Pregnancy Flashcards
Dialysis targets in pregnancy?
- >=36 hours in 5-6 sessions per week (if no residual kidney fxn)
- Intensive HD decreases the risk of polyhydramnios, helps control hypertension, increases birth weight and gestational age, improves maternal nutrition, and increases the chances of live birth
- Target pre-dialysis urea <16
- Target bicarb 18-22
- Target normal calcium (increase dialysate Ca, po Ca and Vit D)
- Target postdialysis normal phosphate (dialysate and/or oral phos)
- Dialysate K>= 3
- Target weight adjustments regularly
- Wt gain of 2-4 lbs in first 3 months, then 1 lb/wk after
- Avoid intradialytic hypotension
- BP <140/90
- Heparin needs may increase (hypercoagulable in pregnancy)
- Other:
- Anemia: Hb 100-110
- Adequate protein intake (1.5-1.8 g/kg/day), dietitian consult
Pre-conception management in CKD/dialysis?
- Ensure stability of underlying kidney disease (eg. lupus)
- Discuss maternal and fetal risks of pregnancy - miscarriage, HELLP, fetal growth restriction, prematurity, fetal death, pre-eclampsia
- Ensure medication safety in pregnancy and adjust as needed
- ASA 75-150 mg daily
- Folic acid 5 mg daily
Indications for dialysis during pregnancy in non-dialysis CKD?
Consider elective initiation of HD if:
- GFR <20
- Urea > 19 mmol/L
- Polyhydramnios
Also traditional indications for HD start
Anti-HTN meds safe for pregnancy?
Methyldopa
Labetolol
Nifedipine
Hydralazine
Which anti-HTN meds in pregnancy may have an anti-proteinuric effect?
Diltiazem
Which anti-hypertensive meds are safe for breastfeeding?
Enalapril or captopril
Labetolol, metoprolol, propranolol
Calcium channel blockers (Nifedipine, Amlodipine, Verapamil, Diltiazem)
How to differentiate non-pregnancy vs. pregnancy-related kidney disease
- With pregnancy-related:
- Timing: >20 wks GA
- Urine microscopy: inactive
- Normal complements
- Placental flow (reversed or absent end-diastolic flow)
- No systemic symptoms
- Features of preeclampsia: Elevated uric acid, Hypocalciuria, Neurologic signs (hyperreflexia, visual symptoms)
- Features of HELLP (hemolysis, elevated liver enzymes, thrombocytopenia)
What did the CHIPS trialshow
In a 2015 trial (Control of Hypertension in Pregnancy Study [CHIPS]) that randomly assigned pregnant women with gestational or chronic hypertension to diastolic blood pressure treatment targets of 85 or 100 mmHg, there were no differences in maternal, fetal, or neonatal outcomes for the two blood pressure targets, although fewer women in the lower diastolic blood pressure target group developed severe hypertension. However, this study did not include dialysis patients.
Quantify physiologic changes in pregnancy of the following:
GFR, Cr, renal blood flow, blood volume, total body water
Cardiac output, BP, SVR
Tubular secretion
Lytes and acid/base
Urinary tract
Kidney size
- GFR increase ~50% by 12 weeks
- Cr decrease to 35-70 umol/L (>70 in pregnancy is abnormal)
- RBF increase ~80%
- Blood volume increase 50%
- Total body water increase to 6-8L
- Cardiac output increase 40-50% (increased stroke volume and HR), but BP drops due to SVR decrease
- Increased glucosuria and proteinuria
- Lytes/AcidBase: Decreased serm Osm by 10mOsm/kg, hyponatremia, hyperventilation and resp alkalosis, compensatory metabolic acidosis
- Urinary tract: Dilated calyces, urinary stasis, incr risk of pyelo
- Kidney size increased by 1-1.5cm
3 changes in osmoregulation during pregnancy
Despite changes, urinary concentrating ability remain intact, however there is a slight reduction in the maximum urine concentration in the second part of pregnancy
1) Increase in hCG (via relaxin) resets osmostat for ADH release to Posmo of 270 mosmo/Kg and pNa decreased by 4-5mEq/L
2) Increase in vasopressinases resulting in increased metabolism of ADH (some women develop DI)
3) Threshold for ADH release also adjusts to increase in plasma volume
