Extravascular lung water: effects of using ionic contrast media at varying levels of left atrial pressure and during myocardial ischemia.

Intravenous injections of ionic contrast media are widely used in the performance of radiographic techniques. The effects of ionic contrast media on lung water are unclear in the setting of elevated left atrial pressure, particularly in the presence of myocardial ischemia. In this study, we examined the effects of bolus injections of intravenous sodium meglumine diatrizoate (Renografin 76, 1 ml/kg, injected at 20 ml per second) on measures of extravascular lung water (EVLW) at several levels of left atrial pressure and in the presence of myocardial ischemia. Bolus injections of Renografin 76 produced significant increases in EVLW, with similar mean peak increases of approximately 26% EVLW at low (initial pressure less than 3 mm Hg), moderate (approximately 15 mm Hg), and elevated left atrial pressures (approximately 25 mm Hg). At matched pressures, the peak change in EVLW in the ischemic dogs was +45%, +60%, and +70%, respectively (all P less than .001 vs. the nonischemic dogs). Thus, use of intravenous ionic media precipitated acute transient increases in lung water, which were exaggerated by myocardial ischemia. While the effects were time limited in this experimental model, caution is advised in using intravenous ionic media in patients who have left ventricular dysfunction, particularly if underlying ischemia is present.