Renal Flashcards
What type of anaemia is seen in chronic kidney disease?
normocytic anaemia
What is the management for most blunt renal injuries and when does this differ?
most managed conservatively and result in haematuria; usually heals on its own
What are the more serious forms of blunt renal injury?
laceration - high velocity injuries, blood/urine may leak into surrounding tissue
if torn from blood vessel attachments - likely to bleed profusely - can be fatal
If a serious blunt kidney injury is suspected how can this be investigated?
contrast CT
What is the most common type of bladder injury and how does this occur?
extraperitoneal bladder rupture - occurs due to pelvic fractures or penetrating trauma
What proportion of patients with pelvic fracture suffer from genituourinary injuryes, and what should be done as a result?
25% - inspect urinary meatures for blood before inserting urinary catheter
How can most cases of extraperitoneal bladder leak from bladder injury be managed?
maximal bladder drainage with urethral or suprapubic catheter for 7-10 days (then TWOC)
Is surgery often required for extraperitoneal bladder leak after trauma/pelvic fractures?
no - majority heal within 3 weeks but if surgery done for other indications can be repaired surgically at the same time
What are 2 types of urethral injuries?
- posterior - membranous + prostatic urethra - usually major blunt trauma (RTA, falls, pelvic fractures)
- anterior - distal to membranous urethra - blunt trauma to perineum (straddle injuries), may be delayed presentation - stricture
What type of trauma can cause posterior urethral injuries?
major blunt trauma e.g. RTA and falls, associated with pelvic fracture
What type of trauma causes anterior urethral injuries?
blunt trauma to perineum e.g. straddle injuries, may have delayed presentation e.g. strictures many years later
How do urethral injuries present?
perineal bruising, blood at external urethral meatus
PR exam - abnormally high riding prostate/ inability to palpate
What is the management of urethral injury?
don’t perform urinary catheterisation; refer to urology; some perform retrograde urethrogram / some prefer suprapubic catheteristion, then imaging
On which chromosome do the majority of patients with ADPKD have an abnormality?
chromosome 16
In addition to kidneys what are 3 other organs where cysts are seen in ADPKD?
- liver (75% patients >60y)
- pancreas
- spleen
What factors can influence hepatic cysts in ADPKD?
affected by female steroid hormones; massive cysts occur almost exclusively in women
What are 4 non-cystic manifestations of ADPKD?
- mitral valve prolapse
- intracranial berry aneurysms (40% of cases)
- colonic diverticula
- renal cell carcinoma
What are 7 presenting features in ADPKD?
- haematuria (cyst rupture)
- flank pain
- hypertension
- stroke (SAH)
- renal failure
- palpable masses
- increased incidence UTIs
What may be seen on urinalysis in ADPKD?
microalbuminuria in 1/3 (heavy proteinuria rare), haematuria
Why may Hb be raised in ADPKD?
polycystic kidneys can produce excess EPO and raise Hb
What size kidney cysts can US detect?
from 1-1.5cm diameter
What imaging can detect smaller cysts in ADPKD?
CT, MRI
What is the treatment of ADPKD?
- usually supportive
- tolvaptan (vasopressin receptor 2 antagonist) in select patients
What are the diagnostic criteria for stage 1 AKI?
- increase in creatinine to 1.5-1.9x baseline OR
- increase in creatinine by >26.5 µmol/L OR
- reduction in UO to <0.5ml/kg/hr for ≥ 6 hours
What are the diagnostic criteria for AKI stage 2?
- increase in creatinine to 2.0-2.9x baseline OR
- reduction in UO to <0.5ml/kg/hr for** ≥12 hours**
What are 4 criteria for stage 3 AKI?
- increase in creatinine to ≥ 3.0x baseline
- increase in creatinine to >353.5µmol/L
- Reduction in urine output to <0.3 mL/kg/hour for ≥24 hours
- initiation of kidney replacement therapy
- inpatients <18 years, decrease in eGFR to <35 mL/min/1.73 m2
What is the median age of presentation of Wilms’ nephroblastoma?
3 years
What are 4 associations of Wilms tumour?
