Rational use of dopamine in hypotensive newborns: Improving our understanding of the effect on cerebral autoregulation.

This study found an association between dopamine therapy and impaired cerebral autoregulation. (III) An experimental animal study examining whether dopamine affected cerebral autoregulation in newborn piglets with low blood pressure. We found that dopamine did not negatively affect cerebral venous saturation, cerebral blood flow, or cerebral autoregulation capacity in hypotensive newborn piglets. (IV) An in vitro experiment where middle cerebral arteries from newborn piglets were examined by wire myography and pressure myography. In the wire myograph, increasing concentrations of dopamine caused a biphasic response: starting with vasodilation at low concentrations followed by vasoconstrictions at higher concentrations. In the pressure myograph, dopamine mainly induced vasodilation and the internal arterial diameter only tended to decrease at the highest concentrations. In summary, dopamine has been associated with impaired cerebral autoregulation and our conclusions in study II accorded with this. However, other work has found that initiation of dopamine infusion does not affect cerebral autoregulation. This may indicate that dopamine itself does not lead to impaired cerebral autoregulation. In support of these counter-observations, we did not find any causal relationship between dopamine therapy and impaired cerebral autoregulation in newborn piglets in study III. Also, dopamine in therapeutic concentrations did not induce vasoconstriction in pial arteries in study IV. Based...
Source: Danish Medical Journal - Category: General Medicine Tags: Dan Med J Source Type: research