These tests may include pulling back on the plunger of the syringe to see if blood flows in, injecting a small dose of anesthetic and asking if you experience certain symptoms, or injecting a dose of adrenalin (epinephrine), which is supposed to increase pulse rate if the needle is in a blood vessel. If all seems well, the anesthesiologist will thread a tiny, flexible, plastic catheter through the needle, withdraw the needle and inject the full dose of medication. The catheter will be looped and taped to your back to keep it from shifting position. None of these precautions is failsafe.
To maintain anesthesia, the anesthesiologist may connect the catheter to a syringe and place the syringe in a pump that slowly depresses the plunger (continuous infusion). This delivers a continuous dose. Alternatively, the anesthesiologist may cap the catheter and return to inject more anesthetic at intervals or when you complain of returning pain (periodic top-ups).
Ideally you will feel no pain, but have some control over your legs. Anesthesiologists may reduce the anesthetic concentration when you approach full cervical dilation so that again, ideally, you remain comfortable but have enough sensation to push effectively.
The procedure can easily take over an hour from the time you request the epidural to the time the anesthetic takes effect. It can take longer if the anesthesiologist isn’t readily available when you ask. The period during which you must hold still generally lasts five to ten minutes.