Natural surfactant extract versus synthetic surfactant for neonatal respiratory distress syndrome

  • Review
  • Intervention

Authors

  • Roger Soll,

    Corresponding author
    1. University of Vermont, Division of Neonatal-Perinatal Medicine, Burlington, Vermont, USA
    • Roger Soll, Division of Neonatal-Perinatal Medicine, University of Vermont, Fletcher Allen Health Care, Smith 552A, 111 Colchester Avenue, Burlington, Vermont, 05401, USA. Roger.Soll@vtmednet.org.

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  • Fermin Blanco

    1. University of Vermont , College of Medicine, Department of Pediatrics, Burlington, VT, USA
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Abstract

Background

Surfactant preparations are now widely used and have been credited with recent improvements in overall infant mortality (Horbar 1993b, Schwartz 1994). A wide variety of surfactant preparations have been developed and tested. These include synthetic surfactants and surfactants derived from animal sources. Although clinical trials have demonstrated that both synthetic surfactants and natural surfactant preparations are effective, comparison in animal models has suggested that there may be greater efficacy of natural surfactant products, perhaps due to the protein content of natural surfactant (Tooley 1987).

Objectives

To compare the effect of synthetic surfactant to natural surfactant in premature infants at risk for or having respiratory distress syndrome.

Search methods

Searches were made of the Oxford Database of Perinatal Trials, Medline 1975 through December 2000 (MeSH terms: pulmonary surfactant; limits: age groups, newborn infant; publication type, clinical trial), previous reviews including cross references, abstracts, conference and symposia proceedings, expert informants, and journal hand searching in the English language.

Selection criteria

Randomized controlled trials comparing administration of synthetic surfactants to administration of natural surfactant extracts in premature infants at risk for or having respiratory distress syndrome were considered for this review.

Data collection and analysis

Data regarding clinical outcomes including pneumothorax, patent ductus arteriosus, necrotizing enterocolitis, intraventricular hemorrhage (all intraventricular hemorrhage and severe intraventricular hemorrhage), bronchopulmonary dysplasia, chronic lung disease, retinopathy of prematurity, and mortality were excerpted by both reviewers. Data analysis was conducted according to the standards of the Cochrane Neonatal Review Group.

Main results

Eleven trials met inclusion criteria. The meta-analysis shows that the use of natural surfactant rather than synthetic surfactant results in a significant reduction in the risk of pneumothorax (typical relative risk 0.63, 95% CI 0.53, 0.75; typical risk difference -0.04, 95% CI -0.06, -0.03) and the risk of mortality (typical relative risk 0.87, 95% CI 0.76, 0.98; typical risk difference -0.02, 95% CI -0.05, 0.00). Natural surfactant extract is associated with a marginal increase in the risk of intraventricular hemorrhage (typical relative risk 1.09, 95% CI 1.00, 1.19; typical risk difference 0.03, 95% CI 0.00, 0.06), but no increase in grade 3 to 4 intraventricular hemorrhage (typical relative risk 1.08, 95% CI 0.92, 1.28; typical risk difference 0.01, 95% CI -0.01, 0.03). The meta-analyses support a marginal decrease in the risk of bronchopulmonary dysplasia or mortality associated with the use of natural surfactant preparations (typical relative risk 0.95, 95% CI 0.90, 1.01; typical risk difference -0.03, 95% CI -0.06, 0.00). No other relevant differences in outcome are noted.

Authors' conclusions

Both natural surfactant extracts and synthetic surfactant extracts are effective in the treatment and prevention of respiratory distress syndrome. Comparative trials demonstrate greater early improvement in the requirement for ventilator support, fewer pneumothoraces, and fewer deaths associated with natural surfactant extract treatment. Natural surfactant may be associated with an increase in intraventricular hemorrhage, though the more serious hemorrhages (Grade 3 and 4) are not increased. Despite these concerns, natural surfactant extracts would seem to be the more desirable choice when compared to currently available synthetic surfactants.

