Lumbar Puncture (Spinal Tap) In Babies – Everything You Need To Know

Lumbar Puncture In Babies

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It is perplexing if your baby is continuously ill. Despite seeking consultation from the best pediatricians, babies do not recover from their illness, as the doctors fail to diagnose the exact cause of the disease. That is when the doctor might suggest lumbar puncture or spinal tap. From the very sound of it, you wonder if such intrusive diagnostic method is needed for a tiny baby.

But lumbar puncture is a simple way to determine the presence of several life-threatening infections and conditions. MomJunction talks about lumbar puncture and whether it involves any risk.

What Is Lumbar Puncture?

Lumbar puncture, also referred to as a spinal tap, is the process of inserting a syringe in the lower spine to extract cerebrospinal fluid. This is a clear liquid that circulates within the nervous system, from the brain to the lower tip of the spine. The fluid is drawn out from subarachnoid space, which is a cavity or pocket of cerebrospinal fluid that surrounds the entire nervous system.

Cerebrospinal fluid is significant because it cushions the spine and brain from physical impact and carries vital nutrients for the nervous system. Therefore, it can provide valuable insights into the health of the nervous system and display pathogens in case of neural infection.

[ Read: Scoliosis In Babies ]

Why Is Lumbar Puncture Done?

Lumbar puncture or spinal tap is recommended when the doctor suspects a nervous system disorder, infection, or cancer (1). The fluid can be tested externally for anomalies or the presence of diseases. In fact, sometimes it is the only way to determine the presence of certain infections. Following are scenarios where the spinal tap is recommended over general diagnostic procedures:

  1. Neonatal sepsis: It is a blood infection in infants caused by a host of diseases including those that affect the nervous system such as meningitis and encephalitis (2). If the doctor suspects the cause of sepsis to be an infection of the nervous system, then he would conduct a spinal tap to determine the presence of pathogens in the cerebrospinal fluid.
  1. Bacterial and viral infections: Microbes may find their way from blood or nerves to the cerebrospinal fluid, where they may harm the body by affecting the nervous system. Syphilis can be reliably diagnosed using spinal tap procedure (3).
  1. Detect cancers: The cerebrospinal fluid can display the presence of cancerous cells if the baby has cancer affecting the blood such as leukemia and lymphoma, nervous system, or lymph nodes. The high pressure of cerebrospinal fluid in the nervous system can also help determine an abnormality in the cell functions (4).
  1. Subarachnoid hemorrhage: It is the bleeding within the subarachnoid space, which lines the nervous system including the brain. The presence of blood here can indicate hemorrhage, which can occur due to head trauma or due to an aneurysm. This causes the arterial walls to form a balloon-like pocket that bursts to leak blood into the surrounding tissue. An aneurysm is itself caused by bacterial or viral infections.
  1. Nervous system disorders: Lumbar puncture is a direct means of tapping into the nervous system to diagnose abnormalities or ailments. Degenerative neural diseases such as multiple sclerosis and Guillain-Barre syndrome are determined through laboratory testing of the cerebrospinal fluid, which can be obtained using spinal tap.

There are certain other scenarios where a doctor may perform a lumbar puncture to inject a substance rather than extract fluids:

  1. Inject dye into the cerebrospinal fluid: A special medical dye is injected into the subarachnoid space to help the doctor observe the X-rays of the nervous system better. This enables proper inspection of the spinal cord and associated nerves, which can be used to determine the presence of a disease.
  1. Injecting chemotherapy drugs: Lumbar puncture is utilized for the delivery of chemotherapy drugs in the nervous system or even other parts of the body in cases of cancer.
  1. Injecting medicines or anesthetics: Anesthetics can work faster if injected directly into the nervous system through a spinal tap. Doctors may also use lumbar puncture to inoculate the body with medicines in case they see it as the best means of administering the drug.

In some cases, the doctor may inject a needle only to measure the pressure of the cerebrospinal fluid, using a medical device called manometer. High cerebrospinal fluid pressure is a critical indicator of some diseases such as meningitis (5).

[ Read: Meningitis In Babies ]

What Is The Procedure For Lumbar Puncture in babies?

