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
- David G McNamara, Gillian M Nixon, Brian J Anderson Methylxanthines for the treatment of apnea associated with bronchiolitis and anesthesia. Paediatr Anaesth: 2004, 14(7);541-50 [PubMed:15200650]
- L G Welborn, L J Rice, R S Hannallah, L M Broadman, U E Ruttimann, R Fink Postoperative apnea in former preterm infants: prospective comparison of spinal and general anesthesia. Anesthesiology: 1990, 72(5);838-42 [PubMed:2187377]
- E J Krane, C M Haberkern, L E Jacobson Postoperative apnea, bradycardia, and oxygen desaturation in formerly premature infants: prospective comparison of spinal and general anesthesia. Anesth. Analg.: 1995, 80(1);7-13 [PubMed:7802303]