Haemodynamic assessment and management of hypotension in the preterm.

The management of low blood flow states in premature neonates is fraught with many challenges. We remain over-reliant on regimented stepwise protocols that use mean blood pressure as a threshold for intervention to guide treatment, without giving due consideration to the underlying pathophysiology. The current available evidence does not reflect the need to concentrate on the unique pathophysiology of the preterm infant and thus leads to widespread misuse of vasoactive agents that often do not provide the desired clinical effect. Therefore, understanding the underlying pathophysiological underpinnings of haemodynamic compromise may better guide choice of agent and assess physiological response to the selected intervention.

Reproducibility of the EL-Khuffash PDA severity score and PDA diameter measurements in extremely preterm infants.

BACKGROUND & AIM: Almost all randomised controlled trials use a Patent Ductus Arteriosus (PDA) diameter ≥ 1.5 mm as the primary criterion to ascribe haemodynamic significance to the PDA. The aim of this study was to evaluate if calculation of a PDA Severity Score (PDAsc) possessed superior intra- and inter-rater reproducibility when compared with the measurement of PDA diameter alone. METHODS: This cross-sectional study assessed echocardiograms performed on infants <30 weeks gestation at 36 to 72 h of age between July 2020 and December 2022 to calculate the PDAsc. Intra-observer reproducibility of the PDA diameter and PDAsc were assessed by blinded repeated measurements performed by one investigator (AS) 4 weeks apart. One set of those measurements was compared with blinded measurements by another investigator (RM) to assess inter-rater reliability. RESULTS: Echocardiograms from 150 infants with mean ± SD gestation and birthweights of 26.5 ± 1.7 weeks and 903 ± 249 g respectively were examined. The PDAsc demonstrated near perfect agreement both within raters (Cohen's Kappa 0.97, p < 0.01) and between raters (Cohen's Kappa 0.94, p < 0.01) with regards to the threshold for treatment (a cut off ≥5.0). The PDA diameter threshold only demonstrated moderate agreement within raters (Kappa 0.57, p < 0.01) and between raters (Kappa 0.54, p < 0.01). In this cohort, 31 % of infants with a low risk PDAsc (< 5.0) also had a PDA diameter >1.5 mm. CONCLUSION: Future RCTs for PDA treatment should strongly consider abandoning the use of PDA diameter in isolation as a criterion for recruitment into clinical trials.

Inhaled nitric oxide in preterm neonates with preterm prelabour rupture of membranes, a systematic review.

AIM: To perform a systematic literature review to determine the effect of inhaled nitric oxide (iNO) on oxygenation, mortality and morbidity in preterm neonates with preterm prelabour rupture of membranes (PPROM) and early hypoxaemic respiratory failure (HRF). METHODS: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, Web of Science, Zetoc and ProQuest were searched. Studies including neonates <34 weeks' gestation with PPROM, oligohydramnios or pulmonary hypoplasia and HRF in the first 28 days of life treated with iNO were included. Studies were critically appraised and assessed for potential risk of bias using standardised checklists. RESULTS: Six hundred and two records remained after duplicates were removed. Seven studies were included in the critical appraisal process. Quality of available evidence was very low to low. Six studies described an improvement in oxygenation after commencement of iNO. One hundred and three of 284 (36%) neonates exposed to iNO died. Seventy-seven of 92 (84%) neonates that had an echocardiogram performed before commencement of iNO had pulmonary hypertension (PH) present. CONCLUSION: iNO may improve oxygenation when standard care fails. Improvement in oxygenation is likely associated with increase in survival. Survival may lead to an increase in morbidity. Efficacy of iNO in this cohort is likely secondary to relatively high prevalence of PH.

Pulmonary haemorrhage in neonates: Systematic review of management.

AIM: Pulmonary haemorrhage (PH) is an acute catastrophic event with low incidence yet high mortality among neonates. We aimed to systematically review the management of PH. METHODS: A search was carried out of the PubMed, EMBASE and Cochrane databases according to the PRISMA guidelines. Data were extracted on study design and size, patient demographics, primary and adjunctive treatment methods, and treatment outcomes. RESULTS: Sixteen studies with 385 newborn infants were included and were significantly heterogeneous regarding treatment methods. Primary treatments included surfactant, high-frequency oscillatory ventilation (HFOV), epinephrine, coagulopathy management, intermittent positive pressure ventilation, cocaine and tolazoline. Adjunctive treatment methods included blood products, HFOV, increased positive end-expiratory pressure, vitamin K, surfactant, adrenaline, vasopressors and inotropes. All five studies using surfactant as primary treatment were effective in improving oxygenation index measures and preventing recurrence of PH, and three studies found no association between surfactant and death or long-term disability. Ventilatory support, epinephrine, management of coagulopathy and tolazoline were all found to be effective primary treatments for PH. CONCLUSION: There are several effective methods of managing PH in neonates. Further understanding of the aetiology of PH and ongoing research will allow future prevention and improvements in management of PH.