Surfactant therapy in neonates with respiratory failure due to haemorrhagic pulmonary oedema

Use of surfactant beyond respiratory distress syndrome, what is the evidence?

Surfactant replacement therapy is currently approved by the United States Food and Drug Administration (FDA) for premature infants with respiratory distress syndrome (RDS) caused by surfactant deficiency due to immaturity. There is strong evidence that surfactant decreases mortality and air leak syndromes in premature infants with RDS. However, surfactant is also used "off-label" for respiratory failure beyond classic RDS. This review discusses current evidence for the use of off-label surfactant therapy for (1) term infants with lung disease such as meconium aspiration syndrome (MAS), pneumonia/sepsis, and congenital diaphragmatic hernia (2) premature infants after 72 h for acute respiratory failure, and (3) the use of surfactant lavage. At last, we briefly describe the use of surfactants for drug delivery and the current evidence on evaluating infants for surfactant deficiency.

Neonatal surfactant therapy beyond respiratory distress syndrome

Whilst exogenous surfactant therapy is central to the management of newborn infants with respiratory distress syndrome, its use in other neonatal lung diseases remains inconsistent and controversial. Here we discuss the evidence and experience in relation to surfactant therapy in newborns with other lung conditions in which surfactant may be deficient or dysfunctional, including meconium aspiration syndrome, pneumonia, congenital diaphragmatic hernia and pulmonary haemorrhage. We find that, for all of these diseases, administration of exogenous surfactant as bolus therapy is frequently associated with transient improvement in oxygenation, likely related to temporary mitigation of surfactant inhibition in the airspaces. However, for none of them is there a lasting clinical benefit of surfactant therapy. By virtue of interrupting disease pathogenesis, lavage therapy with dilute surfactant in MAS offers the greatest possibility of a more pronounced therapeutic effect, but this has yet to be definitively proven. Lavage therapy also involves a greater degree of procedural risk.

Surfactant Replacement Therapy: What’s the New Future?

Surfactant replacement therapy (SRT) can be lifesaving for preterm babies with respiratory distress because of surfactant deficiency. Attempts have been made over the last two decades to make surfactant administration as smooth and as nontraumatic as possible. Lesser invasive techniques, such as less invasive surfactant administration, minimally invasive surfactant therapy, intrapartum pharyngeal surfactant therapy, and the laryngeal mask airway, are preferred over invasive techniques like intubate surfactant extubation to reduce trauma and peridosing adverse effects. However, at present, aerosolized surfactant (AS) via nebulization remains the only truly noninvasive method of SRT. Many animal and human studies have shown promising results with the use of AS with similar clinical effects to an instilled surfactant with greater safety potential. But still AS has not been adapted to routine neonatal care. There is still scope for studies to further strengthen the role of AS. Also, SRT is a constantly changing field with new innovations revolutionizing and replacing old techniques.

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.

Ultra-slim flexible bronchoscopy-guided topical hemostatic drugs administration for the management of life-threatening refractory pulmonary hemorrhage in a preterm infant: Case report

Pulmonary hemorrhage (PH) is a rare acute catastrophic event with high mortality among neonates, especially preterm infants. Primary treatments included pulmonary surfactant, high-frequency oscillatory ventilation, epinephrine, coagulopathy management, and intermittent positive pressure ventilation. However, there are still challenges in diagnosing and treating refractory or focal pulmonary hemorrhages. Ultra-slim bronchoscopy has been widely used in the field of critically ill children and is increasingly being done in neonates with critical respiratory disease in recent years. In this study, we report a case with refractory pulmonary hemorrhage in premature infants, which was finally diagnosed as localized hemorrhage in the upper left lobe and cured by ultra-slim bronchoscopy-guided topical hemostatic drug administration. Bronchoscopy is an optional, safe, and practicable technique for early diagnosis and direct injection therapy of neonatal PH in managing life-threatening PH.