- Beckwith-Wiedemann syndrome
- WAGR syndrome: aniridia, genitourinary malformations, mental retardation
- hemihypertrophy
- 1/3 associated with loss of function mutation in WT1 gene on chromosome 11
What is the commonest presenting features of Wilms nephroblastoma?
abdominal mass
What is a common site of metastases for Wilms nephroblastoma?
lung (mets found in 20% of patients)
What is the management of suspected Wilms tumour in primary care?
refer for paediatric review within 48h
What are the management options for Wilms’ nephroblastoma?
nephrectomy, chemotherapy, radiotherapy if advanced disease
What is the prognosis of Wilms tumour?
good - 80% cure rate
What is the advice regarding creatinine / renal function monitoring and ACE inhibitors?
- U+Es should be checked before treatment initiated + after increasing dose
- rise in serum creatinine up to 30% from baseline + K+ up to 5.5 mmol/L is acceptable
What is the triad that defines nephrotic syndrome?
- proteinuria (>1g/m2 /24h)
- hypoalbuminaemia (<25g/L)
- oedema
What causes the majority of cases of nephrotic syndrome in children?
Minimal change disease
What is the management of minimal change disease?
High dose steroids (90% of cases responsive)
What age is the peak incidence of minimal change disease?
2-5 years
In addition to the 3 cardinal features of minimal change disease, what are 3 additional associated features?
- Hyperlipidaemia
- Hypercoagulable state (loss of antithrombin III)
- Infection (loss of immunoglobulins)
What is the commonest formula used to provide an accurate estimate of renal function with eGFR?
Modification fo Diet in Renal Disease (MDRD)
What are 4 variables that the MDRD uses to work out eGFR?
- age
- gender
- ethnicity
- serum creatinine
What are 3 factors that may falsely affect the result of the eGFR from MDRD?
- pregnancy
- muscle mass (e.g. amputees, body builders)
- eating red meat 12 hours prior to the sample being taken
What are the 5 stages of CKD as per GFR range?
- > 90, with some sign of damage on other tests (other U+Es, proteinuria)
- 60-90
3a. 45-59
3b. 30-44
4 . 15-29
5 . <15
What is the definition of contrast media nephrotoxicity?
25% increase in creatinine occurring within 3 days of IV administration of contrast media
How long after contrast administration does nephropathy occur?
2-5 days
What treatment is given to prevent contrast-induced nephropathy?
- IV 0.9% saline 1ml/kg/hour for 12hours pre and post procedure
- if high-risk - withhold metformin for minimum 48h
also evidence for isotonic sodium bicarbonate
What electrolyte abnormalities are seen with rhabdomyolysis?
- hypocalcaemia - myoglobin binds calcium
- hyperphosphataemia - released from myocytes
- hyperkalaemia
metabolic acidosis
What is the treatment of rhabdomyolysis?
IV fluids to maintain good urine output; urinary alkalinisation sometimes used
What are 3 indications for treatment with tolvaptan in ADPKD?
- chronic kidney disease stage 2 or 3
- rapidly progressing disease
- company provides it with the discount agreed in the aptient access scheme
3
What are the 3 sets of US diagnostic criteria in ADPKD?
- 2 cysts unilateral or bilateral if < 30 y
- 2 cysts in both kidneys if 30 - 59 y
- 4 cysts in both kidneys if > 60 y
What are 2 drug causes of minimal change disease?
- NSAIDs
- rifampicin
What are 3 non-drug causes of minimal change disease?
- Hodgkins lymphoma
- thymoma
- infectious mononucleosis
What is blood pressure like in minimal change disease?
normotension
What are the key features of the proteinuria of minimal change disease?
only intermediate-sized proteins such as albumin and transferrin leak through the glomerulus
What is seen on renal biopsy in minimal change disease?
- normal glomeruli on light microscopy;
- electron microscopy shows fusion of podocytes and effacement of foot processes
What is the next step in steroid-resistant cases of minimal change disease?
cyclophosphamide
What is an examples of an INITIAL (not maintenance) regime of immunosuppression after renal transplant?
