Nephrology Flashcards
What is enuresis?
involuntary bed wetting after the age of 7- most children toilet trained by age 5
Give 5 possible causes of enuresis
- small bladder
- nerves slow to mature so cannot recognise full bladder
- low ADH
- UTI
- sleep anoea
- diabetes
- chronic constipation
- structural problems in the urinary tract or nervous system
How should enuresis be managed?
- avoid caffeine and limit fluid intake at night
- treat cause if any identified (constipation/ sleep apnoea)
- moisture alarms: go off when moisture detected- effective but take 16 weeks
- desmopressin (synthetic ADH)- only if over 5 yrs
- oxybutynin (anticholinergic)- reduced contractions and increases bladder capacity
What is henoch- schonlein purpura?
- AKA IgA vasculitis
- causes small blood vessels in skin, joints, intestines and kidneys to become inflamed and bleed
What may cause/ trigger henoch schonlein purpura
- cause is autoimmune
- triggers inc URTI, chickenpox, strep throat, measles, hepatitis, meds, food, insect bites, exposure to cold
How does HSP present// what body systems are affected?
- skin: palpable red- purple non blanching purpuric rash on buttocks, legs and feet
- joints: arthritis, pain and swelling around knees and ankles- can preceed rash
- GI: acute, diffuse, colicky belly pain, nausea, vomiting, bloody stools
- Kidney: protein or blood in urine, red cell clasts, IgA deposition on biopsy
Give risk factors for HSP
- age 2-6
- M>F
- white or asian
how is HSP diagnosed
Purpura or petichae with lower limb predominance + 1 of:
- diffuse abdo pain at onset
- biopsy showing IgA deposits
- arthritis or arthralgia of acute onset
- proteinuria/ haematuria
Give 2 complications of HSP
- permanent kidney damage- may require dialysis or transplant
- bowel obstruction from intussusception
How is HSP managed?
- rest, plenty of fluids and pain releif if mild as self resolving
- prednisolone if significant GI involvement or complications (decreases duration of abdo and joint pain but not complications)
- IVIg and plasmapheresis if severe
- DMARDs inc aza if chronic renal disease
- surgery if complications develop
- monitor BP and urinalysis for 6 months after diagnosis if nephritic
What is the most common cause of nephrotic syndrome in paediatrics
minimal change disease (steroid responsive)
other steroid responsive= SLE, HSP, post strep
Steroid resistant: congenital, FSGS, Menangiocapillary glomerular nephritis, membranous nephropathy
Describe the clinical features of nephrotic syndrome
- odema (typically facial/ periorbital and in morning)
- scrotal/ vaginal/ leg/ ankle odema
- ascites
- breathlessness from pleural effusion + abdo distension
- infections (sepsis, peritonitis, septic arthritis) due to immunoglobulin loss in urine
- proteinuria
- hypoalbuminaemia
How is nephrotic syndrome managed?
- high dose steroids- need admission and monitoring for at least 24 hrs as intravascularly deplete- dont give diuretics
- some may need low dose maintenance therapy or immunomodulatory drugs (ciclosporin, rituximab, mycophenolate) if steroid resistant, dependant or relapsing
- low salt diet, fluid restriction
- prophylactic abx as at high risk of infections as leak immunoglobulins
- 30% FSGS, 100% congenital (unilateral nephrectomy initially to control hypoalbuminuria), mesangiocapillary glomerular nephritis may need renal transplant
What may cause acute glomerular nephritis in a child? (4)
- post strep/ any inf
- vasculitis (HSP, SLE, wengers)
- IgA nephropathy
- mesangiocapillary glomerularnephritis
- anti GBM (rare)
describe the clinical features of acute glomerular nephritis
- haematuria + oliguria
- HTN
- sometimes odema, fever, loin pain, GI disturbance
- complicated: hypertensive encephalopathy, uraemia, arrhythmias
How does post streptococcal glomerularnephritis present?
- 7-21 days after strep infection
- with gross haematuria, odema, HTN, anorexia, fever and abdo pain
How is post streptococcal glomerular nephritis managed?
- restrict protein, sodium
- give diuretics, anti hypertensives
- penicillin orally for 10 days
- nitroprusside if hypertensive encephalopathy
- odema resolves in 5-10 days but HTN and proteinuria can last weeks
Other than acute glomerularnephritis, what can haematuria in children? (3)
- UTI
- wilms tumour
- calculi
- polycystic kidney disease
- sickle cell disease
- surgery/ trauma
- IgA nephropathy
- thin basement membrane disease
- alports/ famillairl nephritis
How may a UTI present in a child that is preverbal
- vomiting
- fever
- lethargy
- poor feeding
- failure to thrive
- irritability
- offensive smelling urine
- haematuria
What are the indications for a USS in a child with UTIs?
