Ultrasound evaluation of lumbar spine anatomy in newborn infants: implications for optimal performance of lumbar puncture

Positioning for lumbar puncture in newborn infants

BACKGROUND

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.

OBJECTIVES

To assess the benefits and harms of the lateral decubitus, sitting, and prone positions for lumbar puncture in newborn infants.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 24 January 2023.

SELECTION CRITERIA

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.

DATA COLLECTION AND ANALYSIS

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.

MAIN RESULTS

We included five studies with 1476 participants. Compared to sitting position: lateral decubitus position probably results in little to no difference in successful lumbar puncture procedure at the first attempt (RR 0.99, 95% CI 0.88 to 1.12; RD 0.00, 95% CI -0.06 to 0.05; I2 = 47% and 46% for RR and RD, respectively; 2 studies, 1249 infants, low-certainty evidence). None of the studies reported the total number of lumbar puncture attempts as specified in this review. 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). Lateral decubitus position results in little to no difference in time to perform the lumbar puncture compared to sitting position (I2 = not applicable; 2 studies; 1102 infants; high-certainty evidence; in one of the study median and IQR to report time to perform the lumbar puncture were 8 (5-13) and 8 (5-12) in the lateral and sitting position, respectively, I2 = not applicable; 1 study, 1082 infants; in the other study: mean difference 2.00, 95% CI -4.98 to 8.98; I2 = not applicable; 1 study, 20 infants). 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.

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. Lateral decubitus position results in little to no difference in time to perform the lumbar puncture compared to sitting position. 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.

Positioning for lumbar puncture in newborn infants

BACKGROUND

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.

OBJECTIVES

To assess the benefits and harms of the lateral decubitus, sitting, and prone positions for lumbar puncture in newborn infants.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search date was 24 January 2023.

SELECTION CRITERIA

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.

DATA COLLECTION AND ANALYSIS

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.

MAIN RESULTS

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.

AUTHORS' CONCLUSIONS

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 position in infants-a systematic review and meta-analysis

To analyze the optimal lumbar puncture position in infants. A systematic review and meta-analysis. Infants (age < 1 year). December 2022 in PubMed, Scopus, and Web of Science. Randomized controlled trials focusing on lumbar puncture positions were included. Other lumbar puncture position than standard lateral decubitus position. First puncture success and overall success rate. Secondary outcome was desaturation during puncture and procedure-related harms. Risk of bias 2.0 assessment was performed. Outcomes are reported as risk ratios (RR) with 95% confidence intervals (CI). We screened 225 abstracts, and six studies were included. Four studies compared sitting position, one study head elevated lateral position, and one study prone position to lateral position. Risk of bias was high in two studies. First puncture success rate in sitting position (RR 1.00, CI: 0.78-1.18; 2 studies) and overall success rate in sitting position were similar to lateral position (RR 0.97, CI: 0.87-1.17; 3 studies). First attempt success rate was higher in elevated lateral position (RR 1.48, CI: 1.14-1.92; 1 study) and in prone position (RR 1.09, CI: 1.00-1.17; 1 study).  Conclusion: Sitting position seems to be equally effective in terms of first attempt and overall success in lumbar puncture than standard lateral position. Elevated lateral position and prone positions had better first attempt success than standard lateral position, but these were assessed only in one study each and thus further studies in these positions are needed.  Trial registration: This review was registered in PROSPERO. ID: CRD42022382953. What is Known: •  Success rate in lumbar puncture has been poor and first attempt success rate has varied between 50 to 80% in literature. •  Optimal lumbar puncture positions for infants have been debated between sitting and lateral decubitus position mostly. What is New: •  This is the first meta-analysis focused on lumbar puncture positions in infants, and it found that sitting position was equal to standard lateral position. • Prone position and head elevated lateral positions had higher first puncture success rates, but these were assessed both only in one study, which creates uncertainty to the finding.

Indications, Measurements, and Complications of Ten Essential Neonatal Procedures

About 10% of newborns require some degree of assistance to begin their breathing, and 1% necessitates extensive resuscitation. Sick neonates are exposed to a number of invasive life-saving procedures as part of their management, either for investigation or for treatment. In order to support the neonates with the maximum possible benefits and reduce iatrogenic morbidity, health-care providers performing these procedures must be familiar with their indications, measurements, and potential complications. Hence, the aim of this review is to summarise ten of the main neonatal intensive care procedures with highlighting of their indications, measurements, and complications. They include the umbilical venous and arterial catheterizations and the intraosseous line which represent the principal postnatal emergency vascular accesses; the peripherally inserted central catheter for long-term venous access; the endotracheal tube and laryngeal mask airway for airway control and ventilation; chest tube for drainage of air and fluid from the thorax; and the nasogastric/orogastric tube for enteral feeding. Furthermore, lumber puncture and heel stick were included in this review as very important and frequently performed diagnostic procedures in the neonatal intensive care unit.

