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Bolus before infant LP

3 week old infant is brought in with fever of 38.5. The baby is well appearing and does not have any high risk factors in the birth history. You plan to get urine, blood, and CSF cultures and give empiric IV antibiotics.

Do you bolus before infant LP to improve success in obtaining the LP?

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pemsou5_wp • October 11, 2016

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  1. Kelly October 12, 2016 - 4:22 pm Reply

    Could not find any literature on this – anyone for an RCT? The only paper I found was this one: from CHLA where they cleverly used ultrasound to measure the subarachnoid space before and after a fluid bolus, and found no significant change, which would seem to imply that fluid bolus is unlikely to increase LP success.

  2. Tim October 12, 2016 - 4:37 pm Reply

    Other: true-true and unrelated. I give a bolus, because the baby typically needs it. I don’t wait for the bolus because the return on waiting investment is marginal acutely.

    The CHLA paper is probably the best it gets — an ingenious proxy cohort study.

    Thanks for the question and discussion!

  3. Ben October 13, 2016 - 12:45 am Reply

    My tip for LP’s in babies is that it’s not about the person holding the needle, it’s about the person holding the baby. The most common mistake I see is that the baby is flexed in the upper back or neck which does not help and can actually be dangerous by causing airway obstruction.
    The other common mistake occurs when the provider does not hold the baby tight enough.

    I like to hold the baby myself while the resident performs the LP. This also frees up a nurse and allows me to do something while supervising the resident.

    Another trick I like when teaching LP’s is that I will inject the lidocaine, then let the resident do the LP. There is usually a small red dot where I injected the lidocaine which serves as a target for the resident to hit with the LP needle. Then you only need to coach on the needle angle.

    I suspect that hydration as a factor in LP is less important than commonly believed. I typically do the LP as the first test in a septic workup, before the IV is placed. From an anatomic and physiologic standpoint, the spinal canal does not change significantly in volume with hydration, and thus one would not expect hydration to improve success rates.

  4. Seth October 16, 2016 - 7:21 pm Reply

    I only bolus before the LP if I get a history of a significantly dehydrated child or if the child is unstable. Data aside and only using my personal “n’s” there was a time where i was a big believer in bolusing first for better success. However, I will echo what Ben has said. LP is the FIRST test for me in a <28 day rule out sepsis patient. I usually call for the tech to get the equipment as I head into the room for the H&P. After my exam, and telling the parents why the full workup is necessary, I immediately grab an extra pair of hands and perform the LP.

    This is for several reasons:
    1. LP is now NOT the rate limiting step to antibiotics. Nurses can then do the urine, blood, iv start and immediately start antibiotics making their time more efficient.
    2. CSF takes the longest (at my hospital) to come back from lab so my time to dispo improves (we keep <28 day olds with meningitis in the PICU not the Floor) and this lab result is a bottle neck for admission.
    3. You don't have to deal with the dreaded situation when the child has had multiple pokes for a failed IV attempts and parents are over it and you have to re-convince the parents that an LP is a good idea.
    4. You don't have to worry about your holder dislodging a difficult to place IV.
    5. I can now move on to the next patient. I will touch base again when all results have come back, perform a re-exam and admit on my second pass through making me more efficient with my time.

  5. Mike October 29, 2016 - 9:39 am Reply

    I like Ben’s suggestions. Also, ultrasound studies have shown that multiple attempts at the same interspace are often futile due to small otherwise non-significant epidural hematomas that form and push the CSF out of that interspace (infants are great subjects to image with spine US due to the limited ossification of the vertebral bodies.)

    Coley BD, Shields WE 2nd, Hogan MJ. Diagnostic and interventional ultrasonography in neonatal and infant lumbar puncture. Pediatr Radiol. 2001 Jun;31(6):399-402.

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