exp date isn't null, but text field is
This guideline replaces previous guidance for the use of surfactant in neonates. This reflects current evidence for the use of primary respiratory support with nasal CPAP, commenced immediately after birth, in selected infants. It continues to provide guidance for the use of intubation and surfactant therapy for those infants for infants who require this level of support or who fail on CPAP support alone.
This Guideline is intended for use by the medical and nursing staff of the Neonatal Units in the West of Scotland. Please refer to Local Pharmacy guidelines for use of any medications including surfactant.
Staff should be familiar with the function of all respiratory support devices (Resuscitaires, CPAP devices & Ventilators) in use within their local service.
Worldwide approximately 10% of deliveries are preterm deliveries and majority of this population need some form of respiratory support (CPAP, NIPPV, intubation-surfactant) at the time of delivery and thereafter. Every form of respiratory support is aimed at improving survival, survival with out Neuro-Developmental Impairment (NDI) and survival without BPD.
In spite of advances in neonatal medicine and improved survival the incidence of BPD is not increased or decreased. The incidence ranges from 30% among VLBW infants and 40% among infants<28 weeks1. BPD has a huge impact on health economics and it is a predictor of significant neuro-motor, developmental and behavioural sequelae 2,3.
This guideline presents two alternative strategies for initial respiratory support of the preterm infant at risk of respiratory distress syndrome.
1) Primary therapy with nasal CPAP with mechanical ventilation as a rescue strategy
2) Initial ventilation & surfactant administration, with consideration of early extubation to CPAP.
The choice of strategy will depend on a number of factors including the size and gestation of the infant, exposure to antenatal steroids, condition at delivery, experience of the staff in the delivery unit, any requirement for transportation to another hospital postnatally etc. All these factors will require consideration by the paediatric team at the time of delivery and an appropriate strategy chosen. See later sections of the document for a review of the evidence for these strategies.
Types of CPAP Machine & Interfaces:
The preferred method of CPAP delivery is by short binasal prongs or nasal mask using an Infant flow driver interface with humidification of the inspired gases (devices using this interface include – Infant Flow Driver, Viasys SiPAP and the Inspiration Systems Fabian ventilators / CPAP). This method of CPAP delivery, utilising the fluidic flip model, is more physiological, reduces the work of breathing and has been shown to be more effective. Where a device utilising such an interface is not available e.g. in labour ward, or for transfer to the neonatal unit, CPAP may be given via a face mask for transfer. The infant should be transferred to an appropriate CPAP device as soon as is practicable.
CPAP initiation and Maintenance:
Complications associated with CPAP:
Predictors of CPAP Failure:
Current evidence suggests that more than 50% of preterm infants not manage on CPAP therapy alone. These babies will require intubation and surfactant therapy. Evidence from systematic review would suggest that the effects of surfactant are greater when given early in the disease process. It is therefore essential to identify early those infants who are going to fail CPAP. Such a decision is based on multiple factors and a thorough clinical assessment, which should take into account the size and maturity of the infant, whether they received antenatal steroids, and the stage of their respiratory illness
(NB - lower thresholds should apply for an infant in the first few hours after birth).
The following factors should prompt a consideration of the need to ventilate the infant.
Intubation in the labour suite
Clinical assessment at the time of delivery should take into account the size and maturity of the infant, antenatal steroid therapy, and the condition immediately following delivery. The clinician may choose to intubate electively, on the basis of this assessment, or if one of the following is true.
Where intubation is required in the delivery suite this will normally be performed without sedation. Clinicians should refer to the intubation guideline to choose an appropriately sized ETT and determine the insertion length. A method of detecting exhaled CO2 should be used to ensure that the ETT is correctly placed. The appropriate insertion length should be confirmed both by ensuring that the position at the lips matches the predetermined insertion depth and by confirmation of equal air entry by auscultation.
Following this assessment the clinician may choose to administer an initial dose of surfactant prior to transfer or they may elect to administer surfactant following a confirmatory CXR on arrival in NICU. See below regarding surfactant administration.