SHORT-TERM OUTCOME OF MASSIVE PULMONARY HEMORRHAGE IN PRETERM INFANTS IN TUZLA CANTON

Massive pulmonary hemorrhage (MPH) in neonates is a severe condition followed by many complications and associated with a high mortality rate. The aim of this study was to present the incidence, possible risk factors, and short-term outcome of neonatal MPH in Tuzla Canton. We retrospectively analyzed data on neonates with MPH from January 2015 to December 2017. On statistical analysis, standard methods of descriptive statistics were used. During the three-year study period, 16 neonates developed MPH, 5 (31.25%) male and 11 (68.75%) female. Their mean gestational age was 29.48±2.21 weeks and mean birth weight 1276.69±387.65 grams. Seven (43.75%) neonates survived and 9 (56.25%) died. Significant differences between the two outcome groups (survivors/died) were found in gestational age, birth weight, birth length, 5-minute Apgar score, and length of treatment at the Neonatal Intensive Care Unit. In Tuzla Canton, MPH occurred mainly in preterm neonates requiring mechanical ventilation, with the incidence of 1.91% of total premature births. The short-term outcome was uncertain, with a high mortality rate of 56.25%. Lower gestational age, lower birth weight, lower birth length and lower 5-minute Apgar score were confirmed as risk factors for poor short-term outcome.

Guidelines for surfactant replacement therapy in neonates

Surfactant replacement therapy (SRT) plays a pivotal role in the management of neonates with respiratory distress syndrome (RDS) because it improves survival and reduces respiratory morbidities. With the increasing use of noninvasive ventilation as the primary mode of respiratory support for preterm infants at delivery, prophylactic surfactant is no longer beneficial. For infants with worsening RDS, early rescue surfactant should be provided. While the strategy to intubate, give surfactant, and extubate (INSURE) has been widely accepted in clinical practice, newer methods of noninvasive surfactant administration, using thin catheter, laryngeal mask airway, or nebulization, are being adopted or investigated. Use of SRT as an adjunct for conditions other than RDS, such as meconium aspiration syndrome, may be effective based on limited evidence.

Les directives pour le traitement par surfactant exogène chez le nouveau-né

Le traitement par surfactant exogène joue un rôle essentiel dans la prise en charge des nouveau-nés atteints du syndrome de détresse respiratoire (maladie des membranes hyalines) parce qu’il améliore la survie et limite les troubles respiratoires. Puisque la ventilation non invasive est de plus en plus utilisée comme principal mode d’assistance respiratoire chez le nouveau-né prématuré à la naissance, l’administration prophylactique de surfactant n’est plus bénéfique. L’administration précoce de surfactant sous forme de traitement de rattrapage est préconisée chez les nouveau-nés dont le syndrome de détresse respiratoire s’aggrave. La stratégie qui consiste à intuber, administrer du surfactant, puis extuber (INSURE) est largement acceptée en pratique clinique, mais des méthodes non invasives plus récentes à l’aide d’un cathéter fin, d’un masque laryngé ou d’un nébuliseur sont en cours d’adoption ou d’exploration. Selon des données limitées, un traitement d’appoint par surfactant exogène pourrait être efficace pour traiter d’autres affections que le syndrome de détresse respiratoire, telles que le syndrome d’aspiration méconiale.

Surfactant for pulmonary haemorrhage in neonates

BACKGROUND

In the 1960s and 1970s, pulmonary haemorrhage (PH) occurred mainly in full-term infants with pre-existing illness with an incidence of 1.3 per 1000 live births. Risk factors for PH included severity of illness, intrauterine growth restriction, patent ductus arteriosus (PDA), coagulopathy and the need for assisted ventilation. Presently, PH occurs in 3% to 5% of preterm ventilated infants with severe respiratory distress syndrome (RDS) who often have a PDA and have received surfactant. The cause of PH is thought to be due to rapid lowering of intrapulmonary pressure, which facilitates left to right shunting across a PDA and an increase in pulmonary blood flow. Retrospective case reports and one prospective uncontrolled study have shown promising results for surfactant in treating PH.

OBJECTIVES

To evaluate the effect of surfactant treatment compared to placebo or no intervention on mortality and morbidities in neonates with PH.

SEARCH METHODS

For this update The Cochrane Library, Issue 2, 2012; MEDLINE; EMBASE; CINAHL; Clinicaltrials.gov; Controlled-trials.com; proceedings (2000 to 2011) of the Annual Meetings of the Pediatric Academic Societies (Abstracts2View) and Web of Science were searched on 8 February 2012.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that evaluated the effect of surfactant in the treatment of PH in intubated term or preterm (< 37 weeks) neonates with PH. Infants were included up to 44 weeks' postmenstrual age. The interventions studied were intratracheal instillation of surfactant (natural or synthetic, regardless of dose) versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

If studies were identified by the literature search, the planned analyses included risk ratio, risk difference, number needed to treat to benefit or to harm for dichotomous outcomes, and mean difference for continuous outcomes, with their 95% confidence intervals. A fixed-effect model would be used for meta-analyses. The risk of bias for included trials would be assessed. Heterogeneity tests, including the I2 statistic, would be performed to assess the appropriateness of pooling the data and the results would be reported.

