From the Research
For local anesthesia in a finger thoracostomy, a 25-gauge needle is recommended, as it provides a balance between adequate anesthetic delivery and minimal patient discomfort, considering factors such as tissue density and the patient's condition. The procedure usually involves infiltrating the intended incision site with 1-2% lidocaine, with or without epinephrine. When performing the anesthesia, inject approximately 5-10 mL of the lidocaine solution into the skin, subcutaneous tissue, and down to the periosteum of the rib at the intended insertion site, which is typically the 4th or 5th intercostal space in the mid-axillary line. Allow 2-3 minutes for the anesthetic to take effect before proceeding with the thoracostomy. Smaller gauge needles (higher numbers) cause less pain during injection but deliver medication more slowly, while larger gauge needles (lower numbers) allow for faster delivery but may cause more discomfort.
The choice of needle gauge is supported by studies such as 1, which found that the addition of sodium bicarbonate to 2% lidocaine decreases the pain associated with an intradermal skin wheal, and although the use of a 30-gauge needle decreases the pain of injection, the addition of sodium bicarbonate seems to have a greater overall effect than needle size. However, considering the need for a balance between anesthetic delivery and patient discomfort, a 25-gauge needle is a more practical choice.
It's also worth noting that the use of finger thoracostomy has been shown to be effective and associated with a low rate of major complications, as seen in studies such as 2, which found that finger thoracostomy was frequently performed by intensive care flight paramedics and was associated with a low rate of major complications.
In terms of the specific procedure, the FINGER mnemonic, as described in 3, can be a useful aid in learning and retention of the key procedural steps, including injecting lidocaine/pain medicine.
Overall, the choice of needle gauge for local anesthesia in a finger thoracostomy should prioritize minimal patient discomfort while ensuring adequate anesthetic delivery, and a 25-gauge needle is a suitable choice.