Assessment of infant position and timing of stylet removal to improve lumbar puncture success in neonates (NeoCLEAR): an open-label, 2 × 2 factorial, randomised, controlled trial

BACKGROUND

Newborn infants are the highest-risk age group for bacterial meningitis. Lumbar punctures are therefore frequently performed in neonates, but success rates are low (50-60%). In Neonatal Champagne Lumbar punctures Every time-A Randomised Controlled Trial (NeoCLEAR), we sought to optimise infant lumbar puncture by evaluating two modifications to traditional technique: sitting position versus lying down and early stylet removal (stylet removal after transecting the subcutaneous tissue) versus late stylet removal.

METHODS

NeoCLEAR was an open-label, 2 × 2 factorial, randomised, controlled trial, conducted in 21 UK neonatal and maternity units. Infants requiring lumbar puncture at 27⁺⁰ to 44⁺⁰ weeks corrected gestational age and weighing 1000 g or more were randomly assigned (1:1:1:1) to sitting position and early stylet removal, sitting position and late stylet removal, lying position and early stylet removal, or lying position and late stylet removal using a 24/7, web-based, secure, central randomisation system. Block randomisation was stratified within site by corrected gestational age (27⁺⁰ to 31⁺⁶ weeks, 32⁺⁰ to 36⁺⁶ weeks, 37⁺⁰ to 40⁺⁶ weeks, or 41⁺⁰ to 44⁺⁰ weeks), using variable block sizes of four and eight with equal frequency. Laboratory staff were masked to allocation. The primary outcome was successful first lumbar puncture, defined as obtaining a cerebrospinal fluid sample with a red blood cell count of less than 10 000 cells per μL. The primary and secondary (including safety) outcomes were analysed by the groups to which infants were assigned regardless of deviation from the protocol or allocation received, but with exclusion of infants who were withdrawn before data collection or who did not undergo lumbar puncture (modified intention-to-treat analysis). This study is registered with ISRCTN, ISRCTN14040914.

FINDINGS

Between Aug 3, 2018, and Aug 31, 2020, 1082 infants were randomly assigned to sitting (n=546) or lying (n=536), and early (n=549) or late (n=533) stylet removal. 1076 infants were followed-up until discharge and included in the modified intention-to-treat analysis. 961 (89%) infants were term, and 936 (87%) were younger than 3 days. Successful first lumbar puncture was more frequently observed in sitting than in lying position (346 [63·7%] of 543 vs 307 [57·6%] of 533; adjusted risk ratio 1·10 [95% CI 1·01 to 1·21], p=0·029; number needed to treat=16). Timing of stylet removal had no discernible effect on the primary outcome (338 [62·0%] of 545 infants in the early stylet removal group and 315 [59·3%] of 531 in the late stylet removal group had a successful first lumbar puncture; adjusted risk ratio 1·04 [95% CI 0·94-1·15], p=0·45). Sitting was associated with fewer desaturations than was lying (median lowest oxygen saturations during first lumbar puncture 93% [IQR 89-96] vs 90% [85-94]; median difference 3·0% [2·1-3·9], p<0·0001). One infant from the sitting plus late stylet removal group developed a scrotal haematoma 2 days after lumbar puncture, which was deemed to be possibly related to lumbar puncture.

INTERPRETATION

NeoCLEAR is the largest trial investigating paediatric lumbar puncture so far. Success rates were improved when sitting rather than lying. Sitting lumbar puncture is safe, cost neutral, and well tolerated. We predominantly recruited term neonates younger than 3 days; other populations warrant further study. Neonatal lumbar puncture is commonly performed worldwide; these results therefore strongly support the widespread adoption of sitting technique for neonatal lumbar puncture.

FUNDING

UK National Institute for Health and Care Research.