- UTI age < 6 months (get one within 6 weeks)
- Atypical UTI: seriously ill, failure to respond to abx within 48hrs, septicaemia, infection with non e. coli organism, raised creatinine, abdominal or bladder mass
- Recurrent UTI: >2 episodes of severe/ acute pyleonephritis/ upper UTI, 1 episode upper and one episode lower UTI, >3 episodes lower UTI
How are lower UTIs managed?
- trimethoprim for 3 days (if low risk of resistance (4mg/kg/ 12hrs)
- or nitrofurantoin if eGFR >45ml/min for 3 days
How are upper UTIs managed?
- cefalexin for 10 days
- or co amox for 10 days is culture susceptible
- if IV needed: cefuroxime, ceftriaxone, gentamicin
How are UTIs managed if <3 months old?
- IV amoxicillin + gent or IV cephalosporin
- USS, MCUG
What advice can be given to help prevent UTIs
- encourage high fluid intake
- treat constipation
- encourage full voiding
- avoid nylon underwear
- clean perineum front to back
What investigations should be done to confirm UTI?
- urine dip: nitrites, leukocyte esterase, blood, (leukocytes and protein may be present from fever of any cause) can be used from >3yrs. LE and nitritis +ve= treat as UTI, one +ve= MCS to confirm, neither -ve= UTI unprobable
- urine collection: microscopy and culture (>10x5 colony forming units/ ml of same organism) OR WCC>40 if age <3yrs or inconclusive dipstik
What is vesicoureteric reflux and what causes it?
- abnormal flow or urine from bladder back up ureters
- primary: born with defect in valve which normally prevents urine from flowing backward from bladder into ureters- as child grows ureters lengthen and valve function tends to improve
- secondary vesicoureteric reflux: urinary tract malfunction often due to abnormally high pressure in bladder from blockage or nerve damage
How should suspected vesicoureteric reflux be investigated?
- urinalysis
- kidney and bladder US
- voiding cystourethrogram (VCUG)
- consider DSMA for renal scarring
How is vesicoureteric reflux graded?
- on extent of urine back up and dilation of ureter/ pelvis/ calyces
- 1= urine backs up to ureter only
- 5= severe hydronephrosis and twisting of ureter
Describe the clinical features of vesicoureteric reflux?
- strong persistent urge to urinate
- burning sensation when urinating
- passing frequent but small amounts of urine
- frequent/ severe UTIs
- flank or abdo pain
- hesitancy
- hydronephrosis
- enuresis, constipation, renal scarring, HTN, kidney failure and proteinuria if untreated
How is vesicoureteric reflux managed?
- manage UTIs promptly
- prophylactic abx
- monitor kidney function, height, weight, BP, proteinuria
- many dont need sugrical correction- unless severe, specific cause eg posterior urethral valves or renal parenchymal damage
how should nephrotic syndrome be investigated?
- bloods: fbc,u&e, complement, esr, crp, albumin
- urine: mcs, pcr, dip, sodium
- throat swab and anti streptolysin O titres
- hep b and c
- autoantibodies
- biopsy if atypical (steroid resistant, age <1 or >12, haematuria, high BP, abnormal complement levels, abnormal renal function)
When should DMSA and MCUG scans be done?
MCUG= whenever abnormal USS, severe or recurrent UTIs if <6 months DMSA= 6 months after acute infection(also need to give prophylactic abx 3 days before) and when recurrent UTIs OR severe or atypical and age <5 ATYPICAL= septic, non ecoli, febrile 48 hrs after appropriate treatment, high creatinine, abdo mass or poor urine flow RECURRENT= two or more UTIs w/ systemic illness// upper UTIs or 3 or more without
How can dipstik results be interpreted? When can they be used to diagnose UTI and you dont need MC&S?
Can be used age >3. If <3yrs, need MCS
- Nitrite and LE +ve= UTI, treat,
- Nitrite -ve, LE +ve= possibly UTI, clinical judgement/ MCS
- Nitritie +ve, LE -ve= probably UTI, treat/ MCS
- both -ve= not UTI,
When should urine be sent for M,C and S? (6 indications)
- Systemically unwell child or - age <3 or - single +ve result for nitrites or leukocyte esterase or - Recurrent UTIs or - No response to tx in 24-48hrs or -clinical symptoms and dipstik dont correllate
