Intrathoracic blood volume and extravascular lung water in critical illness: methods of measurement, clinical applications and limitations

摘要

The limitations of central venous pressure and pulmonary artery occlusion pressure as measures of cardiac preload are widely recognized. In this context, measuring intrathoracic blood volume (ITBV) using transpulmonary indicator dilution technology offers an alternative approach to haemodynamic monitoring. This review summarizes some of the theoretical and practical limitations of ITBV as a measure of cardiac preload. The added benefit of estimating extravascular lung water using this technology is highlighted, with particular emphasis being placed on current clinical trends that favour a more conservative approach to fluid resuscitation in patients with acute lung injury or acute respiratory distress syndrome.