Renal Conditions Flashcards
CKD (triple whammy, definition, causes, facts, RF)
Triple whammy - ACEI/ARB + diuretic + NSAID
Definition
1. eGFR <60 that is present for >=3 months OR
2. >=3 months of albuminuria, haematuria (non-urological cause), structural abnormalities and/or pathological
abnormalities
Causes
Common: diabetes, glomerulonephritis, hypertension, polycystic kidney disease
Facts ● CKD is twice as common as diabetes ● 1 in 3 have risk factors for CKD ● 2-3x high risk of cardiac death ● Fewer than 10% are aware they have CKD
Risk factors ● Cardiovascular disease ● Family history ● BMI >=30 ● > 60 years ● Aboriginal and Torres Strait Islander ● Acute kidney injury
CKD - screening, kidney health check
Screening
> 60 years
● Screening not indicated in the absence of other risk factors
Aboriginal and Torres Strait islander
● >=30 years and 18-29 years with >1 CKD risk factor
● Every two years
Kidney health check
- Benefits
● Urinary albumin correlates directly with progression to end stage kidney disease
● eGFR correlates with cardiovascular morbidity and mortality
● Early use of ACEI can reduce progression and cardiovascular risk by up to 50%
- Components
● Blood test - UEC (eGFR)
○ eGFR more sensitive than serum creatinine
■ Normal serum creatinine does not exclude serious loss of kidney function
○ Factors affecting eGFR: cooked meat, vegetarian, protein, body size, paraplegia/amputees, high
muscle mass, children, medications (fenofibrate, trimethoprim), pregnancy.
● Urine test - urine ACR
○ First morning void (most accurate), dipstick not recommended
○ Criteria for albuminuria - two out of three positive ACR results
○ Factors affecting albuminuria: UTI, protein intake, cardiac failure, febrile illness, heavy exercise,
menstruation, genital discharge, NSAIDs
● BP check
CKD - detection
Summary
- urine ACR 2/3 present for >3 months
- eGFR minimum 3 reduced eGFR for > 3 months
- Refer to page 85 and 86 of GP Study Notes
CKD - orange clinical action plan (indication, goals of management, frequency of review, Ix)
For: eGFR 30-59 with microalbuminuria OR eGFR 30-44 with normoalbuminuria
Goals of management:
● Investigate underlying cause
● Reduce progression of disease
● Assess cardiovascular risk
● Avoid nephrotoxic medications or volume depletion
Frequency of review: 3-6 months
Investigations: calcium, phosphate, PTH every 6-12 months if eGFR <45
CKD - diagnostic evaluation
Always
● Renal ultrasound
● FBE, CRP, ESR
● Fasting lipids and glucose
● Urine MCS for dysmorphic red cells, red cell casts or crystals
Sometimes
● Signs of systemic: Anti-glomerular basement membrane antibody, anti-neutrophil cytoplasmic antibody,
antinuclear antibodies, extractable nuclear antigens, complement studies
● Risk factors for HBV, HV, HIV: HBV, HCV, HIV serology
● >40 years, suspected myeloma: serum and urine protein electrophoresis
CKD - goals of management (strategies, sick days, BP aim)
Goals of management ● Identify the underlying cause ● Reduce the progression ● Assess cardiovascular risk ● Avoid nephrotoxic medications or volume depletion
Management strategies
● Review every 3-6 months
● Laboratory assessments: FBE, UEC/eGFR, fasting lipids and glucose, calcium and phosphate, PTH every
6-12 months if eGFR <45.
Medications Sick days S - sulfonylurea A - ACE inhibitors D - diuretics M - metformin A - ARB N - NSAIDs S - SGLT2 inhibitors
Hypertension
Aim BP 130/80
CKD - Hypertension (ACEi/ARB, diuretics,
ACEI or ARBs
Can cause initial reduction in eGFR when treatment is initiated
● Continue if <25% reduction in 2 months of starting therapy
● Cease if >25% reduction and refer to nephrologist
Rises in serum potassium of 0.5 is expected
● Caution if baseline K+ >=5.5
● If remains >6 despite dose reduction, diuretic therapy and dietary potassium restriction then ACE/ARB
should be ceased
Can be prescribed at all stages of CKD
Cease ACE/ARB during acute illness (sepsis, hypovolaemia or hypotension)
Diuretics
Effective in all stages of CKD
Non-loop diuretics if eGFR >45, loop diuretics if eGFR ,45
Frusemide can be used in all stages (even if eGFR <30)
● Efficacy is improved if doses are divided
CKD - when to refer
** Rapidly declining eGFR + signs of acute nephritis (oliguria, haematuria, acute hypertension and oedema) =
medical emergency
Referral recommended
- eGFR <30
- Persistent significant albuminuria (urine ACR >=30)
- Sustained decrease in eGFR of 25% or more in 12
months or sustained decrease in eGFR 15/year
- CKD with poorly controlled hypertension despite at least three anti-hypertensive agents
Referral not needed
- Stable eGFR >=30
- Urine ACR <30 with no haematuria
- Controlled blood pressure
Tests prior to referral
● FBE, UEC, CMP, CRP/ESR
● Blood pressure
● Renal US
CKD - diabetes medication
Metformin
- eGFR 30-60 reduce dose
- eGFR <30 cease
SGLT2 inhibitor
- eGFR <45 cease
DPP4 inhibitors
- Safe with dose adjustment
Sulphonylurea
- eGFR <30 cease
GLP-1 agonist
- eGFR <30 cease
Insulin
- Monitor for hypoglycaemia
Electrolyte disorders - hypomagnaesemia
common causes, RF, presentation, treatment
Common causes
- severe malnutrition
- gastrointestinal losses (diarrhoea, malabsorption, bowel resection)
- kidney losses (hypercalcaemia)
- drugs (diuretics, alcohol, PPIs)
Risk factors: diabetes, alcoholism, diuretic drug therapy, malabsorption syndromes, poor oral intake
Presentation: tetany, muscle weakness, cardiac arrhythmias, neuropsychiatric changes and convulsions.