The EFSUMB Guidelines and Recommendations for Musculoskeletal Ultrasound - Part II: Joint Pathologies, Pediatric Applications, and Guided Procedures

The second part of the Guidelines and Recommendations for Musculoskeletal Ultrasound (MSUS), produced under the auspices of EFSUMB, following the same methodology as for Part 1, provides information and recommendations on the use of this imaging modality for joint pathology, pediatric applications, and musculoskeletal ultrasound-guided procedures. Clinical application, practical points, limitations, and artifacts are described and discussed for every joint or procedure. The document is intended to guide clinical users in their daily practice.

Seated Position Does Not Change Lumbar Dimensions Compared With Lateral Position

OBJECTIVE

The infant lumbar puncture (LP) can be a technically challenging procedure. Understanding the anatomical lumbar dimensions may optimize LP conditions. Data from preterm neonates, older children, and adults indicate measurements of the lumbar spine in the seated LP position may be superior when compared with the lateral position. We use point-of-care ultrasound (US) to determine if the seated position, when compared with the lateral decubitus position, significantly affected the lumbar dimensions of infants 12 months or younger presenting to the pediatric emergency department.

METHODS

We conducted a prospective observational study of a convenience sample of patients 12 months or younger. We used US to obtain 3 still images oriented longitudinally in the midline over the L3 to L4 interspace in the lateral decubitus and seated positions. A US fellowship-trained emergency physician, blinded to patient position, measured interspinous space, subarachnoid space width, and spinal canal depth. We then compared the means of all 3 dimensions in the lateral and seated positions.

RESULTS

From 50 subjects, 49 subjects provided 46 evaluable sets of images for each measure. Interspinous space, spinal canal depth, and subarachnoid space width did not differ significantly between positions. Mean differences did not exceed 0.02 cm for any of the measured dimensions. We report no significant differences in the 3 lumbar dimensions at the seated position when compared with the lateral decubitus position.

CONCLUSIONS

For infants younger than 12 months, sonographic measurements of lumbar dimensions did not differ between the positions commonly used for LP.

Seeing Is Believing: Ultrasound in Pediatric Procedural Performance

Point-of-care ultrasound is currently widely used across the landscape of pediatric care. Ultrasound machines are now smaller, are easier to use, and have much improved image quality. They have become common in emergency departments, ICUs, inpatient wards, and outpatient clinics. Recent growth of supportive evidence makes a strong case for using point-of-care ultrasound for pediatric interventions such as vascular access (in particular, central-line placement), lumbar puncture, fluid drainage (paracentesis, thoracentesis, pericardiocentesis), suprapubic aspiration, and soft tissue incision and drainage. Our review of this evidence reveals that point-of-care ultrasound has become a powerful tool for improving procedural success and patient safety. Pediatric patients and clinicians performing procedures stand to benefit greatly from point-of-care ultrasound, because seeing is believing.

Prospective Investigation of a Novel Ultrasound-assisted Lumbar Puncture Technique on Infants in the Pediatric Emergency Department

OBJECTIVE

The objective was to describe a novel ultrasound-assisted lumbar puncture (UALP) technique and to compare it to standard lumbar puncture (SLP) technique in infants.

METHODS

A prospective, randomized, controlled study in infants 60 days old and younger undergoing a lumbar puncture (LP) in a pediatric emergency department. Patients with a spinal anomaly or ventriculoperitoneal shunt were excluded. Eligible infants were randomized to UALP or SLP. A spinal sonogram was performed on all patients by an investigator not involved in performing the LP. Spinal landmarks and maximum safe depth were identified for the UALP providers. Providers in the SLP group were blinded to sonographic measurements. A successful LP was defined as the collection of cerebrospinal fluid (CSF) with a red blood cell count of less than 10,000 cells/mm³ . Statistical analysis included chi-square, Mann-Whitney U-test, and number needed to treat (NNT).

RESULTS

Forty-three patients were enrolled, 21 in the UALP group and 22 in the SLP group. Prematurity, weight, length, provider experience, anesthesia use, stylet technique, and number of attempts were similar between groups. The median age in the UALP group was 38 days (interquartile range [IQR] = 33 days) versus 45 days (IQR = 19 days) in the SLP group (p = 0.02). CSF was obtained in all UALP subjects (100%) versus in 18 of 22 (82%) in the SLP group (p = 0.04); 20 (95%) UALP subjects versus 15 (68%) SLP subjects met our definition of success (p = 0.023). The odds ratio of successful LP using UALP technique was 9.33 (95% confidence interval [CI] = 1.034 to 84.026) and the NNT was 3.7 (95% CI = 2.02 to 24.18).

CONCLUSION

The UALP technique increases the rate of a successful LP in infants compared to standard technique.