Assess kidney function.
Filtration
Reabsorbtion
Secretion
Waste excretion Water level balancing Blood pressure regulation Red blood cell regulation Acid regulation
Describe obstructive disorders of the urinary tract.
Ureter (hydroureter)
– Calculi
– Pregnancy
– Tumour
Bladder and urethra – Tumour – Neurogenic bladder – Enlarged prostate – Urethral strictures
Neurogenic bladder
– Bladder dysfunction caused by neurological
disorders
– Types of dysfunction related to location of
nervous system lesion
- Detrusor hyperreflexia (brain & SC nerves)
- Flaccid bladder (sacral or peripheral nerves)
Obstruction to urine flow
– Urethral stricture, prostate enlargement (men)
– Pelvic organ prolapse (women)
Compare and contrast glomerular diseases (nephritic and nephrotic syndromes).
Nephrotic syndrome involves the loss of a lot of protein, whereas nephritic syndrome involves the loss of a lot of blood. Tip: Nephrotic & Protein both have an “O” which may help you remember! Nephritic: "PIG ARM" Poststreptococcal gn IgA nephropathy Goodpasture's syndrome Alport's syndrome Rapidly Progressive GN (RPGN) Membranoproliferative GN
Nephrotic: "Mum* Fights*** with Me** and i'm SAD" Membranous GN Focal segmental glomerulosclerosis Minimal change glomerulonephritis SLE nephropathy Amyloidosis Diabetic nephropathy
Distinguish between acute kidney injury and chronic kidney disease.
CAUSE
a - Event leading to kidney malfunction (dehydration,
blood loss, medications), often reversible
c - Long-term disease (high BP, DM) that damages kidney
and reduces function
SYMPTOMS
a - Fluid build up
Electrolyte imbalance
Dehydration, light-headedness, weak rapid pulse.
Symptoms reflect actual cause (eg – urinary tract
obstruction = haematuria, reduced urine output)
Sudden creatinine increased
c - May not develop until little kidney function remains.
Anaemia
Increased phosphates in blood
TREATMENT
a - Discontinue nephrotoxic meds Renal replacement
therapy (dialysis, haemofiltration).
c - First: dietary control, restrict protein, Na & fluid control,
Restrict K, manage lipids and EPO, ACE inhibitors
Later: Supportive, dialysis, transplantation
Treat anaemia: Epoetin alfa Vit D activation
Explain structural and functional abnormalities in children.
Enuresis – involuntary passage of urine beyond age of bladder control (4-5).
- Primary enuresis – Child has never been continent
- Secondary–Diurnal, nocturnal, or both
- Treatment: fluid measurement, diett herapy, drugs
(desmopressin), treat obstructive sleep apnoea,
behavioural modification therapy
Wilms’s Tumour (Nephroblastoma)
- Common primary neoplasm (3-6years)
- Affects transitional/squamous renal pelvis cells
- Solid mass–Rapid growth. Distorts kidney. Presents as
abdominal mass.
- Treatment: Surgery, chemo/radio therapy
List drugs used to treat UTIs.
Trimethoprim/Sulfamethoxazole (Bactrim) preferred treatment
Cephalexin (Keflex)
Ceftriaxone
• Location/nature of UTI determines treatment duration
• Most treated with oral medication
• Severe infections may require IV delivery
• HAI may be associated with resistance to Bactrim therefore
requires use of other drugs
Discuss neoplasia of the kidney.
- Two most common types: Renal cell carcinoma (RCC) - ~80% primary renal cancers, and transitional cell carcinoma (TCC)
- Common signs/symptoms: Haematuria, tiredness, loss of appetite, high temperature, weight loss, heavy sweating, abdominal pain.
- Causes: smoking, regular NSAIDs, obesity, family history, Hepatitis C, renal calculi, high BP
- Pathophysiology: Originates in renal tubule and renal pelvis.
- Treatment: Surgery, Chemotherapy, Radiotherapy, Immunotherapy
Discuss glomerular diseases and the differences between nephritic and nephrotic syndromes.
.
Discuss the relationship between the cardiovascular and renal systems.
Dosing should be minimal and slowly ↑ to avoid HTN and
adverse cardiovascular events associated with ↑ blood
viscosity due to excessively high haematocrit
Discuss the relationship between urinary tract infections and acute kidney injury.
.
Explain the connection between the GFR and progression to end-stage kidney disease.
GRF decreases as CKD progresses.
Stage 1 with normal or high GFR (GFR > 90 mL/min)
Stage 2 Mild CKD (GFR = 60-89 mL/min)
Stage 3A Moderate CKD (GFR = 45-59 mL/min)
Stage 3B Moderate CKD (GFR = 30-44 mL/min)
Stage 4 Severe CKD (GFR = 15-29 mL/min)
Stage 5 End Stage CKD (GFR <15 mL/min)
Explain the connection between urinary tract infection and confusion in the elderly.
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Review RAAS
.
Review ACE inhibitors
.
List and explain the action of different types of diuretics.
.
Define kidney stones
Masses of crystals, protein or other substances that form within and may obstruct the urinary tract.
