Regional anaesthesia methods | How can birth pains be relieved?

Regional anaesthesia methods

Spinal anaesthesia involves the injection of a local anaesthetic into the cavity containing liquor (subarachnoid space) where the spinal cord is located. The injection (injection) is made at the level of the lumbar spine (vertebral body L3/L4 or L2/L3), the spinal cord itself ends a little higher so that it cannot be injured during the injection. The analgesic successively switches off the autonomic nervous system, the sensation of temperature, the sensation of pain, the sensation of touch, movement (motor function) and the sensation of vibration and position.

Surgery such as a caesarean section can therefore be started when the patient can still move her legs, as the pain sensation is switched off relatively sooner. Spinal anaesthesia is the procedure of choice for planned or urgent caesarean sections or for necessary operations during pregnancy below thoracic vertebrae 4 – 6. Spinal anaesthesia should not be used if the patient refuses, in emergencies before and during birth (emergency section or emergency caesarean section), coagulation disorders, certain pre-existing conditions and allergies to local anaesthetics.

Frequent side effects are severe headaches after spinal anaesthesia (cause: leakage of nerve fluid from the spinal canal and thus different pressure ratios), difficult urination and sensory disturbances. Synonym: Epidural anaesthesia) Epidural anaesthesia (PDA) is the most effective method of eliminating pain in obstetrics. A local anaesthetic (local anaesthetic) can be injected by inserting a catheter, more rarely by a single injection (injection), into the space outside the skins (meninges or dura) surrounding the spinal cord, the so-called epidural space.

This temporarily and locally eliminates the nerve tracts that transmit the pain. Epidural anaesthesia (PDA) is possible in the thoracic (thoracic PDA) as well as in the lumbar (lumbar PDA) region, in obstetrics the lumbar PDA is preferred.In addition to the local anesthetic, opioids (strong painkillers that act on the opiate receptors) can be injected; in Germany, only the opioid sufentanil is approved for this purpose. With this method, local anesthetic can be dispensed with, thus it is possible to eliminate pain, but leave movement (motor function) relatively unrestricted.

In the ideal case, the patient can still walk when the pain is completely eliminated. A further advantage of epidural anaesthesia (PDA) with leaving a catheter in place is the so-called patient-controlled anaesthesia. The patient can determine herself by a button whether more painkiller is injected through the catheter (limited per hour, thus preventing overdosage).

An epidural is an option for all patients with an inconspicuous course of birth and an unremarkable CTG. The epidural does not lead to an increased rate of Caesarean section births. However, if the epidural catheter is in place, it can be used to eliminate pain in the event of an unscheduled birth (if an urgent caesarean section is necessary), a very effective and time-saving option.

Epidural anaesthesia should not be performed if the patient refuses, in emergencies before and during birth (emergency dissection), coagulation disorders, certain pre-existing conditions and allergies to local anaesthetics. The nervus pudendus (pubic nerve) is present twice and supplies the genital area from the mons pubis to the anus. It transmits sensations and pain, but is also responsible for some muscles.

In case of pain during birth (expulsion phase) or during difficult births (forceps or suction bell birth), the nerve can be injected with a local painkiller (local anesthetic) at several points and thus temporarily switched off, i.e. the pain transmission is interrupted in this area. However, a pudendal blockage is a local anaesthetic that only affects the vagina and perineal area, the pain of contractions is still felt. A pudendal block should not be performed if the patient refuses, infections in the area of the injection, allergies to local anesthetics and coagulation disorders.

In contrast to spinal or epidural anesthesia (purely medical activity), pudendal block can be performed by obstetricians themselves. Intubation anesthesiaIn intubation anesthesia, pain sensation and consciousness are completely eliminated by medication. Furthermore, a tube is inserted into the trachea in order to ventilate the patient and to protect her from inhaling stomach contents (aspiration).

Intubation is always necessary in advanced pregnancy (after the 12th week of pregnancy) to protect against aspiration, pure mask ventilation or the use of so-called laryngeal masks for ventilation are absolutely contraindicated, as these forms of ventilation do not offer sufficient protection. During the intubation itself, an additional medicinal muscle relaxation may be necessary. Before intubation anesthesia, no food must be taken for at least 6 hours and no liquids for at least 2 hours. After the anaesthesia, breastfeeding should also be avoided for at least 24 hours, as the anaesthetic medication can pass to the newborn via breast milk. Intubation anesthesia should only be used if there are no alternatives, e.g. in emergencies such as emergency cesarean sections or heavy bleeding, as well as for diagnostic or therapeutic procedures during pregnancy and childbirth that cannot be performed under local or regional anesthesia.