Lumbar Puncture in Babies

Spinal taps used to diagnose and sometimes treat illness

Spinal_tap_newborn.JPG
A lumbar puncture (spinal tap) being performed on a newborn baby. Bobjgalindo used under a Creative Commons license.

A lumbar puncture, also known as an LP or spinal tap, is a procedure that doctors use to collect spinal fluid. During an LP, a needle is inserted between the bones of the lower back and into the spinal column. A small amount of spinal fluid is then extracted and the needle withdrawn.

The very thought of a spinal tap can be scary to many people, the feeling of which may only increase when a baby is involved.

But, in truth, when performed by a professional experienced in pediatrics, it is often more uncomfortable than painful.

Indications for a Spinal Tap in Babies

Most lumbar punctures in babies are done to check for meningitis, an infection of the membranes that line the brain and spinal column (called the meninges). Meningitis is a very serious infection, and only a spinal tap can conclusively confirm the illness.

Many parents are surprised when informed that their baby needs a spinal tap, especially if the child doesn't appear all that sick. But the test is often vital in making a diagnosis since certain causes, such a group B strep bacteria, don't always manifest with the classic signs of the disease.

The lack of symptoms doesn't make the condition any less serious. By performing an LP, a doctor can confirm the diagnosis and quickly prescribe the right course of treatment.

In addition to meningitis, spinal taps may be used as a means of therapy rather than diagnosis.

This includes a condition called hydrocephalus in which fluid accumulates in the brain, most commonly in babies with severe intraventricular hemorrhage. In such instances, doctors may use a spinal tap to drain excess blood and fluid to either prevent or delay the need for a shunt.

Benefits and Complications

A lumbar puncture is an invasive procedure that requires careful consultation to ensure that it is the appropriate course of treatment, especially for premature babies.

Deciding whether or not to do one is never an easy choice.

The benefits of a lumbar puncture include:

  • Spinal taps can quickly diagnose serious and life-threatening illnesses.
  • Meningitis can only be diagnosed using a spinal tap.
  • The results of a spinal tap can prevent a child from being exposed to incorrect or inappropriate medications.

The potential risks include:

  • Spinal taps can be uncomfortable and emotionally distressing to parents.
  • Infection is a risk of any invasive procedure.
  • Headaches and bleeding can sometimes occur.
  • Premature or sick babies may experience a decreased heart rate or oxygen saturation during the procedure and require careful regulation of supplemental oxygen.

How a Spinal Tap Is Performed

Depending on the situation, the parent may or may not be allowed into the room during the LP. The procedure takes about 30 minutes and involves the insertion of a thin needle between the bones of the lower spine.

Babies are often positioned on their sides with their knees tucked under their chin. Newborns may be seated upright in a curled position. Once the child is correctly placed, the lower spine area will be cleansed with an antiseptic. The doctor performing the procedure will also wear sterile gloves to prevent infection.

A small puncture will then be made through the skin of the lower back, and a liquid anesthetic will be injected to prevent pain. A numbing cream may also be applied before the injection to better minimize discomfort.

Source:

Srinivasan, L.; Harris, M.; and Shah, S. "Lumbar puncture in the Neonate: Challenges in Decision Making and Interpretation." Seminars in Perinatology. 2012; 36(5):445-53. DOI: 10.1053/j.semperi.2012.06.007.

Continue Reading