RT 256

Meconium Aspiration Syndrome

Meconium

Material that collects in the intestine of the fetus Intestinal tract secretions Amniotic fluid Pulmonary fetal fluid Intrauterine debris

Forms the first stools of the newbornThick and sticky, highly viscousGreen to black in color

Aspiration of Meconium

1.Physical presence in the airways

2.Chemical pneumonitis3.Hypoxia induced

pulmonary arterial vasoconstriction and vasospasm

Physical presence in the airways leads to:

• Upper airway obstruction

• Migration past glottis

• Penetration into smaller airways

• Ball-valve effect – alveolar rupture

Chemical Pneumonitis

Acute inflammatory reaction EdemaExcessive bronchial

secretionsAlveolar consolidationPromotes the growth of

bacteriaDecreases pulmonary

surfactant production

Hypoxemia

Hypoxia induced pulmonary arterial vasoconstriction and vasospasm

Shunts blood right to left through the ductous arterious and foramen ovale

Intrapulmonary shuntingPulmonary hypoperfusion

Etiology

10% of birthsHigh risk for MAS include

Post-term Small for gestational age Breech presentation Mother with toxemia, hypertension, or obesity

Cause of meconium passage, consistency, and timing

1. A PHYSIOLOGIC MATURATION EVENT

2. RESPONSE TO ACUTE HYPOXIC EVENTS OCCURRING LATE IN PREGNANCY

3. RESPONSE TO CHRONIC INTRAUTERINE HYPOXIA

Meconium passage

Presentation

Amniotic fluid examined Meconium staining of skin, nails, umbilical

cordManifestations of Respiratory Distress:

Barrel chest Breath sounds – rhonchi, crackles, wheezing Retractions Cyanosis Increased respiratory rate Increased heart rate

Management

PREVENTION!Suctioning during delivery (not current NRP guideline)Current NRP guidelines for meconium:

Vigorous vs Not Vigorous Strong respiratory efforts Good muscle tone Heart rate >100beats/min

Intubate and suction with ETT Do NOT ventilate until all meconium is cleared

Oxygen TherapySupport ventilation as requiredMedications