Surfactant administration via a thin endotracheal catheter during spontaneous breathing in preterm infants

A clinical study evaluating the combination of LISA and SNIPPV for the treatment of respiratory distress syndrome in preterm infants

To compare the therapeutic effect of less invasive surfactant administration (LISA) followed by synchronized nasal intermittent positive pressure ventilation (SNIPPV) and traditional intubate-Surfactant-Extubate (InSurE) strategy for the treatment of neonatal respiratory distress syndrome (NRDS). A single-center, non-randomized and single- blinded study Tertiary neonatal intensive care unit 89 infants enrolled were preterm with gestational age < 366/7 weeks and clinically diagnosed with neonatal RDS (NRDS) Interventions: 32 infants were assigned to the LISA + SNIPPV group and 57 infants to the InSurE + nCPAP group. No statistically significant differences were noted in the baseline characteristics of the enrolled infants. A lower proportion of infants developed BPD in the LISA + SNIPPV group compared to the InSurE + CPAP group [10 (31.25%) vs. 21 (36.84%), P > 0.05]; however, there was no statistically significant difference. The number needed to treat (NNT) with LISA + SNIPPV to prevent BPD development is 18. The mortality rate was not significant between our study arms [1 (3.13%) vs 2 (3.51%), P > 0.05]. There were no statistically significant differences in the durations (days) of MV [(12.18 ± 13.89) vs. (11.35 ± 11.61), P > 0.05], oxygen therapy [(35.03 ± 19.13) vs. (39.75 ± 17.91), P > 0.05] and re-intubation rates [(0.19 ± 0.40) vs. (0.21 ± 0.45), P > 0.05] between the two study groups. In terms of complications, the incidence of patent ductus arteriosus (PDA) [24 (75.00%) vs. 27 (47.37%), P < 0.05] was higher and a lower rate of disturbed liver function [1 (3.23%) vs. 19 (33.33%), P < 0.05] were observed in the LISA + SNIPPV group. Acid-base imbalances were reportedly significantly higher in the InSurE group (P < 0.05). No significant differences in other complications were noted. In the interventional group, FiO2 requirements were significantly lower up until the 3rd week of treatment [FiO2 at day 0, (30.75 ± 4.78) vs. (34.66 ± 9.83), P < 0.05; FiO2 at day 21, (25.32 ± 3.74) vs. (29.11 ± 8.17), P < 0.05], as was RSS on days 2 [(0.77 ± 0.38) vs. (1.94 ± 0.75), P < 0.05] and 3 [(0.66 ± 0.33) vs. (1.89 ± 0.82), P < 0.05] after treatment. Additionally, infants in the standard group had a significantly prolonged hospital stay (days) [(45.97 ± 16.93) vs. (54.40 ± 16.26), P < 0.05]. The combination of LISA and SNIPPV for NRDS can potentially lower the rate of BPD, FiO2 demand and shorten the length of hospitalization.

Surfactant therapy via thin catheter in preterm infants with or at risk of respiratory distress syndrome

BACKGROUND

Non-invasive respiratory support is increasingly used for the management of respiratory dysfunction in preterm infants. This approach runs the risk of under-treating those with respiratory distress syndrome (RDS), for whom surfactant administration is of paramount importance. Several techniques of minimally invasive surfactant therapy have been described. This review focuses on surfactant administration to spontaneously breathing infants via a thin catheter briefly inserted into the trachea.

OBJECTIVES

Primary objectives In non-intubated preterm infants with established RDS or at risk of developing RDS to compare surfactant administration via thin catheter with: 1. intubation and surfactant administration through an endotracheal tube (ETT); or 2. continuation of non-invasive respiratory support without surfactant administration or intubation. Secondary objective 1. To compare different methods of surfactant administration via thin catheter Planned subgroup analyses included gestational age, timing of intervention, and use of sedating pre-medication during the intervention.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL), in the Cochrane Library; Ovid MEDLINE(R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Daily and Versions(R); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL), on 30 September 2020. We also searched clinical trials databases and the reference lists of retrieved articles for randomised controlled trials (RCTs) and quasi-randomised trials.

SELECTION CRITERIA

We included randomised trials comparing surfactant administration via thin catheter (S-TC) with (1) surfactant administration through an ETT (S-ETT), or (2) continuation of non-invasive respiratory support without surfactant administration or intubation. We also included trials comparing different methods/strategies of surfactant administration via thin catheter. We included preterm infants (at < 37 weeks' gestation) with or at risk of RDS.

