Effects of a continuous epinephrine infusion on regional blood flow in awake newborn piglets.
Biol Neonate
; 73(3): 198-206, 1998.
Article
em En
| MEDLINE
| ID: mdl-9535538
ABSTRACT
OBJECTIVE:
To determine the effects of a continuous epinephrine infusion on renal and mesenteric blood flow in both healthy newborn piglets and animals subjected to hemorrhagic shock.METHODS:
Superior mesenteric artery (SMA) and left renal artery ultrasonic flow probes were implanted into 16 1- to 3-day-old piglets. Two days later, the effects of epinephrine on SMA and renal blood flow, mean arterial pressure (MAP) and central venous pressure were measured in conscious, non-sedated normovolemic piglets. Epinephrine doses of 0.2, 0.4, 0.8, 1.6 and 3.2 microg/kg.min were used in random order. Piglets were subsequently hemorrhaged (20 ml/kg) to mild hypotension and again received epinephrine infusion in the same doses.RESULTS:
Doses of epinephrine less than 3.2 microg/kg.min had no significant effects on renal or mesenteric arterial flow. At 3.2 microg/kg.min of epinephrine during normovolemia, there was a significant decrease in SMA blood flow (34% [SD 42], p < 0.05) and increase in SMA vascular resistance (147% [SD 114], p < 0.05). Similar results were shown during hypovolemia, SMA flow decreased by 32% (SD 33), and SMA vascular resistance increased by 220.3% (SD 177). At 3.2 microg/kg.min renal artery flow decreased by 43% (SD 21) during normovolemia and a similar decrease occurred during hypovolemia, 37% (SD 31). Renal vascular resistance increased by about 200% at this dose (normovolemia 211% [SD 185], hypovolemia 186% [SD 150], p < 0.01). Low-to-moderate dose epinephrine caused no significant change in SMA or renal blood flow. During hypovolemia low dose epinephrine infusion was associated with a trend to increased SMA blood flow.CONCLUSION:
Low-dose epinephrine does not cause vasoconstriction in the renal or mesenteric circulations during normovolemia or hypovolemia. High doses of epinephrine above 1.6 microg/kg.min may cause renal or mesenteric ischemia, in either the normovolemic or hypovolemic neonate.
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Base de dados:
MEDLINE
Assunto principal:
Artéria Renal
/
Epinefrina
/
Animais Recém-Nascidos
/
Artérias Mesentéricas
Limite:
Animals
Idioma:
En
Ano de publicação:
1998
Tipo de documento:
Article