Use of Fiberoptic vs Conventional Pulmonary Artery Catheters

To the Editor.—We read with interest the recent report by Rajput and coworkers¹ comparing the use of fiberoptic vs conventional pulmonary artery (PA) catheters. The authors remind us that measurements of mixed-venous oxygen (MvO₂) levels may inadequately assess tissue oxy(Continued on p 2142.) (Continued from p 2139.) genation in the adult respiratory distress syndrome (ARDS) and in septic shock. They also report the wide fluctuations in MvO₂ saturation detected with fiberoptic catheters during periods of agitation or suctioning. These fluctuations in MvO₂ saturation have recently been reported to influence hemodynamics.² These points may be directing our attention toward a more focused study of fiberoptic catheters. If continuous assessment of MvO₂ saturation is not helpful in ARDS or in septic shock, fiberoptic catheters should not be used in these situations, but not necessarily abandoned entirely. Could the rapid detection of decreasing MvO₂