Study of Dopamine Versus Vasopressin for Treatment of Low Blood Pressure in Low Birth Weight Infants

Dopamine Versus Vasopressin for Cardiovascular Support in Extremely Low Birth Weight Infants: A Randomized, Blinded Pilot Study

Low blood pressure or hypotension is a very important problem that is often seen in premature babies, especially those with low birth weight. Severe hypotension leads to significant problems including brain bleeds, developmental delays, kidney and liver problems, and other issues that can affect babies for the rest of their lives. An important aspect in the management of infants with hypotension is the decision of when to treat and with what agent. Research is being conducted to try to find the best medication to use in these situations. Dopamine is often used first, but it does not always prove to be effective, and it has several concerning side effects. This study will look at vasopressin, which has fewer side effects, as a first-line medication for low blood pressure in extremely low birth weight infants.

Hypotheses and Specific Aims: This study will show superiority of vasopressin to dopamine in preterm, extremely low birth weight infants who have hypotension within the first 24 hours of life. We will specifically look at its ability to raise blood pressure values, improve clinical symptoms seen, any adverse effects, and clinical outcomes of babies being treated.

Hypotension in the low birth weight (LBW) and extremely low birth weight (ELBW) infant is often encountered in the postnatal adaptation phase. Severe, prolonged hypotension contributes to cellular dysfunction and cell death. Systemic hypotension affects close to half of all ELBW infants and a significant portion of LBW infants. The true definition of hypotension remains to be a question. There is a linear association between birth weight, gestational age, and mean blood pressure but blood pressure can vary significantly in the first day of life. The critical period tends to be the first 24-36 hours of life as blood pressure tends to rise significantly in the first 72 hours of life regardless of gestational age. Preterm infants suffering from hypotension have a higher incidence and increased severity of intraventricular hemorrhage (IVH), periventricular leukomalacia (PVL), and long-term neurodevelopmental sequelae compared to normotensive preterm infants. Effects on other organ systems can result in renal injury, hepatic injury, and the development of necrotizing enterocolitis among other complications. An important aspect in the management of infants with hypotension is the decision of when to treat and with what agent. Dopamine is commonly used as first-line therapy, but issues with efficacy and its side effect profile have lessened its favorability over the years. Few studies compare dopamine to other agents as a first -line treatment. This study hopes to contribute to the literature information on vasopressin as a potential first-line agent for treatment of neonatal hypotension in low birth weight infants.

Inclusion Criteria:

• Infants less than 24 hours of age
• Infants with birth weight of <1001 grams and/or gestational age of <29 weeks
• Not initiated on any continuous pressor therapy prior to enrollment
• Intravenous line in place
• Outborn infants meeting eligibility criteria

Exclusion Criteria:

• Infants not meeting eligibility criteria
• Infants with life-threatening congenital defects
• Infants with congenital hydrops
• Infants with frank hypovolemia (perinatal history consistent with decreased circulating blood volume plus clinical signs of hypovolemia)
• Infants with other unresolved causes of hypotension (air leaks, lung overdistention, or metabolic abnormalities).