No Radiographic Safe Margin Found in the "Easy IJ" Internal Jugular Vein Procedure

The Easy IJ procedure involves placement of a 4.8-cm intravenous catheter into the internal jugular (IJ) vein using ultrasound guidance. It is not known whether this needle length has the potential to cause a pneumothorax.

The objective of this study was to determine if a radiographic "safe margin" exists. We hypothesized that an average margin of ≥2 cm would exist between the catheter tip and the pleura.

Operators used a central approach to the IJ vein. We reviewed radiographic images taken immediately after the Easy IJ procedure. Using digital software, we measured the distance from the catheter tip to the closest point of the pleura and from the catheter tip to the level of the lung apex. We defined distances exceeding the margin of safety-either passing the pleura or ending inferior to the apex-as negative for the purpose of calculating an average. We used the t distribution to calculate 95% confidence intervals (CIs) for average values.

Radiographs showing the catheter tip were available from 62 patients. The mean needle-to-pleura distance was -0.1 cm (95% CI -0.7 to 0.5 cm). The mean vertical distance to the apex was -0.2 cm (95% CI -0.8 to 0.3 cm), with a standard deviation of 2.25 cm.

Radiographic analysis failed to show a margin of safety for the Easy IJ procedure. Postprocedure imaging may still be necessary to exclude pneumothorax.