Impact of Medical Treatment of Hemodynamically Significant Patent Ductus Arteriosus on Cerebral and Renal Tissue Oxygenation Measured by Near-Infrared Spectroscopy in Very Low-Birth-Weight Infants.

Background and objective: Hemodynamically significant patent ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes in preterm infants. Near-infrared spectroscopy (NIRS) allows us to continuously evaluate regional tissue oxygenation (rSpO2) and perfusion changes in underlying organs. The aim of this study was to evaluate the effect of medical treatment for hsPDA on cerebral and renal rSpO2 in infants less than 32 weeks of gestational age, and older than 72 h of life. Materials and methods: Infants with a gestational age of <32 weeks with hsPDA were prospectively studied before and during medical treatment. Two-site (cerebral and renal) rSpO2 monitoring by NIRS was performed 1 h before treatment (T0) and 24 h (T1), 24−48 h (T2), 48−72 h (T3) after the infusion of the first drug dose. Results: A total of 21 infants were studied. The mean day of life at treatment initiation was 8.2 (SD, 2.75). The DA diameter, LA/Ao ratio, and resistive index in the anterior cerebral artery (RI ACA) were significantly lower after treatment (p < 0.05). There were no significant differences in cerebral rSpO2, cerebral fractional tissue oxygen extraction (FTOE), and SpO2 comparing different time points. A significantly higher renal SpO2 value was recorded at T2 as compared with T0 (75.0%, SD 4.9%, vs. 69.4%, SD 7.6%; p < 0.013), while for renal FTOE, a tendency to lower values at T2 was observed (0.18, SD 0.05, vs. 0.24, SD 0.09; p = 0.068). Conclusions: Late (later than 7 days postpartum) hsPDA medical treatment with paracetamol or ibuprofen completely closed the duct only in a small proportion of preterm infants, despite a statistically significant reduction in the DA diameter, LA/Ao ratio, and RI ACA. Continuous renal, not cerebral, NIRS measurements can help to anticipate the efficacy of medical treatment of hsPDA in preterm infants. Large-scale prospective studies are needed to ascertain that renal and cerebral NIRS can be used as a reliable tool for evaluating the effectiveness of medical treatment for hsPDA.

Brain and renal oxygenation measured by NIRS related to patent ductus arteriosus in preterm infants: a prospective observational study.

BACKGROUND: Patent ductus arteriosus (PDA) is common among preterm neonates. Haemodynamically significant ductus arteriosus (hsPDA) can cause ductal steal and contribute to poor outcomes. Our aim was to evaluate ductus arteriosus patency and significance using two-site near-infrared spectroscopy (NIRS) measurements in preterm infants older than 72 h as a supplemental tool to echocardiography. METHODS: In this prospective observational study, 123 preterm infants (gestational age (GA) < 32 weeks, birth weight < 1500 g) were enrolled. Sixty-four newborns had closed ductus arteriosus (noPDA), and 41 and 18 patients were assigned to the PDA and hsPDA groups, respectively, per predefined echocardiographic criteria. Cerebral and renal oxygenation were assessed during NIRS monitoring. RESULTS: A higher renal mean (±SD) regional tissue oxygen saturation (rSpO2) (76.7 (±7.64)) was detected in the noPDA group than in the PDA (71.7 (±9.02)) and hsPDA (67.4 (±13.48)) groups (p < 0.001). Renal fractional tissue oxygen extraction (FTOE) (0.18 (±0.079)) was lower in the noPDA group than in the PDA (0.23 (±0.092)) and hsPDA (0.24 (±0.117))0.117 groups (p = 0.002). Cerebral oxygenation was significantly lower in the hsPDA group (77.0 (±5.16)) than in the noPDA (79.3 (±2.45)) and PDA (79.7 (±2.27)) groups (p = 0.004). There was no significant difference in cerebral fractional tissue oxygen extraction (FTOE) between any of the groups. CONCLUSIONS: Our results suggest that renal oxygenation is affected by ductus patency in preterm infants older than 72 h. Significant differences in cerebral oxygenation were observed between the hsPDA group and the PDA and noPDA groups. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04295395. Registration date: 4 March 2020. This study was retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04295395 .

Nasal high-frequency oscillatory ventilation and CO2 removal: A randomized controlled crossover trial.

OBJECTIVE: To compare short-term application of nasal high-frequency oscillatory ventilation (nHFOV) with nasal continuous positive airway pressure (nCPAP). WORKING HYPOTHESIS: nHFOV improves CO2 removal with respect to nCPAP in preterm infants needing noninvasive respiratory support and persistent oxygen supply after the first 72 h of life. STUDY DESIGN: Multicenter non-blinded prospective randomized crossover study. PATIENT SELECTION: Thirty premature infants from eight tertiary neonatal intensive care units, of mean ± SD 26.4 ± 1.8 weeks of gestational age and 921 ± 177 g of birth weight. METHODOLOGY: Infants were randomly allocated in a 1:1 ratio to receive a starting treatment mode of either nCPAP or nHFOV delivered by the ventilator CNO (Medin, Germany), using short binasal prongs of appropriate size. A crossover design with four 1-h treatment periods was used, such that each infant received both treatments twice. The primary outcome was the mean transcutaneous partial pressure of CO2 (TcCO2 ) value during the 2-h cumulative period of nHFOV compared with the 2-h cumulative period of nCPAP. RESULTS: Significantly lower TcCO2 values were observed during nHFOV compared with nCPAP: 47.5 ± 7.6 versus 49.9 ± 7.2 mmHg, respectively, P = 0.0007. A different TcCO2 behavior was found according to the random sequence: in patients starting on nCPAP, TcCO2 significantly decreased from 50.0 ± 8.0 to 46.6 ± 7.5 mmHg during nHFOV (P = 0.001). In patients starting on nHFOV, TcCO2 slightly increased from 48.5 ± 7.8 to 49.9 ± 6.7 mmHg during nCPAP (P = 0.13). CONCLUSIONS: nHFOV delivered through nasal prongs is more effective than nCPAP in improving the elimination of CO2 .