Title: Recommendations on the Use of Ultrasound Guidance for Adult Lumbar Puncture: A Position Statement of the Society of Hospital Medicine. J Hosp Med. 2019 Oct 1;14(10):591-601. doi: 10.12788/jhm.3197. Epub 2019 Jun 10.

1. What is already known about this topic?
   1. Previous meta-analysis with multiple RCTs have shown that ultrasound-guided LP is superior to landmark-guided LP for multiple reasons including first pass and overall success of LP, reduced traumatic taps, shorter procedure time, fewer attempts with the needle and reduction in pain. 
2. What is the PICO question?
   1. Population: Patients requiring lumbar puncture

1. Intervention: ultrasound-guided LP
2. Comparison: landmark-guided LP
3. Outcome: successful LP
4. This was a systematic review with a 4,389 references pooled and a final selection of 77 articles. The selected articles were abstracted into a data table and incorporated into the draft of recommendations. The final recommendation count was 10 which were given a strength and degree of consensus. 
5. What are the main findings?
   • Recommendations are summarized as follows:
     1. When available use ultrasound  
     2. Mark insertion site and patient should remain in the same position for LP
     3. A low-frequency transducer, preferably a curvilinear array transducer, should be used.
     4. high-frequency linear array possible in nonobese patients
     5. Map the lumbar spine, starting at the level of the sacrum and sliding the transducer cephalad
     6. Transverse plan to mark the midline of the lumbr spine, and longitudinal plane to mark the insterspinous spaces, with intersection markings used for procedure evaluation
     7. Preprocedural evaluation to measure the distance from the skin surface to the ligamentum flavum
     8. Simulation training before with initial procedure supervision.

What are its limitations?

• With any meta-analysis or systematic review the primary limitation is the quality of literature gathered. 
• There was lack of consistent literature on whether US guidance reduces postprocedural back pain or actually improves patient satisfaction, which are patient oriented outcomes. 
• Interestingly, this paper was titled ultrasound guided which is a dynamic approach, but there recommendations describe an ultrasound “assisted” or static approach. Most of the data describes the static approach but there is a decent amount of literature describing a dynamic approach. Currently, there isn’t data comparing dynamic to static US guided LP, which could be investigated. 
• Other relevant outcomes could be explored including comparing the effect of US guidance on timelines, clinical-decision making, and cost-effectiveness, although difficult to study. 
• It may be a limitation that this was an internal medicine based review, but one could argue that emergency physicians and residents are more familiar and skilled with the use of ultrasound. Therefore, it could be argued that if medicine physicians are recommending adopting this practice in the hands of trained individuals then EM providers fit the recommendation. 

How will this article change practice?

• This appears to be a well done systematic review. It positively supports at least the adoption of dedicated practice and training similar to the training we receive for other ultrasound procedures. Lumbar punctures seem to be one of the more difficult procedures, especially for residents, and if there is a way to increase proficiency it should be considered. It seems reasonable with appropriate simulation and training to incorporate this into our clinical practice. 

Written by: Taylor Brittan, MD