Prevalence of Arterial Hypertension in a neonatal intensive care unit

Abstract

The prevalence of neonatal hypertension in neonatal intensive care units (NICU) ranges between 3 and 9%. However, there is no current data on Latin America.

Objective: To estimate the prevalence of neonatal hypertension and to assess its association with causes previously related to this condition.

Patients and Method: cross-sectional study. All patients admitted to the NICU during one year were included, excluding those transferred to the cardiovascular NICU. The following maternal and neonatal variables were registered: maternal arterial hypertension, type of delivery, gestational age, age, sex, birth weight, Apgar score, history of pulmonary maturation with corticosteroids, and umbilical vessel catheterization as well as the reason for admission to the NICU, medications, and complications during hospitalization. Blood pressure was measured with an automated oscillometric device, defining neonatal hypertension according to standards in gestational age. Prevalence was expressed as percentage (confidence interval 95%, CI95%). Descriptive data were reported as median (range) and frequency of presentation (percentage). Finally, we used the Wilcoxon, Chi2 o Fisher exact test to identify factors related to NH as applicable (p < 0.05).

Results: 169 patients were included (60% males). Gestational age was 38 weeks (range 26-42 weeks), 38% were preterm. Birth weight was 3000 g (range 545-4950 g) and 32% presented low birth weight. Eight patients presented hypertension during hospitalization (4.7% prevalence, CI95% 2.4-9). The presence of hypertension was associated with prematurity (p = 0.0003), low birth weight (p = 0.01), prenatal corticosteroid treatment (p = 0.002), umbilical catheterization (p = 0.03), administration of ≥ 2 nephrotoxic drugs (p = 0.02), caffeine treatment (p = 0.0001), acute kidney injury (p = 0.02), and intracranial hypertension (p = 0.04). Only one patient required antihypertensive pharmacologic treatment and in all cases, hypertension was resolved during follow-up.

Conclusion: Prevalence of neonatal hypertension in our NICU was 4.7% and in all cases occurred in preterm newborns with previously recognized factors associated with this condition.