Since the lungs are the last major organ system to mature in the womb, breathing complications are common during the first few hours and days of a premature baby’s life. Depending on the type and severity of the problem, there are several ways in which treatment can improve breathing. For the most part, these methods attempt to enhance gas exchange in the lung and therefore increase oxygen delivery to the body.
In general terms, lung complications interfere with breathing, resulting in respiratory distress. Frequently, there is a lower oxygen level and higher carbon dioxide level in the blood. Lung complications may also interfere with the heart. The lungs and heart are dependent upon each other: the lungs providing the mechanism for gas exchange and the heart providing the mechanism by which oxygen is delivered to all regions of the body. Since the heart and lungs are interdependent in this way, problems with the function of the lungs can interfere with the physical action of the heart and vice versa.
That being said, the management or treatment of lung problems involves trying to achieve the correct amount of oxygen in the blood by improving the gas exchange that occurs within the lungs. Unfortunately, weakened, immature, or damaged lungs can only be pushed so far; at a certain point, the effort to improve the amount of oxygen in the blood by treating the lung can cause injury that may result in lung damage or make it worse. Treatment of the lungs must take into consideration the balance between the benefit of improving oxygen levels and the risk of creating lung damage, which may be permanent, in the process.
Complications arising from treatment
All treatments have some measure of risk. In most cases, the risks are small and are outweighed by the benefits of the treatment. For example, some babies may need a form of mechanical ventilation to help them breathe. However, given the fragility of many premature babies’ lungs, mechanical ventilation may cause complications. When this occurs, the most common effects are pneumothorax, or a puncture in the lung resulting in air entering the chest cavity; infection, usually ventilator-acquired pneumonia; and permanent injury to the lung, commonly referred to as chronic lung disease (CLD) or bronchopulmonary dysplasia (BPD), These possible risks are well known and so, when a baby is placed on ventilation, the staff at the Neonatal Intensive Care Unit (NICU) will pay close attention and look out for these possible complications.
Monitoring and assessment of treatment effectiveness
The effect of treatments is assessed at frequent intervals. Since the goal is to improve the delivery of oxygen and remove carbon dioxide from the blood, which are the prime functions of the lungs, measurement of these blood gases will be frequent and more or less continuous.
In most cases, the amount of oxygen in the blood, called oxygen saturation, can be measured with a test called pulse oximetry, avoiding the repeated drawing of blood to determine levels of blood gases. In pulse oximetry, a long, thin wire is attached to a monitor. This wire connects to a sensor that is usually put over the baby’s finger or toe. The probe has a small red light on one side and a detector on the other side. The red light shines through the baby’s finger or toe and is “seen” by the detector on the other side. In this way, the detector can measure the amount of oxygen in the blood.
Carbon dioxide levels can also be monitored using a non-invasive monitor which has a special probe that sits on the surface of the skin. This probe can estimate the amount of carbon dioxide in the blood stream.