Reference: Pessano S, et al. Positioning for lumbar puncture in newborn infants. Cochrane Database Syst Rev. December 2023 Date: February 7, 2025 Dr. Lauren Rosenfeld Guest Skeptic: Dr. Lauren Rosenfeld is a PGY-3 emergency medicine resident at George Washington University. She is also a new podcast host for Emergency Medicine Residents’ Association (EMRA) Cast Series. Case: A five-day-old girl is brought to the emergency department (ED) for fever by her parents. She was born full-term and seemed to be doing very well after the family returned home. Her mother had an uneventful pregnancy and delivery. Today, the parents thought she was feeling warm and took the girl’s temperature, which was 101°F (38.3°C). They called the pediatrician, who told them to go to the ED for more testing and warned them of the likelihood that their baby may need a lumbar puncture. The worried father asks you, “What is a lumbar puncture? Will it hurt?” Her mother asks you, “Is it like when I got an epidural before delivering? Will you sit her up for it? She can’t sit yet.”  Background:  We have covered the topic of febrile infants and lumbar punctures (LP) before on the SGEM. However, we typically focused on the febrile infant part. Today we’re going to talk more about performing the procedure of a lumbar puncture on babies.  In the ED, lumbar punctures are typically performed in infants with fever in the evaluation for invasive bacterial infections including meningitis. There are many thoughts and bits of advice around how to perform an LP including the proper position, when to remove the stylet from the needle, what kind of analgesia to use, etc. There are multiple positions to set up the lumbar puncture. Commonly, patients can be placed on their side in the lateral decubitus, bend the neck so the chin is close to the chest, hunch the back, and bring the knees toward the chest to approximate the fetal position. Alternatively, patients may also sit upright and then bend their head and shoulders forward. When it comes to infants, most of the time, we are relying on someone else to help hold the baby in those positions as we’re performing the LP. Sometimes, these babies can have episodes of oxygen desaturation when they get held in that position for too long. Clinical Question: How does the positioning of infants during lumbar puncture (lateral decubitus vs sitting vs prone) affect success rates and adverse events?  Reference: Pessano S, et al. Positioning for lumbar puncture in newborn infants. Cochrane Database Syst Rev. December 2023 Population: preterm and term infants of postmenstrual age up to 46 weeks and 0 days. Age 4.9 hours to 5 weeks Intervention: Infants positioned in a lateral decubitus position. Comparison: Infants positioned in a sitting position or prone position​. Outcome: Primary Outcome(s): Successful lumbar puncture on the first attempt, with < 500 red blood cells/mm3. Total number of lumbar puncture attempts (successful or unsuccessful). Episodes of bradycardia, defined as a decrease in HR of more than 30% below baseline or less than 100bpm for 10 seconds or longer. Secondary Outcomes: Time to perform LP, episodes of desaturation (SpO2 <80%), apnea, need for pain/sedation medication, skin changes at LP site, infection rate related to LP, pain, and parental satisfaction. Type of Study: Systematic Review Meta-analysis Authors’ Conclusions: “When compared to sitting position, lateral decubitus position probably results 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 as specified in this review. Furthermore, infants in a sitting position likely experience less episodes of bradycardia and oxygen desaturation than in the lateral decubitus, and there may be little to no difference in episodes of apnea.