International Expert Consensus and Recommendations for Neonatal Pneumothorax Ultrasound Diagnosis and Ultrasound-guided Thoracentesis Procedure

Lung ultrasound is more sensitive, accurate, and reliable for diagnosing of pneumothorax than chest x-ray. Ultrasonic guide to the thoracentesis is also safer and more convenient than traditional measures. Diagnosing neonatal pneumothorax by ultrasound is easy to learn, can be performed at the bedside without radiation.

It also can be used to precisely locate the puncture point for safer thoracentesis. Before beginning the ultrasound, select a high frequency linear probe and sterilize the transducer. Select the lung ultrasound preset.

To optimize the imaging settings for an examination when no lung ultrasound preset is available, select one of the small parts presets and use the depth button to adjust the depth to 45 centimeters. Use the focus zone button to select one or two focuses and adjust the focus close to the plural line. Click the speckle reduction imaging button and select a level of two to three to reduce the speckle noise.

Turn on cross beam reduction imaging and select a level of two to improve the contrast resolution. Then, select fundamental imaging for sharper A or B lines. Next, apply an appropriate volume of warm gel to the transducer to keep it in good contact with the skin surface and place the infant in a suitable position.

To partition the lung into six regions, divide each side of the lung into three regions along the anterior axillary and posterior axillary lines, with anterior, lateral, and posterior sections. To partition the lungs into 12 regions, further divide each lung into upper and lower lung fields by the nipple connection line. For B mode scanning of the infant lung, press the 2D button and place the transducer perpendicular to the ribs.

To identify the presence of plural A and B lines, use realtime ultrasound to observe whether there is lung sliding or lung point. Then, rotate the probe 90 degrees and starting at the highest part of the thorax, perform parallel scanning. For M mode scanning, press the M button and look for the presence of a stratosphere sign or lung point, both of which signify pneumothorax.

For lung ultrasound guided thoracentesis, select an appropriate puncture needle and puncture site based upon the ultrasound readings. In an infant model, the intracostal spaces can be used as a puncture point marker, where the disappearance of lung sliding, which represents this area, can be visualized in realtime. Place the calm, quiet infant in the appropriate position, allowing the air on the affected side to rise up, and wearing sterile gloves, disinfect the puncture site.

The puncture site of this infant is located between the fourth and fifth intracostal spaces, left of the mid axillary line. Holding the infant in a suitable position, evacuate the pleural air by needle aspiration at the selected puncture point. Normal neonatal lung appears as a bamboo sign on B mode ultrasound and as a seashore sign on M mode ultrasound, while lung sliding is evident under realtime ultrasound.

Pneumothorax is diagnosed as illustrated in the flowchart. If severe pneumothorax is present, the thoracentesis must be performed immediately. In moderate pneumothorax, if thoracentesis is indicated, the needle can be inserted anywhere in the field in which lung sliding is absent.

Bile pneumothorax generally does not require a thoracentesis. However, if the primary pulmonary disease of the infant is more severe and the infant presents with clinical deterioration, then thoracentesis may be indicated. When performing this procedure, it's important to identify the presence and the degree of pneumothorax and to locate the exact puncture point.