Inotropes do not increase cardiac output or cerebral blood flow in preterm piglets

Abstract

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.

Reduced blood volume decreases cerebral blood flow in preterm piglets

“…We have previously reported that preterm piglets have lower cardiac outputs and MAPs than term piglets (Eiby et al . ). This study shows that, in preterm piglets, blood volume removal leads to further reductions in cardiac output, MAP and cerebral blood flow.…”

“…The piglets included in this study are a subset of the animals in which we described the response to dopamine and dobutamine under baseline conditions (Eiby et al . ). Piglets were delivered by Caesarean section at either 97 days (preterm; developmentally similar to a human neonate at 27 weeks’ gestation) or 113 days (term) where full term is 115 days (Eiby et al .…”

“…Piglets were resuscitated and maintained under standard neonatal intensive care conditions as previously described (Eiby et al . ).…”

“…Following the baseline period and prior to blood volume reduction, some animals received inotropic support as part of a separate study (Eiby et al . ). A total of 19 preterm and 24 term piglets were studied of which seven preterm and 10 term piglets received dopamine, and six preterm and eight term piglets received dobutamine, with similar sex ratios across these drug groups.…”

“…) may assist the term neonate to successfully adapt by increasing systemic vasculature resistance but the preterm neonate is less responsive to catecholamines (Eiby et al . , ) and has a reduced ability to vasoconstrict (Fletcher et al . ; Wassink et al .…”