Frequency and Etiologies of Hypotension in Extremely Low Birth Weight Infants

ABSTRACT

PURPOSE:Hypotension is common in extremely low birth weight infants (ELBWI) and the treatment becomes important as the survival rate of ELBWI is increasing. This study is to investigate frequency and etiologies of hypotension in ELBWI. METHODS:40 patients admitted to the NICU of Seoul National University Children's Hospital from September 2004 to June 2006 were included retrospectively. Definition of hypotension was 1) mean arterial blood pressure below 30 mmHg or below the gestational age, 2) decreased urine output or metabolic acidosis, and 3) use of inotropics. Hydrocortisone was used for inotrope-resistant hypotension. Clinical characteristics of patients with hypotension were compared with those of others without hypotension. RESULTS:Mean gestational age and mean birth weight of 40 patients was 26(+6)+/-2(+1) weeks and 787+/-149 g. 20 patients had hypotension. 17 events were within 1 week of postnatal age, 5 from 1 to 2 weeks, and 9 after 2 weeks. The etiologies of hypotension within 1 week were PDA in 12 cases, and bleeding in 4 cases. PDA, post-operative condition, adrenocortical insufficiency, and sepsis were the probable etiologies of hypotension after 2 weeks. Among 12 patients recieved hydrocortisone, 9 responded to hydrocortisone. Patients with hypotension were significantly low in gestational age and birth weight. Incidence of IVH and ROP were significantly high in patients with hypotension. CONCLUSIONS:Hypotension was frequent in ELBWI and the etiologies of hypotension were various according to postnatal ages. Significant proportion of hypotension was inotrope-resistant in ELBWI. Further studies about etiologies are in need with reference of this study.