Renal & Urology Flashcards
What is acute kidney injury?
An acute decline in the GFR from baseline, with or without oliguria/anuria
What is the aetiology of acute kidney injury?
Pre-renal:
- Various causes of reduced renal perfusion such as hypovolaemia, haemorrhage, sepsis, third spacing of fluid (e.g. severe pancreatitis), overdiuresis, heart failure
Intrinsic:
- Acute tubular necrosis, rapidly progressive glomerulonephritis, interstitial nephritis
Post-renal:
- Mechanical obstruction of the outflow tract. Retroperitoneal fibrosis, lymphoma, tumour, prostate hyperplasia, strictures, renal calculi, ascending urinary infection and urinary retention
What is the epidemiology of acute kidney injury?
- Rate of hospitalisation for kidney disease has increased, particularly amongst adults over 65
What are the risk factors for acute kidney injury?
- Advanced age
- Underlying renal disease
- Malignant hypertension
- Diabetes mellitus
- Myeloproliferative disorders e.g. multiple myeloma
- Connective tissue disease
- Trauma
- Haemorrhage
- Exposure to nephrotoxins
- Sepsis
- Pancreatitis
- Drug overdose
- Surgery
- Recent vascular intervention
- Excessive fluid loss
- Nephrolithiasis
What are the presenting symptoms of acute kidney injury?
- Reduced urine production
- Vomiting
- Dizziness
- Orthopnoea
- Paroxysmal nocturnal dyspnoea
- Seizures
- Fever
- Haematuria
- Rash
What are the signs of acute kidney injury on examination?
- Pulmonary oedema
- Tachycardia
- Orthostatic hypotension
- Hypertension
- Peripheral oedema
- Muscle tenderness
- Limb ischaemia
- Prostatic obstructive symptoms
- Arthralgia/arthritis
- Altered mental status
- Signs of uraemia
What are the investigations for acute kidney injury?
- Basal metabolic profile (including urea & creatinine): Acutely elevated serum creatinine, high serum potassium, metabolic acidosis
- Ratio of serum urea to creatinine: 20:1 or higher supports pre-renal azotaemia
- Urinalysis: RBCs, WBCs, cellular casts, proteinuria, bacteria, positive nitrite and leukocyte esterase
- Urine culture: Bacterial or fungal growth may occur
- FBC: anaemia, leukocytosis, thrombocytopenia
- Renal US: Dilated renal calcyces
- CXR: pulmonary oedema, cardiomegaly
- ECG: Peak T waves, increased PR interval, widened WRS, atrial arrest and deterioration to a sine wave pattern (if severe hyperkalaemia)
How is acute renal injury managed?
- Volume expansion and/or RBC transfusion
- Vasopressor
- Diuretic
- Renal replacement therapy
What are the possible complications of acute renal injury?
- Hyperphosphataemia
- Uraemia
- Volume overload
- Hyperkalaemia
- Metabolic acidosis
- Chronic progressive kidney disease
- End-stage renal disease
What is the prognosis of acute renal injury?
- Variable, depends on cause of injury and severity and duration of AKI
- Up to 6% of patients admitted to ICU have AKI requiring renal replacement therapy (RRT). In hospital, when AKI requires dialysis, mortality exceeds 50%, especially in those with multiorgan failure. Mortality rates are high due to death from underlying disease and complications, not just the AKI.
What is benign prostatic hyperplasia?
A noncancerous increase in the size of the prostate
- Involves hyperplasia of prostatic stromal and epithelial cells, resulting in the formation of large, fairly discrete nodules in the transition zone of the prostate
What is the aetiology of benign prostatic hyperplasia?
- Hyperplasia of epithelial and stromal compartments, may be attributed to various factors including shifts in age-related hormonal changes creating androgen/oestrogen imbalances
- Progression from pathological BPH to clinical BPH may require additional factors such as prostatitis, vascular effects and changes in the glandular capsule
What is the epidemiology of benign prostatic hyperplasia?
Prevalence of histological BPH does increase with age and affects approximately 42% of men between the ages of 51 and 60 years, and 82% of men between the ages of 71 and 80 years.
What are the presenting symptoms of benign prostatic hyperplasia?
- Presence of risk factors (over 50yrs)
- Storage symptoms: Frequency, urgency, nocturia
- Voiding symptoms: Weak stream, hesitancy, intermittency, straining, incomplete emptying and post-void dribbling
What are the signs of benign prostatic hyperplasia on examination?
- Bladder enlargement on abdo exam
- Rectum exam: enlarged prostate feels smooth, cannot obtain accurate representation of prostate size
What are the investigations for benign prostatic hyperplasia?
- MSU, U&Es
- Ultrasounds: large residual volume-?hydronephrosis
- Rule out cancer: transrectal USS, biopsy, PSA
How is benign prostatic hyperplasia managed?
- Lifestyle: Reassure against prostate cancer, avoid caffeine and alcohol, drink less at night, relax when voiding, voiding twice in a row to aid emptying, control urgency by practicing distracting methods, train bladder to hold on
- Mild to moderate: watchful waiting
- Moderate: alpha blockers (decrease smooth muscle tone of prostate and bladder). Competitive inhibitor of 5a-reductase (finasteride)
- Surgery: when decreased renal function and upper tract dilation
What are the possible complications of benign prostatic hyperplasia?
Acute retention/retention with overflow
What is the prognosis for benign prostatic hyperplasia?
The majority of patients with BPH can expect at least moderate improvement of their symptoms with a decreased bother score and improved quality of life. L
What is chronic kidney disease?
Defined either as kidney damage or GFR of less than 60mL/min/1.73m2 for 3 months
- Kidney damage is defined as pathological abnormalities or markers of damage, including abnormalities in blood or urine tests or imaging studies
What is the aetiology of chronic kidney disease?
- Diabetes mellitus and hypertension are two most common causes
- Vascular disease: hypertension, renal artery atheroma, vasculitis
- Glomerular disease: Glomerulonephritis, diabetes, amyloid, SLE
- Tubulointerstitial disease: Pyelonephritis/interstitial nephritis, nephrocalcinosis, tuberculosis
- Obstruction and others: Myeloma, HIV nephropathy, scleroderma, gout, renal tumour, inborn errors of metabolism (e.g. Fabry’s disease)
- Congenital/inherited: Polycystic kidney disease, Alport’s syndrome, congenital hypoplasia
What is the epidemiology of chronic kidney disease?
- Incidence of end stage CKD in England more than 110 per million population per year
- Higher incidence in Asian immigrants than native British population
What are the presenting symptoms of chronic kidney disease?
- Anorexia, nausea, pruritis
- Later: diarrhoea, drowsiness, convulsions, coma
- Symptoms of cause and other complications
What are the signs of chronic kidney disease on examination?
- Systemic: Kussmaul’s breathing (acidosis), signs of anaemia, oedema, pigmentation, scratch marks
- Hands: Leuconychia, brown line at distal end of nail
- May be an arteriovenous fistula (buzzing lump in wrist or forearm)
- Signs of complications (e.g. neuropathy, renal bone disease)