ADME of neonates
a: slower gastric emptying
d: higher proprotion of body water, so water souble drugs become less concentrated in the blood stream so higher dose may be required.
m: metabolsim slower due to immature liver enzymes
e: reduced kidney function, slower drug elimintaion
- dose adjustments required
3 main neonatal conditions
Neonatal sepsis
Respiratory distress syndrome- due to surfactant deficiency, causing increased surface tension in the alveoli causing altelectasis (lung collapse). Harder to breath and build up of CO2
Juandice: caused by immature liver function
treated with phototheraepy or exchange transfusion.
PMA
gestational age + chronological age
used for NICU decisions
like apnea and feeding readiness
PMA is total age from conception
CGA
chronological age - (40-GA at birth)
used for growth and development tracking
APGAR test
Appearance
Pulse
Grimace (reflex)
Activity (musle tone)
Respiration
the higher the score the better
its done at 1 mins and at 5 mins and if necessary at 10 mins after birth
normal score: 7-10
Admission cocktail for preterm/sick neonates
1) Surfactant- via ET tube
2) Caffeine citrate- respiratory stimulant
3) Vitamin K- intraventricular hemorrhage
4) Morphine- if on ventilator long term
5) 10% dextrose fluid- TPN within the first few hours
6) Antibiotics- for early onset sepsis
Kidneys of neonates
- underdeveloped
- little urine output first few days
- RISK of hypernatremia
- pda stays open- so more oxygen flows from the aorta and into the lungs rather than the rest of the body. Not good
PDA
patent ductus arteriosus
cause of open pda:
decrease in oxygen concentrations and incraese in prastaglndalin e2 levels causing vasodilation of pda.
What happens if too much fluids is given in PDA to neonate
- delays closure of DA
- increases pulmonary blood flow through PDA
- can lead to Pulmonary oedmea, RDS, HF
What happenes if too less fluids is given in PDA to neonate
- risk of dehydration, renal impairment, poor perfusion
- could compromise growth and organ function
PDA staying open manangement
Restrict fluids for the first few days to 60-80ml/kg/day intially
monitor: weight, urine output, serum electrolytes daily
Echocardiography: to assess pda size
Drug treatment reccomendation if PDA closure is significant: Indomethacin, ibuprofen.
Gastro of neonates
- Gastric pH: 6-8 at birth
pH then falls to 1-3 within a few hours - drug absorption:
Acid labile drugs have higher bioavailbility in new borns
weakly acid drugs exist in ionised form, reducing absoprtion. - Prolonged gastric emptying - may increase drug absoprtion
Drug treatment of gastro of neonates
alginates: sodium alginate (gaviscon)
H2 antagonists: cimetidine famotidine
PPi: omeprazole
D2 antagonist: Domperidone
Caffeine citrate for respiratory
caffeine citrate is a methylxanthine used to stimulate the respiratory system
however the main side effect is tachycardia
what is used UAC used for
Umbilical arterial catheter
- used for bp monitoring
- very slow infusion with either
1) heparin sodium 100 units/50 ml of 0.9 %
2) Infusate mixture:
contains heparin + sodium bicarbonate
- made up to 20 ml solution
run even slower: at 0.3ml/hr
what is UVC used for
Umbilical venous catheter
- to deliver IV fluids glucose parenteral nutirion and drugs
can be used for up to 10 days max
First-Line Antibiotic for Early-Onset Neonatal Sepsis
Benzylpenicillin + Gentamicin
* Covers common pathogens like Group B Streptococcus and E. coli
* Dosing must be adjusted for gestational and postnatal age
