How is spinal anesthesia performed?
Spinal anesthesia is usually applied shortly before the operation. For the puncture, the patient can assume a lying or sitting position. In this case, the patient is asked to make a so-called “cat’s hump”, i.e. to curve the back as much as possible; this should increase the distance between the individual vertebrae.
To make the puncture site sterile, a disinfectant is sprayed on the back. Palpation of the vertebral bodies enables the physician to locate the correct puncture site on the back. Before the puncture needle is inserted, the corresponding skin area is locally anaesthetized with a much thinner needle.
Thus, the application of spinal anesthesia is usually not perceived as painful. The puncture needle is inserted a few centimeters below the skin level into the spinal space. This is where the local anesthetic, i.e. the medication that causes the pain to be relieved, is injected.
In contrast to the insertion of a catheter that remains for a longer period of time, this technique is called “single shot”. The insertion of such a thin plastic catheter, as is the case with a periduary catheter, serves to continuously supply the local anesthetic during longer surgical procedures. A further advantage compared to single shot is that the continuous administration of the medication ensures freedom from pain even in the days following the operation.
All in all, the application of one of the spinal anaesthetics usually takes no longer than ten minutes. The period between the injection of the local anesthetic and the onset of action lasts only a few minutes. In order to check whether the spinal anaesthesia is working correctly, the patient is asked to assess a cold stimulus.
This is usually set by spraying the legs with disinfectant. Since temperature sensation and pain sensation are equally eliminated by the local anesthesia, not feeling the cold stimulus automatically means that this region is also insensitive to pain. When combining spinal and general anesthesia, the SPA is performed first, because the patient can provide the doctor with information about the temperature sensation during a cold stimulus.
