Oxygen Physiology in a Neonate
Oxygen remains the most widely utilized therapy in neonatal healthcare. However, the optimal levels of oxygen management have remained uncertain to health practitioners. One out of every[M1] ten newborns requires assistance to start breathing once out of the uterine environment after birth. Thus supplemental oxygen has become the most common form of therapy for neonate across the globe. Nevertheless, uncertainty regarding optimal oxygen levels and insufficient knowledge have been reported among neonatal healthcare providers. This setback is despite its common usage as a therapeutic agent. Balancing the oxygen requirements is essential to prevent any harm from too little or excess oxygen for the neonate. Besides neonatologists, nurse practitioners, respiratory therapists, and neonatal nurses are accountable for the administration of supplemental oxygen and should thus comprehend how to attain optimal oxygen levels for therapeutic usage. The essence of this essay to create an exposition on oxygen physiology, outline the significance of balancing oxygen in infants, and analyze techniques for sufficient oxygen usage in neonatal healthcare units.
While in the uterus, gaseous exchange across the placenta provides the fetus with oxygen. During this time, pulmonary resistance is high while the pulmonary vascular resistance is minimal and thus the flow of blood towards the uterine wall is shunted. The pulmonary vasculature plus the fetal lungs grow and develop in the hypoxic environment which prepares them for taking over the gaseous exchange process after birth.
At birth, an improved flow of blood to the lungs follows as a result of vasodilation caused by oxygen, and a drop in the pulmonary vascular resistance occur. These two processes facilitate the normal transition of breathing as the air enters the lungs (Kayton et al, 2018). The pressure increase is higher in the left atrial compared to the right atrial and this causes foramen ovale to close. The blood flow is gradually reversed following the removal of low-resistance placental circulation. Subsequently, the systemic vascular resistance rises while a drop in pulmonary vascular resistance is noted. A few hours or days after birth, the ductus arteriosus closes down and this marks the last in creating a normal postnatal circulation. Also, endogenous nitric oxide relaxes the vascular smooth muscles and this aids in the transition to a pulmonary circulation after birth.
A vasoconstriction that inhibits the decrease in pulmonary vascular resistance causes hypoxia or a hypoxeria affecting the usual transitioning process. When pulmonary vascular resistance persists for long, it can cause persistent pulmonary hypertension of the newborn that is chronic to preterm babies (Kayton et al, 2018). Delivering preterm exposes the infant to oxygen prior to the maturation of the pulmonary circulation ad they are unable to handle exposure to oxygen.
Strategies for Achieving Appropriate Oxygen Levels
Regardless of the uncertainty concerning how to balance oxygen saturation levels, studies have revealed crucial strategies for applying during the administration of supplemental oxygen to neonates. For instance, room air should be utilized instead of pure oxygen when initiating the resuscitation process for neonates both preterm and in-term. However, when preventing both hyperoxia and hypoxia, it is crucial to individualize the oxygen saturation levels for each infant.
All the oximeter readings should not be sustained at higher than 95.0% levels. In order to achieve this, alarm limits are essential and should be set at 85.0% for low alarm and 95.0% for high alarms (Kayton et al, 2018). Whenever the oxygen saturation levels exceed 95.0%, then it is vital to reduce the levels of inhaled oxygen. How to maintain a narrow oxygen saturation margin is the big challenge for healthcare practitioners and frequent cases of increased limits above 95.0% are reported.
Small margins for oxygen saturation has been credited with a shorter duration for admission in hospital, reduced necessity for supplemental oxygen and a decreased rate of ROP I in infants with low birth weights. Also, reduced cases of chronic lung diseases are reported plus infants are discharged with oxygen protocols that are less restrictive than it was previously. Neonates with PPHN experience chronic respiratory failures marked by systemic hypoxia and the normal therapy is inclusive of physical ventilation with pure oxygen. In order to lower the need for supplemental oxygen, studies on vasodilators have been carried out (Sheak et al, 2017). For instance, treatment accompanying inhaling of nitric oxide enhance the oxygen flow process in neonates suffering from PPHN. Moreover, inhaled nitric oxide lowers the necessity for extra-corporeal oxygenation of membranes, a procedure is difficult and expensive.