Intubation in NICU
Initial intubation in NICU usually results from the infant having met the above criteria for CPAP failure detailed above, although it may be required for other reasons, such as the need to transport an infant to another centre for ongoing care. A persistent and rising oxygen requirement in the first few hours after birth may be an indication for intubation even at relatively low levels of oxygen requirement, especially if associated with a an increased work of breathing. Later in the infant’s course, a higher level of FiO2, up to around 0.40, may be tolerated if none of the other criteria are met
Unless the infant requires urgent intubation this should be performed with sedation and paralysis - clinicians should refer to the separate guideline for premedication and intubation.
Following intubation a CXR should be performed promptly to ensure appropriate positioning prior to surfactant administration (if required).
NB - If FiO2 is rising rapidly consider DOPE
D – Displacement of ETT or CPAP prongs
O – Obstruction of ETT or nasal airway. Consider suction of ETT or nose as appropriate
P – Pneumothorax listen to air entry bilaterally, consider cold light / CXR
E - Equipment failure
If these are excluded then this may represent worsening RDS and need an increase in respiratory support. Senior review is advised
Type - The surfactant currently used in all neonatal units in the West of Scotland is Poractant alpha (Curosurf).
Timing of administration – Early (<2h) surfactant therapy is more effective than delayed surfactant therapy. An initial dose may be given at birth in infants at high risk of RDS who are intubated on labour ward, or after an early CXR if electively intubated on the neonatal unit.
Initial Dose – The licensed initial dose is 100-200 mg / kg with evidence that the higher dose is more effective and results in the need for fewer repeat doses. Given the cost per vial, it is usual practice to give multiples of whole vials (120 / 240 mg vials available) to approximate this dose. If administering surfactant on labour ward where the weight is unknown it is reasonable to administer a whole 120mg vial and to consider a supplementary aliquot on arrival in NICU once the weight is known.
Repeat doses - Additional doses of surfactant may not be required for infants with low respiratory support requirements after the initial dose. Such infants may meet the criteria for early extubation – see below. One or two further doses may be administered if the infant continues to require high FiO2 or Inspiratory pressures. The licensed dose for such additional treatments is 100 mg/kg, again usually giving a multiple of whole vials to approximate this dose.
Technique – To ensure even distribution, ensure the correct length of ETT insertion as described above. Administer via a fine bore catheter inserted down the ETT, ensuring that the catheter is slightly shorter than the length of the ETT. Administer as a single aliquot over 5-10 seconds (more rapid administration may induce a cough reflex forcing expulsion of part of the dose). Ensure there is no surfactant bubbling up into the ETT connector before reconnecting to a ventilator, as this may damage the sensitive flow monitor of the ventilator. (This may require a few manual breaths via a NeoPuff or Ambubag until surfactant is no longer visible in the ETT). For a few minutes only, keep the head upright and the ETT held above the baby to ensure the whole dose has been absorbed before returning the infant to a developmentally appropriate position for ongoing care.
Post surfactant management – Lung compliance may improve rapidly after surfactant administration. This will require close attention to weaning the Inspiratory pressures, or the use of a volume targeted ventilation strategy. (see below)
All infants <30 weeks gestation and any infant <32 weeks with poor respiratory drive should be commenced on caffeine therapy, even if there are no immediate plans to extubate. This improves respiratory mechanics and is a prerequisite for the consideration of early extubation.
Ventilation strategies should aim to minimize lung injury by avoiding overinflation.
Volume targeted ventilation (Volume guarantee (VG) / Targeted Tidal Volume (TTV)) as an adjunct to a Patient triggered ventilator mode (Patient triggered ventilation (PTV) / Synchronised intermittent positive pressure ventilation (SIPPV) / Assist-Control (A/C)) has been shown to reduce lung injury and subsequent Chronic Lung Disease. If such a mode is not used then close attention will be needed to ventilation to ensure that appropriate weaning occurs as compliance improves.
It is unnecessary, and potentially injurious, to target “normal” CO2 values. CO2 values of up to 8-8.5 kPA may be tolerated, assuming the infant can maintain an acceptable H+ <60 – 65 nmol/l).
Routine use of sedation or paralysis is discouraged as it is known to prolong the time on ventilation. Infants should be regularly assessed for pain or discomfort and offered appropriate analgesia as indicated.
