly outpatient cases)
Explain the model of CKD.
A person will be normal + screened for CKD factors -> increased risk will mean there is CKD risk factor reduction + screening for CKD -> damage so diagnosis, treatment + treating of comorbid conditions occurs (slow progression) -> decreased GFR so estimate progression, treat complications + prepare for replacement -> kidney failure so replacement by dialysis + transplant -> end-of-life care
Complications can occur at each stage which will all contribute to the end of life of the patient
What are the complications of CKD?
Cardiovascular disease Hypertension Anaemia Bone-mineral metabolism Poor nutritional + functional status Progression of CKD AKI -> associations of complications with eGFR
Explain the complication of hypertension with CKD.
80% of haemodialysis patients + 50% of peritoneal dialysis patients get it
CKD progression is associated with hypertension which is associated with the level of eGFR
What is taken into consideration when staging CKD?
GFR
Albuminuria
ACR
What is the relationship of cardiovascular disease to eGFR?
As eGFR decreases -> cardiovascular disease is more likely in CKD
How do you measure CKD?
Test for renal excretory function
Test for albuminuria (proteinuria)
Test for complications (Hb, K+, sodium bicarbonate, cCa, PTH)
Diagnostic blood tests (ANCA, electrophoresis, glucose)
Radiological tests (USS, CT, dimercaptosuccinic acid (DMSA) scan)
How do you test for renal excretory function in CKD?
Using:
Creatinine (increases with decreased eGFR)
Cystatin C
eGFR (calculated via MDRD or CKD-EPI)
What urine measurements would you do in a CKD patient?
Urinalysis (for haematuria)
Urine protein:
- Urine albumin:creatinine ratio (greater sensitivity at low levels, recommended in diabetic patients)
- urine protein:creatinine ratio (not often done)
- 24h urine collection (not often done)
CKD classification ___ _ ______ a diagnosis
Does not mandate
Do most patients with CKD progress to established renal failure (ERF)?
No
Define accelerated progression of CKD.
A sustained decrease in GFR of 25% or more + a change in GFR category within 12 months
OR
A sustained decrease in GFR of 15 ml/min/1.73m^2 per year
What risk factors are associated with progression of CKD?
Hypertension Diabetes mellitus Albuminuria Cardiovascular disease Smoking Ethnicity NSAIDs
What are the consequences of late presentation of CKD?
Higher mortality, morbidity, hospital stay + cost
Lack of vascular access due to poorer clinical state at presentation
No possibility of pre-emptive transplantation
Define established renal failure (ERF).
The stage of chronic kidney disease where renal replacement therapy (RRT) is required to safely sustain life.
Also known as end-stage renal disease (ESRD), end-stage renal failure (ESRF) or end-stage kidney disease (ESKD).
What are the 4 types of RRT?
- Haemodialysis (hospital, satellite, home)
- Peritoneal dialysis (continuous ambulatory PD, automated PD)
- Transplantation (deceased-donor, living-donor including pre-emptive + other options like kidney-pancreas, paired exchange, desensitisation)
- Conservative care
What considerations should you think about when discussing RRT modality?
Physical + social factors (eyesight & manual dexterity, mobility & functional status, family & social support + work) Medical factors (abdominal surgery, vascular disease + hypotension/left ventricular dysfunction) Geographical factors (distance from haemodialysis unit + space/cleanliness of house)
