Renal System

Question 1

Most of the fetal waste material is removed by the

Answer 1

Maternal placenta

• fetal kidneys are passive, receive little renal blood flow and have low GFR

Question 2

4 major reasons for LOW GFR

Answer 2

1. Low systemic arterial pressure
2. High renal vascular resistance
3. Low permeability of the glomerular capillaries
4. Small size and number of glomeruli

Question 3

Cardiac output

In utero ___%
In adulthood ___%

Answer 3

In utero 3%

In adulthood 25%

Question 4

At birth, GFR is low, but increases in first few days of life, doubles in the first 2 weeks and reaches ADULT levels by ___

Answer 4

2 years of age

Question 5

During _____ days of life, circulatory changes increase RBF and GFR, improving neonate’s ability to concentrate and dilute URINE

Answer 5

3-4 days

Question 6

Kidneys are 60% mature by ___

Answer 6

1 month of age

Question 7

URINE OUTPUT is low in the forst 24 hours of life but increases to an EXPECTED LEVEL of at least _____ ml/kg/hr

Answer 7

1-2 ml/kg/hr

• <1ml/kg/hr may be indicative of HYPOVOLEMIA or decreased renal function

Question 8

TBW (total body water)

1. Term neonate at birth
2. Preterm
3. Very low birth weight (VLBW)
4. First 6 months of life

Answer 8

1. Term neonate at birth - 80%
2. Preterm - 85%
3. Very low birth weight (VLBW) - 90%
4. First 6 months of life - 60%

Question 9

BLOOD VOLUME: ___ ml/kg

1. Normal full term newborn
2. Preterm, VLBW, critically ill

Answer 9

1. Normal full term newborn - 90 ml/kg

2. Preterm, VLBW, critically ill - 100 ml/kg

Question 10

Electrolyte values in neonatal period are the same as in the child/adult EXCEPT:

Answer 10

POTASSIUM

can be 1-2 mmol/L higher than average for the first 2 days of life

Question 11

Maintenance fluid requirements

1. First 7 days of life
2. The rest of neonatal period

Answer 11

ADD 15 for each day

Day 1 - 60 ml/kg/24h 
Day 2 - 75
Day 3 - 90
Day 4 - 105
Day 5 - 120
Day 6 - 135
Day 7 - 150 

The rest of neonatal period - 150 ml/kg/24h