THERAPY FOR HYPOTENSION IN EXTREMELY LOW BIRTH WEIGHT INFANTS. CHOICE OF OPTIMAL TACTICS

Objective. To compare two therapeutic procedures (volemic saline loading and the use of dopamine without volemic preload) for hypotension in extremely low birth weight (ELBW) infants. Subject and methods. The investigation included newborn infants with birth weights of less than 1000 g who were recorded to have hypotension. Neonates with congenital malformations and those with obvious signs of hypovolemia and shock were excluded from the investigation. When included into the investigation, all the neonates received adequate respiratory therapy. After randomized, 18 and 21 infants were included into the saline and dopamine groups, respectively. The following indicators, such as the efficacy of an agent in normalizing blood pressure (BP) (achieving the mean BP being equal or greater than that for gestational age per week, diuresis before and after the intervention, 24-hour diuresis, needs of dopamine and its effective dose, weekly cumulative dose, total duration of inotropic support, were thereafter estimated:. Before the intervention and 30 minutes after initiation of therapy, all the newborn infants underwent echocardiography (cardiac output, ejection fraction, fractional shortening, the presence and diameter of patent ductus arteriosus (PDA), heart rate, and blood flow in the anterior cerebral, renal, and superior mesenteric arteries). Acid-base balance and blood lactate concentrations were estimated prior to and following the intervention. The frequency of PDA, bronchopulmonary dysplasia (BPD), necrotizing enterocolitis, periventricular leukomalacia, pre-discharge death, the duration of mechanical ventilation (MV), and the length of intensive care unit (ICU) follow-up were assessed as outcome measures. Results. Antihypotensive therapy with dopamine and no rapid saline administration showed a high efficiency in normalizing mean BP in the ELBW infants. Dopamine was more effective than a saline bolus in increasing left ventricular ejection fraction while saline was more effective in raising cardiac output, however, without elevating BP. Dopamine and saline were equally effective in normalizing blood flow in the anterior cerebral, mesenteric, and renal arteries. The incidence of severe BPD was significantly higher in the group receiving saline as antihypotensive therapy. The diameter of PDA was also larger in this neonatal group. The patients having a volemic load were significantly longer on MV and needed ICU treatment. Conclusion. Based on the findings, refusal of volemic loading may be recommended as initial antihypotensive treatment in favor of dopamine infusion in ELBW neonates without clinical signs of shock.

newborn infant, extremely low birth weight, hypotension, saline, volume load, dopamine