By Lauren Harnois, Alex Muller, Urvinder Kaur, Anna Kuruc
Premature infants face numerous challenges when they are born. Many of these challenges stem from their lungs not being mature at birth. Infants born before 28 weeks are at an even greater risk for respiratory distress because they have very few alveoli present, and the ones that are present are not mature enough to function properly. In order to save these infants, respiratory therapists may implement therapeutic interventions such as oxygen therapy, surfactant administration, and mechanical ventilation. These treatments are life saving at the time, but prolonged need for them can actually damage the infant’s lung structure and lead to bronchopulmonary dysplasia (BPD). Oxygen and mechanical ventilation cause scarring of the alveoli and inflammation in the lungs. This poses an even bigger problem because the need for oxygen and mechanical ventilation are still required, but they are also causing damage at the same time leading to the development of BPD. There is not a specific test to diagnose BPD, but most consider a preterm infant to have BPD if they still need oxygen at 36 weeks postmenstrual age. BPD can be also cause pulmonary hypertension, a “failure to thrive,” and lung dysfunction into adulthood.1 With the risk of BPD being high in premature infants, much research has gone into finding a method to prevent BPD.
Providing mechanical ventilation via an endotracheal tube is a major risk factor for BPD because it is associated with volutrauma (damage to the lungs caused by overdistension), increased inflammation, and a possible source of infection. Many research studies have suggested avoiding early intubation as a way to prevent BPD. Instead of intubating the infant right away, the respiratory therapist can implement a trial of nasal continuous positive airway pressure (CPAP) to try and stabilize the infant. In an animal study done on lambs, two hours of CPAP compared to two hours of mechanical ventilation led to higher lung compliance and fewer indicators of lung injury in the sheep who were given CPAP.3 This supports the idea that CPAP causes less lung inflammation and may help to prevent BPD. Although this method sounds promising, not all researchers agree that avoiding endotracheal mechanical ventilation decreases the incidence of BPD. In one meta-analysis study they compared seven randomized control trials, all of which looked at the incidence of BPD and death occurrence when using endotracheal mechanical ventilation versus a noninvasive approach. The meta-analysis concluded that avoiding intubation had a lower incidence of BPD and death.2 However, in another meta-analysis using two randomized controlled trials, they found no significant difference in the occurrence of BPD and death when comparing CPAP to intubation.3 More research needs to be conducted in order to determine if using noninvasive forms of ventilation can reduce the occurrence of BPD in premature infants.
In reality, not all infants will benefit from noninvasive forms of ventilation, and some will require intubation. This has led researchers to conduct studies to try and determine the optimal ventilator settings to use in order to prevent BPD. A meta-analysis of two randomized control trials, concluded that volume controlled ventilation (VCV) proved beneficial for premature infants. Not only did VCV show a lower incidence of BPD, but they also found it was associated with decreased mortality and a shorter duration of mechanical ventilation. They believe the benefits of VCV were due to a reduction in volutrauma, and auto weaning of pressures with changing compliance, such as when surfactant is administered.3
Overall, there are many ideas that exist regarding how to prevent BPD in infants, but more research needs to be conducted to determine which ones are the most beneficial. It is important for respiratory therapists to be aware of the current research available, so they can make suggestions to other health care providers. Nasal CPAP and VCV are two potential methods of preventing BPD in premature infants.
References
- “Bronchopulmonary Dysplasia.” American Lung Association. N.p., n.d. Web. 11 Apr. 2016.
- 1. Fischer HS, Buhrer C. Avoiding endotracheal ventilation to prevent bronchopulmonary dysplasia: a meta-analysis. Pediatrics 2013;132(5):e1351-60.
- Gupta S, Sinha SK, Donn SM. Ventilatory management and bronchopulmonary dysplasia in preterm infants. Semin Fetal Neonatal Med 2009;14(6):367-373.
- https://hackadaycom.files.wordpress.com/2015/09/infant.jpg?w=800
Respiratory Care 
Bronchopulmonary Dysplasia is a condition that is unavoidable in my opinion, especially in infants born at very low gestational period. As you have mentioned, these infants are usually born at a critical point in development. The alveoli of the lungs have not yet developed and most lack surfactant that coats the lining of lungs. Therefore, these infants are born with respiratory distress syndrome which includes shallow breathing and in some cases collapsed lungs. These infants require immediate lifesaving therapies that are available. Due to the many medical breakthroughs, medical professionals can use oxygen therapies, ventilation and even medication. Unfortunately, these treatments are not use for a short period of time. Rather, these infant require continuous and long term care to improve their conditions. Unfortunately, these same therapeutic treatments can and often lead to BPD. So as we can see, BPD is many cases cannot be avoided. However, I do believe the severity of BPD can be reduce and it is at this point that RTs play a vital role. It is important for RTs to implement treatments that are supported by research to improve RDS only. This will ensure that outdated practices are not in use which subsequently worsen RDS and can later cause BPD. Lastly, I believe continuous research to improve the available treatment will only allow RTs to administer proper care to these tiny patients.
Kelvin Opoku, Ryan Cutro, Afnan Al Raimi, Erin Sventy
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Very informative blog! I do agree with the thought that Respiratory therapist play such an important role in administering therapeutic interventions to help the ones in need. It is very important that it was mentioned that before considering the thought of ventilating an infant, CPAP should be administered. This method reduced the risk of BPD in infants, which all RTs should be aware of.
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