DATA COLLECTION AND ANALYSIS

Review authors independently assessed study quality and risk of bias and extracted data. Authors of all studies were contacted regarding study design and/or missing or unpublished data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included 16 studies (18 publications; 2164 neonates) in this review. These studies compared surfactant administration via thin catheter with surfactant administration through an ETT with early extubation (Intubate, Surfactant, Extubate technique - InSurE) (12 studies) or with delayed extubation (2 studies), or with continuation of continuous positive airway pressure (CPAP) and rescue surfactant administration at pre-specified criteria (1 study), or compared different strategies of surfactant administration via thin catheter (1 study). Two trials reported neurosensory outcomes of of surviving participants at two years of age. Eight studies were of moderate certainty with low risk of bias, and eight studies were of lower certainty with unclear risk of bias. S-TC versus S-ETT in preterm infants with or at risk of RDS Meta-analyses of 14 studies in which S-TC was compared with S-ETT as a control demonstrated a significant decrease in risk of the composite outcome of death or bronchopulmonary dysplasia (BPD) at 36 weeks' postmenstrual age (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.48 to 0.73; risk difference (RD) -0.11, 95% CI -0.15 to -0.07; number needed to treat for an additional beneficial outcome (NNTB) 9, 95% CI 7 to 16; 10 studies; 1324 infants; moderate-certainty evidence); the need for intubation within 72 hours (RR 0.63, 95% CI 0.54 to 0.74; RD -0.14, 95% CI -0.18 to -0.09; NNTB 8, 95% CI; 6 to 12; 12 studies, 1422 infants; moderate-certainty evidence); severe intraventricular haemorrhage (RR 0.63, 95% CI 0.42 to 0.96; RD -0.04, 95% CI -0.08 to -0.00; NNTB 22, 95% CI 12 to 193; 5 studies, 857 infants; low-certainty evidence); death during first hospitalisation (RR 0.63, 95% CI 0.47 to 0.84; RD -0.02, 95% CI -0.10 to 0.06; NNTB 20, 95% CI 12 to 58; 11 studies, 1424 infants; low-certainty evidence); and BPD among survivors (RR 0.57, 95% CI 0.45 to 0.74; RD -0.08, 95% CI -0.11 to -0.04; NNTB 13, 95% CI 9 to 24; 11 studies, 1567 infants; moderate-certainty evidence). There was no significant difference in risk of air leak requiring drainage (RR 0.58, 95% CI 0.33 to 1.02; RD -0.03, 95% CI -0.05 to 0.00; 6 studies, 1036 infants; low-certainty evidence). None of the studies reported on the outcome of death or survival with neurosensory disability. Only one trial compared surfactant delivery via thin catheter with continuation of CPAP, and one trial compared different strategies of surfactant delivery via thin catheter, precluding meta-analysis.

AUTHORS' CONCLUSIONS

Administration of surfactant via thin catheter compared with administration via an ETT is associated with reduced risk of death or BPD, less intubation in the first 72 hours, and reduced incidence of major complications and in-hospital mortality. This procedure had a similar rate of adverse effects as surfactant administration through an ETT. Data suggest that treatment with surfactant via thin catheter may be preferable to surfactant therapy by ETT. Further well-designed studies of adequate size and power, as well as ongoing studies, will help confirm and refine these findings, clarify whether surfactant therapy via thin tracheal catheter provides benefits over continuation of non-invasive respiratory support without surfactant, address uncertainties within important subgroups, and clarify the role of sedation.

Systematic Reviews in Neonatal Respiratory Care: Are Some Conclusions Misleading?

An increasing amount of information is currently available in neonatal respiratory care. Systematic reviews are an important tool for clinical decision-making. The challenge is to combine studies that address a specific clinical question and have similar characteristics in terms of populations, interventions, comparators, and outcomes, so that their combined results provide a more precise estimate of the effect that can be validly extrapolated into clinical practice. The concept of heterogeneity is reviewed, emphasizing that it should be considered in a wider perspective and not just as a mere statistical test. A case is made of how well-designed studies of the neonatal respiratory literature, when equivocally combined, can provide very precise but potentially biased results. Systematic reviews in this field and others should be rigorously peer-reviewed before publication to avoid misleading readers to potentially biased conclusions.

Surfactant Administration via Thin Catheter: A Practical Guide

Exogenous surfactant replacement is the most effective evidence-based therapy for respiratory distress syndrome in preterm infants. The mode of administration has evolved in the last decade towards less invasive techniques that aim to effectively provide an adequate dose of surfactant, while allowing spontaneous respiration to continue, and with the support of continuous positive airway pressure. Surfactant delivery via aerosolisation, pharyngeal instillation, and laryngeal mask are being actively pursued in research, but have not yet been adopted to any significant degree in clinical practice. Surfactant administration via thin catheter, on the other hand, is becoming more widely used in neonatal intensive care units worldwide and is now an acknowledged alternative to the standard mode of surfactant delivery. Different devices, including nasogastric tubes, vascular catheters, and purpose-built surfactant instillation catheters are used. We present here a contemporary review of surfactant administration via thin catheter, in a practical guide format that reflects the individual and collective scientific opinions of the clinicians who participated in formulating the guide.