Respiratory Distress Management with
Pulmonary Recruitment in Preterm Newborns, Preliminary Report
Orozco-Gutiérrez Alberto1*, Sánchez-Gómez Regina2, Orozco-del-Pino Pedro3 and Nuñez-del-Prado-Alcoreza José4
1Head of the Neonatology Department, Professor of Pediatrics and Neonatology, Ángeles del Pedregal Hospital, Mexico
2Facultad Mexicana de Medicina, la Salle University, México
3Department of Probability and Statistics, Mathematics Investigation Center (CIMAT), México
4Pediatrics and Neonatology Department at Angeles del Pedregal Hospital, México City
Submission: December 01, 2017; Published: January 08, 2018
*Corresponding author: Orozco-Gutierrez, Head of the Neonatology Department, Professor of Pediatrics and Neonatology, Ángeles del Pedregal Hospital, Mexico, Camino a Santa Teresa 1055-109.Heroes de Padierna, D.F. 10700, Mexico.
How to cite this article:Orozco-Gutiérrez A, Sánchez-Gómez R, Orozco-del-Pino P, Nuñez-del-Prado-Alcoreza J. Respiratory Distress Management
with Pulmonary Recruitment in Preterm Newborns, Preliminary Report. Acad J Ped Neonatol. 2018; 6(2): 555739. DOI: 10.19080/AJPN.2018.06.555739
This work studies the employment of CPAP with mask, administered in 3 periods of 10 minutes each hour (pulmonary recruitment) for the management of neonatal respiratory difficulty in 22 premature infants between 29 and 34 weeks of gestational age. The average weight was 1663 g in the recruited children and 1724 g in the non-recruited children. There was no difference in weight, gestational age, prenatal steroids and severity of respiratory difficulty. One of eleven patients in the recruited group required mechanical ventilation and six of eleven patients in the non-recruited group. Surfactant was used in 3/11 of the recruited and 6/11 of the non-recruited children. The period of hospitalization was 22.9 days in the recruited group versus 25.7 in the non-recruited group. The relative risk shows that a recruited patient is 6 times less likely to be intubated.
At birth, the amniotic fluid found in the alveoli must be reabsorbed to allow the exchange of gases. The other fundamental change during adaptation at birth is the vasodilation of the pulmonary vessels and the following transportation of oxygen to the entire organism . In the mature and healthy lung, gas exchange depends on the diffusion gradient of the gases, the alveolar surface area and the thickness of the alveolar-capillary membrane. The re absorption of pulmonary liquid depends on the hydrostatic pressures generated by inhalation and on the sodium re absorption osmotic gradient, which causes the movement of fluids to the interstitial tissue . In preterm babies, the sodium re absorption mechanisms are immature and the respiratory force is weaker, so the hydrostatic pressure is lower and can affect the re absorption of the liquid . In a structurally immature lung that is partially occupied by liquid, with increased alveolar wall thickness due to immaturity, the diffusion of gas is lower. These children often have consumption of surfactant, which causes alveolar collapse and ventilatory problems [3-5]. Ventilating premature infants with continuous positive pressure prevents the collapse of the airway
at the end of exhalation and helps to increase the re absorption of liquid in the airway. This improves ventilation, oxygenation, increases pulmonary volume and elasticity, which increases the pressure at the end of exhalation and decreases the resistance of the airways. It also maintains the surfactant, alveolar collapse and the synthesis of pro inflammatory mediators [4,5]. In studies with immature animals, using positive end-expiratory pressure (PEEP) of 5 cm of H2O during stabilization at birth improves uniform lung aeration and the elimination of pulmonary fluid thus increasing residual functional capacity, oxygenation, lung compliance and decreasing lung damage . Continuous positive pressure has been used to prevent and treat respiratory distress syndrome (RDS) and reduces bronchopulmonary dysplasia and mortality . A randomized controlled study application of 10 seconds of continuous ventilation continuous positive nasal airway pressure (CPAP) versus bag-mask ventilation in premature babies showed reduction in the need for intubation in the first 72 hours, lower duration of respiratory assistance, less use of surfactant and decreased risk of bronchopulmonary dysplasia . The use of PEEP and/CPAP in the delivery room (15 minutes after birth)
reduces the number of children requiring intubation and stabilizes
premature babies with respiratory difficulties [3,9]. Hany Aly found
that the early administration of nasal CPAP reduces the need for
intubation, mechanical ventilation and the use of surfactant .
Mulrooney reports that the use of CPAP between 5 and 8 cm. H2O
in sheep increases the secretion of phosphatidylcholine between
2 and 6 hours of life and helps with the onset of spontaneous
ventilation . A study similar to ours with alveolar recruitment,
using continuous PEEP and increasing the pressure 0.2cm H2O
every 5 minutes, until reaching (FiO2)=0.25, showed a lesser need
for FiO2, lower number of doses of surfactant and less dependency
on supplementary oxygen . This work aims to determine if
the intermittent application of continuous distending pressure
in premature infants with moderate respiratory difficulty, at the
onset of respiratory difficulty, reduces the need for mechanical
ventilation, use of surfactant and the duration of hospitalization.
