Renal Disease Flashcards
What causes the dilatation of the urinary collecting system during pregnancy?
- Progesterone inducing Ureteral smooth muscle relaxation
- Enlarging uterus or iliac vessels compressing the ureters
Dilatation more pronounced on the right
Up to what measurement, can the pelvicaliceal diameter be normal in pregnancy?
2cm
What happens to renal plasma flow and glomerular filtration rate in pregnancy?
They both increase
Creatinine clearance rises by 50%
Results in a fall in the serum urea and creatinine levels
What happens to protein excretion in pregnancy?
Increases
Hence why the upper limit of normal in pregnancy is 30mg / mmol
What % of women develop some oedema in pregnancy?
80%
What % women have asymptomatic bacteruria in pregnancy?
Of these, how many will develop
A) Symptomatic UTI
B) Acute pyelonephritis
4-7%
A) 40%
B) 30%
What is the course of treatment for asymptomatic bacteruria in pregnancy?
3 days
What non-pharmacological measures may help prevent recurrent UTIs
- Increasing fluid intake
- Emptying the bladder following sexual intercourse
- Double voiding
- Front to back cleaning of perineum
What are risk factors for acute pyelonephritis?
Polycystic kidneys
Congenital abnormalities of the renal tract
Neuropathic bladder
Urinary tract calculi
What is the effect of pregnancy on CKD?
Possible accelerated decline in renal function
Escalating HTN
Worsening proteinuria
Flare / relapse of glomeurlonephritis
What is the effect of CKD on pregnancy?
HTN / PET FGR PTB Polyhydramnios (due to uraemia) Miscarriage Fetal death
What should women with CKD Stage 5 be advised?
Against conceiving
What is the pathogenesis of polyhydramnios in CKD?
High maternal urea
Osmotic load
Fetal polyuria
Polyhydramnios
What % women with reflux nephropathy develop PET?
25%
How is reflux nephropathy inherited?
AD
What are the adverse outcomes in pregnancy with
- diabetes with nephropathy
Compared to
- diabetes without nephropathy
Doubled
What are the risks of nephrotic syndrome in pregnancy?
Hypoalbuminaemia
Therefore,
Pulmonary oedema
Thrombosis
How is polycystic kidney disease inherited?
Autosomal Dominant
What are complications / associations with polycystic kidney disease?
Polycystic liver disease
Subarachnoid haemorrhage from intracranial aneurysm
Ruptured renal cyst
CKD
What vitamin supplementation is required in CKD?
Vitamin D
What is the effect of pregnancy on dialysis?
- Increased requirements for dialysis
up to 20h / week or 5-6 times per week - aim to keep urea <15-10mmol/L - Exacerbate anaemia - increased Epo and iron transfusions in pregnancy
- Heparin requirement increases
- Pregnancy causes fluctuations in fluid balance and BP
- Chronic ambulatory peritoneal dialysis (CAPD) - increased risk of peritonitis and lower volume exchange as pregnancy advances
What is the effect of pregnancy on women with renal transplants?
If Creat < 100, no adverse effect
If Creat > 130, renal graft survival is only 65% at 3 years
What immunosuppressive drugs are safe in pregnancy?
Renal transplant
Prednisolone
Azathioprine
Ciclosporin
Tacrolimus
What immuunosuppressive drugs are not safe in pregnancy?
Mycophenolate
Sirolimus
How would you manage pyelonephritis?
- Hospital admission
- Collect MSU
- IV antibiotics for at least 24 hours; orals for 2 weeks.
- Check renal function regularly; associated with AKI.
- IV fluids if volume depleted from inadequate intake, vomiting etc.
- Renal USS: exclude hydronephrosis, congenital abnormalities, renal calculi.
- Consider abs prophylaxis in pregnancy: 250mg cefalexin od or 50mg nitrofurantoin od
What factors predict adverse outcome in pregnancy due to CKD?
- Presence and degree of HTN
- Presence and degree of renal impairment
- Presence and degree of proteinuria
- underlying cause of CKD
Women without HTN or renal impairment prior to pregnancy tend to have uncomplicated pregnancies’ and experience no worsening in CKD during pregnancy
What are potential causes of CKD?
- Glomerulonephritis
- Diabetic nephropathy
- PKD
- Reflux nephropathy
- Lupus nephropathy
How does maternal urea level affect pregnancy risk?
Urea ≥10mmol/L - causes polyhydramnios
Urea ≥20mmol/L - risk of fetal death
Management of pregnancy with CKD.
- Pre-pregnancy assessment and counselling - check creatinine, urea, proteinuria, BP
- MDT ANC
- LDA from 1st trimester
- Close monitoring BP
- Commence antihypertensives at lower threshold 130/80 and tighter control
- Regular assessment creatinine and proteinuria; also Hb, plt, albumin, bicarbonate
- Vitamin D supplementation
- Uterine artery doppler at 20-24 wks
- Growth scans from 28 wks
Effect of dialysis on pregnancy.
- Significantly reduces fertility and live birth rate
- Miscarriage
- Stillbirth
- FGR
- PET
- Polyhdramnios
- PTB/PPROM
- placental abruption
- increased bleeding risk due to heparinisation to prevent dialysis lines clotting
Pre-pregnancy counselling for women with renal transplant.
- Rapid return of ovulation and fertility
- Use contraception for at least first year to allow graft function to stabilise and dose of anti-rejection drugs reduces to maintenance dose
- Drugs should be reviewed- change to prednisolone, azothioprine, tacrolimus, ciclosporin - safe in pregnancy. Doses same as pre-pregnancy.Ensure stable for ≥3 months prior to conception.
- Outcomes proportional to graft function, degree of hypertension, diabetes
- For many women with good graft function - after 12 weeks >95% liver birth rate
- Risks: PET, FGR, PTB, deterioration in graft function or graft rejection, maternal hypo and hypercalcemia, infection
- Delivery by NVD - CS only for obstetric indications
- Will need prophylactic Abs if any surgical intervention (even episiotomy)