Response to dopamine in prematurity: a biomarker for brain injury?

Abstract

Objective Identify factors associated with responsiveness to dopamine therapy for hypotension and the relationship to brain injury in a cohort of preterm infants. Study Design The pharmacy database at St. Louis Children’s Hospital was retrospectively queried to identify infants who (a) were born < 28 weeks gestation between 2012–14, (b) received dopamine, and (c) had blood pressure measurements from an umbilical arterial catheter. A control group was constructed from contemporaneous infants who did not receive dopamine. Mean arterial blood pressure (MABP) at baseline, 1h and 3h after initiating dopamine were obtained for each dopamine-exposed infant. MABP measurements at matched time points were obtained in the control group. Results Sixty-nine dopamine-treated and forty-five control infants were included. Mean ΔMABP at 3h was 4.5±6.3 mm of Hg for treated infants versus 1±2.9 for the control. Median dopamine starting dose was 2.5 µg/kg/min. Dopamine-treated infants were less mature and lower birth weight while also more likely to be intubated at 72h, diagnosed with intraventricular hemorrhage (IVH), and to die. Failure to respond to dopamine was associated with greater likelihood of developing IVH (OR 5.8, 95% CI 1.1–42.3), while a strong response (ΔMABP >10 mmHg) was associated with a reduction in risk of IVH (OR 0.1, 95% CI 0.01–0.8). Conclusions Low-moderate dose dopamine administration results in modest blood pressure improvements. A lack of response to dopamine is associated with a greater risk of IVH while a strong response is associated with a decreased risk. Further research into underlying mechanisms and management strategies is needed.

Low Variability of Blood Pressure Predicts Abnormal Electroencephalogram in Infants with Hypoxic Ischemic Encephalopathy

“…In a prior study, we noted that preterm infants with depressed blood pressure variability were poorly responsive to antihypotensive treatment. 40 A novel study by Semenova et al described the coupling of EEG activity and the mean arterial blood pressure. 41 In this study, the authors describe a higher level of coupling between brain activity and blood pressure variability in association with increased severity of illness.…”

Low-frequency blood pressure oscillations and inotrope treatment failure in premature infants

“…Although there is evidence that a mean arterial blood pressure persistently Ͻ30 mmHg may be associated with an increased risk of intraventricular hemorrhage (IVH), a devastating complication of prematurity associated with adverse neurodevelopmental outcomes (12), the threshold at which interventions (e.g., fluid resuscitation, initiation of inotropic agents) should be made remains unclear (16). Recent work by us (27) suggests that there is a differential response in blood pressure to inotropes among hypotensive preterm infants that can be divided into three categories, nonresponse, nominal response, and superresponse, but the underlying mechanism of this differential response is not known.…”