Implementation | Epidural anaesthesia: Is it painful? When is it used?

Implementation

Epidural anesthesia is performed under sterile conditions. This means that the physician performs a surgical hand disinfection beforehand, and all materials that come into contact with the patient’s body (especially the needle) must be sterile – i.e. guaranteed to be free of pathogens. In addition, the area around the puncture site is covered with a sterile cloth that leaves a hole free at the puncture site.

At the beginning of the epidural anesthesia, the physician palpates two spinous processes of the spine on the back of the sitting patient – the height of the spine at which this is done depends on the height at which the operation is later performed. For example, for an operation in the upper abdomen, the spinous processes of the lower thoracic spine are palpated. After re-disinfecting the puncture site thus found, a local anesthetic is injected under the skin between the two spinous processes.

Then a so-called Tuohy needle is inserted at the same point through the various skin layers and parts of the ligamentous apparatus of the spinal column into the so-called epidural space – hence the name epidural anesthesia. The epidural space is a space rich in fatty tissue and blood vessels that surrounds the spinal cord and its protective sheaths, the meninges. In order to recognize the correct insertion depth, the physician places a syringe with liquid on the needle before inserting the needle and exerts light pressure on the syringe during insertion.

As soon as the resistance decreases noticeably, the doctor knows that he has punctured the necessary layers of skin and ligaments and the tip of the needle is now in the epidural space. Now a local anesthetic such as bupivacaine can be injected into the epidural space. This spreads upwards and downwards in the epidural space and develops its anaesthetic effect after a period of approx.

20-30 minutes in the corresponding areas of the body. The Tuohy needle can then be removed and the injection site can be treated with plasters, thus ending the epidural anaesthesia. Alternatively, it is also possible to insert a small plastic tube into the epidural space through the hollow interior of the needle.

This so-called catheter can remain on the patient for days and thus offers the possibility of a longer-term pain inhibition by means of epidural anesthesia. A pump connected to the catheter ensures a steady supply of medication.Under certain circumstances, even the patient himself can be instructed in the operation of the pump, so that he can vary the dose of the medication administered depending on the current intensity of pain. This can serve in particular the purpose of early restoration of the patient’s mobility and thus counteract the development of joint stiffness and similar complications. Epidural anesthesia is usually performed shortly before surgery. This is done in direct connection with further preparations for the operation by the anaesthesia team, such as applying the ECG and monitoring the oxygen content of the blood.