Intra-amniotic surfactant for women at risk of preterm birth for preventing respiratory distress in newborns

Laryngeal mask airway surfactant administration for prevention of morbidity and mortality in preterm infants with or at risk of respiratory distress syndrome

BACKGROUND

Laryngeal mask airway surfactant administration (S-LMA) has the potential benefit of surfactant administration whilst avoiding endotracheal intubation and ventilation, ventilator-induced lung injury and bronchopulmonary dysplasia (BPD).

OBJECTIVES

To evaluate the benefits and harms of S-LMA either as prophylaxis or treatment (rescue) compared to placebo, no treatment, or intratracheal surfactant administration via an endotracheal tube (ETT) with the intent to rapidly extubate (InSurE) or extubate at standard criteria (S-ETT) or via other less-invasive surfactant administration (LISA) methods on morbidity and mortality in preterm infants with or at risk of respiratory distress syndrome (RDS).

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, and three trial registries in December 2022.

SELECTION CRITERIA

Randomised controlled trials (RCTs), cluster- or quasi-RCTs of S-LMA compared to placebo, no treatment, or other routes of administration (nebulised, pharyngeal instillation of surfactant before the first breath, thin endotracheal catheter surfactant administration or intratracheal surfactant instillation) on morbidity and mortality in preterm infants at risk of RDS. We considered published, unpublished and ongoing trials.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion and extracted data. We used GRADE to assess the certainty of the evidence.

MAIN RESULTS

We included eight trials (seven new to this update) recruiting 510 newborns. Five trials (333 infants) compared S-LMA with surfactant administration via ETT with InSurE. One trial (48 infants) compared S-LMA with surfactant administration via ETT with S-ETT, and two trials (129 infants) compared S-LMA with no surfactant administration. We found no studies comparing S-LMA with LISA techniques or prophylactic or early S-LMA. S-LMA versus surfactant administration via InSurE S-LMA may have little or no effect on the composite outcome of death or BPD at 36 weeks' postmenstrual age (risk ratio (RR) 1.50, 95% confidence interval (CI) 0.27 to 8.34, I 2 = not applicable (NA) as 1 study had 0 events; risk difference (RD) 0.02, 95% CI -0.07 to 0.10; I 2 = 0%; 2 studies, 110 infants; low-certainty evidence). There may be a reduction in the need for mechanical ventilation at any time (RR 0.53, 95% CI 0.36 to 0.78; I 2 = 27%; RD -0.14, 95% CI -0.22 to -0.06, I 2 = 89%; number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 5 to 17; 5 studies, 333 infants; low-certainty evidence). However, this was limited to four studies (236 infants) using analgesia or sedation for the InSurE group. There was little or no difference for air leak during first hospitalisation (RR 1.39, 95% CI 0.65 to 2.98; I 2 = 0%; 5 studies, 333 infants (based on 3 studies as 2 studies had 0 events); low-certainty evidence); BPD among survivors to 36 weeks' PMA (RR 1.28, 95% CI 0.47 to 3.52; I 2 = 0%; 4 studies, 264 infants (based on 3 studies as 1 study had 0 events); low-certainty evidence); or death (all causes) during the first hospitalisation (RR 0.28, 95% CI 0.01 to 6.60; I 2 = NA as 2 studies had 0 events; 3 studies, 203 infants; low-certainty evidence). Neurosensory disability was not reported. Intraventricular haemorrhage ( IVH) grades III and IV were reported among the study groups (1 study, 50 infants). S-LMA versus surfactant administration via S-ETT No study reported death or BPD at 36 weeks' PMA. S-LMA may reduce the use of mechanical ventilation at any time compared with S-ETT (RR 0.47, 95% CI 0.31 to 0.71; RD -0.54, 95% CI -0.74 to -0.34; NNTB 2, 95% CI 2 to 3; 1 study, 48 infants; low-certainty evidence). We are very uncertain whether S-LMA compared with S-ETT reduces air leak during first hospitalisation (RR 2.56, 95% CI 0.11 to 59.75), IVH grade III or IV (RR 2.56, 95% CI 0.11 to 59.75) and death (all causes) during the first hospitalisation (RR 0.17, 95% CI 0.01 to 3.37) (1 study, 48 infants; very low-certainty evidence). No study reported BPD to 36 weeks' PMA or neurosensory disability. S-LMA versus no surfactant administration Rescue surfactant could be used in both groups. There may be little or no difference in death or BPD at 36 weeks (RR 1.65, 95% CI 0.85 to 3.22; I 2 = 58%; RD 0.08, 95% CI -0.03 to 0.19; I 2 = 0%; 2 studies, 129 infants; low-certainty evidence). There was probably a reduction in the need for mechanical ventilation at any time with S-LMA compared with nasal continuous positive airway pressure without surfactant (RR 0.57, 95% CI 0.38 to 0.85; I 2 = 0%; RD -0.24, 95% CI -0.40 to -0.08; I 2 = 0%; NNTB 4, 95% CI 3 to 13; 2 studies, 129 infants; moderate-certainty evidence). There was little or no difference in air leak during first hospitalisation (RR 0.65, 95% CI 0.23 to 1.88; I 2 = 0%; 2 studies, 129 infants; low-certainty evidence) or BPD to 36 weeks' PMA (RR 1.65, 95% CI 0.85 to 3.22; I 2 = 58%; 2 studies, 129 infants; low-certainty evidence). There were no events in either group for death during the first hospitalisation (1 study, 103 infants) or IVH grade III and IV (1 study, 103 infants). No study reported neurosensory disability.

