Blood transfusions in preterm infants: changes on perfusion index and intermittent hypoxemia.

BACKGROUND: Red blood cell (RBC) transfusion decreases intermittent hypoxemia (IH) events beyond the first week of life. This benefit may be related to improved perfusion to the respiratory control network. Perfusion index (PI) is a perfusion measure provided by the pulse oximeter. We hypothesized that the benefit in IH after RBC transfusion is associated with an increase in PI. In addition, we assessed the value of PI and clinical measures in predicting the effect of RBC transfusion on IH. STUDY DESIGN AND METHODS: We prospectively enrolled infants less than 30 weeks' gestation age. PI and oxygen saturation (SpO2 ) were monitored with high-resolution pulse oximeters 24 hours before and after RBC transfusion. Data were analyzed at three postnatal periods: Epoch 1, first week of life (1 to 7 days of life); Epoch 2, 2 to 4 weeks of life (8 to 28 days of life); and Epoch 3, 4 to 8 weeks of life. RESULTS: A total of 118 transfusions were analyzed. IH measures significantly decreased after transfusion in Epochs 2 and 3. PI significantly increased after transfusion, but it did not correlate with the decrease in IH measures. Mechanical ventilation, fraction of inspired oxygen (FiO2 ), and IH measures influenced the effects on oxygenation. CONCLUSIONS: RBC transfusion improved IH after the first week of life. The benefit in IH did not correlate with PI increase after transfusion. Pretransfusion respiratory support and IH measures predicted the effect of transfusion on oxygenation.

Relationship between perfusion index and patent ductus arteriosus in preterm infants.

BACKGROUND: Perfusion index (PI) is a noninvasive measure of perfusion. ΔPI (difference between pre- and postductal PI) may identify hemodynamically significant PDA. However, studies are limited to brief and intermittent ΔPI sampling. Our objective is to assess the value of continuous high resolution ΔPI monitoring in the diagnosis of PDA. METHODS: Continuous ΔPI monitoring in preterm infants was prospectively performed using two high-resolution pulse oximeters. Perfusion Index measures (ΔPI mean and variability, pre- and postductal PI) were analyzed over a 4-h period prior to echocardiography. A cardiologist blinded to the results evaluated for PDA on echocardiography. Linear mixed regression models were utilized for analyses. RESULTS: We obtained 31 echocardiography observations. Mean ΔPI (-0.23 vs. 0.16; P < 0.05), mean pre-PI (0.86 vs. 1.26; P < 0.05), and ΔPI variability (0.39 vs. 0.61; P = 0.05) were lower in infants with PDA compared to infants without PDA at the time of echocardiography. CONCLUSION: Mean ΔPI, ΔPI variability, and mean pre-PI measured 4 h prior to echocardiography detect PDA in preterm infants. PI is dynamic and should be assessed continuously. Perfusion index is a promising bedside measurement to identify PDA in preterm infants.

Simplification of the Finnegan Neonatal Abstinence Scoring System: retrospective study of two institutions in the USA.

OBJECTIVE: To develop a simplified Finnegan Neonatal Abstinence Scoring System (sFNAS) that will highly correlate with scores ≥8 and ≥12 in infants being assessed with the FNAS. DESIGN, SETTING AND PARTICIPANTS: This is a retrospective analysis involving 367 patients admitted to two level IV neonatal intensive care units with a total of 40 294 observations. Inclusion criteria included neonates with gestational age ≥37 0/7 weeks, who are being assessed for neonatal abstinence syndrome (NAS) using the FNAS. Infants with a gestational age <37 weeks were excluded. METHODS: A linear regression model based on the original FNAS data from one institution was developed to determine optimal values for each item in the sFNAS. A backward elimination approach was used, removing the items that contributed least to the Pearson's correlation. The sFNAS was then cross-validated with data from a second institution. RESULTS: Pearson's correlation between the proposed sFNAS and the FNAS was 0.914. The optimal treatment cut-off values for the sFNAS were 6 and 10 to predict FNAS scores ≥8 and ≥12, respectively. The sensitivity and specificity of these cut-off values to detect FNAS scores ≥8 and ≥12 were 0.888 and 0.883 for a cut-off of 6, and 0.637 and 0.992 for a cut-off of 10, respectively. The sFNAS cross-validation resulted in a Pearson's correlation of 0.908, sensitivity and specificity of 0.860 and 0.873 for a cut-off of 6, and 0.525 and 0.986 for a cut-off of 10, respectively. CONCLUSION: The sFNAS has a high statistical correlation with the FNAS, and it is cross-validated for the assessment of infants with NAS. It has excellent specificity and negative predictive value for identifying infants with FNAS scores ≥8 and ≥12.