MAIN RESULTS

No trials were identified.

AUTHORS' CONCLUSIONS

No randomised or quasi-randomised trials that evaluated the effect of surfactant in PH were identified. Therefore, no conclusions from such trials can be drawn. In view of the promising results from studies with less strict study designs than a randomised controlled trial, there is reason to conduct further trials of surfactant for the treatment of PH in neonates.

Surfactant replacement therapy: from biological basis to current clinical practice

This review summarizes the current knowledge on the physiological action of endogenous and exogenous pulmonary surfactant, the role of different types of animal-derived and synthetic surfactants for RDS therapy, different modes of administration, potential risks and strategies of ventilation, and highlights the most promising aims for future development. Scientists have clarified the physicochemical properties and functions of the different components of surfactant, and part of this successful research is derived from the characterization of genetic diseases affecting surfactant composition or function. Knowledge from functional tests of surfactant action, its immunochemistry, kinetics and homeostasis are important also for improving therapy with animal-derived surfactant preparations and for the development of modified surfactants. In the past decade newly designed artificial surfactants and additives have gained much attention and have proven different advantages, but their particular role still has to be defined. For clinical practice, alternative administration techniques as well as postsurfactant ventilation modes, taking into account alterations in lung mechanics after surfactant placement, may be important in optimizing the potential of this most important drug in neonatology.

Pulmonary Hemorrhage in the Neonate

A case study of a 37 weeks' gestational age male infant, presenting with bloody fluid orally shortly after birth. The presentation, etiology, diagnosis, and management of pulmonary hemorrhage are addressed.

Loss of Surfacten® during bolus administration with a feeding catheter

BACKGROUND

Surfactant replacement therapy is widely used for treating neonatal respiratory distress syndrome, but insufficient evidence is available on the use of Surfacten® (S-TA). This study investigated the inadvertent loss of S-TA during instillation via feeding catheters with different bore sizes.

METHODS

In this bench-based study, we measured the weight of syringes and tubes before and after surfactant treatment using a high-accuracy balance, and determined the amount of S-TA lost in tubes. We injected 120 mg of S-TA suspended in 4 or 3 mL into tubes followed with or without air boluses. Experiments were performed in triplicate. Percent weight loss of S-TA in each tube was calculated with or without air boluses.

RESULTS

Percent weight loss of S-TA was significantly higher in larger-bore tubes (P < 0.01, overall ANOVA), and was significantly lower after air bolus flushing in 3 Fr, 4 Fr, and 5 Fr tubes (P < 0.005, respectively). The 3 mL S-TA suspensions had a significantly higher percent loss than the 4 mL S-TA suspensions when using 4 Fr and 5 Fr tubes, and the 5 Fr closed system (P < 0.05, respectively).

CONCLUSIONS

Routine air bolus flushing effectively reduces S-TA loss in tubes. The 3 mL S-TA suspensions appear to be more susceptible to inadvertent S-TA loss during instillation. Therefore, caution is warranted for this procedure.

Surfactant Replacement Therapy Beyond Respiratory Distress Syndrome in Neonates

BACKGROUND

Surfactant replacement therapy is an established modality of treatment in preterm neonates with respiratory distress syndrome. In addition, there are various neonatal respiratory disorders which are characterized by surfactant deficiency in which surfactant therapy can be a feasible and safe option.

OBJECTIVE

To collate the literature on the use of surfactant replacement therapy in neonates beyond respiratory distress syndrome and examine the evidence and newer developments.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE, and EMBASE up to June 2015; and previous reviews, including cross-references, abstracts, and conference proceedings.

RESULTS

Evidence supports surfactant administration via bolus route in neonates with meconium aspiration syndrome, but additional robust evidence is required before its adoption in clinical practice. There is limited evidence to support surfactant therapy in neonates with pneumonia, pulmonary hemorrhage and bronchopulmonary dysplasia. Large multicenter randomized trials are needed to cement or refute the role of surfactant therapy in these disorders.

Pulmonary Hemorrhage (PH) in Extremely Low Birth Weight (ELBW) Infants: Successful Treatment with Surfactant

We report a case of an extremely low birth weight (ELBW) infant presenting with pulmonary hemorrhage (PH) in which we have given surfactant after an acute episode of bleeding with severe intractable hypoxemia. Surfactant replacement therapy showed improvement in Mean Airway Pressure (MAP) and oxygenation indices. Our case suggests that surfactant replacement therapy is useful in PH.

