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As an invasive instrument, any negligence during the use of a cannula needle may lead to serious consequences. Based on clinical practice, this article systematically summarizes the key precautions for the use of cannula needles, helping medical staff minimize risks and ensure safe and efficient operations.

I. Risk Assessment Before Operation

1. Patient Factors:

• Abnormal coagulation function: Patients with platelet count < 50×10⁹/L or INR > 1.5 have a significantly increased risk of bleeding after puncture. If it is not an emergency, the coagulation disorder should be corrected first.
• Anatomical variations: Obesity, spinal deformity, history of abdominal surgery, etc. can lead to unclear anatomical landmarks. Before the operation, carefully review the films and, if necessary, use ultrasound for positioning.
• Children and the elderly: Children have thin abdominal walls and delicate organs, so small gauge cannulas should be selected and the puncture depth should be controlled; the elderly have loose skin and fragile blood vessels, so gentle operation is required.

2. Equipment Inspection:

Before use, check whether the packaging of the cannula is intact and whether the sterilization validity period has expired.

Remove the obturator and check if the tip is sharp, whether there is rust or burrs; insert the obturator back into the cannula and feel if the sliding is smooth and if there is any jamming.

Check if the sealing valve of the cannula is flexible and if the rebound is strong. Aging sealing valves are prone to leakage, which affects the maintenance of pneumoperitoneum.

II. Key Considerations During Operation

1. Needle Insertion Direction and Force:

• Always keep the needle perpendicular to or slightly inclined to the skin (no more than 45°), avoiding slanting insertion which may cause the subcutaneous tunnel to be too long, increasing the risk of infection and exudation.
• Use the "rotational advancement" technique instead of "direct and forceful insertion." Rotation can cut tissue fibers, reducing lacerations; at the same time, it is easier to perceive changes in resistance at different layers.

Once entering the abdominal cavity or the target cavity, stop advancing immediately. Excessive penetration may damage the posterior organs.

2. Management of Pneumoperitoneum (for Laparoscopic Surgery):

• Before the first puncture, it is necessary to confirm that the pneumoperitoneum pressure is within the standard range (12-15 mmHg). If the pressure is too low, the distance between the abdominal wall and the internal organs is insufficient, and the puncture risk is extremely high.
• During the puncture process, if the air pressure drops suddenly, it may be that the cannula needle has entered the free peritoneal cavity (such as the preperitoneal space), and should immediately stop and re-evaluate.
• The selection of auxiliary puncture points should be done under laparoscopic direct vision, avoiding areas with blood vessels, intestinal tubes, and adhesions.

3. Special Attention in Drainage Operations:

During thoracic drainage, instruct the patient to hold their breath at the end of exhalation. At this time, the diaphragm rises and the lung volume decreases, which can reduce the probability of lung injury.

• After connecting the drainage bottle, observe the fluctuation of the water column and the expulsion of bubbles. If there is no fluctuation, it may be that the catheter is blocked or not in the correct position, and应及时adjust.
• For viscous fluids such as empyema, a larger inner diameter cannula (such as 24Fr or above) can be selected, and regular irrigation with normal saline can be performed.

III. Postoperative Management and Complication Identification

1. Needle Puncture Site Care:

Change the dressing daily and observe for redness, swelling, exudation, or subcutaneous emphysema. Subcutaneous emphysema is usually benign and can resolve on its own, but severe pneumothorax should be ruled out.

The suture fixation should be neither too tight nor too loose. If it is too tight, it can cause skin ischemia and necrosis; if it is too loose, it is prone to dislodgement.

2. Early Identification of Common Complications:

• Bleeding: If the drainage fluid suddenly turns bright red and the volume increases, consider vascular injury. Immediately clamp the catheter and notify the doctor for treatment.
• Infection: Postoperative fever, purulent secretion at the puncture site, indicates a possible infection. A bacterial culture should be performed and antibiotics should be used based on the drug sensitivity results.
• Organ injury: Postoperative severe abdominal pain, abdominal distension, abdominal peritoneal signs, or the drainage fluid containing intestinal contents, bile, etc., should raise suspicion of internal organ perforation. Urgent imaging examination or surgical exploration is required.

IV. Training and Team Collaboration

The operation of the cannula needle should be performed by specially trained physicians or nurses. It is recommended to conduct at least 20 or more puncture practices on the simulator before entering clinical practice.

Team cooperation is of vital importance: the main operator is responsible for the puncture, while the assistant is responsible for stabilizing the patient, passing the instruments, and monitoring vital signs. Before the operation, a brief verbal check should be conducted to clarify the puncture point, puncture direction, and emergency plans.

Summary

The safety and efficiency of using a cannula needle are not in conflict; rather, they are mutually reinforcing. By strictly following the operating procedures, carefully assessing risks, proficiently mastering techniques, and promptly identifying complications, the risks can be minimized. Remember: Every successful puncture is a respect for the patient's life and a test of one's professional competence.