Charles P. Barfield

Assessment of neonatal resuscitation performance using video recording in a perinatal centre

Aim:  To assess the quality of neonatal resuscitation using video recordings in a perinatal centre.

The effect of sildenafil on evolving bronchopulmonary dysplasia in extremely preterm infants: a randomised controlled pilot study

Abstract Objective: Sildenafil has been shown to preserve alveolar growth and lung angiogenesis in a rat model of bronchopulmonary dysplasia. We conducted a proof-of-concept randomised controlled pilot study to assess the feasibility of oral sildenafil treatment in extremely preterm infants with evolving bronchopulmonary dysplasia. Methods: Preterm infants <28 weeks gestational age were eligible if they were mechanically ventilated on day 7 of life. Infants were randomised to a 4-weeks course of either oral sildenafil (3 mg/kg/day) or placebo solution. Pre-discharge cardiorespiratory outcomes and medication side effects were collected. Results: Twenty infants were randomised, 10 received sildenafil (mean gestational age 24 + 5 weeks (SD 4.9 days), mean weight 692 g (SD 98)) and 10 received placebo (mean gestational age 24 + 5 weeks (SD 6.5 days), mean weight 668 g (SD 147)). One infant in the sildenafil group did not receive treatment because of an early pneumoperitoneum. Two infants did not complete the study (transferred out). Of the remaining seven treated infants, three died (two from respiratory-related causes). One infant in the control group died from a non-respiratory cause. Sildenafil did not reduce length of invasive (median 688 versus 227 h) or non-invasive ventilation (median 1609 versus 1416 h). More infants in the sildenafil group required postnatal steroid treatment. One infant developed hypotension following sildenafil administration and was excluded after three doses. Conclusions: In this pilot study, oral sildenafil treatment did not improve any short-term respiratory outcomes in extremely preterm infants.

Randomized controlled trial to compare sleep and wake in preterm infants less than 32weeks of gestation receiving two different modes of non-invasive respiratory support

AIM To determine whether respiratory support via heated humidified high flow nasal cannulae (HHHFNC) results in infants <32weeks gestation spending a greater proportion of time in sleep compared to those receiving nasal continuous positive airway pressure (NCPAP). METHODS A subgroup of infants enrolled in a randomized controlled trial to compare HHHFNC or NCPAP post-extubation had sleep and wake activity measured by actigraphy for 72hours post-extubation. Activity diaries were completed contemporaneously to record episodes of infant handling. Actigraphy data were downloaded with known periods of handling excluded from the analysis. RESULTS 28 infants with mean gestation of 28.3weeks (SD 2) and birth weight 1074g (SD 371) were studied. Infants receiving HHHFNC spent a lesser proportion of time in sleep 59.8% (SD 18.5) than those on NCPAP 82.2% (SD 23.8) p=0.004. Infants receiving HHHFNC had a lower sleep efficiency and higher mean activity score than those on NCPAP (p=0.003, p=0.002, respectively). CONCLUSION Infants receiving HHHFNC had a higher mean activity score and spent less time in sleep than those allocated NCPAP. Further study of sleep wake activity in preterm infants receiving respiratory support is required as this may impact on neurodevelopmental outcomes.

Association of BNP, NTproBNP, and early postnatal pulmonary hypertension in very preterm infants

Summary Objective B-type natriuretic peptide (BNP) has been shown to correlate with pulmonary hypertension (PH) in term neonates with persistent pulmonary hypertension of the newborn or congenital diaphragmatic hernia, and in very preterm infants with bronchopulmonary dysplasia. This study investigated the potential association of BNP and N-terminal-pro-BNP (NTproBNP) and PH within the first 72 hr of life in very preterm infants. Methods Preterm infants <32 weeks gestational age who received an echocardiogram within the first 72 hr of life were eligible. BNP and NTproBNP were sampled at the time of the echocardiogram. Right ventricular systolic pressure (RVSP) was calculated as a surrogate marker of PH. Simple and multiple linear regression analysis was performed to examine associations and potential confounding factors. Results Sixty-one infants were included with a median (IQR) birth weight of 983 g (826–1,167) and a median (IQR) gestational age of 272 weeks (262–286). There was no difference between BNP or NTproBNP levels for infants with or without measurable RVSP. There was no significant correlation of BNP and RVSP in multiple linear regression analysis (regression coefficient −0.0035 (95%CI: −0.020 to 0.013), P = 0.67). Also, NTproBNP and RVSP were not significantly correlated in multiple linear regression analysis (regression coefficient 0.0071 (95%CI: −0.019 to 0.033), P = 0.58). Conclusion B-type natriuretic peptides did not correlate with RVSP in the early postnatal period of very preterm infants. Pediatr Pulmonol.

