In a 3‑day‑old preterm male infant born at 32 weeks gestation in the neonatal intensive care unit who has 10–15 apnea episodes per hour lasting about 15 seconds, beginning with absent chest wall movement then progressing to irregular respiratory effort with intermittent obstruction, perioral cyanosis and mild bradycardia, what type of apnea is most likely?

Mixed Apnea

This preterm infant is experiencing mixed apnea, characterized by the initial absence of chest wall movement (central component) followed by irregular respiratory effort with intermittent obstruction (obstructive component), making option C the correct diagnosis. 1

Clinical Pattern Recognition

The clinical presentation provides clear diagnostic clues:

• Initial absent chest wall movement indicates a central apneic pause where the brainstem fails to initiate respiratory effort 1
• Subsequent irregular respiratory effort with intermittent obstruction demonstrates the obstructive component that follows the central pause 1
• Duration of 15 seconds with perioral cyanosis and bradycardia confirms these are clinically significant apneic events 2, 1
• Frequency of 10-15 episodes per hour is consistent with severe apnea of prematurity in an infant at 32 weeks gestation 2

Understanding Apnea Types in Preterm Infants

Mixed apnea represents the most common pattern in preterm infants with apnea of prematurity:

• Central apnea would show complete absence of respiratory effort throughout the entire episode with no chest wall movement at any point 1
• Obstructive apnea would demonstrate continuous chest wall movement against a closed airway throughout the episode 1
• Mixed apnea begins with central apnea (no chest wall movement) and transitions to obstructive efforts (chest wall movement with airway obstruction), which is exactly what this infant demonstrates 1

Epidemiology and Risk Factors

This 32-week gestational age infant falls squarely within the high-risk population:

• Apnea of prematurity affects >50% of premature infants and is almost universal in infants <1000g at birth 2
• At 32 weeks gestation, this infant has immature respiratory control mechanisms that predispose to mixed apneic events 3, 1
• The 3-day postnatal age is typical for presentation of apnea of prematurity 1

Why Not the Other Options

Central apnea alone (Option A) is excluded because the infant demonstrates chest wall movement with obstructive efforts after the initial central pause 1

Obstructive apnea alone (Option B) is excluded because the initial phase shows no chest wall movement, indicating a central component 1

Benign periodic breathing (Option D) is excluded because:

• The episodes last 15 seconds (periodic breathing involves shorter pauses <10 seconds) 2
• Associated bradycardia and cyanosis indicate pathologic apnea, not benign periodic breathing 2, 1
• The frequency of 10-15 episodes per hour with oxygen desaturation represents clinically significant apnea requiring intervention 2, 1

Clinical Significance and Management Implications

Recognizing this as mixed apnea is critical because:

• Clinically significant apnea is defined as breathing pauses >20 seconds OR >10 seconds when associated with bradycardia or oxygen desaturation 2, 1
• This infant meets criteria with 15-second pauses accompanied by both bradycardia and desaturation 2, 1
• Treatment with caffeine citrate and potentially CPAP should be initiated, as these remain the mainstay therapies for apnea of prematurity 3, 1
• Therapeutic caffeine levels should be maintained at 5-20 mg/L to ensure efficacy while avoiding toxicity 4, 5