Gad Ashraf, Al-Shouli Jihad, Akomolafe Aishat, Alkamel Loay, Gaffari Mohammed Abdul Khader, Albaridi Ahmad, Elfakharany Alaa, Bayoumi Mohammad A A
Hamad Medical Corporation, Doha, Qatar.
Qatar University, Doha, Qatar.
BMJ Paediatr Open. 2025 May 2;9(1):e003079. doi: 10.1136/bmjpo-2024-003079.
Lumbar punctures (LP) in very low birth weight (VLBW) infants often have low success rates. Point-of-care ultrasound (POCUS)-based spinal canal depth (SCD) measurements may provide better outcomes.
To provide POCUS-based SCD measurement values for VLBW infants using different calculation methods at the L4/5 and L3/4 levels.
This prospective observational study involved 31 VLBW infants in the neonatal intensive care unit at Women's Wellness and Research Center, Doha, Qatar, from March 2022 to September 2023. The outcome measures included anterior (ASCD), mid (MSCD) and posterior spinal canal depth (PSCD) measurements. The study compared results from different calculation methods at the L4/5 and L3/4 levels.
A total of 63 ultrasound examinations were performed on 31 infants. The median gestational age was 25.0 weeks (IQR 24-27), with a birth weight of 817.9±170.2 g and a birth height of 31.6±2.8 cm. The MSCD at L4/5 was 7.1±0.5 mm and 6.9±0.5 mm at L3/4, with a mean difference (MD) of 0.20 (95% CI 0.15 to 0.24; p<0.001). The mean SC anteroposterior diameter at L4/5 was 3.8 mm versus 4.2 mm at L3/4 (MD -0.334, 95% CI -0.45 to 0.22; p<0.001). Weight-based and body surface area (BSA) calculations correlated best with MSCD at both levels. The MSCD in millimetres was determined by the equations 2×weight (kg)+6 (R²=0.71) at L4/5 and (R²=0.70) at L3/4 and 25×BSA (m²)+5 (R²=0.71) at L4/5 and (R²=0.73) at L3/4 levels. Moreover, body weight and BSA showed a slightly stronger correlation with ASCD measurements compared with PSCD. All SCD measurements demonstrated a poor linear correlation with body length (cm) and body mass index (kg/m²).
This study offers reference data for POCUS-based SCD measurements in VLBW infants, demonstrating that body weight and BSA effectively predict SCD. These findings could enhance the accuracy of LPs in this population when ultrasound guidance is unavailable, supporting personalised care.
极低出生体重（VLBW）婴儿的腰椎穿刺（LP）成功率往往较低。基于床旁超声（POCUS）测量的椎管深度（SCD）可能会带来更好的结果。
提供基于POCUS在L4/5和L3/4水平使用不同计算方法测量的VLBW婴儿的SCD值。
这项前瞻性观察性研究纳入了2022年3月至2023年9月在卡塔尔多哈妇女健康与研究中心新生儿重症监护病房的31例VLBW婴儿。观察指标包括前椎管深度（ASCD）、中椎管深度（MSCD）和后椎管深度（PSCD）测量。该研究比较了L4/5和L3/4水平不同计算方法的结果。
对31例婴儿共进行了63次超声检查。中位胎龄为25.0周（四分位间距24 - 27周），出生体重为817.9±170.2 g，出生身长为31.6±2.8 cm。L4/5水平的MSCD为7.1±0.5 mm，L3/4水平为6.9±0.5 mm，平均差值（MD）为0.20（95%置信区间0.15至0.24；p<0.001）。L4/5水平的椎管前后径平均为3.8 mm，L3/4水平为4.2 mm（MD -0.334，95%置信区间 -0.45至0.22；p<0.001）。基于体重和体表面积（BSA）的计算与两个水平的MSCD相关性最佳。L4/5水平以毫米为单位的MSCD由公式2×体重（kg）+6（R² = 0.71）和L/L3/4水平的（R² = 0.70）以及L4/5水平的25×BSA（m²）+5（R² = 0.71）和L3/4水平的（R² = 0.73）确定。此外，与PSCD相比，体重和BSA与ASCD测量的相关性略强。所有SCD测量值与身长（cm）和体重指数（kg/m²）的线性相关性均较差。
本研究为基于POCUS测量VLBW婴儿的SCD提供了参考数据，表明体重和BSA可有效预测SCD。这些发现可在无超声引导时提高该人群LP的准确性，支持个性化护理。
