Estimation of central venous pressure by measurement of proximal axillary venous pressure using a "half-way" catheter.

The pressure in the proximal axillary vein (AVP) was compared with central venous pressure (CVP) in eight patients during and after elective abdominal surgery. Both pressures were recorded from soft, elastic, polyurethane catheters inserted in the basilic or cephalic veins ("half-way" catheters), punctured at the fossa cubiti (AVP), and via the right jugular vein (CVP). The AVP and CVP were recorded simultaneously using hydrostatic, conventional disposable venous pressure measurement sets. The measurements were performed during intermittent positive pressure ventilation with positive end-expiratory pressure from 0 to 7.5 cmH2O (0-0.74 kPa), as well as during spontaneous breathing. During both controlled and spontaneous respiration, small mean differences (0.2-1.0 cmH2O) (0.02-0.1 kPa), and a highly significant (P less than 0.001) positive correlation between CVP- and AVP-values were found. An increase of 1 cmH2O (0.10 kPa) in the CVP was associated with an increment of practically identical order (0.99-1.04 cmH2O) (0.10-0.11 kPa) in the AVP. The results suggest that monitoring of the AVP by a basilic "half-way" catheter produces diagnostic information similar to that from the measurement of the CVP from subclavian, external or internal jugular, as well as "long-way" brachial catheter, with no risk of the major mechanical complications which accompany the use of the latter catheters.