AUTHORS' CONCLUSIONS

In preterm infants less than 36 weeks' PMA, rescue S-LMA may have little or no effect on the composite outcome of death or BPD at 36 weeks' PMA. However, it may reduce the need for mechanical ventilation at any time. This benefit is limited to trials reporting the use of analgesia or sedation in the InSurE and S-ETT groups. There is low- to very-low certainty evidence for no or little difference in neonatal morbidities and mortality. Long-term outcomes are largely unreported. In preterm infants less than 32 weeks' PMA or less than 1500 g, there are insufficient data to support or refute the use of S-LMA in clinical practice. Adequately powered trials are required to determine the effect of S-LMA for prevention or early treatment of RDS in extremely preterm infants. S-LMA use should be limited to clinical trials in this group of infants.

Prevalence and risk factors associated with birth asphyxia among neonates delivered in Ethiopia: A systematic review and meta-analysis

BACKGROUND

A number of primary studies in Ethiopia address the prevalence of birth asphyxia and the factors associated with it. However, variations were seen among those studies. The main aim of this systematic review and meta-analysis was carried out to estimate the pooled prevalence and explore the factors that contribute to birth asphyxia in Ethiopia.

METHODS

Different search engines were used to search online databases. The databases include PubMed, HINARI, Cochrane Library and Google Scholar. Relevant grey literature was obtained through online searches. The funnel plot and Egger's regression test were used to see publication bias, and the I-squared was applied to check the heterogeneity of the studies. Cross-sectional, case-control and cohort studies that were conducted in Ethiopia were also be included. The Joanna Briggs Institute checklist was used to assess the quality of the studies and was included in this systematic review. Data entry and statistical analysis were carried out using RevMan 5.4 software and Stata 14.

RESULT

After reviewing 1,125 studies, 26 studies fulfilling the inclusion criteria were included in the meta-analysis. The pooled prevalence of birth asphyxia in Ethiopia was 19.3%. In the Ethiopian context, the following risk factors were identified: Antepartum hemorrhage(OR: 4.7; 95% CI: 3.5, 6.1), premature rupture of membrane(OR: 4.0; 95% CI: 12.4, 6.6), primiparas(OR: 2.8; 95% CI: 1.9, 4.1), prolonged labor(OR: 4.2; 95% CI: 2.8, 6.6), maternal anaemia(OR: 5.1; 95% CI: 2.59, 9.94), low birth weight(OR = 5.6; 95%CI: 4.7,6.7), meconium stained amniotic fluid(OR: 5.6; 95% CI: 4.1, 7.5), abnormal presentation(OR = 5.7; 95% CI: 3.8, 8.3), preterm birth(OR = 4.1; 95% CI: 2.9, 5.8), residing in a rural area (OR: 2.7; 95% CI: 2.0, 3.5), caesarean delivery(OR = 4.4; 95% CI:3.1, 6.2), operative vaginal delivery(OR: 4.9; 95% CI: 3.5, 6.7), preeclampsia(OR = 3.9; 95% CI: 2.1, 7.4), tight nuchal cord OR: 3.43; 95% CI: 2.1, 5.6), chronic hypertension(OR = 2.5; 95% CI: 1.7, 3.8), and unable to write and read (OR = 4.2;95%CI: 1.7, 10.6).

CONCLUSION

According to the findings of this study, birth asphyxia is an unresolved public health problem in the Ethiopia. Therefore, the concerned body needs to pay attention to the above risk factors in order to decrease the country's birth asphyxia.

REVIEW REGISTRATION

PROSPERO International prospective register of systematic reviews (CRD42020165283).