Renal Calculi Formation
Supersaturation of one or more salts
– Salt in a higher concentration than the volume able to
dissolve the salt
Precipitation of a salt from liquid to solid state
Growth into a stone via crystallization or aggregation
Type of kidney stones
Calcium oxalate or calcium phosphate, struvite, uric acid stones
Manifestations of kidney stones
– Renal colic (pain +++)
– Haematuria
– Nausea & vomiting
Treatment of kidney stones
– High fluid intake
– Decreasing dietary intake of stone-forming substances
– Stone removal
– Drug treatment
Manifestations of LUT infection
– Frequent voiding
– Nocturia
– Poor force of stream
– Intermittent urinary stream
– Urinary urgency, often combined with hesitancy
– Feelings of incomplete bladder emptying despite
micturition
Define UTI
Inflammation of the urinary epithelium caused by bacteria
Types of UTI
Lower urinary tract: bladder and urethra
Upper urinary tract: kidney (acute pyelonephritis)
Complicated UTIs: infection associated with underlying complication (calculi, IV line, prostatic hypertrophy etc)
Recurrent infections: > 3/yr, re-infection often due to sexual activity
Risk factors of UTIs
• Gender • Age • Intercourse • Indwelling urinary catheters • Obstruction and stagnation • Impaired host defences • Postmenopausal • Special populations: diabetes, pregnancy, children, elderly
Define acute cystitis
Cystitis is an inflammation of the bladder
Manifestations of acute cystitis
Frequency Dysuria Urgency Lower Abdominal and/or suprapubic pain
Treatment of acute cystitis
Antimicrobial therapy
Increased fluid intake
Avoidance of bladder irritants
Urinary analgesics
Define acute pyelonephritis
Acute infection of the renal pelvis & interstitium
Define chronic pyelonephritis
Persistent or recurring episodes of acute pyelonephritis that leads to scarring
Risk of chronic pyelonephritis increases in individuals with renal infections and some type of obstructive pathologic condition
Effect of nephrotoxic drugs
Kidney damage occurs as kidneys are often exposed to drugs because of their filtering and excretion role
Damage may occur due to:
• Reduced renal blood flow
• Obstructions
• Hypersensitivity reactions
What are some drug-related nephropathies
Reduced renal blood flow:
NSAIDs (aspirin) block prostaglandin synthesis→ reduce blood flow to tubules → tubule cell damage and necrosis
Obstruction:
Older sulphonamide drugs form crystals in renal structures, lesser problem w/ current drugs, hydration important
Hypersensitivity:
Synthetic antibiotics, thiazide diuretics, frusemide can lead to nephritis w/sensitivity. Signs- fever, haematuria, proteinuria. Drugs withdrawn promptly to encourage recovery
Define renal failure
Condition in which kidneys fail to remove metabolic products from blood and regulate fluid, electrolyte and pH
balance
What are the underlying causes of renal failure
– Renal disease
– Systemic disease
– Other urological defects
Types of renal failure
Acute kidney injury
Chronic kidney disease
Outline acute kidney injury
– Abrupt onset; often reversible if detected early
– Progressive kidney alterations lead to failure, classified
using RIFLE staging system
– Prerenal, intrarenal, postrenal causes
Outline chronic kidney injury
– Irreparable kidney damage
– Develops slowly, usually over number of years
– Mirrors: diabetes, hypertension, obesity (rising)
What is Prerenal Acute Kidney Injury
Decreased blood flow to kidneys resulting in kidney injury
Hypovolemia
- haemorrhage - burns - heart failure/ cardiogenic shock
Decreased renal perfusionsepsis
- vasoactive mediators/drugs - diagnostic agents
Clinical manifestations of Prerenal Acute Kidney Injury
Oligurea, azotaemia (+BUN, creatinine, uric acid)
Intrarenal Acute Kidney Injury
.
Postrenal Acute Kidney Injury
.
5 categories of acute kidney injury
Risk Injury Failure Loss End-stage
Phases of acute kidney injury
- Onset (hrs - days)
- Oliguric/Anuric (8-14 days)
- Diuretic (7-14 days)
- Recovery (months-yr)
Outline the onset stage of acute kidney injury
Injury through cell death period (hrs - days).
Characteristics:
– Tissue oxygenation at 25% of normal
– Renal flow 25% of normal
– Urine output 30 ml/hr (or less)
– 50% of patients are oliguric. With prompt treatment,
damage can be reversedOutline the oliguric/anuric stage of acute kidney injury
Damage to tubular walls (8-14 days)
Characteristics: – < BUN/Creatinine – Electrolyte abnormalities (hyperkalemia, hyperphosphatemia and hypocalcemia) – Metabolic acidosis
Outline the diuretic stage of acute kidney injury
Pathology resolved, scarring/edema of tubules remain (7-14 days)
Characteristics: – >GFR – Urine output 2-4 L/day – Renal tubules cannot concentrate urine – Increased GFR linked to loss of electrolytes; (requires IV crystalloids to maintain hydration)
Outline the recovery stage of acute kidney injury
Tubules begin to function adequately (months-yr)
Characteristics:
–
Define chronic kidney disease
Irreversible loss of renal function that affects nearly all organ systems
Stages of CKD
1 - normal kidney function or high GFR
2 - mild kidney damage + mild reduction in GFR
3 - moderate kidney damage + moderate reduction in GFR
4 - severe kidney damage + severe reduction in GFR
5 - end stage kidney disease + kidney failure
Signs of CKD
• Proteinuria and uraemia
•
Risk factors of CKD
- Hypertension, smoking, family history
- Obesity, Type II Diabetes mellitus
- Over 50 years old, Indigenous
- Polycystic kidney disease
- Obstructions of the urinary tract
- Glomerulonephritis
- Cancers
- Autoimmune disorders (SLE)
- Diseases of the heart or lungs
- Chronic use of pain medication
Effect of aging on renal function
- Decrease in renal blood flow and GFR
- Number of nephrons decrease
- Increased risk for drug toxicity
- Alterations in thirst and water intake
How is renal function assessed
Blood tests-
• Creatinine: 0.6–1.2mg/dL (50–100mmol/L)
• Creatinine Clearance: 115–125 mL/min
• Blood Urea Nitrogen (BUN): 8.0–20.0 mg/dL (3–8mmol/L)
• Potassium: 3.5–5 mEq/L (3.5–5.0 mmol/L)
• Cystoscopy, Ultrasound, Radiological & Other Imaging
