A spinal block, also called a spinal injection or simply a spinal, is a form of local anesthesia that is delivered into the fluid of the spinal column just below the end of the spinal cord. Spinal blocks are given for back surgeries, labor pain or to diagnose the specific location and cause of back pain. These injections work by numbing the area below the block while leaving the patient conscious. The numbness typically begins right away and lasts only one to two hours.
The injection site of the spinal block may feel sore for a few days following the procedure. In some individuals, a painful or uncomfortable tingling sensation may occur in the lower body or legs for a few days after the injection. Bladder pain may also occur immediately after the block wears off, if the bladder becomes distended due to an inability to empty itself during the surgery.
Some people who receive a spinal block develop a severe headache. This headache can last for up to a week, but it can be treated with over-the-counter or prescription pain relief drugs. Patients who develop a spinal block-induced headache typically notice head pain between 12 to 24 hours after the spinal injection, explains the World Federation of Societies of Anesthesiologists. This type of headache pain may also feel better when lying down and worse when raising the head. Larger gauge needles are more likely to result in headaches than smaller gauge needles.
Infections as a result of a spinal block are rare, but they can be serious if they do occur. Because of the location of the needle insertion, an infection may develop in or around the spinal cord or may travel to the brain and develop into meningitis. The infection may cause an abscess in the spinal column.
Permanent Nerve Damage
In some cases, a person who receives a spinal block may develop permanent nerve damage from the procedure. Elderly patients who experience a prolonged drop in blood pressure during their block are most at risk for permanent nerve damage, resulting in paralysis of one or both legs.
A total block may occur if the anesthesiologist delivers too much medicine via the spinal block or delivers the wrong type of medication. In a total block, the medicine travels up the spine as well as down, causing the muscles of the chest and neck to become numb as well as the lower extremities. If this occurs, the patient may become unable to breathe. The blood pressure will drop and the arms and hands become numb. If untreated, the patient may go into cardiac arrest, fall unconscious or even die from the effects of the block.