Antenatal and intrapartum interventions for preventing cerebral palsy: an overview of Cochrane systematic reviews

BACKGROUND

Cerebral palsy is an umbrella term encompassing disorders of movement and posture, attributed to non-progressive disturbances occurring in the developing fetal or infant brain. As there are diverse risk factors and causes, no one strategy will prevent all cerebral palsy. Therefore, there is a need to systematically consider all potentially relevant interventions for their contribution to prevention.

OBJECTIVES

To summarise the evidence from Cochrane reviews regarding the effects of antenatal and intrapartum interventions for preventing cerebral palsy.

METHODS

We searched the Cochrane Database of Systematic Reviews on 7 August 2016, for reviews of antenatal or intrapartum interventions reporting on cerebral palsy. Two authors assessed reviews for inclusion, extracted data, assessed review quality, using AMSTAR and ROBIS, and quality of the evidence, using the GRADE approach. We organised reviews by topic, and summarised findings in text and tables. We categorised interventions as effective (high-quality evidence of effectiveness); possibly effective (moderate-quality evidence of effectiveness); ineffective (high-quality evidence of harm or of lack of effectiveness); probably ineffective (moderate-quality evidence of harm or of lack of effectiveness); and no conclusions possible (low- to very low-quality evidence).

MAIN RESULTS

We included 15 Cochrane reviews. A further 62 reviews pre-specified the outcome cerebral palsy in their methods, but none of the included randomised controlled trials (RCTs) reported this outcome. The included reviews were high quality and at low risk of bias. They included 279 RCTs; data for cerebral palsy were available from 27 (10%) RCTs, involving 32,490 children. They considered interventions for: treating mild to moderate hypertension (two) and pre-eclampsia (two); diagnosing and preventing fetal compromise in labour (one); preventing preterm birth (four); preterm fetal maturation or neuroprotection (five); and managing preterm fetal compromise (one). Quality of evidence ranged from very low to high. Effective interventions: high-quality evidence of effectiveness There was a reduction in cerebral palsy in children born to women at risk of preterm birth who received magnesium sulphate for neuroprotection of the fetus compared with placebo (risk ratio (RR) 0.68, 95% confidence interval (CI) 0.54 to 0.87; five RCTs; 6145 children). Probably ineffective interventions: moderate-quality evidence of harm There was an increase in cerebral palsy in children born to mothers in preterm labour with intact membranes who received any prophylactic antibiotics versus no antibiotics (RR 1.82, 95% CI 0.99 to 3.34; one RCT; 3173 children). There was an increase in cerebral palsy in children, who as preterm babies with suspected fetal compromise, were born immediately compared with those for whom birth was deferred (RR 5.88, 95% CI 1.33 to 26.02; one RCT; 507 children). Probably ineffective interventions: moderate-quality evidence of lack of effectiveness There was no clear difference in the presence of cerebral palsy in children born to women at risk of preterm birth who received repeat doses of corticosteroids compared with a single course (RR 1.03, 95% CI 0.71 to 1.50; four RCTs; 3800 children). No conclusions possible: low- to very low-quality evidence Low-quality evidence found there was a possible reduction in cerebral palsy for children born to women at risk of preterm birth who received antenatal corticosteroids for accelerating fetal lung maturation compared with placebo (RR 0.60, 95% CI 0.34 to 1.03; five RCTs; 904 children). There was no clear difference in the presence of cerebral palsy with interventionist care for severe pre-eclampsia versus expectant care (RR 6.01, 95% CI 0.75 to 48.14; one RCT; 262 children); magnesium sulphate for pre-eclampsia versus placebo (RR 0.34, 95% CI 0.09 to 1.26; one RCT; 2895 children); continuous cardiotocography for fetal assessment during labour versus intermittent auscultation (average RR 1.75, 95% CI 0.84 to 3.63; two RCTs; 13,252 children); prenatal progesterone for prevention of preterm birth versus placebo (RR 0.14, 95% CI 0.01 to 3.48; one RCT; 274 children); and betamimetics for inhibiting preterm labour versus placebo (RR 0.19, 95% CI 0.02 to 1.63; one RCT; 246 children).Very low-quality found no clear difference for the presence of cerebral palsy with any antihypertensive drug (oral beta-blockers) for treatment of mild to moderate hypertension versus placebo (RR 0.33, 95% CI 0.01 to 8.01; one RCT; 110 children); magnesium sulphate for prevention of preterm birth versus other tocolytic agents (RR 0.13, 95% CI 0.01 to 2.51; one RCT; 106 children); and vitamin K and phenobarbital prior to preterm birth for prevention of neonatal periventricular haemorrhage versus placebo (RR 0.77, 95% CI 0.33 to 1.76; one RCT; 299 children).