- ciclosporin / tacrolimus with a monoclonal antibody
What is an example of MAINTENANCE immunosuppression after renal transplant?
ciclosporin / tacrolimus with MMF or sirolimus
When should steroids be added to the immunosuppressino regmie in renal transplant?
if more than 1 steroid responsive acute rejection episode
What is the mechanism of action of ciclosporin for immunosuppression?
inhibits calcineurin, a phosphotase involved in T cell activation
What are 3 advantages of tacrolimus over ciclosporin?
- lower incidence of acute rejection compared to ciclosporin
- less hypertension
- hyperlipidaemia
What is a disadvantage of tacrolimus compared with ciclosporin?
high incidence of impaired glucose tolerance and diabetes
What is the mechanism of action of mycophenolate mofetil (MMF)?
blocks purine synthesis by inhibition of IMPDH therefore inhibits proliferation of B and T cells
What are 2 side effects of mycophenolate mofetil?
- GI side effects
- marrow suppression
What is the mechanism of sirolimus?
blocks T cell proliferation by blocking the IL-2 receptor
What is a side effect of sirolimus?
can cause hyperlipidaemia
What are the monoclonal antibodies used in renal transplant and what are 2 examples?
selective inhibitors of IL-2 receptor
1. daclizumab
2. basiliximab
What are 3 key complications of long-term immunosuppression after renal transplant?
- cardiovascular disease (tacrolimus/ciclosporin cause HTN And hyperlgycaemia)
- renal failure
- malignancy - greatest risk squamous cell carcinoma of skin (also basal cell, lymphoma, cervical)
How does immunosuppression after renal transplant cause renal failure? 3 ways
- nephrotoxic effects of tacrolimus and ciclosporin
- graft rejection
- recurrence of original disease in transplanted kidney
Which cancer are patients at the greatest risk of developing after renal transplantation?
squamous cell carcinoma
What dietary advice should be given to patients with CKD?
- low potassium diet
- low phosphate
- low sodium
- low protein
What must be present to diagnose CKD stage 1+2?
if eGFR >60 then there must be other abnormal U+Es or proteinuria (i.e. evience of kidney damage) to diagnose
What distinguishes poststreptococcal glomerulonephritis from IgA nephropathy (Berger’s disease)?
- IgA nephropathy occurs 24-48h after URTI, poststreptococcal occurs 1-3 weeks after streptococcal infections
- both present as nephritic syndorme with visible haematuria, oliguria and oedema
- IgA nephropathy treated with steroids, poststreptococcal treated supportively only
What distinguishes GPA, EGPA, Goodpasture’s syndrome?
- GPA: upper and lower respiratory tract involvement, pauci-immune glomerulonephritis
- EGPA: asthma, GI and cardiac involvement, eosinophilia
- Goodpasture’s: pulmonary haemorrhage, glomerulonephritis but NO URT involvement
Which renal disease may anti-streptolysin O titres be seen?
poststreptococcal glomerulonephritis
What are 8 causes of nephritic syndrome?
- post-streptococcal glomerulonephritis
- IgA nephropathy
- GPA
- EGPA
- Microscopic polyangiitis
- Rapidly progressive glomerulonephritis
- Alport syndrome
- Thin basement mebrane disease
What are 2 causes of nephritic-nephrotic syndrome?
- membranoproliferative glomerulonephritis
- diffuse proliferative glomerulonephritis
What is the commonest cause of glomerulonephritis in adults?
IgA nephropathy
What are 5 caues of nephrotic syndrome?
- minimal change disease
- focal semgental glomerulosclerosis
- membranous nephropathy
- diabetic nephropathy
- amyloid light-chain (AL) amyloidosis, light chain deposition disease
What is the most common cause of nephroptic syndorme in adults?
focal segmental glomerulosclerosis
What are the 2 types of ADPKD and what are 3 differences?
Type 1 and 2
1. ADPKD1 more common - 85%
2. type 1 chromosome 16, type 2 chromosome 4
3. type 1 presents with renal failure earlier
What is the investigation of choice when a bladder injury is suspected?
CT cystogram - may show variable path of extravasated contrast material