CHAPTER 212 Tube Thoracostomy and Emergency Needle Decompression of Tension Pneumothorax
Emergency Needle Decompression
Equipment
• 10-mL syringe half-filled with 2% lidocaine with epinephrine (or equivalent) attached to a large-bore (18-gauge or larger), 2-inch catheter-over-needle (angiocatheter)
Technique
2 Provide supplemental oxygen. If available, continuous cardiac and blood pressure monitoring is helpful.
4 Apply antiseptic solution to a generous area of the second intercostal space where a line drawn laterally from the level of the sternomanubrial junction (Lewis’s line) would intersect a line drawn down from the mid-clavicle (mid-clavicular line).
6 Insert the catheter-over-needle perpendicular to the skin just above the upper border of the rib (Fig. 212-1). (Remember that the neurovascular bundle runs below the ribs.) Once through the skin, infiltrate the tissue with half of the anesthetic solution.
7 Before proceeding further, attempt aspiration. If air is obtained, then the catheter-over-needle is not secured to the syringe tightly enough. Use the hemostat to tighten the catheter hub on the syringe before advancing the catheter-over-needle any farther.
8 After creating the skin wheal and testing the seal, advance the catheter-over-needle at a moderate rate with continuous aspiration until air is obtained—this will be noted by bubbles in the syringe and easy aspiration.
9 Advance the catheter-over-needle an additional half centimeter to prevent accidental dislodgement.
10 Using the hemostat, unscrew the syringe to allow free passage of air. Do not hook up the needle to suction. The air in the thoracic cavity is under pressure (under tension) and will exit the needle spontaneously; it should gush out. Intrathoracic pressure will equilibrate with room air, which is acceptable until tube thoracostomy is placed.
11 Do not remove the needle at this point. In older texts, it was advised to remove the needle because the plastics in older catheters were much harder than the soft Silastic catheters now used. Unlike the older catheters, the new catheters are too soft to endure the tissue pressure of the intercostal muscles and will rapidly collapse, causing reaccumulation of the tension pneumothorax. Concerns that the re-expanding lung will be impaled on and lacerated by the needle (pulmonary laceration) are generally unfounded. There is a 100% pneumothorax present, and it is unlikely that lung tissue is near the needle tip so long as suction is not used. The purpose of this procedure is to relieve excessive intrathoracic pressure and allow blood circulation. Subsequent tube thoracostomy, hopefully performed very soon after emergency needle decompression, will provide full lung re-expansion. The time to remove the catheter-over-needle (angiocatheter) is just prior to applying suction to the chest tube.
-inch-long catheter-over-needle would fail to reach the pleural space in 65% of adults; however, a 
-inch catheter-over needle should reach the pleural space in 96% of adults.Tube Thoracostomy
Contraindications
There are many methods to determine whether or not a pneumothorax is greater than 20%. One method is to use the “1 cm and one third rule”: if a pneumothorax creates no more than 1 cm distance between the pleural line and the inner chest wall and is also confined to the upper one third of the chest on an AP upright radiograph, then the pneumothorax is less than 20%. These may resolve without any intervention (see Fig. 212-2). Stability is gauged by comparing a chest radiograph taken initially to one obtained 6 hours later. Although it may require thoracostomy, a simple pneumothorax is the accumulation of air, not under pressure, within the pleural space.
