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Thoracic puncture and closed thoracic drainage are common procedures in respiratory medicine, thoracic surgery, and emergency departments, used for diagnosing and treating diseases such as pleural effusion, pneumothorax, and pyothorax. The application of the cannula needle in this field enables "one-step" precise catheterization, significantly improving operational efficiency and patient comfort.

I. The Unique Advantages of Cuff Needle in Thoracic Procedures

The traditional thoracic puncture adopts a simple mode of "puncture → aspiration of fluid → removal of needle", and if drainage is required, a separate catheter needs to be inserted. The process is cumbersome and increases the risk of infection. However, the cannula needle (especially the pigtail type with side holes) can combine the puncture and catheter insertion into one operation: after the puncture is successful, the occluder is removed, and the cannula remains directly in the thoracic cavity. By connecting a drainage bag or negative pressure bottle, drainage can begin. This design reduces the trauma of repeated punctures and lowers the incidence of complications such as pneumothorax and bleeding.

II. Preoperative Evaluation and Localization

1. Imaging examination: Chest X-ray or CT is essential. It is necessary to determine the location and extent of the effusion or pneumothorax, as well as whether there is a partition. For small effusions or localized encapsulated effusions, ultrasound-guided puncture is more accurate.
2. Puncture site selection: The conventional sites are the 7th to 9th intercostal spaces along the subscapular line or posterior axillary line. For pneumothorax, the 2nd intercostal space along the midclavicular line is chosen. Avoid areas of pleural adhesions, bullae of the lung, and large blood vessels. Mark the site and use a marker pen to mark the location.

III. Detailed Explanation of Operating Steps

• Positioning and Disinfection: The patient should sit upright, facing the back of the chair, with both hands crossed and placed on the chest, fully exposing the back. Routine disinfection and draping are performed, and local infiltration anesthesia is administered to the parietal pleura.
• Puncture and Catheter Insertion: Use a surgical blade to make a small incision (about 3-5mm) at the puncture site. The left hand fixes the skin, and the right hand holds the cannula needle (with a sacral retractor). Insert the needle vertically along the upper edge of the rib slowly. When a sense of penetration (passing through the pleura) is felt, stop advancing. At this point, liquid or gas can be seen flowing out from the tail of the cannula (or confirmed by connecting an injection device for aspiration).
• Pushing the Cannula: One hand fixes the cannula, and the other hand removes the sacral retractor. Then, continue to push the cannula inward 1-2cm to ensure that all side holes are within the thoracic cavity. For pigtail catheters, it is necessary to insert the guide wire or guiding steel wire first, and then guide the catheter into the body along the guide wire.

Fixation and Connection: Use sutures to fix the cannula to the skin and cover it with a sterile dressing. Connect the drainage bag or water-sealed bottle, observe whether the drainage is unobstructed. Record the drainage volume, color, and nature.

IV. Precautions and Prevention of Complications

• Avoid injury to intercostal nerve vessels: When performing the puncture, always insert the needle along the upper edge of the rib, as the intercostal arteries and nerves run within the rib groove on the lower edge of the rib. Keeping close to the upper edge of the rib can effectively avoid this.
• Prevent re-expansion pulmonary edema: For patients with a large amount of pleural effusion (>1500ml), the first drainage should not exceed 1000ml, or an intermittent drainage method should be used to prevent rapid lung re-expansion and subsequent pulmonary edema.
• Risk of pneumothorax: If the patient suddenly coughs or takes a deep breath during the puncture, it may cause the lung to be injured. During the operation, instruct the patient to hold their breath or complete the puncture quickly at the end of exhalation.

Catheter blockage and detachment: Regularly flush the catheter to keep it unobstructed. Properly fix it to prevent traction-induced detachment.

V. Special Scenario: Precise Needle Puncture Under Ultrasound Guidance

For small or scattered effusions, ultrasound guidance can display the needle tip position in real time, ensuring that the cannula needle accurately enters the liquid-dark area. During the operation, the ultrasound probe is covered with a sterile cover and placed beside the puncture site. The strong echogenic bright spot of the puncture needle is observed on the screen until it enters the target area. This method significantly improves the success rate, especially for critically ill patients in the intensive care unit.

Summary

The application of cannula needles in thoracic puncture and drainage embodies the concepts of "minimally invasive, efficient and safe." Standardized operation procedures, meticulous preoperative assessment, and vigilance against complications are the core factors ensuring the interests of patients. With the continuous improvement of puncture tools (such as those with anti-backflow valves and flexible catheters), this technique will play a more significant role in more clinical scenarios.