Surfactant

Exogenous pulmonary surfactant, widely used in neonatal care, is one of the best-studied treatments in neonatology, and its introduction in the 1990s led to a significant improvement in neonatal outcomes in preterm infants, including a decrease in mortality. This chapter provides an overview of surfactant composition and function in health and disease and summarizes the evidence for its clinical use.

Oxygen requirement and surfactant therapy in preterm infants after delivery

BACKGROUND

Several reports have shown the beneficial effects of early or prophylactic surfactant therapy for preterm infants, who often develop respiratory distress syndrome. No report, however, has addressed which infants should receive surfactant therapy in the delivery room. Therefore, the aim of this study was to assess the validity of identifying infants who need surfactant therapy based on fraction of inspiratory oxygen (FiO2 ) requirement in the delivery room.

METHODS

In this observational, retrospective study, FiO2 given in the delivery room, use of surfactant therapy, stable microbubble test (SMT) results, and changes in FiO2 both before and after surfactant therapy were reviewed in infants born at <33 weeks' gestation.

RESULTS

Overall, 170 infants were included. Forty infants were given oxygen with FiO2 ≥0.6, and all received surfactant therapy. Of these 40 infants, FiO2 could be reduced in 36 (90%) by an average of 0.46 after surfactant therapy. SMT was done in 22 of 40 infants, and surfactant insufficiency was suspected in 20 (91%). In contrast, 81 of 102 infants (79%) with FiO2 <0.4 did not need surfactant therapy within 48 h after birth.

CONCLUSIONS

Preterm infants who need FiO2 ≥0.6 in the delivery room appear to be at high risk of surfactant insufficiency and would benefit from surfactant. Surfactant therapy would provide a more effective resuscitation method for preterm infants, and thus a larger prospective study is needed to confirm these results.

Exogenous surfactant therapy in 2013: what is next? Who, when and how should we treat newborn infants in the future?

Background

Surfactant therapy is one of the few treatments that have dramatically changed clinical practice in neonatology. In addition to respiratory distress syndrome (RDS), surfactant deficiency is observed in many other clinical situations in term and preterm infants, raising several questions regarding the use of surfactant therapy.

Objectives

This review focuses on several points of interest, including some controversial or confusing topics being faced by clinicians together with emerging or innovative concepts and techniques, according to the state of the art and the published literature as of 2013. Surfactant therapy has primarily focused on RDS in the preterm newborn. However, whether this treatment would be of benefit to a more heterogeneous population of infants with lung diseases other than RDS needs to be determined. Early trials have highlighted the benefits of prophylactic surfactant administration to newborns judged to be at risk of developing RDS. In preterm newborns that have undergone prenatal lung maturation with steroids and early treatment with continuous positive airway pressure (CPAP), the criteria for surfactant administration, including the optimal time and the severity of RDS, are still under discussion. Tracheal intubation is no longer systematically done for surfactant administration to newborns. Alternative modes of surfactant administration, including minimally-invasive and aerosolized delivery, could thus allow this treatment to be used in cases of RDS in unstable preterm newborns, in whom the tracheal intubation procedure still poses an ethical and medical challenge.

Conclusion

The optimization of the uses and methods of surfactant administration will be one of the most important challenges in neonatal intensive care in the years to come.

Short-term outcome of pulmonary hemorrhage in very-low-birth-weight preterm infants

BACKGROUND

Severe pulmonary hemorrhage is a serious complication with a high mortality rate in preterm infants with respiratory distress syndrome (RDS) after surfactant therapy. The aim of this study is to evaluate the efficacy of our current management strategy for neonates with severe pulmonary hemorrhage.

MATERIALS AND METHODS

Very-low-birth-weight (VLBW) infants who developed severe pulmonary hemorrhage were studied from January 2006 to August 2011. Treatment for severe pulmonary hemorrhage in our neonatal intensive care unit (NICU) included intratracheal epinephrine spraying/irrigation, blood component therapy, and as necessary, surfactant supplement therapy was administered in cases that secondary RDS was diagnosed. High frequency oscillatory ventilation (HFOV) was utilized when hypoxia or respiratory acidosis persisted under conventional mechanical ventilation (CMV). We then described the clinical courses of severe pulmonary hemorrhage following our management.

