How is chronic kidney disease defined?
GFR < 60 mL/min/1.73m2 for >3 months with or without evidence of kidney damage (eGFR normally falls by 10mL/min per decade 40+ but a reduction is associated with increased CVD risk at all ages)
Evidence of kidney damage (with or without decreased GFR) for >3 months:
- Glomerular haematuria
- Pathological abnormalities (e.g. on renal biopsy)
- Anatomical abnormalities (e.g. cysts on ultrasound)
At what GFR do symptoms of chronic kidney disease usually present?
< 15ml/min (severe disease)
How are the stages of CKD defined by eGFR?
What conditions can give false proteinuria readings on urinalysis dipstick?
Heavy protein intake
What are the risk factors for development of CKD?
Target - < 130/80mmHg
< 125/75mmHg in proteinuria/diabetes
1st degree relative with CKD
NOTE - HTN and proteinuria are the two most important modifiable risk factors for reducing progression of CKD
What are the basic management principles for CKD?
Identify and treat underlying cause
Reduce progression - BP, lipid and glucose control
Manage metabolic complications - low calcium and phosphate, high PTH, acidosis
Cessation of nephrotoxic and renally excreted drugs
SNAP - smoking cessation, nutrition, alcohol reduction, physical activity
Renal replacement therapy (CKD 4-5)
How does CKD cause anaemia?
Low EPO production - reduced stimulus for red blood cell production
How does CKD cause hypocalcaemia?
Poor functioning kidneys - don't get active form of vitamin D (calcitriol) - so don't get aid for calcium absorption in the GIT
How can CKD lead to osteoporosis?
Low calcitriol --> low calcium absorption --> osteclasts stimulated --> bone breakdown to maintain extracellular calcium levels
Why does CKD cause low phosphate?
Reduce activation of vitamin D to calcitriol so reduced absorption of phosphate in the GIT
How does CKD lead to hyperparathyroidism?
Low levels of calcium absorption (due to low levels of vitamin D activation in the kidneys) leads to hypocalcaemia - triggers activation of the parathyroid gland to secrete PTH to stimulate osteoclasts to breakdown bone to maintain extracellular calcium levels
How does CKD lead to a metabolic acidosis?
Kidneys unable to filter properly so there is increased loss of bicarcbonate and decreased excretion of acids - leading to an acidosis
When should renal replacement start?
GRF < 10ml/min or when symptoms dictate
What is the major complication of CKD?
20x more likely to die from CVD event (before dialysis is even needed)
How is APKD inherited and what is the typical presentation?
Abdo pain, haematuria, nocturia, flank pain, drowsy, clubbing, arthralgia
How is APKD investigated?
US - renal cysts
CT - intracranial aneurysm
What are the features of IgA nephropathy?
Few days post URTI - haematuria
Hypercellularity, fibrosis and inflammation
What are the features of post-strep nephropathy?
1-4 wks post strep pyogenes infection - oliguria and haematuria
Diffuse and global with lots of polymorph nuclei
What are the featrues of membranous nephropathy?
Nephrotic syndrome - proteinuria, oedema, high lipids, low albumin
Secondary to SLE, hep B, malaria
What is syncope?
Abrupt transient loss of consciousness, absence of postural tone with complete and rapid recovery, which is often complicated by injury
18yo F, collapse after standing in hot crowded area, light headed and nauseous before collapse, quick recovery, no witnessed seizure, similar episode 6 months ago - what are the differentials and how can these be investigated?
Vasovagal syncope - hydration status, BG, temperature, hx, prodrome, FBE (anaemia)
Arrhythmia - ECG, echo, U&E
PE - CTPA (whole body contrast - don't use in people with kidney disease or iodine allergy), ECG, V/Q scan (use in people who have contrast allergy or kidney disease - not a specific test (can't tell whether PE is old or new - and it's affected by other pathology))
Fixed output valve disease - echo, TOE
What is the role of a spacer?
Increase lung deposition of medication and reduce oropharyngeal deposition
Useful in kids or elderly with poor metered dose inhaler technique and breath coordination
How should a spacer be cleaned?
Clean before first use, wash in warm water with mild detergent and allow to air dry without rinsing, check regularly for cracks or splits and prime spacer before use
What can cause prolonged QT interval?
High Mg, low K/Ca, sodium channel blockers, raised ICP, hereditary, hypothermia, drugs (SSRIs, antihistamine, amiodarone, tricyclics, antipsychotics)
What is the first line treatment for long QT interval?
What is this ECG representative of, and what is the treatment?
Ventricular fibrillation (cardiac arrest)
Shockable, adrenaline after 2nd shock, amiodarone after 3rd shock
Is this a shockable rhythm?
This is ventricular tachycardia - this is only a shockable rhythm if the patient is unconscious - if conscious treat with amiodarone (or another anti-arrhythmic)