There are alternative vasodilators like prostacyclin, milrinone, sildenafil and bosentan that were experimented in infants that failed to respond to nitric oxide or cases where both extracorporeal and nitric oxide are absent (Lakshminrusimha et al, 2016). However, none of the mentioned vasodilators have been recommended for use on infants with PPHN and their safety profiles and efficacy are yet to be established in such settings. Results from sildenafil tests reveal that such treatments causes the pulmonary arteries to undergo a vasodilation and can enhance oxygen flow in preterm and in-term infants with hypoxemic respiratory failure or PPHN. However, various side effects such as hypotension were noted in various infants treated with sildenafil. Overall, vasodilators are essential alternatives for supplemental oxygen but so far there has been no single vasodilator identified as effective and safe for use in the treatment of infants with PPHN. Therefore it essential to consult a healthcare practitioner for the right treatment of a neonate suffering from a respiratory failure.
Discussion
As a preventive measure against potential hyperoxia or hypoxia and related oxidative stresses on infants at birth, there are guidelines established and updated that are necessary for balancing supplemental oxygen management (Torres-Cuevas et al, 2016). The guidelines are also applicable for neonates with a complete pulmonary transition but still need therapeutic oxygen during the early days at birth. As for infants who require resuscitation, the initial move is to clean the airways and conduct an assessment of oxygen requirements. Crucially, neonates with no complication do attain extra-uterine oxygen saturation for the first ten minutes at birth and their skin color may indicate cyanosis. Where resuscitation is required, pulse oximeters are necessary and an administration of positive pressure should last a number of breaths. If cyanosis persists, then administering supplemental oxygen is essential.
Previously, administering of pure oxygen was preferred for resuscitation due to the established hypoxia detrimental effects and the positive impact of oxygen in facilitating pulmonary transitioning (Torres-Cuevas et al, 2016). However, recent researches have established that excess exposure to oxygen after hypoxia leads to ischemia-free injuries and a build-up of oxygen free radicals. During the pre-clinical studies, the known detrimental effects of pure oxygen resuscitation were pulmonary artery contractility. Further researches were conducted on safety and efficacy of room air which is 21% oxygen for resuscitation. Utilization of room air has been found not only to be safe but also effective for resuscitating neonates. This was contrary to the use of 1005 oxygen for neonatal resuscitation.
Different studies where high oxygen levels (above 65%) were compared with low levels of oxygen (30% and below) for neonatal resuscitation revealed no positive impacts following exposure to high oxygen levels. Instead, these researched revealed that at the time of stabilization, neonates have a 30% oxygen in their lungs.
Therefore, the American Heart Association recommends the utilization of 21.0% oxygen for resuscitating infants who are thirty-five weeks old or more. The association also recommends room air for resuscitation of neonates less than thirty-five weeks old. However, the levels off oxygen levels ought to be titrated based on the pre-ductal pulse oximeter readings in order to attain saturation levels identical to that of neonates with no complications.
Conclusion
Evidently, supplementary oxygen is an essential alternative treatment for hypoxia and hypoxeria in the preterm neonate. However, too much exposure to high oxygen levels is detrimental and can cause oxidative stress which can subsequently damage several organs in the infant such as the lungs, the intestines, and the eyes. Extensive studies have not provided a sufficient and effective recommendation for saturation margins. Nevertheless, targeting high targets of up to 95.0% is safer than lower margins of 89.0% and below. Application of a wider range of 85.0% to 93.0% done by several researchers has improved results with low-birth neonates but more evidence is needed for these ranges in extensive clinical studies. Crucially, quick intervention using pulmonary vasodilators prevents exposure to high levels of oxygen which is toxic. Thus, further research remains to be conducted in this field.
Ask your questions to our best writers for quality and timely essay answers. Learn smartly and seek help from our solution library that grooms your concepts with over 150 courses.
From essays to dissertations, we have experts for all your writing needs!
