Ex-premature: Pulmonary Cx

Common problems associated with prematurity include respiratory distress syndrome, apnea, hypoglycemia, hypocalcemia, hypomagnesemia, hyperbilirubinemia.

The major pulmonary complication found in former-premature infants is post-operative apnea– post-operative apnea is a serious concern in the neonate, particularly if there is a history of prematurity, prior apneic episodes, bradycardia, congenital defects, anemia, or chronic lung disease (ex. respiratory distress syndrome). Infants have a lower percentage of type I fibers and are at risk for fatigue. Residual anesthetic agents may also contribute.

Treatment may be as simple as tactile stimulation with blow-by oxygen, although if this is not adequate caffeine may be required. Caffeine is an adenosine-inhibitor, and can increase central respiratory drive, increase sensitivity to CO₂, and improve muscle contractility. A Cochrane Database Review of methylxanthines for the prevention of apnea in prematurity (five studies) suggests that methylxanthines are effective at reducing post-operative apnea from days 2-7 after initiating treatment. Caffeine appears to be slightly less effective than theophylline but with a better side effect profile (note, also, that the utility of methylxanthines for non-premature infants is still a matter of debate ). As a last resort, endotracheal intubation and mechanical ventilation are used.

Consider a spinal or regional technique in these infants – one prospective, randomized study of 36 former premature infants showed a reduction in apnea from 36% to 0%. A smaller study of 18 ex-premature infants showed no change in central apnea in spinal vs. GA, but the GA cohort had lower minimum HR and SpO₂ values. Note that the addition of sedation (ketamine) to spinal anesthesia in the Welborn study significantly worsened the incidence of apnea