• neonatology
• therapeutics

A term neonate, birth weight 3250 g, was admitted to a tertiary surgical neonatal unit for management of left congenital diaphragmatic hernia (CDH). He was ventilated with a mean airway pressure of 14 mm Hg in 100% oxygen and received inhaled nitric oxide. He required two inotropes. Two experienced neonatal team members inserted a 1Fr Vygon peripherally inserted central catheter (longline) into the mid-arm below the axilla. It was an easy insertion with no excessive bleeding. A chest X-ray (CXR) with contrast illustrated the longline crossing the midline, with the probable position in the superior vena cava (figure 1). Echocardiography performed for haemodynamic assessment showed the longline was within the left subclavian artery tracking into the descending aorta (figure 2). The longline was removed before use, without complications.

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Figure 1

CXR—red arrow shows the tip of the longline. Longline thought to be in the superior vena cava through innominate vein as it crosses midline.

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Figure 2

Echocardiogram—red arrow shows the longline. A is the aortic arch, B is the left subclavian artery and C is the descending aorta.

Plain X-ray is the gold standard to determine longline position.1 This can be difficult as 2D X-rays are unable to demonstrate the complexity of the 3D heart and vessels. The precision of tip detection on X-ray depends on normal anatomical landmarks, the quality of the X-ray, the longline radio-opacity and the viewing clinician’s experience.2 This was important in this case as the CDH caused mediastinal shift of the heart and great vessels. The use of ultrasound to identify neonatal longline positions has been illustrated as an excellent tool,3 4 although it requires an expertly trained operator.

Therefore, X-ray cannot be completely relied on to define longline position with mediastinal shift; ultrasound should be considered to confirm the correct position prior to use.