RESULTS

A total of 18 (3.2%) out of 469 VLBW infants developed severe pulmonary hemorrhage. The mean gestational age was 27 weeks, the mean birth weight was 822 g, and the onset age was 2.5 days after birth. There was no severe pulmonary hemorrhage-associated mortality during this period with the exception of one case, in which an infant died after the parents refused to do further therapy. Sixteen (88.8%) neonates had RDS and 13 received surfactant therapy. Twelve (66.6%) cases developed secondary RDS following the onset of severe pulmonary hemorrhage, and four cases received surfactant supplement therapy. In the surfactant supplement group, alveolar-arterial oxygen difference (AaDO2) and oxygenation index (OI) during the 2-4 hours postpulmonary hemorrhage period showed statistically significant improvement, whereas the other group only showed a tendency toward improvement without reaching statistical significance when compared to the baseline data. Duration of high oxygen requirement [defined as fraction of inspired oxygen (FiO2) > 40%] was also less in the surfactant supplement group.

CONCLUSION

This data suggests that our current strategy is effective for treating severe pulmonary hemorrhage in VLBW infants. Surfactant therapy for severe pulmonary hemorrhage may also be beneficial for improving lung function and may shorten the duration of high oxygen requirement.

Delivery and performance of surfactant replacement therapies to treat pulmonary disorders

Lung surfactant is crucial for optimal pulmonary function throughout life. An absence or deficiency of surfactant can affect the surfactant pool leading to respiratory distress. Even if the coupling between surfactant dysfunction and the underlying disease is not always well understood, using exogenous surfactants as replacement is usually a standard therapeutic option in respiratory distress. Exogenous surfactants have been extensively studied in animal models and clinical trials. The present article provides an update on the evolution of surfactant therapy, types of surfactant treatment, and development of newer-generation surfactants. The differences in the performance between various surfactants are highlighted and advanced research that has been conducted so far in developing the optimal delivery of surfactant is discussed.

Respiratory support practices in infants born at term in the United Kingdom

Infants born at term requiring mechanical ventilation suffer significant mortality and morbidity, yet few studies have tried to identify the optimum respiratory support for such infants. We, therefore, hypothesised that practice would vary, particularly between different levels of neonatal care provision. The lead clinicians of all 212 UK neonatal units were asked to complete an electronic web-based survey regarding respiratory support practices for term-born infants. Survey questions included the level of neonatal care provided, number of term-born infants ventilated per annum, initial and rescue ventilation modes and whether surfactant or inhaled nitric oxide (NO) were used. The overall response rate was 82 %. A greater proportion of neonatal intensive care units (NICUs) compared to local neonatal units (LNUs) stated that they used volume-targeting, particularly for infants with RDS (p = 0.0006) or congenital pneumonia (p = 0.0005). High-frequency oscillatory ventilation was stated as initial mode by a greater proportion of NICUs compared to LNUs and special care units (SCUs), particularly for respiratory distress syndrome (p < 0.0001) or persistent pulmonary hypertension of the newborn (p < 0.001). Continuous mandatory ventilation was stated to be the rescue mode by a greater proportion of LNUs/SCUs compared to NICUs (p < 0.0001). Surfactant was stated to be most commonly given for respiratory distress syndrome (79 % of units) and MAS (61 % of units); surfactant use was lowest in SCUs (p < 0.0001); inhaled NO was infrequently used by LNUs and SCUs. Conclusions There was considerable variation in respiratory support practices for term-born infants, particularly between different levels of neonatal care provision.

Surfactant therapy for maternal blood aspiration: an unusual cause of neonatal respiratory distress syndrome

Surfactant replacement therapy is the main treatment of neonatal respiratory distress syndrome. However, surfactant therapy has been shown to be effective in the treatment of other diseases causing neonatal respiratory diseases such as pulmonary hemorrhage, meconium aspiration syndrome, pneumonia/sepsis, pulmonary edema or acute lung injury resulting a secondary surfactant deficiency (SSD). Rarely, as like as in the present patient, exogenous blood aspiration such as breast milk or formula aspiration may lead to SSD. Blood in alveolus leads to a significant biochemical and functional disturbance of the surfactant system and inhibits surfactant production. Here, the authors report a preterm infant of 33 wk gestational age with secondary surfactant deficiency due to maternal blood aspiration because of abruptio placentae. She was received two courses of beractant, a natural bovine surfactant, therapy in 24 h. She was extubated on second day and did not require oxygen on 4(th) day. To the authors' knowledge, this is the first reported case of SSD due to maternal blood aspiration treated with surfactant. In conditions such as abruptio placentae, infant should be protected from blood aspiration and if respiratory distress occurs, surfactant inhibition and need for surfactant administration should be considered.

