Epidrum
Instructions For Use
INDICATIONS FOR USE
A clear indication for epidural anaesthesia will have been identified.
Important Note: This device is not intended to be interpretive and can merely act as a guide to aid the correct location of an epidural needle tip in an epidural space. The user must rely on her or his judgment to determine the correct placement of the epidural needle.
PREPARATION AND ASSEMBLY
General
The Competent Medical Practitioner, who must have been trained in the use of Epidrum, with responsibility for the procedure, shall direct the timing of the procedure and the sub activities.
The procedure should be carried out under the strictest sterile protocol.
Familiarisation
It is essential that users familiarise themselves with the features and performance characteristics of the device.
Please study the device and the user instructions carefully and do not proceed with a procedure until fully satisfied that the instructions are understood.
Environment and Safety
Epidural procedures should be carried out in an appropriate anaesthetic environment, having all emergency equipment and materials available, to ensure that the patient is safe.
Associated Consumables
An appropriate antiseptic should be used before the pack is opened, in order to minimise the risk of contamination.
Epidural Kits
Use this device with state of the art epidural kits, which have friction-fit Luer connections.
Syringe
Select a scaled and calibrated 5ml syringe.
The clinician must assure that Epidrum fits securely with the Luer fittings of the syringe and epidural needle with which the Epidrum is to be used.
Compatible Luers
The Epidrum Luers meet the British Standard BS EN20594-1: 1994 and are only suitable for use with Luers that meet that same British Standard. If used with Luers, which do not comply with that Standard, the outcome could be unpredictable, and may result in a failure to achieve the intended performance or indeed to perform the procedure at all.
Note: It is a requirement of all device manufacturers to conform with BS EN20594-1: 1994.
Function Testing
The function of the Epidrum may be tested prior to use by occluding the exit port (male Luer) and filling the device with air, so as to witness the expansion of the diaphragm.
The correct function would be assured if the signal membrane expands to a hemispherical shape and remains charged after the removal of the syringe from the inlet port.
Important Note: This device must not be used unless the user is fully familiarised with the user instructions, intended purpose, use, and intended performance of this device. Refer to the diagrams, which clearly demonstrate the expected behaviour of the device and demonstrate the signal mechanism, which can aid identification of the epidural space.
Sequence:
1. Test Epidrum
2. Insert needle
3. Remove stylet
4. Attach Epidrum
5. Charge Epidrum
6. Complete procedure observing Epidrum
1. Test the device (per 'Function Testing' q.v.) and then, following normal protocols, introduce the epidural needle into the best position possible, ensuring that the stylet is in place to minimise the ‘coring effect' and subsequent blocking of the epidural needle. Anchor the epidural needle in the usual way and remove the obturator. |
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Key to numbered layers in diagram 1. |
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2. Select a 5 . 0 ml friction fit syringe , fill it ( to 5 .0 ml ) with air and inspect for the presence of foreign bodies. |
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3. The syringe is then attached with a firm, forward twisting motion, to the Epidrum. |
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4. Remove the obturator from the epidural needle. Attach the syringe and Epidrum assembly, with a firm, forward twisting motion, to the epidural needle, which is already located in the best position possible in the patient's back. |
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The diaphragm, which must be visible to the clinician, is surrounded by a coloured ring, for the purpose of its identification. |
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5. Slowly advance the plunger of the syringe to compress the air in the chamber, which will then charge the Epidrum, as the valve in its inlet port opens. Fill the Epidrum so that the diaphragm expands to form a clearly seen shape. Use no less than 1 ml of air. |
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6. Grasp the wings of the epidural needle with the thumbs and forefingers of both hands, while allowing the remaining fingers to rest against the back of the patient and advance the needle's tip towards the epidural space, whilst continuously observing the signal membrane of the Epidrum. |
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7. When the epidural space is located, the diaphragm will deflate to a level depending on the patient's epidural pressure. In the majority of patients, the deflation will be crisp. |
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N.B. In a small minority who have high epidural pressures, the deflation might be small and not easily noticeable. In these rare occasions, maintaining the inflation of the diaphragm to above a hemisphere throughout the procedure (before entry to the epidural space) as described in the user instruction, coupled with close observation of the membrane, should minimise this risk by identifying a change in the position of the membrane and signalling the entry to the epidural space. In a so called boggy back, the diaphragm, acting like a meniscus of a manometer, may slowly settle until the forces involved have re-equilibrated. Be aware that the signal depends on the pressure gradient from Epidrum to the epidural space. If it is small the signal will be attenuated. Epidural venous pulsation seen on the membrane may be further evidence of epidural needle position. |
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Sometimes the Epidrum may even need to be recharged. It is important to note the qualitative difference between the slow discharging of leak into low density tissue and the crisp discharge that characterises the entry of the needle tip into the epidural space. |
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INTENDED PERFORMANCE
The loss of closed system pressure and deflation of the signal membrane will indicate only that the needle tip has entered a void or that the system is otherwise open.
