After table rounds this morning, one of the residents asked me if I wanted to do a bedside lumbar puncture (LP). I instantly jumped at this opportunity and proceeded to gather the patient’s consent, LP kit, and other supplies necessary for the procedure. In the meantime, I tried to recall the nuances of what we learned during the LP segment of orientation two weeks ago. Needless to say, things are a little different with a real patient. 🙂
I helped the patient assume the proper position (“knees to chest”), located and draped the vertebral site, cleansed the site with chlorhexidine, anesthetized it superficially and then more profoundly with 1% lidocaine, and then grabbed the spinal needle. Telling the patient to take a deep breath, I found myself doing the same as I cautiously guided the needle in.
I first tried to “feel around”, avoiding bone and aiming the needle towards the umbilicus. I hit what I thought was bone, but based on how deep the needle was, I had a strong suspicion it could be a thickened dura. I had seen an LP done in the ER a few months ago where the resident had simply not pushed hard enough to penetrate the dura (fearing that it was bone); an attending basically walked in, pressed a little harder, and had cerebrospinal fluid (CSF) flowing within one attempt. 😀
I tried once more and then deferred to my resident. She was also unable to have any CSF return. Our service’s chief was then called in. I shared my story from the ER, and the chief explained how dural thickening, degenerative disc disease, and other LP-complicating conditions are relatively prevalent in the patient population we’re dealing with. He simply pressed through the dura and had CSF flowing immediately – a champagne tap (no contamination of the sample by blood).
In retrospect, I’d say I did roughly 95% of the procedure properly – the 5% being deferred to someone more experienced who would cause less discomfort to the patient. I’ll take that any day.
Hopefully I’ll get to do another one in the next two weeks! Procedures are awesome. 🙂