Supplementary Material for: Safely Inserting Neonatal Chest Drains

<b><i>Background:</i></b> Inserting a chest drain for a left-sided neonatal pneumothorax carries a risk of penetrating the pericardium. We identified reference ranges for the chest wall thickness (CWT) and distance between the pericardium and parietal pleura to improve safety of chest tube insertion. <b><i>Method:</i></b> We prospectively measured the CWT using ultrasound in 20 neonates (body weight [BW] 640–2,700 g, age &lt;10 days) at the usual site of puncture in the 4th and 5th intercostal space (ICS). Furthermore, we measured the minimal distance between the parietal pleura and the cardiac silhouette in 131 neonatal chest X-rays (birth weight, 420–4,930 g [divided into 11 weight groups]; age &lt;10 days). Both data sets were transformed into weight-dependent percentiles (Ps). We considered the difference between the sum of P 2.5 for the CWT plus P 2.5 for pleura-heart distance minus P 97.5 for the CWT as a safe corridor for placing the tip of the needle. <b><i>Results:</i></b> At both ICSs, curves for the above metrics did not cross, indicating a narrow but safe corridor for each BW with at least 97.5% probability. This safety corridor was 4.6–5.2 mm wide for the 4th and 2.8–3.4 mm for the 5th ICS. <b><i>Conclusion:</i></b> These data offer a reference for left-sided chest drain insertion for BW &lt;2,700 g, which may help to improve safety of the procedure.