Does the optimization of cardiac output by fluid loading increase splanchnic blood flow?
We studied the effects of increasing cardiac output by fluid loading on splanchnic blood flow in patients with haemodynamically stabilized septic shock. Eight patients (five female, 39-86 yr) were assessed using a transpulmonary thermo-dye-dilution technique for the measurement of cardiac index (CI) intrathoracic blood volume (ITBV) as a marker of cardiac preload and total blood volume (TBV). Splanchnic blood flow was measured by the steady state indocyanine-green technique using a hepatic venous catheter. Gastric mucosal blood flow was estimated by regional carbon dioxide tension (PRCO2). Hydroxyethyl starch was infused to increase cardiac output while mean arterial pressure was kept constant. In parallel, mean norepinephrine dosage could be reduced from 0.59 to 0.33 microg kg(-1) min(-1). Mean (SD) TBV index increased from 2549 (365) to 3125 (447) ml m(-2), as did ITBV index from 888 (167) to 1075 (266) ml m(-2) and CI from 3.6 (1.0) to 4.6 (1.0) litre min(-1) m(-2). Despite marked i