Comparison of internal jugular and central venous pressure measurements.

The pressure in the internal jugular vein was measured with the head in three different positions using, first, a short cannula and then a catheter with a round occluded end and two side-holes. These pressures were compared with the central venous pressure. In the horizontal position using the catheter, the two venous pressure measurements were similar. With the open-ended cannula, results could be unreliable with the head turned towards the side of cannulation.