Treatment:
● Mild - magnesium 1000 to 3000 mg orally daily in divided doses with food
● Moderate to severe - magnesium 25 to 50 mmol IV in sodium chloride 500mL to 1000mL over 12 to 24
hours (** aim above 0.4 mmol/L)
Electrolyte disturbances - hypermagnesaemia
common causes, presentation, treatment
Common causes
- Excessive intake (antacids, enemas, IV infusion)
- Decreased excretion (kidney failure, volume depletion)
- Release from cells (rhabdomyolysis)
- Unknown (lithium)
Presentation:
● Common - neuromuscular (eg loss of deep tendon reflexes, muscle paralysis, impaired consciousness,
respiratory depression)
● Other - anorexia, nausea, skin flushing, hypotension, bradycardia/heart block and cardiac arrest
Treatment:
● Cease magnesium infusion
● Sodium chloride 0.9% IV, aiming for urine output of > 60mL per hour
● IV frusemide or IV calcium infusion (transient solution)
● Dialysis in patients with kidney impairment
Electrolyte disturbance - hypercalcaemia
causes
Common
- primary hyperparathyroidism
- hypercalcaemia of malignancy
Less common
- thiazide
- vitamin D toxicity
- sarcoidosis
- severe hyperthyroidism
- primary adrenal insufficiency
Gross haematuria
Key point
● Gross haematuria not related to obvious causes almost always needs to be referred
Management
● Visible clots = Urgent CT KUB and referral to urology for cystoscopy
Microscopic haematuria (key points, causes, assessment, management)
Key points
● Macroscopic haematuria must always be investigated
● Glomerular haematuria = haematuria due to kidney disease
● Isolated haematuria in <40 yrs is usually due to mild underlying glomerulonephritis
Causes
- Renal: benign renal mass, pyelonephritis, malignant hypertension, renal vein thrombus
- Ureter: malignancy, stone, stricture
- Bladder: malignancy, cystitis, bladder stones
- Prostate/urethra: BPH, prostate cancer, urethritis
Assessment
● Dipstick more sensitive for haematuria
● Evaluate if Hb 1+ or more
** Refer to page 211 of GP Study Notes for flow chart
Management
● Persistent microscopic haematuria in absence of albuminuria should be followed up annually with: repeat
testing for haematuria, albuminuria, eGFR and blood pressure monitoring
● Family members should be screened for haematuria
● Examples
○ 67M, health assessment. Ix microalbuminuria, microscopic haematuria 2+, renal US normal, eGFR
normal. BP 128/80.
■ Nephrology input (haematuria + low eGFR with proteinuria)
○ 52M, smoker, persistent microscopic haematuria 2+ with proteinuria. Normal MSU, eGFR and urine
ACR.
■ Risk of TCC
■ Need to investigate - CT IVP, urine cytology x3, referral to urologist for cystoscopy
Urinary incontinence (examination, treatment)
Examination:
- Abdominal: bladder
- Pelvic: atrophic vaginal mucosa, stress test, pelvic organ prolapse, pelvic floor contraction, pelvic mass or tenderness
- Rectal: constipation and anal tone
- Neurological screen: perineal sensation/anal tone, lower limb neuro exam
- Cardiac: volume status, signs of heart failure
Treatment:
Initial = lifestyle modifications, pelvic floor muscle exercises and bladder training in women with urgency. Reassess in
6 weeks for consideration of further therapy.
● Lifestyle: weight loss, dietary changes (reduce ETOH, caffeine and carbonated beverages), avoid constipation, cessation of smoking.
● Pelvic floor: good for stress incontinence
● Bladder training: good for urge incontinence
● Topical vaginal oestrogen: post-menopausal women (vagifem 10mcg PV weekly)
● Antimuscarinic or beta adrenergic: mixed picture
○ Oxybutynin 5mg TDS
○ Mirabegrom 25mg daily
