CompuFlo Thoracic Epidural Study

Overview

Traditionally, loss-of-resistance (LOR) to air or saline with a special ground-glass syringe is the technique used to identify epidural space, but failure rates up to 30% have been reported using this technique for thoracic epidural placement. This failure rate has sparked the search for newer techniques to improve the success rate for placement.The CompuFlo epidural system is a device that provides anesthesiologists and other healthcare providers the ability to quantitatively determine and document the pressure at the needle tip in real time. The device's proprietary dynamic pressure sensing technology (DPS) allows it to provide objective visual and audible in-tissue pressure feedback that allows anesthesiologists to identify the epidural space. The purpose this research study is to compare the success rate of the two different approaches (traditional method v/s CompuFlo assisted) to thoracic epidural placement.

Traditional technique vs CompuFlo use: Using the traditional technique (loss-of-resistance technique), the epidural needle is advanced through the subcutaneous tissues with the needle stylet in place until the needle tip is positioned in the interspinous ligament-this is noted by the proceduralist by an increase in tissue resistance (attempted injection into ligamentous tissue is met with high resistance). The stylet or introducer is removed, and a ground-glass syringe filled with 2-3 mL of saline with an air bubble is attached to the hub of the epidural needle. If the tip of the needle is within the ligament, gentle attempts at injection are met with resistance, and injection of the saline is not possible. The needle is then slowly advanced, millimeter by millimeter, with either continuous or rapidly repeating attempts at injection. As the tip of the needle enters the posterior epidural space, a sudden loss of resistance is noted, and the saline injects easily. Once the needle tip is in the epidural space, the epidural catheter is threaded through the needle and the needle is removed, leaving the catheter sited in the epidural space. The CompuFlo technique complements this basic technique. Similar to the traditional technique, the needle is advanced through the subcutaneous tissues with the stylet in place until the interspinous ligament is entered, as noted by an increase in tissue resistance. After removing the stylet, flexible tubing from the CompuFlo disposable tubing-syringe set is attached to the hub of the needle instead of the traditional ground-glass syringe. The fluid-filled syringe is placed in the CompuFlo device. The needle is then advanced continuously with the device electronically sensing pressure in real time, providing a numerical value (100 to 150 mm Hg) on the read-out screen. As the tip of the needle enters the posterior epidural space, a sudden loss of resistance (associated with a significant loss of pressure to less than 50 mm Hg or 50% of the starting pressure) is noted. The pressure drop needs to be sustained for at least 5 seconds. An audio signal also signals the acute change in pressure.