Surfactant for pulmonary haemorrhage in neonates

BACKGROUND

In the 1960s and 1970s, pulmonary haemorrhage (PH) occurred mainly in full-term infants with pre-existing illness with an incidence of 1.3 per 1000 live births. Risk factors for PH included severity of illness, intrauterine growth restriction, patent ductus arteriosus (PDA), coagulopathy and the need for assisted ventilation. Presently, PH occurs in 3% to 5% of preterm ventilated infants with severe respiratory distress syndrome (RDS) who often have a PDA and have received surfactant. The cause of PH is thought to be due to rapid lowering of intrapulmonary pressure, which facilitates left to right shunting across a PDA and an increase in pulmonary blood flow. Retrospective case reports and one prospective uncontrolled study have shown promising results for surfactant in treating PH.

OBJECTIVES

To evaluate the effect of surfactant treatment compared to placebo or no intervention on mortality and morbidities in neonates with PH.

SEARCH METHODS

For this update The Cochrane Library, Issue 2, 2012; MEDLINE; EMBASE; CINAHL; Clinicaltrials.gov; Controlled-trials.com; proceedings (2000 to 2011) of the Annual Meetings of the Pediatric Academic Societies (Abstracts2View) and Web of Science were searched on 8 February 2012.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that evaluated the effect of surfactant in the treatment of PH in intubated term or preterm (< 37 weeks) neonates with PH. Infants were included up to 44 weeks' postmenstrual age. The interventions studied were intratracheal instillation of surfactant (natural or synthetic, regardless of dose) versus placebo or no intervention.

DATA COLLECTION AND ANALYSIS

If studies were identified by the literature search, the planned analyses included risk ratio, risk difference, number needed to treat to benefit or to harm for dichotomous outcomes, and mean difference for continuous outcomes, with their 95% confidence intervals. A fixed-effect model would be used for meta-analyses. The risk of bias for included trials would be assessed. Heterogeneity tests, including the I(2) statistic, would be performed to assess the appropriateness of pooling the data and the results would be reported.

MAIN RESULTS

No trials were identified.

AUTHORS' CONCLUSIONS

No randomised or quasi-randomised trials that evaluated the effect of surfactant in PH were identified. Therefore, no conclusions from such trials can be drawn. In view of the promising results from studies with less strict study designs than a randomised controlled trial, there is reason to conduct further trials of surfactant for the treatment of PH in neonates.

Use of therapeutic surfactant lavage in a preterm infant with massive pulmonary hemorrhage

We report a case of a premature infant presenting with recurrent pulmonary hemorrhage in which we performed a therapeutic lavage with diluted surfactant after an acute episode of bleeding with severe intractable hypoxemia. Repeated small aliquots of diluted surfactant (10×2 mL) allowed rapid improvement in oxygenation and reduction of required mean airway pressures during high frequency oscillatory ventilation. This observation may suggest that surfactant lavage could be beneficial in massive pulmonary hemorrhage in infants. A randomized controlled trial might be needed to clarify the potential benefit of this therapeutic intervention on outcome of infants suffering from this life-threatening complication.

Surfactant for pulmonary hemorrhage in neonates

BACKGROUND

In the late 1960's and 1970's, pulmonary hemorrhage (PH) occurred mainly in full term infants with severe pre-existing illness. The incidence of PH was quoted as 1.3 per 1,000 live births. In the older medical literature, the risk factors associated with PH included the severity of the associated illness, intrauterine growth restriction, patent ductus arteriosus (PDA), coagulopathy, and the need for assisted ventilation. Presently, PH occurs mainly in preterm ventilated infants with severe respiratory distress syndrome (RDS) who often have a PDA and have received surfactant. Currently, PH complicates the hospital course of 3-5% of preterm infants with RDS. Although not clear, the cause of PH is thought to be due to a rapid lowering of intrapulmonary pressure, which facilitates left to right shunting across a patent ductus arteriosus and an increase in pulmonary blood flow. Retrospective case reports and one prospective uncontrolled study that used surfactant for PH in neonates have shown promising results in treating PH.

OBJECTIVES

To evaluate the effect of surfactant treatment compared to placebo or no intervention on mortality in neonates with pulmonary hemorrhage. In addition, the review will evaluate the effect of surfactant treatment on neonatal morbidities associated with PH compared to placebo or no intervention.

