Adrenaline is extensively used for resuscitation of neonates with RDS. However, effects of adrenaline on systemic, pulmonary and cerebral hemodynamics have not been defined in newborns with RDS. Thirteen anesthetized and ventilated newborn piglets were subjected to repeated series of saline lung-lavage while mean arterial blood pressure (ABP), mean pulmonary arterial pressure (PAP), mean left atrial pressure (LAP), mean central venous pressure(CVP), cardiac output and blood flow in the internal carotid artery (ICA) were measured. Systemic vascular resistance (SVR), pulmonary vascular resistance(PVR) and cardiac index (CI) were calculated. Sixty minutes after lung-lavage, the adrenaline group (A) (n=6) received adrenaline as a continuous infusion of 1.2 μg/kg/min, while the control group (C) (n=7) received saline. None of the variables were changed by saline. However, significant increases in ABP(P<0.0001), PAP (P<0.0001), CI (P<0.001) and SVR (P<0.01) were observed after administration of adrenaline, while PVR and ICA were not modified. Mean±SD for ABP/PAP, PVR/SVR and CI (ml/min/kg) were:Table Ratios of PAP/ABP and PVR/SVR significantly increased following infusion of adrenaline. These data suggest that effect of adrenaline on the systemic circulation is more pronounced than its effect on the pulmonary circulation in newborn piglets with surfactant deficiency.

Table 1
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