Bubble CPAP Clinical

Why Bubble CPAP is Vital

Most respiratory diseases of the neonate occur as a result of the immaturity of the premature neonate's lungs. Despite stimulation, the normal process involved in the first breath does not occur. The respiratory system is underdeveloped and adequate gas exchange cannot take place. With this, there is a need for respiratory support.

Bubble CPAP with the combined effects of CPAP and pressure oscillations from the bubbles provides a lung protective, safe and effective method of respiratory support to spontaneously breathing neonates.

Bubble CPAP effectively maintains Functional Residual Capacity (FRC)¹

Most lung diseases that lead to respiratory failure are commonly associated with a reduced FRC. Maintaining FRC is very important to premature neonates who have a greater tendency of airway closure when FRC falls below closing volume.

Bubble CPAP helps reduce the infant's Work of Breathing (WOB)²

In a prospective randomized cross over trial performed by Lee, Dunn et.al. comparing bubble CPAP with ventilator-derived CPAP, results showed that there was a decrease in the infant's minute volume and respiratory rate with bubble CPAP. They observed chest vibrations caused by the pressure oscillations from the bubbling. These pressure oscillations, according to the study, are reverberated back into the infant's airway and may have provided an alternate form of gas exchange through the principle of facilitated diffusion. This physiologic effect of bubble CPAP may help improve gas exchange and reduce the infant's work of breathing². Measurements done in vitro by Pillow and Travadi as well as in vivo measurements on a baby on bubble CPAP confirmed that the pressure oscillations from the bubbling are transmitted into the neonate's airway and lungs^3,4.

Bubble CPAP may reduce the need for intubation and mechanical ventilation^5,6,7

In the multi-center comparative study of Avery, et.al, it was noted that the use of bubble CPAP avoided the need for intubation reducing the possibility of airway injury, aspirations and secondary infection associated with the use of the ET tube^5,7. Results also showed significant reduction in the need for mechanical ventilation that may minimize the possible incidence of barotrauma^5,1,2.

A historical control study performed by AM De Klerk and RK De Klerk in the use of bubble CPAP further confirmed earlier results with data showing marked reduction in intubation and ventilation rates. There was also a decline in the number of days on oxygen and there were trends indicating less number of days on any respiratory support and to an earlier postnatal day of life when respiratory support is no longer needed⁶.

Faster recovery with less lung injury and better respiratory outcomes are possible using a cost-effective respiratory support system such as bubble CPAP.

Bubble CPAP tends to reduce the incidence of Chronic Lung Disease (CLD)^5,6,7

Early treatment with bubble CPAP for infants with respiratory distress showed a change in the severity and duration of the disease. Significant reduction in the incidence of chronic lung disease which was defined as O₂ dependence at 28 days postnatal age or 36 weeks corrected gestation had been noted in some multi-center and comparative studies^5,6.

A case-cohort study of Linda Van Marter and colleagues suggested that barotrauma and oxygen toxicity were linked with CLD and that most of the increased risk of CLD was a result of the initiation of mechanical ventilation. Comparison of different respiratory care in 3 hospitals supported earlier results of reduced incidence of CLD with the use of bubble CPAP⁷.

Similar outcomes are being reproduced in hospitals that have used bubble CPAP. Below are some of the significant results from the historical control study done by AM de Klerk and RK de Klerk⁶.

Nasal Continuous Positive Airway Pressure and Outcomes of Preterm Infants6
	Period I Apr '93 - May '96 (n = 57)	Period II Jun '96 - Feb '98 (n = 59)	P
Ventilated Infants	65%	14%	0.0001
Receiving Surfactant	40%	12%	0.001
CLD at 28 days	11%	0%	0.02
Death or CLD at 28 days	16%	3%	0.046
Note: Period I - IMV / Conventional CPAP Period II - Bubble CPAP

Bubble CPAP may improve non-pulmonary outcomes

Improved non-pulmonary effects have also been observed in clinical trials such as the tendency to increase mean weight at 36 weeks corrected gestation, increase mean length and head circumference¹, reduction in time to reach full oral feeds and average length of stay⁶.

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References:

1. Vivek Narenderan, Edward F Donovan, et.al. and Alan H Jobe. Comparison between Early Bubble CPAP and Conventional CPAP in Reducing the Incidence of Chronic Lung Disease. Presented at PAS Show in Baltimore. 2002
2. Lee KS, Dunn MS, et al. A Comparison of Underwater Bubble Continuous Positive Airway Pressure with Ventilator-Derived Continuous Positive Airway Pressure in Premature Neonates Ready for Extubation. Biol Neonate 73: 69-75. 1998
3. Travadi JN & Pillow JJ. Effect of Compliance and Flow on Pressure Waveform in the Lung During Bubble CPAP. An in Vitro study. Perinatal Society of Australia and New Zealand 5th Annual Congress
4. Fisher & Paykel Healthcare. Measurements on a baby. Middlemore Hospital, Auckland NZ. 2001
5. Avery, Mary Ellen, Tooley, William, et.al. Is Chronic Lung Disease in Low Birth Weight Infants Preventable? A Survey of Eight Centers. Pediatrics. Vol. 79 No. 1. 1987
6. AM de Klerk and RK de Klerk. Nasal continuous positive airway pressure and outcomes of preterm Infants. J Paediatr. Child Health (2001) 37, 161-167
7. Marter LJ, Pagano M, et al. Do Clinical Markers of Barotrauma and Oxygen Toxicity Explain Interhospital Variation in Rates of Chronic Lung Disease? Pediatrics. Vol 105 No.6: 1194-1201. Jun 2000
8. Verder H, Albertsen P, et al. Nasal Continuous Positive Airway Pressure and Early Surfactant Therapy for Respiratory Distress Syndrome in Newborns of Less than 30 Weeks Gestation. Pediatrics. Vol 103 No.2 Feb 1999