The relationship between BNP, NTproBNP and echocardiographic measurements of systemic blood flow in very preterm infants

Objective:Preterm infants are at risk of circulatory compromise following birth. Functional neonatal echocardiography including superior vena cava (SVC) flow is increasingly used in neonatal medicine, and low SVC flow has been associated with adverse outcome. However, echocardiography is not readily available in many neonatal units and B-type natriuretic peptides (BNPs) may be useful in guiding further cardiovascular assessment. This study investigated the relationship between BNP, N-terminal pro-BNP (NTproBNP) and echocardiographic measurements of systemic blood flow in very preterm infants.Study Design:This is a prospective observational study. Sixty preterm infants <32 weeks gestational age were included after the treating neonatologist had requested an echocardiogram for suspected cardiovascular compromise. BNP and NTproBNP were sampled just before the echocardiogram. Echocardiographic examination included fractional shortening (FS), SVC flow, left and right ventricular output (LVO and RVO). Statistical analysis included simple linear regression of BNP and NTproBNP with echocardiographic measures and multiple regression including potential confounding variables.Result:Mean (s.d.) gestational age at birth was 275 (21) weeks, median (interquartile range, IQR) birth weight was 995 (845 to 1175) grams. Neither BNP nor NTproBNP correlated with SVC flow (BNP 95% confidence interval (CI) −0.0014 to 0.013, P=0.12; NTproBNP 95% CI −0.00069 to 0.01, P=0.085); LVO (BNP 95% CI −0.00078 to 0.0072, P=0.11; NTproBNP 95% CI −0.0034 to 0.0034, P=0.99); RVO (BNP 95% CI −0.00066 to 0.0058, P=0.12; NTproBNP 95% CI −0.0012 to 0.0044, P=0.25); or FS (BNP 95% CI −0.053 to 0.051, P=0.96; NTproBNP 95% CI −0.061 to 0.019, P=0.3). Multivariate linear regression did not significantly alter results.Conclusion:In this cohort of very preterm infants, BNP and NTproBNP did not correlate with echocardiographic measurements of systemic blood flow within the first 72 h of life.

BNP, troponin I, and YKL-40 as screening markers in extremely preterm infants at risk for pulmonary hypertension associated with bronchopulmonary dysplasia

Bronchopulmonary dysplasia (BPD) is often complicated by pulmonary hypertension (PH). We investigated three biomarkers potentially suitable as screening markers for extremely preterm infants at risk of BPD-associated PH. In this prospective observational cohort study conducted in a tertiary neonatal intensive care unit, 83 preterm infants with BPD born <28-wk gestation and still inpatients at 36-wk corrected age received an echocardiogram and blood tests of B-type natriuretic peptide (BNP), troponin I, and YKL-40. Infants were analyzed according to echocardiographic evidence of tricuspid regurgitation (TR). Thirty infants had evidence of TR on echocardiogram at 36-wk corrected age. Infants with or without TR had similar baseline demographics: mean ± SD gestational age 261 ± 12 vs. 261 ± 11 wk and birth weight 830 ± 206 vs. 815 ± 187 g, respectively. There was no difference in duration of respiratory support. The right ventricular systolic pressure of infants with evidence of TR was 40 ± 16 mmHg. BNP was the only biomarker that proved to be significantly higher in infants with evidence of TR: median (interquartile range) serum level 54.5 (35-105) vs. 41.5 (30-59) pg/ml, P = 0.043. Subgroup analysis of infants with severe BPD requiring discharge on home oxygen or BPD-related mortality revealed similar results. There was no difference between groups for troponin I and YKL-40. In conclusion, increased serum levels of BNP were associated with evidence of TR at 36-wk corrected gestational age in extremely preterm infants, suggesting a potential role as a screening biomarker for BPD-associated PH.

