Renal medicine Flashcards
Definition of complicated v uncomplicated UTI
Uncomplicated UTI: occurs in normal urinary tract and resolves rapidly with conventional antibiotics
Complicated UTI: occurs in patients with co-existing pathology (strictures, stones, DM, MS, SCI)
Definition of pyelonephritis
Significant bacteriuria in the presence of systemic illness and symptoms such as flank or renal angle pain, pyrexia, rigors, nausea and vomiting
Most common pathogens in UTIs
E. Coli 80% Staphylococcus saprophyticus 10% Klebsiella 5% Proteus less than 5% Pseudomonas aeruginosa less than 1% (typically opportunistic or hospital-acquired due to catheters, instrumentation etc.)
Cause for increased UTIs during pregnancy
Ureteric dilatation
- progestogenic relaxation of ureteric smooth muscle
- pressure from expanding uterus
Overall effect = increased urinary stasis, compromised ureteric valves, vesicoureteric reflux
Reason for treating asymptomatic bacteriuria in pregnant women
Associated with low birth weight and pre-term delivery
Risk of ascent to pyelonephritis due to ureteric dilatation in pregnancy
CT findings in pyelonephritis
wedge-shaped areas of inflammation in renal cortex
Clinical features of pyelonephritis
Fever
Loin pain with renal/costovertebral angle tenderness
Systemic symptoms common (fever, rigors, nausea and vomiting)
Indications for investigations into anatomy for UTI in adults
Male
Women following 2 or more episodes of acute pyelonephritis
Anyone presenting with a proteus UTI
Management of non-pregnant woman with symptomatic UTI
Trimethoprim 3d
OR
Cephalexin, Augmentin or nitrofuratoin for 5d
Management of pregnant woman with UTI
While awaiting culture results:
Cephalexin, nitrofuratoin or Augmenin duo for 5d
Repeat MCS 48h post completion of antibiotics to ensure clearance of infection
Management of UTI in men
Empirical antibiotics while awaiting culture
- trimethoprim, cephalexin or augmentin for 14 days!
Investigate for underlying abnormality of the urinary tract
Management of pyelonephritis in a non-pregnant patient
Mild:
Oral Augmentin, cephalexin, trimethoprim for 10d
Severe: (septic, vomiting or pregnant with fever)
IV Gentamicin + amoxicillin (gent alone is ok if penicillin allergic)
If Gentamicin resistant: cefotaxime or cephtriaxone
Continue IV until afebrile for 24h, followed by 10-14d oral antibiotics guided by MCS
Repeat MCS 48h after completion of antibiotics to ensure clearance
Management of recurrent UTIS
Cranberry products
Intravaginal oestrogen (post-menopausal)
Prophylactic trimethoprim
Prophylactic cephalexin
Components of nephritic syndrome
Haematuria (macro- or microscopic) Proteinuria Hypertension Oedema Temporary oliguria or uraemia
Causes of nephritic syndrome
Immune response to infection
- Group A strep
- chronic bacteraemia
- sepsis
- staph, pseudomonas, klebsiella
- Hep B or C
- varicella
- coxsackie virus
- EBV
- Rubella
- mumps
Drug induced:
- gold
- penicillamine
Other:
- IgA nephropathy
- SLE
- Membranoproliferative glomerulonephritis (Type I, III - immune-mediated, Type II - complement-mediated)
Rapidly progressive (crescentic) glomerulonephritis
- Goodpasture Syndrome
- Churg-Strauss syndrome
- Polyarteritis nodosa
- idiopathic
Definition of IgA nephropathy
An immune complex-mediated glomerulonephritis characterised by IgA deposition in the glomerular mesangium due to exaggerated marrow and tonsillar IgA response to viral/other antigens
Clinical presentation of IgA nephropathy
Asymptomatic microscopic haematuria OR recurrent macroscopic haematuria sometimes following a viral URTI or GIT infection
Investigations in IgA nephropathy
Bloods: eGFR
Urinalysis
- RBC casts
- +++ protein, +++ blood
- quantify proteinuria
Renal biopsy:
- proliferation of mesangial cells
- increased cellularity in mesangium
- immune complexes in mesangium on immunoperoxidase staining
Management of IgA nephropathy
ACE-I or ARB
If more than 1-3g proteinuria/day with normal GFR: steroids
If GFR under 70: + fish oil OR prednisolone
AND cyclophosphamide for 3m
If recurrent tonsillitis - tonsillectomy
Prognosis of IgA nephropathy
up to 25% will undergo spontaneous remission
15-40% have slow progression to ESRD (5-20y)
Grades of lupus nephritis
Class I: minimal mesangial glomerulonephritis (5%)
- normal on light microscopy
- mesangial deposits on electron
Class II: mesangial proliferative lupus nephritis (20%)
- renal failure rare
- typically responds completely to corticosteroid
Class III: focal proliferative nephritis (25%)
- often responds successfully to high dose steroids
- renal failure uncommon
Class IV: diffuse proliferative nephritis (40%)
- renal failure common!
- treat with steroids and cyclophosphamide
Class V: membranous nephritis (10%)
- renal failure uncommon
- extreme oedema and protein loss
Important side effects of cyclophosphamide
Sterility
Immunosuppression
Bone marrow suppression