Paediatrics: growth disturbance and prematurity Flashcards
What are the periods of neonatal and infancy?
- Neonatal period: first 28 days of life
- Infancy: first 1 year of life
What is gestational age?
What is normal gestation, preterm?
What are the birth weight categories?
What is SGA, LGA and appropriate-for-date?
- Small-for-date (SGA): BW <10thpercentile
- Large-for-date (LGA): BW >90thpercentile
- Appropriate-for-date: BW 10-90thpercentile
What are the cardiopulmonary adaptations at birth?
First Breath: When a baby is born, the first breath is a critical event. Prior to birth, the baby’s lungs are filled with amniotic fluid, and the respiratory system is not involved in gas exchange. As the baby emerges from the birth canal or is delivered via cesarean section, the sudden exposure to air stimulates the respiratory centers in the brain, triggering the reflex to breathe. The expansion of the lungs and the exchange of gases from the air initiate the process of pulmonary respiration.
Clearance of Lung Fluid: Once the baby takes their first breath, the alveoli in the lungs start to expand and produce surfactant, a substance that reduces surface tension and prevents the collapse of the small air sacs. The lung fluid present in the alveoli is gradually cleared as the baby breathes, and it is absorbed into the bloodstream or expelled through exhalation and coughing.
Closure of Fetal Shunts: During fetal life, certain blood vessels and structures bypass the lungs because fetal oxygenation occurs through the placenta. After birth, these shunts close or change direction to redirect blood flow to the lungs for oxygenation. The three main shunts are:
Ductus Arteriosus: This is a blood vessel that connects the pulmonary artery and the aorta in the fetal heart. It normally closes within a few hours or days after birth, allowing blood to flow to the lungs for oxygenation.
Foramen Ovale: This is an opening between the right and left atria of the fetal heart. It allows blood to bypass the non-functioning fetal lungs. After birth, increased blood oxygen levels and changes in pressure cause the foramen ovale to close, directing blood flow to the left side of the heart and into the systemic circulation.
Ductus Venosus: This blood vessel connects the umbilical vein to the inferior vena cava, bypassing the liver in the fetus. After birth, with the clamping of the umbilical cord, the ductus venosus constricts and closes, redirecting blood flow to the liver for metabolic processing.
Establishment of Pulmonary Circulation: As the baby takes their first breath and the lungs expand, the pulmonary blood vessels also dilate, reducing resistance and allowing blood to flow freely through the lungs for oxygenation. This increases the oxygen saturation in the blood and facilitates the delivery of oxygen to the body’s tissues.
Increase in Pulmonary Blood Flow: The increase in oxygenation and decrease in resistance within the pulmonary circulation result in an increased blood flow to the lungs. This increased blood flow helps optimize the exchange of oxygen and carbon dioxide, supporting the baby’s oxygenation and removal of waste products.
Umbilical cord clamping
Benefits & Risks
Delayed clamping of cord for 30-60 seconds or until pulsation stops is beneficial
- Less iron deficiency anemia
- Less intraventricular hemorrhage of preterm infants
How to calculate Apgar score?
When is Apgar score scored? What are normal and abnormal parameters?
Scored at 1st and 5th minutes of life
* ≥7 normal
* ≤3 abnormal
* Poor AS associated with neonatal mortality
* Poor late AS associated with poor neurological outcome
Score until it reaches 7
If too low, may need to stop resuscitation
What is the normal temperature of newborns? Why are newborn babies prone to excessive heat loss?
Temperature regulation in newborns
Thermal neutral zone: Temperature range that causes lowest metabolic demand to the baby (too high or too low temperature may increase metabolic demand to the baby)
How do we keep the newborn warm after birth?
No need to dry pre-term baby, immediately wrap in plastic wrap
In normal birth, let mother carry immediately (around 1 HR), monitor and check tempreature while baby is still with the mother
Consequences of excessive heat loss
- Hypoxia
- Hypoglycemia
- Metabolic acidosis
- Decreased growth
- Apnoea
- Pulmonary hypertension
Consequences of hypothermia
- Clotting disorders
- Shock
- Intraventricular hemorrhage
- Severe sinus bradycardia
- Increased neonatal mortality
Fluid requirement and body weight of baby
Water makes up 75% of body weight in term infant; 85-90% in preterm infants
Physiologic contraction of ECW after birth –diuresis
* 5-7% body weight loss for term infants
* 10% body weight loss for preterm infants
Daily fluid intake
* Follow “normal” breast milk production
– 30-60ml/kg/day
– Increase to 150-160ml/kg/day at the end of the first week
Cord care
Immediately after delivery, cord clamping will be done
What are complications of the umblicial cord?
- True knot: may cause foetal distress
- Allantoid cyst: patent urachus (connection to bladder, thus urine comes out = clear fluid in umbilicus)
- Umbilical granuloma: remnant of umbilical tissue (yellowish secretion) [must differentiate from patent urachus/patent vitelline duct (may have faeces)] = cauterise with silver nitrate
- Omphalitis (umbilical veins and umbilical arteries may be affected, cause blood stream infection = treat with IV ABx)
What is this conidition?
Neonatal Conjunctivitis
* Swab the sticky eye discharge
* Gram + and Gram –organisms
* Neisseria gonorrhoea
* Chlamydia trachomatis
How should newborn sleep?
Prone position for ICU baby to open up lungs (they have monitors, thus okay in ICU, but don’t do this at home)
Don’t put pillow as baby will flex their neck, closing the airway
Use of pacifier
- Pros
- Cons
