In order to provide better cardiovascular support, it may be necessary to develop treatments that target receptors with a more mature profile than adrenoceptors in the preterm newborn.

Preterm infants often have impaired cardiovascular function that may contribute to poor neurodevelopmental outcomes. The study aimed to determine the effects of reduced blood volume on cardiovascular function, including cerebral blood flow, in preterm and term piglets. In preterm (97/115 days) and term piglets, up to 10% of the estimated blood volume was removed. Removal of blood was stopped if MAP dropped below 20 mmHg. Heart rate, cardiac contractility and relaxation, cardiac output, mean arterial pressure (MAP), and cerebral blood flow were measured at baseline and again after blood volume reduction. The volume of blood removed was less in preterm piglets than in term piglets (5.1 ± 1.8 vs. 7.7 ± 0.9 mL kg , mean ± SD, P < 0.001). Cardiac output and MAP decreased to the same extent in term and preterm piglets. Cerebral blood flow decreased in preterm but not term piglets and cerebral vascular conductance increased in term piglets only. Compensatory responses to maintain cerebral blood flow after blood volume reduction are active in term piglets but not in preterm piglets. As a result, even a small reduction in blood volume, or an increase in the capacity of the circulatory system leading to functional hypovolaemia, may lead to a significant reduction in cerebral blood flow and contribute to brain injury in preterm neonates.

Factor XII (FXII) deficiency presents as a prolonged activated partial thromboplastin time (aPTT) but is not associated with clinically significant bleeding. Activated clotting time (ACT) is used routinely to monitor anticoagulation with unfractionated heparin in patients undergoing cardiopulmonary bypass (CPB). The coagulation activator reagents in most ACT tests are dependent on adequate FXII concentrations to initiate contact factor coagulation pathways. We report the case of a 14.7 kg girl undergoing CPB with a pre-admission FXII concentration of <1% and aPTT >200 seconds. The child was transfused with fresh-frozen plasma to replenish FXII, allowing safe ACT monitoring of heparin anticoagulation throughout CPB.

The Maquet Heater Unit 35 (HU35) is widely used to maintain patient body temperature during extracorporeal life support. Water is used as a medium for heat transfer though it also provides a medium for the growth of pathogens. Thus, the use of a heating unit presents a risk for transmission of water-borne pathogens in critically ill patients. Recently, a Mycobacterium chimaera outbreak in cardiac surgery has been linked to the production of bioaerosols by heater-cooler devices. Consequently, manufacturers have revised cleaning recommendations, with significant impact on staff, budget and environment. Heterotrophic plate counts (HPC) and non-tuberculous mycobacterium growth were assessed following three disinfection processes over a 16-month period. It was found that water quality was acceptable in HU35s when disinfecting with a lower concentration of Chloramine-T than currently recommended, provided exposure of the device to potential pathogens was minimised by the use of a 0.2 μm water filter.