Volume-limited versus pressure-limited hemodynamic management in septic and nonseptic shock*

Abstract

To evaluate the effect of hemodynamic management guided by upper limits of cardiac filling volumes or pressures on durations of mechanical ventilation and lengths of stay in critically ill patients with shock. Prospective, randomized, clinical trial. Mixed intensive care unit of a large teaching hospital and mixed intensive care unit of a tertiary care, academic medical center. A total 120 septic (n = 72) and nonseptic (n = 48) shock patients, randomized (after stratification) to transpulmonary thermodilution (n = 60) or pulmonary artery catheter (n = 60) between February 2007 and July 2009. Hemodynamic management was guided by algorithms including upper limits for fluid resuscitation of extravascular lung water (<10 mL/kg) and global end-diastolic volume index (<850 mL/m) in the transpulmonary thermodilution group and pulmonary artery occlusion pressure (<18-20 mm Hg) in the pulmonary artery catheter group for 72 hrs after enrollment. Primary outcomes were ventilator-free days and lengths of stay in the intensive care unit and the hospital. Secondary outcomes included organ failures and mortality. Cardiac comorbidity was more frequent in nonseptic than in septic shock. Ventilator-free days, lengths of stay, organ failures, and 28-day mortality (overall 33.3%) were similar between monitoring groups. Transpulmonary thermodilution (vs. pulmonary artery catheter) monitoring was associated with more days on mechanical ventilation and longer intensive care unit and hospital lengths of stay in nonseptic (p = .001) but not in septic shock. In both conditions, fewer patients met the upper limit of volume than of pressure criteria at baseline and transpulmonary thermodilution (vs. pulmonary artery catheter) monitoring was associated with a more positive fluid balance at 24 hrs. Hemodynamic management guided by transpulmonary thermodilution vs. pulmonary artery catheter in shock did not affect ventilator-free days, lengths of stay, organ failures, and mortality of critically ill patients. Use of the a transpulmonary thermodilution algorithm resulted in more days on mechanical ventilation and intensive care unit length of stay compared with the pulmonary artery catheter algorithm in nonseptic shock but not in septic shock. This may relate to cardiac comorbidity and a more positive fluid balance with use of transpulmonary thermodilution in nonseptic shock.