Spinal tap is conducted at the neurologist or pediatrician’s clinic, which should be well-equipped for the procedure. The process involves a series of steps:

1. Discussion with parents:

The doctor explains the process and significance. He will also discuss the apprehensions over the procedure and assuage any concerns. Parents play a vital role in deciding the use of sedation.

Lumbar puncture is performed using local anesthesia, where the spot of injection stays numb while the baby is alert. It is also performed using general anesthesia where the baby is completely unconscious. The doctor may even choose to give an intravenous sedative, which will make the infant drowsy.

The type of sedative would depend on the age and health of the infant as well as the preference of the parents.

2. Preparing for the day:

Once you achieve a consensus, the doctor will hand you a list of ‘dos and don’ts’ to prepare the baby for the lumbar puncture. There is no special preparation required, but the doctor may give a diet to be followed a couple of days before the procedure.

If your baby is on some other medicines, then the doctor may ask you to stop using them temporarily as they can distort the test results of lumbar puncture. You can continue breastfeeding your baby since it does not have an impact on the results of the procedure.

3. The lumbar puncture procedure:

On the day of the test, here is what the doctor does:

  • The baby is made to lie on his side with his feet curled up and his arms in the front. The nurse or a parent can help the baby stay put in this position. Parents are permitted to remain with the infant through the entire procedure since their presence will keep the baby calm and steady.
  • The doctor will feel the spine of the baby to determine a gap in the lumbar region of the vertebral column. The hole for lumbar puncture is drilled between L3 and L4 or between L4 and L5 vertebra (6).
  • Once the spot is determined, the doctor will rub it with a disinfectant solution apply a cold gel on the area to partially numb the nerve endings.
  • A local anesthesia is injected into the muscles of the lower back to numb the spot. If the parents have opted for general anesthesia or an intravenous sedative, then it can be injected from a vein in the arm.
  • If it is a general anesthesia or sedative, then the baby will slowly fall unconscious. In the case of local anesthesia, he will have to be calmed down by a parent so that he stays still and does not shake his legs.
  • The numbing effect initiates within minutes, and the baby will calm down soon after.
  • The next step is to insert the lumbar puncture needle. The doctor determines the length of the lumbar puncture needle after considering the baby’s height, age, and referring to the contemporary medical formulas (7). The needle is inserted into the lower back till it enters the subarachnoid space, which contains the cerebrospinal fluid. A baby under the influence of local anesthesia stays conscious, therefore, may experience the pressure and a pinching sensation in the spine.
  • The puncture needle is hollow and has another needle within called a stylet. After the puncture, the stylet is gently withdrawn, drawing out the clear cerebrospinal fluid, and collecting it in test tubes. The fluid drips slowly, and it takes two to five minutes to complete the collection.
  • The tapping needle is slowly retracted, and a sterile bandage is placed on the injection site.

Once the injection site is dressed, your baby can slowly move to his back and lie down the usual way. The entire procedure of pediatric lumbar puncture takes about 30 minutes (8). Test results can be shared within hours or days depending on the objective of spinal tapping. After the procedure, though, comes the crucial post-procedural care.

[ Read: Neurofibromatosis In Babies ]

What Care Is Needed After Lumbar Puncture?

You need to take good care of the baby for him to recover in the shortest time. Here are some points to remember after a lumbar puncture for an infant:

  1. Rest is essential: Your baby must sleep well for the next 24 hours. Keep the lighting in his room low and maintain a noise-free environment.
  1. Give him fluids: If your baby is older than six months, then give him small sips of water once every couple of hours. You can continue with breastfeeding as usual to provide ample fluids.

If the baby is younger than six months, then breastmilk is the only source of fluids. You could have additional breastfeeding sessions in the first 24 hours after spinal tapping to replenish the cerebrospinal fluid.

  1. Prevent vigorous play: Babies can be quite active and playful, but you must avoid this for one week after the spinal tapping. The puncture hole would still be fresh and may drip cerebrospinal fluid during agitated movement and play, thus complicating the healing process.
  1. Dress the area of injection with new bandages: You must put fresh bandages on the puncture site, as directed by the doctor. Changing the bandage at regular time intervals will keep the area aseptic and speed up the healing process.

