Back to mostly actual neonatology this week
Kumral A, Tuzun F, Yesilirmak DC, Duman N, Ozkan H: Genetic basis of apnoea of prematurity and caffeine treatment response: Role of adenosine receptor polymorphisms. Acta Paediatrica 2012, 101(7):e299-e303. The paper suffers from a complete lack of detail about how apnea was ascertained. As it includes preterm babies some of whom were probably less than 30 weeks gestation who are noted to be “without apnea” this could be a problem. Having performed prolonged recordings of hundreds of preterm babies, I would say that the baby less than 30 weeks who goes 24 hours without an apnea is a very rare baby indeed. Also the division of babies with apnea into caffeine responsive and unresponsive is not explained, no definition is given and no details of how this was ascertained. So with all those important caveats, it seems that there are adenosine receptor polymorphisms which correlate with being in their “with apnea” group, and correlate with being in their “caffeine resistant” group. That being in their caffeine resistant group correlates with having more BPD, and that the adenosine receptor types therefore correlate with BPD. So it may be that the adenosine receptor subtypes are important in variations in breathing control, and that as caffeine works by blocking the receptors, variations in the receptor might affect caffeine responsiveness.
Larsen BMK, Goonewardene LA, Joffe AR, Van Aerde JE, Field CJ, Olstad DL, Clandinin MT: Pre-treatment with an intravenous lipid emulsion containing fish oil (eicosapentaenoic and docosahexaenoic acid) decreases inflammatory markers after open-heart surgery in infants: A randomized, controlled trial. Clinical Nutrition 2012, 31(3):322-329. This small single center RCT had physiologic rather than clinical end-points, the concentration of TNF-α. The report lacks a good description of the eligibility criteria, including for example how old the “infants” were and whether they were already hospitalized and already on TPN when randomized, or whether TPN was started in both groups for the study (even the results only give the gestational age at birth, the postnatal age is not mentioned). Anyway infants who got pre-operative omega3 fatty acids in their lipids had lower pro-inflammatory cytokines after surgery than the controls who received omega6 exclusive fat.
Hillman NH, Moss TJ, Nitsos I, Jobe AH. Moderate tidal volumes and oxygen exposure during initiation of ventilation in preterm fetal sheep. Pediatr Res. 2012. 15 minutes of positive pressure ventilation with 6 to 7 mL/kg tidal volumes compared to CPAP increased pro-inflammatory cytokines in partially exteriorized preterm fetal lambs. 15 minutes of oxygen had no effect. 6 to 7 mL/kg is not a very large tidal volume, but it was administered in this study without PEEP, in a previous study they showed that PEEP was partially protective .