Chapter 19: Meconium Aspiration Syndrome (Newborn)

Question 1

Meconium Aspiration Syndrome (MAS)

Answer 1

occurs when a newborn is delivered through meconium stained amniotic fluid (MSAF)
-mostly in post-term infants
>the passage of meconium in utero is believed to be either a response to intrauterine hypoxia or a maturational occurrence for the newborn
-meconium can be aspirated at birth if it is not removed from the trachea at delivery
-meconium in the lungs causes obstruction in the small airways and hyperinflation with areas of atelectasis (collapse of a portion or the entire lung because blockage of air passage) leading to hypoxia
>some infants with meconium aspirated pneumonia have elevated pulmonary arterial pressures and develop persistent hypertension (PPHN)

Question 2

Signs and Symptoms of MAS

Answer 2

-meconium-stained skin, nails, and umbilical cord
-initial respiratory distress
-barrel-shaped chest from overinflated lungs
-rales and rhonchi are heard on auscultation
>the respiratory symptoms get progressively worse over the first 12 to 24 hours
>MAS is often complicated by pneumothorax (collection of gas in the space surrounding lungs) and pneumomediastinum (condition in which air is present in the space in the chest between the two lungs)

Question 3

MAS is often Complicated by:

Answer 3

> Pneumothorax: collection of gas in the space surrounding the lungs
Pneumomediastinum: condition in which air is present in the space in the chest between the two lungs

Question 4

Pneumothorax

Answer 4

collection of gas in the space surrounding the lungs
-medical emergency
-requires chest tubes
>chest tubes require frequent monitoring to ensure patency and prevent air leaks

Question 5

Diagnosis

Answer 5

confirmed through chest x-ray which shows bilateral diffuse opacities with areas of atelectasis and hyperinflation from trapped air

Question 6

Prevention

Answer 6

-delivering an infant before 42 weeks gestation because increased gestational age is associated with MAS
-nasopharynx suctioning before delivery of their shoulders and were then intubated and suctioned before being stimulated to breathe (intubation is only now done if shows signs of respiratory distress)
>continuous fetal monitoring for intrapartum fetal stress would indicate if the fetus is experiencing stress, which is associated with passing meconium in utero and MAS

Question 7

Nursing Care

Answer 7

-chest physiotherapy (PT) and oxygen administration
>Chest PT can be done by percussion with a small cup, base of a feeding nipple, or specifically made neonatal chest PT device or by vibration by a battery-operated vibrator
>Chest PT done every 3 to 4 hours tp help maintain a clear airway
>postural drainage with percussion or vibration is followed by suctioning the nasopharynx

Question 8

Medical Care

Answer 8

continuous positive airway pressure (CPAP) to provide oxygen
-if new born cannot maintain a Pao2 of 50 mm Hg or higher in 100% oxygen, mechanical ventilation is then used

Question 9

Medications

Answer 9

because many newborns with MAS are post-term and neurologically more mature than ventilated preterm newborns, neuromuscular medications such as pancuronium (Pavulon), or Vecuronium (Norcuron) are used to increase the effectiveness of ventilation efforts
>analgesic and sedation medications are also used (eg. fentanyl (Sublimaze) or lorazepam (Ativan)
>morphine is used to prevent the newborn from “fighting” the ventilator