Ultrasound, as one of the important imaging examination methods in clinical diagnosis, its importance is self-evident. However, for the diagnosis of lung diseases, it used to rely solely on chest CT and X-ray examinations. However, due to the presence of gas in the alveoli of pediatric patients, total reflection occurs when ultrasound encounters gas during the examination process. Therefore, early ultrasound examination of the lungs is considered a forbidden zone. In recent years, with the continuous development of ultrasound technology and the improvement of people's awareness, this forbidden zone has gradually been broken down and applied to the diagnosis of lung diseases in patients, especially for neonatal lung examination. Ultrasound can be said to be a green and reliable imaging examination method, non radiative, bedside operation, convenient for real-time dynamic examination, and has obvious advantages in diagnostic sensitivity compared to chest X-rays.
1. Basic principle of pulmonary ultrasound
Under normal circumstances, the alveoli are filled with gas, and ultrasound will undergo total reflection when encountering gas. However, under pathological conditions, the gas in lung tissue decreases and is replaced by substances that can transmit ultrasound, such as exudate, exudate, collagen, blood, etc. Liquid is an excellent medium for sound beam propagation, providing a visual "sound window" for pulmonary ultrasound examination. Different lung lesions have different gas-liquid ratios, resulting in different images, which is the basis for the diagnosis of lung diseases.
2. Object and timing of examination
(1) Object of examination: Patients suspected or unable to rule out lung diseases.
(2) Examination timing: For patients admitted to the hospital with difficulty breathing; Inpatients should be checked at any time when their condition changes, especially when respiratory symptoms occur; Those receiving ventilator treatment; Patients receiving exogenous pulmonary surfactant (PS) therapy; Patients who undergo bronchoalveolar lavage or thoracentesis drainage.
What are the pulmonary diseases in newborns?
(1) Pneumonia: May cause symptoms such as fever, cough, sputum, difficulty breathing, chest pain, etc.
(2) Neonatal respiratory distress syndrome (NRDS): It is more common in preterm infants, especially in preterm infants with 32 weeks of gestational age group, whose incidence rate is higher. The characteristic clinical manifestation is progressive and aggravated dyspnea within 6 hours after birth. The main symptoms include a sustained breathing rate exceeding 60 times per minute, nasal wing flapping, moaning like breathing, obvious inspiratory trilobes, and skin bruising.
(3) Neonatal wet lung: Neonatal wet lung often occurs when the pulmonary fluid in the fetal alveoli cannot be cleared on its own, and can be relieved on its own after birth.
(4) Meconium aspiration syndrome: Typical symptoms include respiratory distress, cyanosis of the skin, and the presence of meconium in the mouth and nose. The child may have complications such as atelectasis, emphysema, and asphyxia.
(5) Pulmonary hemorrhage: Pulmonary hemorrhage may present with symptoms such as hemoptysis, coughing, and chest tightness. In addition, pulmonary hemorrhage may also cause breathing difficulties, confusion, coma, and other conditions.
(6) Atelectasis: atelectasis refers to the collapse of a part of the lung structure, resulting in a decrease in lung gas content, such as a decrease in volume or gas content of one or more lung lobes, segments, and other parts, which can be called atelectasis. In the early stage of atelectasis or when the area is small, patients may experience mild symptoms or even no respiratory symptoms, which can usually be detected through examination. Patients with large areas and rapid onset may experience symptoms such as shortness of breath, difficulty breathing, and cyanosis of the lips or skin.
(7) Pneumothorax: The symptoms of pneumothorax include sudden chest tightness, cough, chest pain, etc. The signs include shortness of breath and inability to lie flat. Pneumothorax is a common respiratory emergency in clinical practice, and most patients experience it due to the rupture of pulmonary bullae, which causes gas from the lungs to enter the pleural cavity and compress lung tissue.
4. Advantages of ultrasound diagnosis of neonatal lung diseases
(1) High cost-effectiveness. Compared to large equipment such as CT and MRI for diagnosis, ultrasound examination is low-cost and can be performed multiple times to dynamically monitor and evaluate the patient's condition and treatment effectiveness.
(2) Safe and radiation free. The safety of newborns in the growth and development stage is higher because they have no radiation and can be repeatedly examined, which facilitates doctors to dynamically observe changes in the child's condition. Secondly, it also avoids X-ray injuries for medical workers who have been in the ward for a long time.
(3) Easy and convenient operation. For newborns with more severe conditions, the equipment can be directly moved to the bedside for examination, which can monitor changes in their condition in a timely and accurate manner, while also avoiding the risks associated with transporting newborns.
(4) Parents can accompany newborns during the diagnosis process, which can effectively eliminate their inner fears.
Conclusion
For pulmonary ultrasound diagnosis, its diagnostic accuracy and reliability are relatively high, and it has become a preferred method for diagnosing neonatal pulmonary diseases. It has even replaced chest X-rays in some advanced neonatal intensive care units. Pulmonary ultrasound examination has the advantages of simplicity, speed, bedside operation, and no radiation. Therefore, it is indeed a safe and green examination method for newborns.