Portex EpiFuse™ epidural connector: Is an improvisation required?

Sir,

The new Portex EpiFuse™ connector (Smiths-Medical, Kent, UK) is a clamp type epidural connector, designed with the intent of avoiding accidental catheter disconnection. It encases an elastomeric tube into which an epidural catheter is advanced until a resistance is felt followed by clamping of its two halves, which occludes the elastic tube around the catheter, thus holding it firmly.[1] We recently encountered a case of malfunctioning EpiFuse™ connector in a patient in whom epidural catheter was sited pre-operatively for perioperative analgesia. Following an easy identification of epidural space, catheter placement and fixation according to manufacturer's recommendation, it was impossible to inject local anesthetic test dose through the EpiFuse™ connector even with additional force. A drill to point out the cause of catheter malfunctioning did not reveal any kinking at its skin exit site or distal to it. Before attempting to re-site the catheter, EpiFuse™ connector was unclamped by attaching a syringe tip into the release port at its back and was replaced after taking all aseptic precautions with a Tuohy-Borst connector.[2] Epidural bolus was reattempted which could now be introduced easily. In vitro, the removed EpiFuse™ connector was re-clamped after insertion of an epidural catheter checked for its patency to simulate the invivo conditions. Saline solution could not be introduced via this assembly, suggesting that the fault lay with this new connector and not with catheter or its position. Examination of this removed connector revealed luminal obstruction due to incomplete elastic recoil of elastic tube, preventing complete insertion of the catheter and inability to inject local anesthetic [Figure 1]. This invitro catheter connector assembly was then disassembled, the unclamped connector was flushed with sterile saline solution, catheter was immediately reinserted and the connector clamped. Saline could now be introduced via this assembly suggesting that the above maneuver was able to overcome the obstruction due to incomplete elastic recoil of the tube resulting in full insertion of the catheter into the connector. Failure to identify troubleshooting connector and catheter reinsertion instead would have subjected the patient to unnecessary discomfort and risks. Anesthetists therefore should always check proper functioning of the Epifuse™ connector epidural catheter assembly before catheter insertion. This case highlights that a simple maneuver such as saline flushing of an unclamped blocked connector can overcome the obstruction resulting from incomplete elastic recoil. We recommend that Portex EpiFuse™ epidural set being a new device, the manufacturers properly mark the release port on the connector [Figure 2] as clamping and unclamping otherwise might result in incomplete elastic recoil of EpiFuse™ connector elastomeric tube.

Figure 1.

The Portex EpiFuse™ connector with blocked elastomeric tube

Figure 2.

Release port at the back of Portex EpiFuse™ connector