AUTHORS' CONCLUSIONS

This overview summarises evidence from Cochrane reviews on the effects of antenatal and intrapartum interventions on cerebral palsy, and can be used by researchers, funding bodies, policy makers, clinicians and consumers to aid decision-making and evidence translation. We recommend that readers consult the included Cochrane reviews to formally assess other benefits or harms of included interventions, including impacts on risk factors for cerebral palsy (such as the reduction in intraventricular haemorrhage for preterm babies following exposure to antenatal corticosteroids).Magnesium sulphate for women at risk of preterm birth for fetal neuroprotection can prevent cerebral palsy. Prophylactic antibiotics for women in preterm labour with intact membranes, and immediate rather than deferred birth of preterm babies with suspected fetal compromise, may increase the risk of cerebral palsy. Repeat doses compared with a single course of antenatal corticosteroids for women at risk of preterm birth do not clearly impact the risk of cerebral palsy.Cerebral palsy is rarely diagnosed at birth, has diverse risk factors and causes, and is diagnosed in approximately one in 500 children. To date, only a small proportion of Cochrane reviews assessing antenatal and intrapartum interventions have been able to report on this outcome. There is an urgent need for long-term follow-up of RCTs of interventions addressing risk factors for cerebral palsy, and consideration of the use of relatively new interim assessments (including the General Movements Assessment). Such RCTs must be rigorous in their design, and aim for consistency in cerebral palsy outcome measurement and reporting to facilitate pooling of data, to focus research efforts on prevention.

Targeting interleukin-6 receptor inhibits preterm delivery induced by inflammation

Intrauterine infection is still a common trigger of preterm delivery (PTD) and also a determinant risk factor for the subsequent development of neurodevelopmental abnormalities in neonates. In this study, we examined the expressional pattern of various inflammatory cytokines such as interleukin-1β (IL-1β), IL-6 and tumor necrosis factor-α (TNF-α) in placentae complicated with severe chorioamnionitis (CAM) and found that IL-6 is mainly expressed in macrophages in villous mesenchyme by immunohistochemical analysis with anti-CD-68 antibody. Using an experimental lipopolysaccharide (LPS)-induced PTD model, the therapeutic potential of targeting this cytokine was investigated. Anti-IL-6 receptor antibody (MR16-1) was delivered 6 h before LPS treatment. Mice in the MR16-1 group had a significantly lower rate of PTD (17%) than in the controls (53%, P = 0.026). As a result, MR16-1 treatment significantly prolonged the gestational period (control; 18.4 ± 1.7d, MR16-1; 19.8 ± 1.5d, P = 0.007) without any apparent adverse events on the mice and their pups. In primary human amniotic epithelial cells, pretreatment with a humanized anti-human IL-6 receptor antibody, tocilizumab, significantly inhibited the production of prostaglandin E2 induced by IL-6. In conclusion, IL-6 was strongly expressed mainly in macrophages in villous mesenchyme in placentae complicated with CAM. Anti-IL-6R antibody significantly decreased the rate of PTD in LPS-induced inflammatory model in mice, and inhibited PGE2 production from human primary amniotic epithelial cells. Targeting IL-6 signaling could be a promising option for the prevention of PTD and needs to be further explored for future clinical application.

The role of surfactant in respiratory distress syndrome

The key feature of respiratory distress syndrome (RDS) is the insufficient production of surfactant in the lungs of preterm infants. As a result, researchers have looked into the possibility of surfactant replacement therapy as a means of preventing and treating RDS. We sought to identify the role of surfactant in the prevention and management of RDS, comparing the various types, doses, and modes of administration, and the recent development. A PubMed search was carried out up to March 2012 using phrases: surfactant, respiratory distress syndrome, protein-containing surfactant, protein-free surfactant, natural surfactant, animal-derived surfactant, synthetic surfactant, lucinactant, surfaxin, surfactant protein-B, surfactant protein-C.Natural, or animal-derived, surfactant is currently the surfactant of choice in comparison to protein-free synthetic surfactant. However, it is hoped that the development of protein-containing synthetic surfactant, such as lucinactant, will rival the efficacy of natural surfactants, but without the risks of their possible side effects. Administration techniques have also been developed with nasal continuous positive airway pressure (nCPAP) and selective surfactant administration now recommended; multiple surfactant doses have also reported better outcomes. An aerosolised form of surfactant is being trialled in the hope that surfactant can be administered in a non-invasive way. Overall, the advancement, concerning the structure of surfactant and its mode of administration, offers an encouraging future in the management of RDS.