The association between carbon dioxide, cerebral blood flow, and autoregulation in the premature infant.

OBJECTIVE: Evaluate the association between carbon dioxide (pCO2), cerebral blood flow (CBF), and cerebral autoregulation (CA) in preterm infants. STUDY DESIGN: Cerebral saturations (rScO2, surrogate for CBF using NIRS) and mean arterial blood pressure (MAP) monitored for 96 h in infants <29 weeks gestation. Relationship between rScO2, the rScO2-MAP correlation (CA analysis) and pCO2 category assessed by mixed effects modeling. RESULTS: Median pCO2 differed by postnatal day (p < 0.0001)-pCO2 increased between day 1 and 2, and low variability seen on day 4. A 5% increase in rScO2 was noted when pCO2 was >55 mmHg on each postnatal day (p < 0.001). No association observed between the overall rScO2-MAP correlation and pCO2. On day 1 only, the correlation coefficient decreased from 0.26 to -0.09 as pCO2 category increased (p = 0.02). CONCLUSIONS: CBF increased above a pCO2 threshold of 55 mmHg, but overall, no association between pCO2 and CA was noted.

Diagnostic limitations and considerations in the imaging evaluation of advanced multicentric infantile myofibromatosis.

Infantile myofibromatosis, the most common fibrous tumor of infancy, is classified in 2 forms; as a solitary nodule or as numerous, widely-distributed multicentric lesions with or without visceral involvement. Although benign, multicentric myofibromas are still associated with a high incidence of morbidity and mortality due to the infiltration of critical structures. Herein, we present a case of an infant with aggressive PDGFRB and NOTCH3 mutation-negative myofibromas distributed throughout the vascular, respiratory, and gastrointestinal systems. The extensive disease resulted in pulmonary hypertension, respiratory failure and gastrointestinal obstruction refractory to chemotherapy and unamenable to surgical resection. Despite the presence of numerous highly invasive myofibromas, multiple imaging modalities largely underestimated, or even missed, tumors found at autopsy. This case demonstrates the limitations of radiographic imaging to assess disease burden in multicentric infantile myofibromatosis. The postmortem findings of extensive disease far exceeding what was demonstrated by multiple imaging modalities suggests that pediatricians should have a high index of suspicion for undetected tumors if clinical deterioration is otherwise unexplained.

Postnatal blood pressure in the preterm small for gestational age neonate.

OBJECTIVE: Determine how blood pressure differs in premature infants born small for gestational age (SGA). DESIGN: A retrospective study was conducted on inborn infants 24-32 weeks gestation. Mean arterial blood pressure (MAP) was collected and averaged every 12 h for the first 96 h of life. For each time point, the difference MAP in SGA vs. AGA infants was evaluated with t-testing. Linear mixed-effects modeling was performed to model MAP over time accounting for GA, BW, gender, and SGA status. RESULTS: 356 subjects were evaluated. 52 (14.6%) were SGA. SGA infants were smaller, more likely male, exposed to maternal hypertension, born via caesarian section, and have chronic lung disease and retinopathy of prematurity. MAP in the SGA group more closely matched the MAP of AGA babies of similar GA for the first 24 h of life. Subsequently, SGA infants had lower MAPs more closely resembling their weight-matched counterparts. Mixed modeling showed GA to be significant, p < 0.0001 while BW though still marginally significant had less of an effect, p = 0.049. CONCLUSION: SGA infants have blood pressure that is strongly associated with GA in the first 24 hours of life, but then fails to increase at the same rate as their AGA counterparts.

A novel urinary biomarker profile to identify acute kidney injury (AKI) in critically ill neonates: a pilot study.

BACKGROUND: The goal of this study was to assess the value of a urinary biomarker profile comprised of neutrophil gelatinase-associated lipocalin (NGAL), fibroblast growth factor-2 (FGF-2), and epidermal growth factor (EGF), to detect acute kidney injury (AKI) in critically ill neonates. METHODS: We conducted a prospective cohort pilot study of at-risk neonates treated in a level IIIC neonatal intensive care unit (NICU) with therapeutic hypothermia (HT) (n = 25) or extracorporeal membrane oxygenation (ECMO) (n = 10). Urine was collected at baseline, 48 h of illness, and > 24 h post-recovery of their corresponding treatments. Control samples were collected from 27 healthy newborns. The data were expressed as urinary concentrations and values normalized for urinary creatinine. AKI was defined as the presence of oliguria >24 h and/or elevated serum creatinine (SCr), or the failure to improve the estimated creatinine clearance (eCCL) by >50% post-recovery. Non-parametric statistical tests and ROC analyses were used to interpret the data. RESULTS: Fifteen at-risk newborns had AKI. In the first 48 h of illness, the urinary levels of NGAL and FGF-2 had high sensitivity but poor specificity to identify neonates with AKI. At recovery, low urinary EGF levels identified neonates with AKI with a sensitivity of 74% and specificity of 84%. Overall, in the early stages of a critical illness, the urinary levels of NGAL and FGF-2 were sensitive, but not specific, to identify neonates at risk of AKI. Low EGF levels post-recovery identified critically ill neonates with AKI. CONCLUSIONS: These findings require validation in larger prospective studies.