The clinician must rely on her/his own experience and skills to confirm that the needle tip is in the epidural space.
An indication that the needle tip has entered the epidural space is given by the deflation of the signal diaphragm.
UNEXPECTED PERFORMANCE
Important Note:
The clinician must be aware that a false signal may be given by the Epidrum if its contents leak into the patients tissues.
In the event that the signal diaphragm does not deflate but the clinician feels entry into the epidural space, it may be that the needle is blocked. In the event that the needle becomes occluded with the patient's own tissue or blood clot, the function of the Epidrum will be impaired when the needle is advanced. Alternatively, it may be that resistance to the needle continues to be felt but the signal diaphragm has deflated. In this event consideration of the following is required.
(a) The Epidrum has discharged into the patient's tissues.
(b) The assembly has leaked.
(c) The needle has entered the epidural or intrathecal space.
In the event of any failure of the equipment the procedure should be terminated and restarted with replacement devices and associated consumables.
Important Warning: Follow the user instructions carefully, failing which the outcome could be unpredictable and even potentially fatal.
Risks
There is a risk, as with all epidural procedures, that potentially dangerous forces could be imposed on a patient if fluid or air is quickly and forcibly delivered through the device. This is misuse and could result in an unpredictable outcome or fatality.
Minimise the amount of air that enters the patient. Do not exceed 3ml!
There is a risk that a false signal may be given by the Epidrum if its contents leak into the tissues or if connections leak.
There is a risk that the Epidrum may not give the required signal if the needle is obstructed by tissue or blood.
There is a risk of dural tap.
If the Epidrum valve leaks and top up procedure proves unable to charge the device, discard it and consider the possibility of a false signal.
If the Epidrum fails to charge, consider whether the tip of the needle is already in the epidural space, in the sub-dural space or in the intrathecal space.
In the event of contamination of the equipment, including gloves, by Chlorhexadine, other surgical soap or any other contaminants, discard all components and restart the procedure with new equipment.
Contra Indications
Absolute contra indications |
Relative contra indications |
Side Effects
Side effects are limited to discomfort from subcutaneous bleeding and bruising from the needle entry point. There are no side effects directly attributable to the Epidrum.
HANDLING
Handle only with sterile gloved hands and, if gloves are punctured, start the procedure again, discard all components and follow local protocols in the event of injury.
Set aside the unit label for patient's notes, peel the pouch and tip the device from the primary wrap onto a dedicated surgical sterile field.
Avoid touching the inlet or exit ports.
Do not use if the sterile pack is breached, damaged or contaminated.
Do not use after the expiry of the use by date of shelf life, which is located on the unit/lot number label.
STORAGE
Store between 18 - 23°C and 30 - 50% relative humidity.
Store out of direct sunlight.
PATIENT BRIEFING (at clinician's discretion)
The user may wish to draw the patient's attention to the possibility of associated risks.
DISPOSAL
Follow local protocols in respect of the disposal of the equipment. Normally, it should be placed in a yellow disposal bin for subsequent incineration.
Failure to dispose of the device correctly could lead to serious infection.
If an incorrect method of disposal is employed, the outcome may be harmful to a third party or to the environment.
In the event that the equipment is exposed to a highly infectious agent, it must be disposed of by way of incineration, following the highest level of local biohazard protocol.