We observed 22 premature infants under 34 weeks who had
moderate respiratory difficulty and were rated as having a ACORN
respiratory score greater than 4 in the first hour of life .
The patients were treated diferently according to the criteria
of the attending physician:
Group 1 (none recruited): received treatment according to
respiratory distress severity, including oxygen, CPAP, surfactant
and mechanical ventilation.
Group 2 (recruited group): received CPAP at 5cm H2O pressure
with continuous flow mask and bag for 10 minutes every hour for
three hours or until the respiratory difficulty disappeared, and
supplementary oxygen to maintain transcutaneous saturation
between 90 and 94%.
The evolution was evaluated observing the need of ventilation
support, administration of surfactant, oxygen requirements and
length of hospital stay.
Weight, gestational age and sex were similar in both groups, as
shown in Table 1. The respiratory evolution in both groups is shown
in. All patients survived without extra-pulmonary complications.
Mechanical ventilation was more frequent in the non-recruited
group (6/11) compared to the recruited group (1/11). In Figure 1,
the likelihood confidence interval shows a diminished tendency of
needing mechanical ventilation in the recruited group.
For the analysis in this study, we employed the likelihood
function. This is a function of the parameters of a statistical model
that allows inferences to be made about the Characteristics of a
Population of interest from a set of observations.
The Figure 2 represents the relative likelihood of each
parameter in graph form; we observed that they intersect at 0.3
with plausibility of 24% of being the proportion that both groups
share. This strongly suggests that the low proportion of children
intubated corresponds with the fact that recruitment was present.
This data supports the hypothesis that recruitment in larger
groups will have the same results: a lesser need for mechanical
ventilation in the presence of alveolar recruitment.
Another method of evaluating the proposal is by obtaining the
odds which is defined as the proportion of those being investigated
who required mechanical ventilation divided by that of the control
group. In this case, the number of intubated children receiving
treatment is (1/11), and not receiving treatment (6/11). This means that it is more likely that a child who receives treatment
does not need mechanical ventilation.
If we obtain a result close to 1, this means that both treatments
are equally effective. In this case, the odds ratio is less than 1,
verifying that the treatment avoids mechanical ventilation.
In Figure 3, it can be seen that the most credible value for
the relationship of probabilities is 0.083, with a 10% likelihood
interval that equals (0.0026, 0.8) which does not reach 1. This
means that the values outside of this interval are at least 10 times
less credible than those within the interval.
The ratio of relative probability of the likelihood is shown in
Figure 3. table. We can see that the most credible value for the
odds ratio is 0.083, with a 10% likelihood interval that equals
(0.0026 to 0.8) which does not contain 1. This means that the
values outside of this interval are 10 times less credible than
those within it and that the value of 1 has a plausibility of 5.9%,
telling us that it is highly improbable that they are equally efficient
and also that the treatment is far superior at avoiding intubation.
As in previous cases, the likelihood function of the relative risk
is shown. Here we can see that the most plausible value of the
relative risk is 0.16 with a 10% likelihood interval that (0.0065,
0.8595) not containing 1, which means that the values outside of
this interval are 10 times less credible that those within it and that
the values for those which the relative risk is greater than 1 have a
probability of less than 6%.
This work describes the treatment of mild and moderate
respiratory distress syndrome in 22 premature infant of less than
34 weeks. The patients were divided into two groups of 11 children
with similar characteristics in each group, with one group using an
alveolar recruitment maneuver and the other following habitual
management with supplementary oxygen. Eight patients in the
recruited group and four patients in the control group were treated
with CPAP. Three recruited patients and no patients in the control
group received surfactant with the Insure method (intubationsurfactant-
extubation). Only one recruited patient required
mechanical ventilation in comparison with six in the control
group. The days of hospitalization were similar in both groups. The
recruited patients in this protocol received Peep of 5cm of H2O and
did not present complications associated with the recruitment.
This must be evaluated with a greater number of patients. The
patients evaluated in this study did not have extra-pulmonary
complications which could have interfered with the results. The
most promising result is the reduction in the need for mechanical
ventilation in recruited patients, which reduces the potential
risk of complications and associated costs. Previous studies have
demonstrated the use of LRM (lung recruitment maneuver) with
progressive increases in Peep in ventilated children reduces the
FiO2 requirements during the first 12 hours of life and reduces
supplementary oxygen dependency. The difference in our study is
that recruitment was only carried out for 10 minutes each hour
for 3 episodes . The evidence in previous studies in animals
and humans has demonstrated that the use of CPAP significantly
diminishes barotrauma and mechanical ventilation in premature
infants with respiratory difficulty. This is the basis for using CPAP
intermittently to reduce the need for mechanical ventilation even
further. This strategy reduces the need for mechanical ventilation
and the use of surfactant. However, the number of days of CPAP
increased and it does not affect hospitalization time. The size of
the sample was small, which is why inferential statistics was used
to obtain valid results in larger scale projections. However, larger
studies must be carried out in order to validate the results.
It is demonstrated that the use of intermittent CPAP as a
recruitment maneuver in newborns with mild to moderate
respiratory difficulty reduces mechanical ventilation and the
application of surfactant without increasing complications. This
can open a new line of investigation in order to determine if it can
be recommended as a safe and easy application strategy in larger