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Lumbar Puncture Pearls

Although the traditional teaching is to use the L4/L5 intervertebral space, the L3/L4 intervertebral space is actually wider and easier to penetrate – I always jump up one space. The legendary “two pops” is subtle and often unappreciated by most providers. Forget about this silly rule all together. Just know that in most patients (with normal BMIs) you will have to insert the needle 50-75% of the total length before obtaining CSF. In the obese, you may need to hub your needle before obtaining CSF. If the patient complains of sciatic-like pain during the procedure this is extremely helpful information – it means your needle is too far lateral and you are hitting either the right or left spinal…

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  Lumbar Puncture

This is one of the most important and overlooked part of the LP. Positioning the patient properly is pivotal to increasing the success rate of the procedure. Increasing the interspinous distance allows for a larger space for the spinal needle to enter. To increase this distance, the patient needs to flex their lumbar spine as much as possible. One way of assisting this is to support the patient’s feet on a stool.

  Procedural Deep Dive – Lumbar Puncture (LP)

Ahhh, the lumbar puncture… This seemingly simple procedure seems to be the Achilles's heel or many resus docs! If you have a good baseline knowledge of how to do the lumbar puncture correctly, it is super easy. If you have bad habits, then you will make your poor patient look like a pin cushion. In this episode, I review my 20 years worth of tips and tricks to excel at the Lumbar Puncture (LP) as well as how to avoid the most common pitfalls I see all the time.

 Unlocking Common ED Procedures – The Impossible Space: Lumbar Punctures

emDocs is proud to introduce a new series focused on emergency medicine procedures! This series will provide key information on procedural steps, indications, contraindications, pearls, and pitfalls. Today, the lumbar puncture!

Articles of Interest

Emergency Procedure: Lumbar Puncture

We prefer the seated position as it improves success rate. Rotation of the back is minimised, as is sideways curvature of the spine from the patient sinking into the mattress.

Brown Sound: Ultrasound Guided Lumbar Puncture

We use ultrasound for a multitude of procedures in the emergency department, including central and peripheral venous access, abscess drainage, and joint aspiration. Less common, but just as useful, is the use of ultrasound to help identify landmarks when performing a lumbar puncture (LP). While the traditional method of LP is based on palpating anatomical landmarks, this is becoming increasingly difficult as the patient population becomes more obese. It may also be difficult in patients who have abnormal spinal anatomy or in those who have had previous spinal surgery. When palpating anatomy is difficult, ultrasound can be a useful tool to help identify appropriate landmarks and increase your LP success rate.

Difficult Lumbar Puncture: Pitfalls and Tips from the Trenches

Lumbar puncture has, for many years, been the responsibility of the internal medicine physician or the neurologist. As more patients have undergone spine surgery and with the current increase in body mass index of the general population, the radiologist has been consulted with increasing frequency to perform lumbar puncture with fluoroscopic guidance. Radiology, in fact, is now the dominant overall provider of lumbar puncture procedures.

How to do a Lumbar Puncture: Instructions from a practising neurologist

Even today the word lumbar puncture still strikes fear in patients and practitioners. Like all fear, education will alleviate it! Ive now done hundreds of LPs, teach about LPs and write LP guidelines. Here's how I go about it.

Lumbar Puncture NEJM

Lumbar puncture is indicated for both diagnostic and therapeutic reasons. Knowledge of the contraindications, the pertinent anatomy, and the methods to minimize the risk of complications is necessary for the safe and efficient performance of lumbar puncture. This procedure video demonstrates how to perform a lumbar puncture.

Positioning is Everything

Half the battle of any procedure is setting up your stage to perform, no matter how complex or simple the task at hand may be. Successful procedures are all about positioning and patient comfort. The better the positioning, the better the procedure and overall outcome.

Techniques for Performing Paramedian Approach to Lumbar Puncture

An alternative method to the traditional lumbar puncture is the paramedian approach. Although scarce in the emergency medicine literature, it has been a successful option that has been performed by anesthesiologists for decades.

The Bloody CSF Tap – Pearls and Pitfalls

Xanthochromia doesn’t reliably appear in the CSF until 12 hours after symptom onset. If your LP is performed prior to this, the absence of xanthochromia cannot be used to exclude SAH. While there is no formal consensus on absolute RBC count or RBC clearing to definitively exclude SAH, on our review of the literature, we find that an absolute count of less than 500 in the final tube coupled with a clearing of >70% is reassuring. While this is conservative, this is the cutoff that we recommend.

When the Easy LP Isn't Easy

Lumbar punctures can be mercurial procedures. There are certainly patients in whom it can be predicted that a lumbar puncture will be challenging. Obesity, patients with known degenerative changes, and agitated patients all present unique challenges when it comes to successfully completing a lumbar puncture. There are patients, however, who throw you a bit of a curveball. Sometimes cooperative patients with good landmarks, in whom you had every expectation that you would find success, become seemingly impossible to successfully complete a lumbar puncture.

Resources

Society for Academic Emergency Medicine

Lumbar puncture is a common emergency department procedure that is used for both diagnostic and therapeutic purposes. As a diagnostic tool, lumbar puncture is used to detect CNS infections, CNS malignancies, and inflammatory processes, such as Multiple Sclerosis or Guillain-Barre. Lumbar puncture also has historically been used in the diagnosis of subarachnoid hemorrhage (SAH) as the next diagnostic step in patients whose initial CT head is negative. However, this topic has become controversial...