SEARCH STRATEGY

The following databases were searched in January 2008: The Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2007) and MEDLINE from 1966 and EMBASE from 1980 to the time of the full review using the OVID interface. The proceedings of the Annual Meetings of the Pediatric Academic Societies and the European Society of Pediatric Research published in Pediatric Research or electronically on their web sites were searched from 1994 to the time of the full review. Science citation index (Web of Science) was searched for authors quoting key references of observational studies.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials that evaluated the effect of surfactant in the treatment of PH in intubated term or preterm (< 37 weeks) neonates with PH. Infants were included up to 44 weeks postmenstrual age. Infants were included regardless of prior treatment with surfactant. The interventions studied were intratracheal instillation of surfactant (natural or synthetic, regardless of dose) vs. placebo or no intervention.

DATA COLLECTION AND ANALYSIS

If studies were identified by the literature search, the planned analyses included calculation of the relative risk (RR), risk difference (RD), number needed to treat (NNT) or number needed to harm (NNH) for dichotomous outcomes, and weighed mean difference (WMD) for continuous outcomes, with their 95% confidence intervals (CI). A fixed effects model would be used for meta-analyses. Heterogeneity tests, including the I- squared (I(2)) statistic, would be performed to assess the appropriateness of pooling the data and the results would be reported.

MAIN RESULTS

No trials were identified.

AUTHORS' CONCLUSIONS

No randomized or quasi-randomized trials that evaluated the effect of surfactant in PH were identified. Therefore, no conclusions from such trials can be drawn. In view of the promising results from studies with less strict study designs than a randomized controlled trial, there is reason to conduct further trials of surfactant for the treatment of PH in neonates.

Secondary surfactant administration in neonates with respiratory decompensation

OBJECTIVE

To evaluate blood gases and ventilatory parameters before and after two doses of surfactant in premature infants with respiratory decompensation after recovery from primary respiratory distress syndrome (RDS).

STUDY DESIGN

This prospective pilot study enrolled infant's > or =500 g birth weight, from 7 days to 3 months of age, with a secondary respiratory decompensation lasting at least 4 h prior to study entry. Infants received two doses of surfactant, 12 h apart.

RESULT

A total of 20 neonates qualified for secondary surfactant administration. PCO2 (P<0.001); pH (P<0.001); mean airway pressure (P<0.05); FiO2 (P<0.05); modified ventilatory indices (P<0.004) and respiratory severity scores (P<0.001) improved significantly at both 12 and 24 h after surfactant administration.

CONCLUSION

Secondary surfactant administration may be effective in reducing short-term ventilatory requirements in neonates who have a respiratory decompensation after recovery from initial RDS. Randomized controlled trials are needed to confirm these preliminary findings.

Surfactant-replacement therapy for respiratory distress in the preterm and term neonate

Respiratory failure secondary to surfactant deficiency is a major cause of morbidity and mortality in preterm infants. Surfactant therapy substantially reduces mortality and respiratory morbidity for this population. Secondary surfactant deficiency also contributes to acute respiratory morbidity in late-preterm and term neonates with meconium aspiration syndrome, pneumonia/sepsis, and perhaps pulmonary hemorrhage; surfactant replacement may be beneficial for these infants. This statement summarizes indications, administration, formulations, and outcomes for surfactant-replacement therapy. The impact of antenatal steroids and continuous positive airway pressure on outcomes and surfactant use in preterm infants is reviewed. Because respiratory insufficiency may be a component of multiorgan dysfunction, preterm and term infants receiving surfactant-replacement therapy should be managed in facilities with technical and clinical expertise to administer surfactant and provide multisystem support.

What's new in surfactant? A clinical view on recent developments in neonatology and paediatrics

Surfactant therapy has significantly changed clinical practice in neonatology over the last 25 years. Recent trials in infants with respiratory distress syndrome (RDS) have not shown superiority of any natural surfactant over another. Advancements in the development of synthetic surfactants are promising, yet to date none has been shown to be superior to natural preparations. Ideally, surfactant would be administered without requiring mechanical ventilation. An increasing number of studies investigate the roles of alternative modes of administration and the use of nasal continuous positive airway pressure to minimise the need for mechanical ventilation. Whether children with other lung diseases benefit from surfactant therapy is less clear. Evidence suggests that infants with meconium aspiration syndrome and children with acute lung injury/acute respiratory distress syndrome may benefit, while no positive effect of surfactant is seen in infants with congenital diaphragmatic hernia. However, more research is needed to establish potential beneficial effects of surfactant administration in children with lung diseases other than RDS. Furthermore, genetic disorders of surfactant metabolism have recently been linked to respiratory diseases of formerly unknown origin. It is important to consider these disorders in the differential diagnosis of unexplained respiratory distress although no established treatment is yet available besides lung transplantation for the most severe cases.

