• Spinal taps are often required in severe infections in newborns but may be difficult to perform, with approximately 50% of attempts ending in failure.
• We identified studies comparing three different body positions during spinal tap: lying sideways (lateral decubitus), sitting, and lying on the stomach (prone). In all positions the infants should keep their legs tucked in and neck bent forward (flexed).
• There may be little or no difference in first-time success rates between sitting and lateral decubitus positions, and there may be a higher chance of success with prone position than with lateral decubitus position. There is likely a higher risk of adverse events with lateral decubitus than with sitting position.
What is a spinal tap?
A lumbar puncture, commonly known as a spinal tap, is a procedure that involves inserting a needle into the spine. Spinal taps may be done for many reasons and in all ages. They are often performed in newborns when searching for severe infections, including those affecting the brain and spine, to collect cerebrospinal fluid (the fluid that cushions the brain and spinal cord) or to insert medications. Because it involves inserting a needle, a spinal tap may cause pain and discomfort.
Various positions may be used to perform a spinal tap. The child may be lying sideways (lateral decubitus), sitting, or lying on their stomach (prone); in all positions they should keep their legs tucked in and neck bent forward (flexed).
What did we want to find out?
We wanted to find out whether in newborns different body positions may affect the chance of a successful spinal tap at the first attempt; the number of tries for a successful spinal tap; and the number of episodes of adverse events, such as slow heart rate, low oxygen levels in the blood, and apnea (episodes of not breathing). We also explored if there were any differences in the time taken to perform the spinal tap; pain and discomfort during a spinal tap; need for pain medication or sedation to perform a spinal tap; bleeding and bruising from spinal taps; and rate of infections related to spinal taps.
What did we do?
We searched for studies comparing different body positions while performing a spinal tap in newborns. We compared and summarized the results of the studies and rated our confidence in the evidence, based on factors such as study methods and sizes.
What did we find?
We found five studies involving 1476 infants undergoing spinal taps. Only one study, with 171 infants, examined infants in prone position; the other studies compared children in lateral decubitus position and sitting. Four studies examined infants undergoing regular spinal taps, while one study examined spinal anesthesia in infants undergoing surgery. The smallest trial had 26 participants, while the largest had 1082. The studies included infants aged approximately five hours to five weeks, with average gestational ages (time since the mother's last menstrual period) from 31 to 41 weeks. The studies included 864 boys, 580 girls, and 32 with unspecified sex. Two trials were conducted in the USA, and one each in Spain, China, and the UK. One study received public funding, while the other four studies did not identify their funding sources.
We found no studies reporting the total number of spinal tap attempts or the number of infants experiencing apnea for either comparison. We found no studies reporting episodes of slow heart rate, low blood oxygen levels, time to perform the spinal tap, or episodes of breathing stops for a short period of time for the comparison of lateral decubitus position versus prone position.
When comparing performing spinal taps in infants in lateral decubitus position and sitting, we found that there may be little or no difference in chance of success at the first attempt; there is likely a higher risk of slow heart rate and low blood oxygen levels with lateral decubitus position; there may be little or no difference in number of episodes of apnea; and we are uncertain whether one position is faster than the other.
When comparing performing spinal taps in infants in lateral decubitus position and in prone position, there may be a lower chance of success at the first attempt in infants in lateral decubitus position.
What are the limitations of the evidence?
Our confidence in our findings is limited because of the low number of studies examining each question for each comparison; moreover, some of the studies used methods likely to introduce errors in their results. In some studies, the investigators may have been aware of which position was used. Furthermore, none of the studies provided data on all the outcomes we aimed to explore, and the differences reported between groups were often quite small.
How up-to-date is this evidence?
The evidence is current to January 2023.
