| During a lumbar puncture, the individual lies on his or her side with the knees drawn up to the abdomen and the forehead bent towards the knees. This position allows for maximum separation of the vertebrae in the lower back, allowing the needle to be inserted more easily. A local anesthetic is injected into the skin near where the needle will be inserted to numb the area. The needle is then inserted through the lower back and into the spinal canal. Depending on the reason for the procedure, a small sample of CSF may be extracted (which takes about 5 minutes), and the needle will be removed. If the purpose of the lumbar puncture is to administer medication, the needle will be left in place, and tubes will be attached through which the medication can enter the spinal canal. If myelography (x-ray examination of the spinal canal, nerve roots, and spinal cord) is to be performed, contrast material will be injected through the needle. If the pressure of the CSF is being measured, a device called a manometer is attached to the lumbar puncture needle. Following the procedure, a bandage will be applied to the puncture site, and the individual will be required to remain in a reclining position for some time (anywhere from 15 minutes to several hours). If a CSF sample has been taken, the body naturally replaces the amount lost in about 1 hour. The individual should not engage in strenuous activities for 24 hours following the procedure. |
Source: Medical Disability Advisor