Mike: Hello, I'm Mike Clarke, podcast editor for the Cochrane Library. The Cochrane Neonatal Group works on producing and updating Cochrane Reviews to provide comprehensive data based on the latest evidence about the care of babies and infants. In December 2023, they added to their more than 450 reviews with one on the position used to perform spinal taps. Here are two co-authors of the review, Marcus Glenton Prescott from St. Olav’s Hospital, Trondheim in Norway and Sara Pessano from Gaslini Children’s Hospital in Genoa Italy, to tell us about the findings.

Marcus: Hello Sara. Do you want to introduce the topic by saying a little about what a spinal tap is and why it is usually performed in Neonatal Intensive Care Units?

Sara: Thanks Marcus, my pleasure. A spinal tap, or lumbar puncture, involves inserting a needle between two bones in a person’s spine, or vertebrae, to collect some of the fluid that surrounds the spinal cord. Spinal taps are done for many reasons and in people of all ages, and are considered to be an invasive procedure which may cause pain and discomfort. They sometimes need to be performed on newborn babies if severe infections, including those affecting the brain and spine, are suspected and need to be diagnosed. However, there is uncertainty about the best position for the baby during the procedure and I’ll pass back to you to say more about that.

Marcus: Thanks. During lumbar puncture, the child may be sitting up, lying sideways in the lateral position or on their stomach in the prone position. In all positions, their legs and neck need to be flexed to help open the space between vertebrae. We did the review to explore whether the choice of position affects the chance of success of the spinal tap, the occurrence of pain, or other adverse events and I’ll let you explain the studies we found.

Sara: Reviewing the literature on positioning for lumbar puncture, we found 5 studies enrolling a total of nearly 1500 newborn babies. Only one study examined infants receiving a spinal tap in the prone position compared to the lateral position, while the other studies compared the lateral position with sitting. The studies included infants aged approximately five hours to five weeks, with average gestational ages from 31 to 41 weeks, where a full-term pregnancy is considered to around 40 weeks. Back to you, Marcus, for a summary of our main findings.

Marcus: None of the studies reported the total number of spinal tap attempts or the number of infants who stopped breathing for a short time, which is called apnea. In the one study comparing the lateral and the prone positions, we found that there may be a lower chance of success at the first attempt in infants in the lateral position; but no data were reported for episodes of slow heart rate, low blood oxygen levels, time to perform the spinal tap, or episodes of apnea. In the studies comparing lateral and sitting positions, we found that there is probably little or no difference in the chance of success at the first attempt; there is likely a higher risk of slow heart rate and low blood oxygen levels with the lateral position; there may be little or no difference in number of episodes of apnea; and we are uncertain whether one position allows the spinal tap to be done faster than the other.

Sara: Thanks, turning to what these findings mean for practice, because the number of studies examining each comparison is small and none of them provided data on all the outcomes that we were exploring, our confidence in our findings is quite low overall. Moreover, the differences between the groups were often small and the methods used could lead to errors, for example, because the investigators may have been aware of the position used. That suggests that more research is needed and we have some suggestions for these.

Marcus: Yes, we’d particularly like future studies to use validated pain scores to explore the effect of the three positions on pain. We also need studies that look at other potential benefits and harms of performing spinal taps on infants lying in different positions. We provide more details on this in the full review and I’ll let you finish, Sara, by telling listeners where they can find it.

Sara: Thanks Marcus. The review is available online at Cochrane Library dot com. If people go to the website and search for 'lumbar puncture position in infants' they'll see the link to it.