The integration of data from a pulmonary artery catheter when used as part of a goal-directed plan of care may benefit certain groups of critically ill patients. Integral to the successful use of the pulmonary artery catheter is to accurately obtain and interpret invasive pressure monitoring data. This article addresses commonly asked clinical questions and considerations for decision making under complex care conditions, such as obtaining hemodynamic measurements when the patient is prone or has marked respiratory pressure variations or increased intraabdominal pressure. Recommendations to optimize the invasive pressure monitoring system are presented. Finally, functional hemodynamic indices, which are more sensitive and specific indices than static indices (pulmonary artery and right artrial pressure) of the ability to respond to a fluid bolus, will be introduced.