Administering analgesics (opioid, alpha2-adrenoreceptor agonist) in the cerebrospinal fluid without a local anaesthetic produces locoregional analgesia: markedly reduced pain sensation (incomplete analgesia), some autonomic blockade (parasympathetic plexi), but no sensory or motor block.

Procedures which use spinal anesthesia include:[citation needed] Spinal anaesthesia is the technique of choice for Caesarean section as it avoids a general anaesthetic and the risk of failed intubation (which is probably a lot lower than the widely quoted 1 in 250 in pregnant women[3]).

The post operative analgesia from intrathecal opioids in addition to non-steroidal anti-inflammatory drugs is also good.

[4] This can also be used to effectively treat and prevent pain following surgery, particularly thoracic, abdominal pelvic, and lower extremity orthopedic procedures.

[5] Prior to receiving spinal anesthesia, it is important to provide a thorough medical evaluation to ensure there are no absolute contraindications and to minimize risks and complications.

Most of the common side effects are minor and are self-resolving or easily treatable while major complications can result in more serious and permanent neurological damage and rarely death.

[5] The following are some major complications: Regardless of the anaesthetic agent (drug) used, the desired effect is to block the transmission of afferent nerve signals from peripheral nociceptors.

The degree of neuronal blockade depends on the amount and concentration of local anaesthetic used and the properties of the axon.

A pressure sensation is permissible and often occurs due to incomplete blockade of the thicker A-beta mechanoreceptors.

In spinal anesthesia, the needle is placed past the dura mater in subarachnoid space and between lumbar vertebrae.

Lateral decubitus – In this position, the patient lies on their side with their back at the edge of the bed and facing the provider.

Differences include: Bupivacaine (Marcaine) is the local anaesthetic most commonly used, although lidocaine (lignocaine), tetracaine, procaine, ropivacaine, levobupivicaine, prilocaine, or cinchocaine may also be used.

Commonly opioids are added to improve the block and provide post-operative pain relief, examples include morphine, fentanyl, diamorphine, and buprenorphine.