Levothyroxine replacement therapy and refractory hypotension out of transitional period in preterm infants.
BACKGROUND
Recent studies suggest that refractory hypotension from causes other than septicaemia or cardiac failure is common in extremely preterm infants even out of the transitional period. Marked response to low-dose cortisol suggests underlying adrenal insufficiency, although the exact mechanism remains unknown.


METHODS
To investigate potential triggers for and related short-term outcomes of early-onset (<Day 7) and late-onset (≥Day 7) refractory hypotension, clinical data for 70 infants <30 weeks gestation were assessed.


RESULTS
The incidence of early-onset refractory hypotension (n=7) was correlated with younger gestational ages <26 weeks (P < 0.05), whereas the incidence of late-onset refractory hypotension (n=14) was correlated with younger gestational ages and levothyroxine supplementation (P<0.05 and 0.01, respectively). The incidence of both early- and late-onset refractory hypotension was correlated with risks of short-term adverse outcomes such as prolonged mechanical ventilation and hospital stay.


CONCLUSIONS
Levothyroxine supplementation was identified as an independent variable correlated with an increased incidence of refractory hypotension out of the transitional period; as seen in hypothyroidism with Addison's disease, the immature hypothalamic-pituitary-adrenal axis may not respond properly to the increased demand for cortisol, which may precipitate premature infants into refractory hypotension. Following the administration of levothyroxine, preterm infants may have to be carefully monitored for early signs of refractory hypotension.
Department of Paediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka, Japan.
Junichiro
J
Okada
Sachiko
S
Iwata
Akiko
A
Hirose
Hiroshi
H
Kanda
Makoto
M
Yoshino
Yasuki
Y
Maeno
Toyojiro
T
Matsuishi
Osuke
O
Iwata
D017668:Age of Onset; D005260:Female; D005865:Gestational Age; D006801:Humans; D007022:Hypotension / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007235:Infant, Premature, Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology; D007564:Japan / Q000453:epidemiology; D008297:Male; D012189:Retrospective Studies; D013974:Thyroxine / Q000097:blood* / Q000627:therapeutic use*; D016896:Treatment Outcome
D013974:Thyroxine