When compared to sitting position, lateral decubitus position may result in little to no difference in successful lumbar puncture procedure at first attempt. None of the included studies reported the total number of lumbar puncture attempts. Furthermore, infants in a lateral decubitus position likely experience more episodes of bradycardia and oxygen desaturation, and there may be little to no difference in episodes of apnea. The evidence is very uncertain regarding time to perform lumbar puncture. Pain intensity during and after the procedure was reported using a pain scale that was not included in our prespecified tools for pain assessment due to its high risk of bias. Most study participants were term newborns, thereby limiting the applicability of these results to preterm babies.
When compared to prone position, lateral decubitus position may reduce successful lumbar puncture procedure at first attempt. Only one study reported on this comparison and did not evaluate adverse effects.
Further research exploring harms and benefits and the effect on patients' pain experience of different positions during lumbar puncture using validated pain scoring tool may increase the level of confidence in our conclusions.
Lumbar puncture is a common invasive procedure performed in newborns for diagnostic and therapeutic purposes. Approximately one in two lumbar punctures fail, resulting in both short- and long-term negative consequences for the clinical management of patients. The most common positions used to perform lumbar puncture are the lateral decubitus and sitting position, and each can impact the success rate and safety of the procedure. However, it is uncertain which position best improves patient outcomes.
To assess the benefits and harms of the lateral decubitus, sitting, and prone positions for lumbar puncture in newborn infants.
We used standard, extensive Cochrane search methods. The latest search date was 24 January 2023.
We included randomized controlled trials (RCTs) and quasi-RCTs involving newborn infants of postmenstrual age up to 46 weeks and 0 days, undergoing lumbar puncture for any indication, comparing different positions (i.e. lateral decubitus, sitting, and prone position) during the procedure.
We used standard Cochrane methods. We used the fixed-effect model with risk ratio (RR) and risk difference (RD) for dichotomous data and mean difference (MD) and standardized mean difference (SMD) for continuous data, with their 95% confidence intervals (CI). Our primary outcomes were successful lumbar puncture procedure at the first attempt; total number of lumbar puncture attempts; and episodes of bradycardia. We used GRADE to assess the certainty of evidence for each outcome.
We included five studies with 1476 participants.
Compared to sitting position: lateral decubitus position may result in little to no difference in successful lumbar puncture procedure at the first attempt (RR 0.93, 95% CI 0.85 to 1.02; RD −0.04, 95% CI −0.09 to 0.01; I2 = 70% and 72% for RR and RD, respectively; 2 studies, 1249 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts. Lateral decubitus position likely increases episodes of bradycardia (RR 1.72, 95% CI 1.08 to 2.76; RD 0.03, 95% CI 0.00 to 0.05; number needed to treat for an additional harmful outcome (NNTH) = 33; I2 = not applicable and 69% for RR and RD, respectively; 3 studies, 1279 infants, moderate-certainty evidence) and oxygen desaturation (RR 2.10, 95% CI 1.42 to 3.08; RD 0.06, 95% CI 0.03 to 0.09; NNTH = 17; I2 = not applicable and 96% for RR and RD, respectively; 2 studies, 1249 infants, moderate-certainty evidence). The evidence is very uncertain regarding the effect of lateral decubitus position on time to perform the lumbar puncture (MD 2.00, 95% CI −4.98 to 8.98; I2 = not applicable; 1 study, 20 infants, very low-certainty evidence). Lateral decubitus position may result in little to no difference in the number of episodes of apnea during the procedure (RR not estimable; RD 0.00, 95% CI −0.03 to 0.03; I2 = not applicable and 0% for RR and RD, respectively; 2 studies, 197 infants, low-certainty evidence). No studies reported apnea defined as number of infants with one or more episodes during the procedure.
Compared to prone position: lateral decubitus position may reduce successful lumbar puncture procedure at first attempt (RR 0.75, 95% CI 0.63 to 0.90; RD −0.21, 95% CI −0.34 to −0.09; number needed to treat for an additional beneficial outcome = 5; I2 = not applicable; 1 study, 171 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts or episodes of apnea. Pain intensity during and after the procedure was reported using a non-validated pain scale. None of the studies comparing lateral decubitus versus prone position reported the other critical outcomes of this review.