CONCLUSION

Research around surfactant is evolving and recent developments include further evolution of synthetic surfactants, evaluation of surfactant as a therapeutic option in lung diseases other than RDS and the discovery of genetic disorders of surfactant metabolism. Ongoing research is essential to continue to improve therapeutic prospects for children with serious respiratory disease involving disturbances in surfactant.

Expanded use of surfactant therapy in newborns

Although there is no doubt that administration of exogenous surfactant to very preterm babies who have respiratory distress syndrome is safe and efficacious, surfactant inactivation or deficiency plays a role in the pathophysiology of other pulmonary disorders affecting newborn infants. Preliminary data suggest that there may be a role for surfactant administration to babies who have meconium aspiration syndrome, pneumonia, and possibly bronchopulmonary dysplasia. Further investigation is necessary but seems warranted.

The Respiratory System

One of the most critical events of birth is the conversion of the fluid-filled lung, unimportant to fetal intrauterine existence, into a hollow organ distended with air and capable of gaseous exchange sufficient to support life. Indeed, it has been argued that the major determinant of perinatal survival is respiratory function (Wigglesworth and Desai 1982).

The failure to make this conversion adequately may lead, directly or indirectly, to infant death, and the pathologist often needs to assess the contribution made by respiratory inadequacy to the sequence of events leading to death. In the preterm infant, problems are mainly related to pulmonary immaturity and associated therapy. In the mature infant, birth asphyxia primarily results in cerebral damage but can engender significant respiratory complications when associated with aspiration of meconium. Even in stillbirths, where primary pulmonary pathology is rarely a cause of death, lung pathology may provide clues to antecedent events. Poor lung growth and maturation may point to the presence of pathology elsewhere. Consequently, adequate pathological investigation of the fetal or infant respiratory system is critical in any perinatal autopsy.

Successful use of surfactant to treat severe intrapulmonary hemorrhage after iatrogenic lung injury--A case report

OBJECTIVE

To describe the beneficial clinical effect of the use of surfactant in a patient with severe unilateral pulmonary hemorrhage after iatrogenic lung injury during corrective surgery for congenital heart defects.

DESIGN

Case report.

SETTING

Pediatric cardiac intensive care unit of a tertiary care hospital.

PATIENT

An 11-wk-old boy.

INTERVENTIONS

Intratracheal instillation of 4 mL (100 mg) of surfactant (Survanta) per kilogram of body weight to treat profound and refractory hypoxia and hypercapnia despite high-ventilation pressures, high respiratory rate, and the use of nitric oxide caused by severe pulmonary hemorrhage and atelectasis.

MEASUREMENTS AND MAIN RESULTS

The aggressive ventilation variables could be reduced within the following 2 hrs after surfactant use (from Fio2 0.8, peak inspiratory pressure 36 cm, positive end-expiratory pressure 10 cm, respiratory rate 50, tidal volume 63 mL, and nitric oxide 10 ppm to Fio2 0.4, peak inspiratory pressure 28 cm, positive end-expiratory pressure 10, respiratory rate 40, tidal volume 38 mL, and nitric oxide 5 ppm). There was rapid improvement of clinical variables (inotropic support, chest radiograph) as well as oxygenation (Pao2 from 56 to 149 mm Hg), CO2 exchange (Paco2 from 85 to 39 mm Hg), and acidosis (from pH 7.13 to 7.44).

CONCLUSIONS

The administration of surfactant may be a promising approach to treat severe respiratory failure caused by severe pulmonary hemorrhage.

Les déficits secondaires en surfactant

Preterm babies born before the 33rd week of gestation often exhibit primary surfactant deficiency responsible for the respiratory distress syndrome or hyaline membrane disease. In that situation, there is a limited and insufficient production of surfactant by type II alveolar cells of the lung due to immaturity. Secondary surfactant deficiencies occur in patients with prior normal surfactant synthesis and can be related to sepsis, hypoxia, ventilator induced lung injury or surfactant inhibition by a variety of substances reaching the alveolar spaces. They occur in full-term newborns with meconium aspiration syndrome, acute respiratory distress syndrome and congenital diaphragmatic hernia. In children and adults, acute respiratory distress syndrome and respiratory syncytial virus bronchiolitis can be responsible. In prematures they occur after the initial primary deficiency during pulmonary hemorrhage, pneumonia and bronchopulmonary dysplasia. Treatment with exogenous surfactant may be beneficial. There is a need for randomized controlled studies for evaluation of this treatment. Next generation of surfactants containing recombinant surfactant protein or synthetic peptides appear as promising agents in these situations of secondary surfactant deficiencies.