摘要

背景

比較天然的表面張力素萃取物與合成的表面張力素用於新生兒呼吸窘迫症候群

表面張力素的製劑現今被廣泛使用,並且被相信與嬰兒的存活率進步有關 (Horbar 1993b, Schwartz 1994) ,很多表面張力製劑的種類被發展與測試,包括合成的表面張力素及從動物萃取的表張力素,雖然臨床試驗顯示合成表面張力素和天然表面張力素兩者都有效,但在動物實驗顯示天然表面張力素有較佳的效力,可能與天然表面張力素的蛋白質成分有關。

目標

比較合成表面張力素和天然表面張力素對於早產兒呼吸窘迫症候群的效用。

搜尋策略

搜尋Oxford Database of Perinatal Trials、MEDLINE從1975年到2000年12月, (MeSH terms: pulmonary surfactant; limits: age groups, newborn infant; publication type, clinical trial) ,並搜尋先前回顧性文章包括交互參考資料、摘要、會議及研討會紀錄和專業資料,以手動搜尋英文期刊。

選擇標準

這篇回顧性文章,將選擇以隨機對照試驗,來比較施打合成表面張力素和施打天然萃取表面張力素用在可能發生或已發生呼吸窘迫症候群的早產兒。

資料收集與分析

有關臨床結果的資料包括氣胸、開放性動脈導管、壞死性腸炎、腦室內出血(所有的腦室內出血及嚴重的腦室內出血)、肺支氣管發育不全、慢性肺疾病、早產兒視網膜病變以及死亡率都被兩位檢閱者節錄。資料分析是依據考科藍新生兒回顧團體(Cochrane Neonatal Review Group)的標準。

主要結論

11個臨床試驗符合標準,統合分析的結果發現天然表面張力素比合成表面張力素明顯降低發生氣胸的風險(典型相對危險性0.63,95% 信賴區間0.53、0.75;典型危險差 −0.04,95% 信賴區間 −0.06、 −0.03)以及死亡的風險(典型相對危險性0.87,95% 信賴區間0.76、0.98;典型危險差 −0.02,95% 信賴區間 −0.05、0.00)。天然萃取表面張力素略增加腦室內出血的風險(典型相對危險性1.09,95% 信賴區間1.00、1.19;典型危險差003,95% 信賴區間0.00、0.06),但沒有增加第3度到第4度腦室內出血(典型相對危險性1.08,95% 信賴區間0.92、1.28;典型危險差001,95% 信賴區間 −0.01、0.03)。統合分析支持使用天然表面張力素製劑略減低肺支氣管發育不全或死亡的風險(典型相對危險性0.95,95% 信賴區間0.90、1.01;典型危險差003,95% 信賴區間 −0.06、0.00)。未發現其他具統計上有意義差別之預後項目。

作者結論

天然表面張力素和合成表面張力素皆對治療及預防呼吸窘迫症候群有效,比較性試驗顯示使用天然萃取表面張力素對於呼吸器支持之需求有較佳的早期改善、較少氣胸及較少死亡。天然表面張力素可能與較多腦室內出血有關,然而並未增加較嚴重的腦室內出血(第3度及第4度)。除了這些擔心,天然萃取表面張力素似乎比現今可用的合成表面張力素為較令人滿意的選擇。

翻譯人

本摘要由馬偕醫院王臻誼翻譯。

此翻譯計畫由臺灣國家衛生研究院 (National Health Research Institutes, Taiwan) 統籌。

總結

某些證據顯示天然萃取表面張力素讓有呼吸窘迫的嬰兒有較佳的預後。肺部表面張力素是一種可以降低表面張力預防肺泡塌陷的物質,發生呼吸窘迫症候群的新生兒因為肺部不成熟而缺乏此物質,可給予天然或合成的表面張力素藉以減輕呼吸窘迫症候群的嚴重度。回顧這些比較天然表面張力素與合成表面張力素的試驗,發現使用天然萃取表面張力素的嬰兒,有較少氣胸(氣體在肺腔)及死亡的風險。

Plain language summary

Natural surfactant extract versus synthetic surfactant for neonatal respiratory distress syndrome

Some evidence that natural surfactant extract leads to better outcomes in babies with respiratory distress syndrome. Pulmonary surfactant is a substance that prevents the air sacs of the lungs from collapsing by reducing surface tension. Newborn babies with respiratory ristress syndrome (RDS) have immature lungs and are often lacking in this substance. Additional natural or synthetic surfactant can be given to these babies. Surfactants have been found to decrease the severity of RDS and increase the survival rates of babies with RDS. The review of trials compared natural with synthetic surfactant extracts and found a decrease in the risk of pneumothorax (air in the lung cavity) and death in babies receiving natural surfactant extracts.

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