Surfactant administration acutely affects cerebral and systemic hemodynamics and gas exchange in very-low-birth-weight infants.
OBJECTIVE
To determine whether surfactant administration affects cerebral and systemic hemodynamics and gas exchange in very low birth weight infants and to determine the predominant factor influencing changes in mean cerebral blood flow velocity (mCBFv) after surfactant instillation.


METHODS
Fourteen very low birth weight infants with respiratory distress syndrome had continuous monitoring of mCBFv, Paco(2), mean arterial blood pressure (MABP), and Pao(2) before, during, and after the second dose of surfactant. Peak values and relative changes of the 4 variables for 45 minutes after surfactant were calculated. Logistic regression was used to determine the predominant factor influencing changes in mCBFv after surfactant.


RESULTS
Birth weight was 832 +/- 162 grams and gestational age was 25.7 +/- 1.5 weeks. The time from birth to monitoring was 6.9 +/- 1.0 hours. Mean CBFv increased 75.7% +/- 51.6% after surfactant and peaked at 14.4 +/- 5.9 minutes. Paco(2) was highly associated (OR=107.3, P <.0001) with mCBFv; as Paco(2) increased, mCBFv increased. In contrast, MABP (OR=6.7, P=.047) had less impact on mCBFv. Pao(2) was not associated with mCBFv.


CONCLUSIONS
The increases in mCBFv after surfactant administration were predominantly due to increases in Paco(2) and not changes in MABP.
Kaiser
Jeffrey R
JR
Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA. kaiserjeffrey@uams.edu
Gauss
C Heath
CH
Williams
D Keith
DK
D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight; D016015:Logistic Models; D008297:Male; D011659:Pulmonary Gas Exchange / Q000187:drug effects*; D011663:Pulmonary Surfactants / Q000494:pharmacology*; D012127:Respiratory Distress Syndrome, Newborn / Q000188:drug therapy* / Q000503:physiopathology
D011663:Pulmonary Surfactants