Epidurals: what could go wrong?

Like I said in my last post, the benefits of the epidural are obvious. Pain gone. Feel much better. (And, in the event of a change of plans requiring a c-section, it's easy to add more medicine to the epidural to make the woman numb enough to have a c-section comfortably and still be awake to see the baby born).

Now I'm not trying to be a big giant buzz kill, but it's my job, as an anesthesiologist, to think like a pessimist and be prepared for problems and complications. I don't expect them (and, fortunately, have had vanishingly few in my career so far), but just considering their possibilities every time I place a catheter is like my little ritual to ward off the bad vibes. Perhaps this knowledge can work for you in the same way. However, if you are someone who is scared witless (or something else rhyming with witless) by knowing too much, then read no further. My intent is not to frighten people out of getting epidurals but to help them enter the procedure realizing the extent of its invasiveness and the things that might (but honestly, probably won't) go wrong.

Just to be simple and organized, I put them in list form.

What could go wrong with your epidural?
1. Infection. That's why it's a sterile procedure, where we wash our hands beforehand, clean your back with sterile soap, then we put on sterile gloves to open a sterile epidural kit. We wear masks and surgical caps for good measure. Infection, fortunately, is incredibly rare nowadays. But the epidural catheter tip is within a centimeter of the spinal cord. If it's dirty, infection can happen, and needless to say, it's NOT a good place to be infected. That's why any anesthesiologist worth their salt takes sterile technique very, very seriously.

2. Bleeding. Again, bleeding is rare unless you have a condition, congenital or acquired, that predisposes you to bleeding. A woman who is suspected of being pre-eclamptic can have low platelet counts, ones this can change quickly. If that is the case, your anesthesiologist will want to see a recent platelet count before placing an epidural. In the rare cases bleeding occurs, it is usually secondary to the catheter being put it or taken out, in combination with some other intrinsic bleeding issue. Epidural bleeding is bad for obvious reasons - it can cause compression of the spinal cord and neurologic compromise. Did I mention how incredibly rare bleeding and infection are? In three years of training, during which about 28,000 deliveries occurred at my training program, I only know of one epidural abscess or bleed. And even there, it wasn't certain if the epidural caused the problem...

3. Nerve injury. This is even rarer than the first two complications, because the epidural by definition doesn't touch nerves or nerve roots. In a combined spinal/epidural, the spinal needle can graze a nerve root as it enters the dural sac, but that is rare and even when it happens, the needle is so small that it almost never causes even the most transient of symptoms.

4. Nerve palsy. This is totally different from direct nerve injury from anesthetic or a needle. Anesthesia plays an indirect role in this, however, though at times when I was a resident we were blamed more directly than we deserved. Nerve palsies, usually femoral or obturator nerve palsies, occur when the nerves from the low lumbar and sacral roots are compressed for a prolonged period of time by the fetal head. It is rare, but when it happens, the woman doesn't know it until afterwards because, of course, she was numb from the epidural as the nerve compression was occurring. I've also heard of numbness in the legs, feet, and lateral thighs from simply being in stirrups, especially if the woman pushed for a long time. Again, it's not a direct result of anesthesia, but the woman often doesn't know until after the epidural has worn off that she has a numbness in the area in question.

5. The finder needle gets pushed too far and enters the dura. This is the dreaded "wet-tap.". Simply put, this happens when, for whatever reason (difficult anatomy, patient movement, operator error and/or inexperience, etc.), the anesthesiologist pushes the large finder needle too far. Instead of stopping at the epidural space behind the dura, the needle gets pushed through the dura and into the sac of spinal fluid. This in and of itself is not a huge problem. The procedure is still sterile and infection is still rare, and the catheter can be placed and threaded at another level if needed. The problem is afterwards.

When the dural lining is pierced by a large needle like that, it can cause a severe headache afterwards. Classically, it is a positional headache. It is worst when sitting up, when the pain is usually in the occiput, back of the neck, and the forehead. It is thought that the hold in the dura causes a leakage of spinal fluid and a tension on the dural linings in the brain. The headache improves significantly when lying down. Within a week to 10 days, the headache almost always resolves on its own; the problem is that when a new mother is at home with an infant, being confined to bed, lying down, is just not an option. So this kind of headache (known as a postdural puncture headache) is treated proactively when it occurs, with IV fluids, caffeine intake, and oral analgesics. If those don't work, the anesthesiologist can be called in to do a procedure called an epidural blood patch, to close, as it were, the hole in the dura. The success rates with the blood patch are very high.

6. The epidural is difficult for the anesthesiologist to place. The first five things on this list are more serious; the next few are mostly inconveniences and annoyances. Getting an epidural requires sitting in a very uncomfortable position, slouched over with your lower back protruding out - very difficult to do with a full term uterus, not to mention a contraction every two or three minutes. When the poor woman is forced to sit in that position for a half hour or more, it can be tough on everyone. Unless there is a medical reason why the woman really should get an epidural, I'll let her choose if I'm struggling to place it. If I have been trying for a half hour to get an epidural, my telling her how great she'll feel later is sure to fall on deaf ears.

A lot of things can contribute to technical difficulties with epidurals, like abnormal bony anatomy (scoliosis, previous surgery, etc), but since the epidural is placed by feel, the biggest obstacle to epidural placement is...yes, obesity. You know those people who are so skinny you can see the bones in their back? Those people are easy to put epidurals in, because their landmarks are easy to see. If your back is covered with a lot of...um, adipose tissue, the bony landmarks of the back are hard (sometimes impossible) to feel, and placing the epidural can be a crapshoot. Oh sure, once in a while you'll find the thin patient with an amorphous, dough-like back, and the obese patient with easily palpable landmarks, but in general, if someone is obese, it greatly increases the chance of difficult epidural placement, which leads to the next two things on the list...

7. Your back is sore afterwards. My wife had her epidural put in by one of my old attendings. 1 pass with the needle and the epidural was in, and it worked great. Even in that total best-case scenario, she said her back felt sore and strange for several months afterwards, right in the spot where she got the epidural. If getting your epidural was difficult for the anesthesiologist for whatever reason and you were poked more than once, you'll probably be a little sore too.

8. The epidural just doesn't work right. All kinds of things fall into this category. The catheter could fall out at some point because it wasn't taped securely. The epidural makes you numb only on one side, or doesn't work at all. The anesthesiologist's soluton in some of those cases is to simply give more local anesthetic through the epidural. Sometimes that works. Sometimes it doesn't. In those situations where all else fails, the dilemma is the same; should you just make do, or is it worth it to have the anesthesiologist try to place it again? That's a call only you and your anesthesiologist can make.

This is just a partial list. I'm sure I missed a few ones, and there are some other crazy obscure things that I won't mention, but these are the big things to watch out for...