Epidural administration systems
AssigneeNovodural Pty Ltd
InventorsKeith Liyanagama, Terry Thyssen
Life of this patent
Estimating the term…
Abstract
The invention relates to improved equipment for the administrations of epidural anaesthetic and to novel methods of administration using the same. Improvements include a needle configured for reduced incidence of post dural puncture headaches, an improved sensitivity loss of resistance syringe and a novel cannula which in one form readily facilitates combined spinal epidural anaesthesia (CSE). Also includes is a catheter having a pre-assembled injection hub and connection means to optionally retain a cannula that is withdrawn over the catheter.
Claims35
A method of administering epidural anaesthesia comprising the steps of:
- inserting an epidural needle of a gauge of 20 or finer into the skin over the epidural space, the epidural needle having a lumen having a first axis parallel to said needle that is sized to receive a guide wire therethrough, a tissue piercing point located at the distal end, and a lumen opening disposed at a location at or closely adjacent the tissue piercing point, the opening being configured to deflect a guide wire exiting from the opening in a direction away from said first axis;
- using a “loss of resistance” syringe to guide the epidural needle through the external tissue until the tip of the needle including the lumen opening is located within the epidural space;
- inserting a guide wire through the needle and into the epidural space;
- removing the needle;
- passing a dilator over said guide wire to the depth of the epidural space;
- removing the dilator;
- inserting an introducing cannula via said guide wire;
- removing the guide wire;
- and
- inserting the epidural catheter through the cannula and into the epidural space.
(canceled)
An epidural anaesthesia kit including:
- an epidural needle of a gauge of 20 or finer having a lumen having a first axis parallel to said needle that is sized to receive a guide wire therethrough, a tissue piercing point located at a distal end, and a lumen opening disposed at a location at or closely adjacent to said tissue piercing point, the opening being configured to deflect a guide wire exiting from said opening in a direction away from said first axis;
- a guide wire sized for use with said epidural needle;
- a “loss of resistance” syringe for connection to said needle;
- a dilator configured for insertion over said guide wire;
- a cannula configured for insertion via said dilator;
- and
- an epidural catheter.
An improved epidural needle for anaesthetic via catheter techniques, the needle having:
- a lumen having a first axis parallel to said needle that is sized to receive a guide wire therethrough;
- a tissue piercing point of pencil point configuration located at a distal end;
- and
- a lumen opening disposed at a location at or closely adjacent said tissue piercing point, said opening being configured to deflect a guide wire exiting from said opening in a direction away from said first axis;
- wherein said needle gauge is greater than 21.
A cannula for introducing an epidural catheter, said cannula having a generally straight tubular portion terminating in a discharge section having a discharge opening, said discharge section being made of a resilient material and the discharge opening being configured such that, in use, a catheter passed therethrough is caused to deflect in a direction away from the axial extent of said generally straight tubular portion, the cannula further including a separate integrally formed at least partially co-extensive needle guide.
An improved sensitivity syringe for use in loss of resistance needle placement techniques, said syringe including:
- an external generally tubular housing of volume A;
- an inner syringe assembly having a barrel of volume B (where A is greater than B) with a plunger rod and piston assembly reciprocally axially movable therein and a discharge opening at its distal end;
- said barrel of said internal syringe assembly being located generally co-extensively within said external tubular housing and sized so as to provide a generally tubular space between an inner surface of the external housing and an outer surface of the inner syringe assembly.
An improved sensitivity syringe for use in loss of resistance needle placement techniques, said syringe including:
- a housing sized to be similar to the external dimensions of a conventional 10 ml syringe;
- and
- an internal syringe assembly disposed within the housing, the internal syringe including a barrel having a plunger and piston assembly reciprocally axially movable therein and a discharge opening at its distal end,
- wherein the volume of the barrel is significantly less than 10 ml such that movement of the plunger is significantly magnified over that of a plunger in a conventional 10 ml syringe.
(canceled)
(canceled)
A method of administering epidural anaesthesia comprising the steps of:
- inserting an epidural needle of a gauge of 20 or finer into the skin over the epidural space, the epidural needle having a lumen having a first axis parallel to said needle that is sized to receive a guide wire therethrough, a tissue piercing point located at a distal end, and a lumen opening disposed at a location at or closely adjacent the tissue piercing point, the opening being configured to deflect a guide wire exiting from the opening in a direction away from said first axis;
- using a “loss of resistance” syringe to guide the epidural needle through the external tissue until the tip of the needle including the lumen opening is located within the epidural space;
- inserting a guide wire through the needle and into the epidural space;
- introducing a cannula that is preloaded onto the outside of the dilator by passing the dilator and cannula assembly over said guide wire until the cannula reaches the noted depth of the epidural space;
- removing the dilator and guide wire;
- and,
- inserting the epidural catheter through the cannula and into the epidural space.
Dependencies are inferred from the claim text.