Spinal tap in babies does not have any long-term repercussions, and your baby can lead a normal life immediately after the procedure. Taking care is all that is needed for a speedy recovery. However, the process is not completely free of side effects, and your baby could experience these right after the process.

Are There Any Side Effects Of Lumbar Puncture?

The side effects of lumbar puncture may show up within hours of the procedure and last for a few days. They fade away as the injection site heals. Following are the lumbar puncture side effects in babies:

  1. Headache: The baby could have a headache due to the change in cerebrospinal fluid pressure on the nervous system, making him irritable and cranky. Soothing, breastfeeding, and cuddling should make him feel better.
  1. Back pain: The baby will writhe in pain every time he moves his legs or when on his back, due to the dull back pain as a result of the procedure. Taking ample rest will alleviate the pain and make the baby feel better.
  1. Localized swelling at the point of injection: The muscles around the lower back inflame as a reaction to the needle insertion, but the swelling subsides as the puncture heals. Also, some cerebrospinal fluid may ooze out and collect under the lower back skin. However, that is not dangerous since it will disappear with proper rest and care.

There will be no serious consequences of lumbar puncture. But it is always good to be aware of the probable risks.

[ Read: Hydrocephalus In Infants ]

What Are The Risks Of Lumbar Puncture?

Lumbar puncture is quite safe since it is conducted only by professional medical practitioners with appropriate medical equipment (9). But some likely complications are:

  1. Bleeding in the tissues of lower back: Blood vessels in the lower back may get ruptured during the puncturing process and leak blood into the subarachnoid space, subsequently passing it to the nervous system. This may cause complications in the functions of the brain and spinal cord, leading to neurological problems.
  1. Infection of the injection wound: When there is a lack of proper hygiene, the injection site may be attacked by bacteria, leading to the infection of the nervous system.
  1. Blood mixing with the extracted cerebrospinal fluid: If the baby is not held properly during the extraction process or due to human error, some blood may get mixed with the cerebrospinal fluid when extracted. The fluid is then of no use since it cannot yield conclusive laboratory results. A repeat spinal tapping will be required, which is possible only after a few months.

These complications seldom happen, but you should still be vigilant about the appearance of any serious aggravation.

When To Take The Baby To A Doctor?

If you notice any of the following situations or conditions, then rush your baby to the doctor:

  1. Seizures and fits: If the baby suffers fits or has had a seizure at least once after the procedure, then seek immediate medical attention. It could be due to low/high cerebrospinal fluid pressure or mixing of blood in the fluid.
  1. Baby is vomiting frequently: Some infants vomit immediately after a lumbar puncture, but if they continue doing so even after several hours or days post procedure, then it could be an indicator of a complication.
  1. Frequent crying: If the baby seems in agony and cries a lot, then it could be due to the pain.
  1. Not eating/drinking: If he does not consume any food, including breastmilk, and feeds for no more than a few minutes, he requires medical attention.
  1. Is drowsy: The little one appears tired to the point he seems semiconscious. He has low levels of alertness and gets fatigued quickly.

Bring your baby to the prompt attention of a doctor if you see of these red flags, to prevent the situation from getting out of control.

Lumbar Puncture Is Still Very Useful:

While many parents are unsure about the viability of an invasive test such as a lumbar puncture to detect the presence of an infection, research has shown that spinal tap is the best way to confirm the presence of several diseases. It is so safe and precise that it is conducted on premature babies as well (10). The benefits of lumbar puncture surely outweigh the risks thus making it an effective way of diagnosing life-threatening diseases in the baby.

Have any experience to share on lumbar puncture? Tell us about it in the comments below.

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Rohit Garoo

Rohit Garoo took writing as a profession right after finishing his MBA in Marketing. Earlier he graduated with a Bachelor’s degree in Botany & Zoology from the autonomous St. Xavier’s College in Mumbai. Rohit has also done a Stanford University certification course on breastfeeding. This botanist-zoologist turned writer excels at life sciences, and at MomJunction he writes everything about pediatrics and maternal care. In between writing and being overly curious, he spends time cooking, reading, and playing video games. LinkedIn profile –
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