The most sensitive part is the skin, which the anaesthetist first numbs by injecting a small amount of local anaesthetic with a tiny needle, almost as thin as a hair. Because of the small size of this needle, this is hardly felt by the patient. After a minute or so, when the skin has become numb, the anaesthetist inserts the epidural needle, which is considerably thicker, but is not felt anymore.

Advertisement

In the tissues underneath the skin, up to the epidural space, there are very few nerve endings or pain receptors, so once the needle has passed the skin, the procedure is hardly, if at all, painful. The epidural needle is inserted to a depth of 2 – 4 cm, where the epidural space will be encountered.

The anaesthetist knows when the needle tip has reached the epidural space by using a “loss of resistance” technique. This means the following: A syringe is attached to the epidural needle, while this is gradually pushed further beneath the skin in the direction of the epidural space. The anaesthetist keeps with his/her thumb continuous pressure on the plunger of this syringe, and when the tip of the needle reaches the epidural space, which has a lower resistance than the surrounding tissues, the plunger will suddenly go into the syringe (“loss of resistance”).

The syringe is then disconnected and through the needle a very thin plastic catheter of about 0.5 mm thick is threaded into the epidural space. The needle is removed and the catheter stays behind for as long as the effect of epidural pain relief is needed. It is so thin and soft that the patient is never aware that it is actually there (so there is no needle left behind in the back once the catheter is in place!). The reason that this catheter is inserted is that it allows the anaesthetist to prolong the pain relief by giving a continuous infusion of local anaesthetic through it for a few days.

A single shot of local anaesthetic would wear off after a few hours, but after most, if not all, operations, longer pain relief is required, which is made possible by the continuous infusion.

Read more:
Managing back pain
The causes of back problems

Links:
Arthritis Foundation of South Africa
Multiple Sclerosis South Africa
The South African Society of Physiotherapy

Rate this article Poor 1 2 3 4 5 Excellent

JOBS

Senior Secretary Gauteng - North/Sandton Infrastructure Resource Gauteng - Johannesburg Management Accountant R450,000-500,000 Per Annum Cost To Company Gauteng - Johannesburg Financial Manager R350,000-400,000 Per Annum Cost To Company Gauteng - Johannesburg Financial and Project Accountant R300,000-360,000 Per Annum Cost To Company Gauteng - Johannesburg Financial Accountant R380,000-420,000 Per Annum Cost To Company Gauteng - Johannesburg SSIS Business Intelligence Specialists (SSIS; SSAS) R350,000-500,000 Per Annum Cost To Company Gauteng - North/Sandton Financial Accountant R350,000-450,000 Per Annum Cost To Company Gauteng - South Find more jobs Register your CV Post a job