Epidural anaesthesia causes a loss of sensation, including pain, by blocking the transmission of signals through nerve fibres in or near the spinal cord.

It is not recommended for people with severe bleeding disorders, low platelet counts, or infections near the intended injection site.

The most common complications of epidural injections include bleeding problems, headaches, and inadequate pain control.

Alternatively, direct imaging of the injection area may be performed with a portable ultrasound or fluoroscopy to confirm correct placement.

When placed properly, an epidural catheter may remain inserted for several days, but is usually removed when it is possible to use less invasive administration methods (such as oral medication).

The child may experience a slow heartbeat, decreased ability to regulate temperature, and potential exposure to the drugs administered to the mother.

[6] There is no overall difference in outcomes based on the time the epidural is administered to the mother,[7] specifically no change in the rate of caesarean section, birth which must be assisted by instruments, and duration of labor.

[8] Epidural analgesia has been demonstrated to have several benefits after other surgeries, including decreasing the need for the use of oral or systemic opioids,[9] and reducing the risk of postoperative respiratory problems, chest infections,[10] blood transfusion requirements,[11] and myocardial infarctions.

[18][19] This may be used to treat post-dural-puncture headache and leakage of cerebrospinal fluid due to dural puncture, which occurs in approximately 1.5% of epidural analgesia procedures.

[20] Some heart conditions such as stenosis of the aortic or mitral valves are also a contraindication to the use of epidural administration, as is low blood pressure or hypovolemia.

[22] Very large doses of some medications can cause paralysis of the intercostal muscles and thoracic diaphragm responsible for breathing, which may lead to respiratory depression or arrest.

[22] Obese people, those who have given birth prior, those with a history of opiate use, or those with cervical dilation of more than 7 cm are at a higher risk of inadequate pain control.

This may result in a high block, or, more rarely, a total spinal, where anesthetic is delivered directly to the brainstem, causing unconsciousness and sometimes seizures.

[26] Epidural administrations can also cause bleeding issues, including "bloody tap", which occurs in approximately 1 in 30–50 people.

A 2018 Cochrane review found no evidence regarding the effect of platelet transfusions prior to a lumbar puncture or epidural anesthesia for participants that have thrombocytopenia.

[33] If bupivacaine, a medication commonly administered via epidural, is inadvertently administered into a vein, it can cause excitation, nervousness, tingling around the mouth, tinnitus, tremor, dizziness, blurred vision, or seizures as well as central nervous system depression, loss of consciousness, respiratory depression and apnea.

[36][37] The sensation of needing to urinate is often significantly diminished or completely absent after administration of epidural local anesthetics or opioids.

[39] The lower maternal oxytocin level negatively affects the baby’s feeding rooting reflex, decreasing the amount of milk produced.

[16] Epidural administration is a procedure which requires the person performing the insertion to be technically proficient in order to avoid complications.

When using a paramedian approach, the tip of the needle passes along a shelf of vertebral bone called the lamina until just before reaching the ligamentum flavum and the epidural space.

[43] Along with a sudden loss of resistance to pressure on the plunger of the syringe, a slight clicking sensation may be felt by the operator as the tip of the needle breaches the ligamentum flavum and enters the epidural space.

The catheter is generally inserted 4–6 cm into the epidural space, and is typically secured to the skin with adhesive tape, similar to an intravenous line.

[47][48][49] Typically, the effects of the epidural block are noted below a specific level or portion of the body, determined by the site of injection.

For example, a thoracic epidural performed for upper abdominal surgery may not have any effect on the area surrounding the genitals or pelvic organs.

[50] For some procedures where both the rapid onset of a spinal anesthetic and the post-operative analgesic effects of an epidural are desired, both techniques may be used in combination.

[55] Subcutaneously tunneled epidural catheters may be safely left in place for longer periods, with a low risk of infection or other complications.

[61] The first record of an epidural injection is from 1885, when American neurologist James Corning of Acorn Hall in Morristown, New Jersey, used the technique to perform a neuraxial blockade.

[71] Some people continue to be concerned that women who are administered epidural analgesia during labor are more likely to require a cesarean delivery, based on older observational studies.

[72] However, evidence has shown that the use of epidural analgesia during labor does not have any statistically significant effect on the necessity to perform a cesarean delivery.

[80] Even in countries with universal healthcare coverage such as Canada, socioeconomic factors such as race, financial stability, and education influence the rate at which women receive epidural analgesia.