Noninvasive technique for the diagnosis of patent ductus arteriosus in premature infants by analyzing pulse wave phases on photoplethysmography signals measured in the right hand and the left foot.

OBJECTIVE: To evaluate the impact of patent ductus arteriosus (PDA) on the pulse phase difference (PPD) between the left foot (postductal region) and the right hand (preductal region). MATERIALS AND METHODS: PPD was determined from arterial photoplethysmography signals (pulse waves) measured by infrared sensors routinely used for pulse oximetry in 56 premature infants less than 32 weeks gestation. Only infants with significant PDA (sPDA) diagnosed by echocardiography were treated with ibuprofen (for 3 days). Patients were classified according to whether or not they responded (Success/Failure) to this treatment. The Control group was composed of infants in whom ductus had already closed spontaneously at the time of the first echocardiography. The 3 groups were compared in terms of PPD at the beginning (T1) and at the end (T2) of the study. For patients in the Failure (n = 17) and Success groups (n = 18), T1 corresponded to the first day of treatment and T2 to the day after completion of the course of ibuprofen. In the Control group (n = 21), T1 corresponded to 1 to 3 days of life (DOL), and T2 to 4-6 DOL. RESULTS: Compared to the Control group, PPD was higher in the Failure (at T1 and T2) and Success (at T1) groups characterized by sPDA. After ibuprofen therapy, PPD in the Success group decreased to about the level observed in the Control group. The area under the ROC curve of PPD for the diagnosis of sPDA was 0.98 (95% CI 0.96-1); for an optimal cut-off of PPD ≥ 1.65 deg/cm, the sensitivity was 94.2% and the specificity was 98.3%. CONCLUSION: In this study, PPD was correlated with ductus arteriosus status evaluated by echocardiography, indicating involvement of the ductal shunt in the mechanism of redistribution in systemic vascular territories. PPD can be considered for the diagnosis of hemodynamically significant PDA.

Patent ductus arteriosus in preterm infants is associated with cardiac autonomic alteration and predominant parasympathetic stimulation.

BACKGROUND: Hemodynamic disorders in patent ductus arteriosus (PDA) may alter the stimulation of the autonomic nervous system. AIM: The objective of this study was to analyze the orthosympathetic-parasympathetic balance in preterm infants with PDA. STUDY DESIGN AND SUBJECTS: Patients were included from consecutive admissions to Amiens University Hospital from 2009 to 2011. We defined a PDA group and a Control group (echographic criteria). For each patient, three 4-minutes segments of ECG were recorded during quiet sleep and the RR chronologic series were extracted, and spectral (Fourier Transform) and time-domain analyses were performed. For each parameter of heart rate variability (HRV), average of three measures was determined and analysed. RESULTS: Forty-four patients were included for analysis. The total HRV power, LF/HF ratio and SDNN were lower in the PDA group (n = 22, gestational age 28.2 w ± 1.9) than in the Control group (n = 22, gestational age 28.8 w ± 2). The decrease in LF power destabilized the autonomic balance in favour of parasympathetic stimulation. After adjustment for postconceptional age, PDA was still associated with parameters of autonomic neural stimulation. CONCLUSION: These results suggest association of PDA with predominance of parasympathetic stimulation in preterm infants. The mechanisms of homeostasis in patients with PDA are very complex and involve both circulatory adaptations and control by autonomic pathway. If confirmed, our results could be interesting for future researches aiming to verify the interest of new targeted therapies for the management of PDA.

(1-3)-ß-D-glucan levels in candidiasis infections in the critically ill neonate.

INTRODUCTION: The diagnosis of neonatal invasive Candida infections (ICIs) is problematic because the clinical signs are not specific and blood cultures are rarely positive. Hence, new diagnostic markers are needed. OBJECTIVE: To assess the contribution of serum (1-3)-ß-d-glucan (BDG) levels to the diagnosis of neonatal ICIs and to analyse the change in this parameter during antifungal therapy. METHODS: This retrospective study (December 2010-March 2012) was performed at Amiens University Medical Center (Amiens, France). We included newborns in whom a BDG assay was performed for a suspected ICI and classified as infected (n = 18) or non-infected (n = 43). RESULTS: Sixty-one patients (median (IQR) gestational age: 28.5 weeks (26.7-30.6); birth weight: 1000 g (910-1440)) were included. The BDG level was higher in the infected group (364 pg/ml (131-976) vs. 89 pg/ml (30-127); p < 0.001). The optimal BDG cut-off for distinguishing between non-infected and infected patients was 125 pg/ml (Se = 84%, Sp = 75%). The BDG level fell over the course of antifungal therapy. CONCLUSION: Our study results suggest that BDG levels were increased in neonatal invasive Candida infections (cut-off for BDG positivity > 125 pg/ml). The change in the serum BDG levels may be of value in evaluating the efficacy of antifungal therapy.