Efficacy of INSURE vs. MIST Surfactant Administration Protocols

Submitted by: Laura Tangelder, SRT

Surfactant deficiency in premature infants often causes respiratory distress syndrome (RDS), where in which the infant displays tachypnea, increasing oxygen demands, and elevated work of breathing (Riaz et al., 2020). This clinical picture often results in the need for exogenous surfactant replacement therapy, and this approach has become the standard of care for premature infants diagnosed with RDS (Deshpande et al., 2017). Surfactant therapy can reduce alveolar surface tension and restore ventilation/perfusion matching, creating functional lung units. While surfactant therapy has been clinically demonstrated as effective in premature infants, the method by which is it administered is still being researched and assessed today (Polin & Carlo, 2014).

Conventionally, the most common practice of administering surfactant to infants who qualify for this therapy is a technique referred to as the INSURE method. This method involves an endotracheal intubation, providing a direct point of entry for surfactant to be instilled, followed by extubation to a non-invasive positive pressure system (Wang et al., 2020). However, endotracheal intubation poses risks that may negate the benefits of surfactant therapy, such as pneumothorax, bleeding, and trauma to fragile airway and lung tissue. Additionally, the positive pressure ventilation experienced during the instillation of surfactant including possible ventilation post-administration, can lead to barotrauma, increased infection risk, and longer hospital stays (Deshpande et al., 2017).

New methods that are becoming further integrated into clinical practice for surfactant administration in premature infants are known as the MIST (minimally invasive surfactant therapy) or LISA (least invasive surfactant administration) methods (Wang et al., 2020). Minimally invasive surfactant therapies include nebulization, laryngeal mask, intrapharyngeal, and thin catheter administration as routes to introduce surfactant to the neonate (Riaz et al., 2020). These methods allow the patient to breath spontaneously while receiving surfactant, reducing the need for positive pressure ventilation and intubation. Currently, the thin catheter method has shown to be the most effective in reducing the need for mechanical ventilation during the first 72 hours of life (Barkhuff & Soll, 2019). This technique involves inserting a vascular catheter or nasogastric tube down the trachea, followed by the instillation of surfactant while the infant is breathing spontaneously. This can also be performed while the infant is receiving nasal continuous positive airway pressure (CPAP). Once the bolus of surfactant is given, the tube is immediately withdrawn (Okur et al., 2019). A study performed from 2014-2015 examined 100 premature infants who developed RDS within two hours of birth (Riaz et al., 2020). Infants were randomly assigned a surfactant administration modality, either the MIST method (Group A) or the INSURE method (Group B). Subjects were monitored post-surfactant administration for oxygen saturation, arterial blood gas values, and chest radiograph. In the MIST group, 36% of infants needed mechanical ventilation within the first 72 hours of life, while 56% of infants in the INSURE group required it. This study concluded that the MIST method via a thin catheter was successful in reducing the need for mechanical ventilation in premature infants, compared to the INSURE technique (Riaz et al., 2020).

While both the INSURE and MIST methods are effective in improving end-expiratory lung volumes and compliance in premature infants with RDS, the complications associated with endotracheal intubation can diminish the benefits of surfactant replacement therapy (Wang et al., 2020). Combining a minimally invasive route for exogenous surfactant with non-invasive positive pressure ventilation, such as CPAP or bi-level positive pressure ventilation, have shown to be the most effective in preventing the need for mechanical ventilation in premature infants (Wang et al., 2020). However, both methods of surfactant administration pose risks to the patient, such as oxygen desaturation, bradycardia, and airway obstruction (Polin & Carlo, 2014). More research is required before it can be clinically concluded that one method is superior to the other for providing surfactant therapy to premature infants.

References

Barkhuff, W., Soll, R. (2019).
Novel surfactant administration techniques: Will they change utcome? Neonatology 115, 411-422.

Deshpande, S., Suryawanshi, P., Ahya, K., Maheshwari, R., Gupta, S. (2017).
Surfactant therapy for early onset pneumonia and late preterm and  term neonates needing mechanical ventilation. Journal of Clinical and Diagnostic Research 11(8).
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5620870/https://www.doi.org/10.7860/JCDR/2017/28523/10520

Okur, N., Uras, N., Buyuktiryaki, M., Oncel, M., Sari, F., Yarci, E., Dizdar, E., Canpolat, F., Oguz, S. (2019). Neonatal pain and heart rate variability in preterm infants treated with surfactant: A pilot study. Pediatric Archives Argentina 117(6), 397-404.

Polin, R., Carlo, W. (2014).
Surfactant replacement therapy for preterm and term neonates with respiratory distress. Pediatrics 133(1), 156-163.
DOI: https://doi.org/10.1542/peds.2013-3443.

Riaz, M., Asmat, S., Shaukat, F., Aslam, M., Majeed, M., Rafiquq, S. (2019).
Efficacy of surfactant administration to preterm infants via thin catheter versus INSURE technique.
The Professional Medical Journal 27(2), 431-436. DOI: 10.29309/TPMJ/2020.27.2.4176.

Wang, X., Chen, L., Chen, S., Su, P., Chen, J. (2020).
Minimally invasive surfactant therapy versus intubation for surfactant administration in very low birth weight infants with respiratory distress syndrome. Pediatrics & Neonatology 61(2), 210-215.
https://doi-org.ezpxy.fanshawec.ca/10.1016/j.pedneo.2019.11.002

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