B-type and N-terminal pro-B-type natriuretic peptides are equally useful in assessing patent ductus arteriosus in very preterm infants.

B‐type natriuretic peptide (BNP) and N‐terminal pro‐BNP (NTproBNP) have been shown to correlate with the size of the patent ductus arteriosus (PDA) in preterm infants. We investigated whether BNP or NTproBNP was more closely correlated with PDA size.

137 High Flow Nasal Cannulae (HFNC) or Nasal Continuous Positive Airway Pressure (NCPAP) Post-Extubation in Premature Infants? a Randomised Controlled Trial

Background NCPAP facilitates successful extubation. It is unclear whether HFNC are as effective as NCPAP in preventing extubation failure. In addition to an alternative modality of respiratory support HFNC may result in less nasal trauma than NCPAP. Methods 132 preterm ventilated infants were randomised and stratified by gestation(< 28 vs 28–32 weeks). Primary outcome was extubation failure defined by a composite of 3 pre-specified failure criteria in the 7 days post-extubation. Individual failure criteria were not mutually exclusive and are defined; Apnoea, > 6 episodes in 6 hours or 1 requiring IPPV, Acidosis, pH< 7.25 & pCO2>66mmHg, and >15% increase in FiO2 from extubation. A nasal trauma score was adapted from Kaufman [E-PAS 2007:61390]. Results Abstract 137 Table 1 HFNC N=67 NCPAP N=65 Male n (%) 33 (49) 41 (63) Birthweight g mean (SD) 1123 (317) 1105 (374) Mean Completed Weeks gestation (SD) 27.9 (1.95) 27.6 (1.97) Failed Extubation in 1st week by Composite Criteria n (%) 15 (22) 22 (34) Apnoea: > 6 in 6hrs or 1 needing IPPV n (%) 14 (21) 17(26) Acidosis:pH < 7.25 & pCO2 > 66mmHg n(%) 0 3 (5) > 15% increase in FiO2 post-extubation n(%) 7 (10) 12 (18) Reintubated in 1st week n(%) 7 (10) 8 (12) Nasal Trauma Score 1st week mean (SD) 3.1 (7.2) 11.8 (10.7) p<0.001* Conclusions Rates of extubation failure were not significantly different between the groups. HFNC resulted in significantly less nasal trauma than NCPAP. This benefit may need to be considered in post-extubation respiratory support for preterm infants.

O-031 Comparison Of Bnp And Nt-pro-bnp For Assessment Of The Patent Ductus Arteriosus In Very Preterm Infants

Background and aims B-type natriuretic peptide (BNP) and N-terminal-pro-BNP (NTproBNP) have been shown to correlate with the size of patent ductus arteriosus (PDA) in preterm infants. We investigated whether BNP or NTproBNP is more accurate for assessment of a PDA. Methods Prospective observational study. Preterm infants born. Results 60 infants were recruited, 58 had complete datasets. The cohort’s mean (SD) gestational age was 273 (22) weeks and had a mean (SD) birth weight of 1032 (315) grams. 46 (79.3%) infants had a PDA with a mean (SD) PDA diameter of 3.2 (0.9) mm. Median (IQR) BNP levels: 486.5 (219–1316) pg/ml for infants with PDA, 190 (95.5–514.5) pg/ml for infants without PDA. Median (IQR) NTproBNP levels: 10858.5 (6319–42108) pg/ml for infants with PDA, and 7488 (3363–14227.5) pg/ml for infants without PDA. Both BNP and NTproBNP showed a significant correlation with PDA size in this cohort: BNP R=0.35 (p = 0.0066); NTproBNP R = 0.31 (p = 0.018). Conclusion BNP and NTproBNP were closely correlated to PDA size. Both markers were useful for assessment of PDA size in this cohort of very preterm infants.