Is refractory hypotension in preterm infants a manifestation of early ductal shunting?
BACKGROUND
Clinicians frequently use hydrocortisone (HC) to treat vasopressor-resistant hypotension even before establishing its cause.


OBJECTIVE
To identify the etiologic factors leading to development of refractory hypotension, and to assess if patent ductus arteriosus (PDA) is associated with refractory hypotension during the first week of life.


METHODS
The medical records of 290 consecutively born infants <or=30 weeks' gestational age (GA) were reviewed to identify the escalating need for vasopressors to maintain mean arterial blood pressure (MABP) at or above a level equal to the GA in completed weeks. Refractory hypotension was defined as MABP unresponsive to fluid boluses and high-dose vasopressors (dopamine and dobutamine at doses 20 microg/kg/min each and/or epinephrine) prompting the use of HC.


RESULTS
Eighty-nine (30.7%) of 290 infants had refractory hypotension between postnatal days 2 and 7. Infants with refractory hypotension were more likely to have a lower birth weight and GA (P<0.001), been treated with surfactant (P=0.004) and received indomethacin for a symptomatic PDA (P<0.001). To identify the etiologic factors, a univariate analysis revealed that the use of high-frequency oscillatory ventilation, presence of air leaks, PDA, sepsis, hyperkalemia and intraventricular hemorrhage (IVH) were significantly associated with refractory hypotension. However, multivariate analysis confirmed the independent association of only PDA (odds ratio (OR) 7.6, 95% confidence interval (CI) 3.3-17.7, P=0.000), severe IVH (OR 2.6, 95% CI 1.1-6.4, P=0.03) and GA (OR 0.7, 95% CI 0.6-0.8, P=0.001).


CONCLUSIONS
Evaluation for early ductal shunting and closure of the ductus, if patent, should be attempted before HC is considered in hypotensive infants with escalating needs for vasopressors.
Sarkar
S
S
Department of Pediatrics, Division of Neonatal-Perinatal Medicine, University of Michigan Health System, C.S. Mott Children's Hospital, Ann Arbor, MI 48109-0254, USA. subratas@med.umich.edu
Dechert
R
R
Schumacher
R E
RE
Donn
S M
SM
D000893:Anti-Inflammatory Agents / Q000008:administration & dosage*; D001724:Birth Weight; D004334:Drug Administration Schedule; D004374:Ductus Arteriosus, Patent / Q000150:complications*; D005260:Female; D005865:Gestational Age; D006801:Humans; D006854:Hydrocortisone / Q000008:administration & dosage; D007022:Hypotension / Q000150:complications / Q000188:drug therapy* / Q000453:epidemiology*; D007213:Indomethacin / Q000008:administration & dosage; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008499:Medical Records; D008923:Missouri / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013501:Surface-Active Agents / Q000008:administration & dosage
D000893:Anti-Inflammatory Agents; D013501:Surface-Active Agents; D006854:Hydrocortisone; D007213:Indomethacin