Late effects
Late effects directly related to spinal anesthesia are virtually non-existent. As already described in the Risks section, undesirable side effects of local anesthetics disappear over time and usually do not cause permanent damage. Nerve injuries, such as those caused by needlestick injuries, are also extremely rare.
One reason for this is that spinal anesthesia has become a routine procedure that is often practiced in clinics and thus shows a high degree of safety through experience. In addition, rounded needles are used in spinal anaesthesia to minimize the risk of injury. However, if nerve damage occurs due to mechanical irritation, late complications can occur.
These primarily include loss of sensitivity of the skin in delimited areas. Paralyses or even paraplegia are not to be expected if the procedure is carried out properly. Bacterial infections can cause extensive permanent damage to the spinal canal or central nervous system. Sterile work prevents such complications.
Contraindications
There are some contraindications against the use of spinal anaesthesia when assessing which of the existing anaesthesia methods is the most suitable for a particular procedure and patient. Absolute contraindications, for which spinal anaesthesia is not to be used under any circumstances, can be distinguished from relative contraindications. Here, the advantages and disadvantages must be carefully weighed against each other.
One of the most frequent contraindications is various coagulation disorders. These can be congenital or caused by medication.In the latter case, the reduced coagulability of the blood can be reversed by discontinuing the medication. Depending on the medication used, it may be necessary to discontinue a few hours (heparin) to over a week before spinal anaesthesia.
However, poor coagulation is an absolute contraindication, as it can lead to bleeding around the area of the spinal cord and thus to paralysis. Spinal anesthesia is also absolutely contraindicated in the presence of bacterial infection. This includes infections affecting the entire body such as sepsis, but also local infectious events occurring at the site of the puncture.
For example, severe acne on the back should be considered a contraindication. Another important contraindication for the use of spinal anesthesia is the presence of an allergy to the local anesthetics used, which should definitely be communicated to the anesthesiologist during the preparatory consultation. Increased intracranial pressure is also a contraindication.
If this has been determined, it is very likely that strong headaches will occur after the anesthesia, so that another procedure should be chosen. In addition, a so-called post-spinal headache that has already occurred previously also speaks against spinal anesthesia. The last absolute contraindication is hypovolemia, i.e. a lack of volume with a reduced amount of blood circulating in the bloodstream.
In contrast to the contraindications mentioned above, spinal anesthesia may be used in the presence of relative contraindications under certain circumstances, after weighing the risks and benefits in favor of the patient. Relative contraindications to spinal anesthesia include chronic back pain or ankylosing spondylitis. Heart valve defects, narrowing of the aortic valve (aortic valve stenosis) and elevated blood pressure in the pulmonary circulation can also be contraindications.
