Complications associated with the current sequential pharmacological management of early postnatal hypotension in extremely premature infants.

Early postnatal hypotension in premature infants is treated with escalating doses of vasopressor-inotropes (VI), followed by hydrocortisone if VI therapy fails. The adverse effects of this standard clinical practice have not been well reported. In a retrospective case-control study, we compared the complications associated with VI and hydrocortisone (HCVI) treatments in extremely low-birth-weight infants (≤1000 g) with contemporaneous normotensive medication-naïve controls via standard univariate and multivariate analyses. Birth weight, gestational age, and receipt of antenatal steroids did not differ between VI (n = 74) and control (n = 124) groups, while the occurrence of gestational diabetes mellitus and risks for patent ductus arteriosus, intraventricular-periventricular hemorrhage, spontaneous intestinal perforation, ventriculomegaly, and bronchopulmonary dsyplasia were higher in VI. Infants in the HCVI group (n = 69) had lower birth weight, gestational age, and receipt of antenatal steroids and higher risks for intraventricular-periventricular hemorrhage, bronchopulmonary dysplasia, air leaks, and patent ductus arteriosus than controls. Whereas the occurrences of spontaneous intestinal perforation, ventriculomegaly, and maternal diabetes mellitus did not differ, that of maternal hypertension trended to be lower in HCVI recipients (P = 0.06). In conclusion, hypotensive extremely low-birth-weight infants treated with VI or with HCVI are susceptible to intraventricular-periventricular hemorrhage, bronchopulmonary dysplasia, and patent ductus arteriosus. Furthermore, those who receive inotropes are at risk for spontaneous intestinal perforation and ventriculomegaly. Maternal diabetes mellitus increases the occurrence of hypotension, which responds to VI. Maternal hypertension does not contribute to VI responsive and tends to decrease the occurrence of VI-refractory hypotension.

A comparative analysis of ante- and postnatal clinical characteristics of extremely premature neonates suffering from refractory and non-refractory hypotension: Is early clinical differentiation possible?

BACKGROUND: About 25% of hypotensive ELBW infants are refractory to intravascular volume expansion and inotropic drugs (VI) and require hydrocortisone (HC). Such neonates suffer from complications of prolonged hypotension and extended therapy with VI. ELBW infants with refractory hypotension (RH) are clinically and biochemically indistinguishable from those who respond to VI. OBJECTIVE: Early identification and differentiation of ELBW infants susceptible to steroid dependent hypotension from those who respond to inotropic medications. METHODS: In a retrospective study the ante- and postnatal clinical characteristics of ELBW infants who received hydrocortisone (HC) for refractory hypotension (RH) were compared to those who responded to volume-inotropes (VI). RESULTS: Infants in HC group had lower birth weight (BW, 675±121g) and gestational age (GA, 25.1±1.3weeks) and higher mean airway pressure and oxygen requirements, all independent of antenatal steroid (ANS) exposure. The receipt of ANS (p 0.01) and occurrences of maternal diabetes mellitus (GDM, p 0.01) were lower in HC group. ANS (OR 0.5, 95% CI 0.2-0.9, p 0.01) and GDM (OR 0.3, 95% CI 0.09-0.9, p 0.04) reduced the risk for RH. HC group had higher risk for IVH (OR 2.1, 95% CI 1.02-4.2 p=0.04) which declined in the multivariate analysis. A trend towards lower risk of ventriculomegaly (VM) was noted in HC group (OR 0.3, 95% CI 0.1-1.1), which became significant after controlling for BW (OR 0.2 95% CI 0.07-0.9, p 0.04). Similar trend was noted for maternal hypertension. CONCLUSION: Hypotension in ELBW infants who are ≤25wks of GA and unexposed to ANS and GDM is refractory to VI therapy. Such neonates may benefit from an initial therapy with, or earlier institution of hydrocortisone. The trend towards a higher risk for VM with VI therapy needs validation in future studies.

Factors Influencing the Accuracy of Noninvasive Blood Pressure Measurements in NICU Infants.

OBJECTIVE: Compare invasive blood pressure (IBP) and noninvasive blood pressure (NIBP) measurement methods in the neonatal intensive care unit (NICU) across various gestational age and postmenstrual age (PMA), and determine the effect of gestational age and PMA on accuracy of NIBP measurements. STUDY DESIGN: Retrospective chart review of paired mean IBP and NIBP measurements from infants admitted to a single NICU from January 2008 through December 2010. Infants with congenital anomalies or receiving therapeutic hypothermia were excluded. Difference between paired measurements was analyzed using Bland-Altman method. We examined the association between PMA, sex, race, mechanical ventilation, medications, and axillary temperature, and the difference in measurements using a mixed effects linear regression model. RESULTS: Eighty-seven infants had 243 observations. The mean (range) gestational age at birth was 31.9 (23-41) weeks and PMA at time of measurement ranged from 26 to 52 weeks. We found poor agreement between IBP and NIBP measurements, with mean difference (95% limits of agreement) of -8.8 (11, -28.7) mm Hg. The mean blood pressure percent difference ( ± SD) was -28.3 ( ± 35.6%). A greater blood pressure percent difference between the two measurement techniques was associated with lower PMA and lower mean IBP. CONCLUSION: NIBP measurements overestimate IBP measurements particularly in smaller, sicker infants at lower IBP measurements.