Consideration of early extubation
If an infant has a good response to Surfactant then consideration should be given to early extubation to non-invasive respiratory support. As with intubation, a full clinical assessment is required but if early extubation is considered the infant should fulfil the following criteria
Extubation may be to CPAP, high flow or to air, dependent on the size and maturity of the infant and the presence or absence of residual respiratory symptoms.
Abbreviation: BPD: Broncho-Pulmonary dysplasia, CLD- Chronic Lung disease CPAP: Continuous Positive airway pressure, FRC: Functional Residual capacity; LISA: Less invasive surfactant administration, MIST: minimally invasive surfactant treatment, NDI: Neuro-Developmental Impairment; NLS: Neonatal life support; PIE: Pulmonary Interstitial emphysema; RCT: Randomized control trial, RDS: Respiratory distress syndrome.
Research Questions & Search strategy: Research questions were developed to define the optimal respiratory management in the preterm population (24+0 weeks to <=32 weeks) to improve both short term and long-term outcomes. We used Systematic review method of literature search.
CPAP at Delivery
Earlier systematic review on prophylactic surfactant showed decreased risk of pneumothorax, a decreased risk of pulmonary interstitial emphysema and a decreased risk of mortality when compared to selective use of surfactant. But there was no routine use of CPAP in the control arm of the studies5.
Four recent major RCTs: SUPPORT (24 wks-27 6/7wks), COIN (25+0/7wks -28 6/7), VON (26-296/7wks), CURPAP (25+0/7wks -28 6/7), showed individually no difference in the primary outcome of death or BPD between the CPAP and intubation groups, but did show a positive short term respiratory outcomes including the need for intubation, days of mechanical ventilation, mechanical ventilation at 7days, and post natal steroids use for BPD in the CPAP group. The overall meta-analysis with 1296 infants in the CPAP group and 1486 in the intubation group showed a significant benefit for the combined outcome of death and/or BPD in the CPAP group (RR 0.91, 0.84 to 0.99, Number needed to treat 25)6. The SUPPORT trial also showed a significant decrease in mortality, [23.9% vs. 32.1%, RR=0.74, (0.57, 0.98), p=0.034] in the immature strata of 24 to 25 6/7 weeks gestation randomized to CPAP. Moreover in the latest Cochrane review it has been shown that prophylactic use of surfactant is associated with higher risk of death /BPD ((RR: 1.12; 95% CI: 1.02–1.24; P <. 05)7.
Limitations of these trails:
With the understanding of these limitations, it is evident from the studies that CPAP is at least as effective/better than intubation in preterm population for prevention BPD or BPD/death.
Rationale for CPAP: CPAP increases the trans-pulmonary pressure and increased thoracic gas volume, thereby maintaining functional residual capacity (FRC) and recruits the collapsed alveoli. This increases surface area for gas exchange, reduces the amount work done by the infant each time and reduces intra-pulmonary shunt. This also triggers the release of surfactant from the pool. In animal studies constant distending pressure was also associated with lung growth.
Types Of CPAP Machine & Interfaces: Infant flow driver, which works on the fluid flip model, is more physiological and shown to reduce the work of breathing and shown to be effective. Use of either short Bi-nasal prongs or nasal mask is the current practice. Discussion about individual CPAP machines/interfaces is beyond the scope of this review.
CPAP initiation and Maintenance:
Complications Of CPAP:
Indication for Intubation.
Ventilation Strategies 10:
Predictors of CPAP Failure:
Early Surfactant (<2hrs) Vs. Delayed surfactant:
Uses of surfactant:
Post Surfactant Management:
Types of surfactant.
Repeat Doses Of Surfactant.
Last reviewed: 14 July 2016
Next review: 14 September 2019
Author(s): Dr Prakash Loganathan, Consultant Neonatologist, NHS Greater Glasgow & Clyde.
Co-Author(s): Other professionals consulted: Dr Joyce O’Shea, Consultant Neonatologist, NHS Greater Glasgow & Clyde; Dr Vrinda Nair, Consultant Neonatologist, NHS Ayrshire & Arran.
Approved By: West of Scotland Neonatology Managed Clinical Network