Cardiorespiratory responses to fluid administration in peritonitis.

Intravascular volume expansion was studied in 59 critically ill patients with a wide variety of sepsis and in a small group of 12 patients with peritonitis; either 500 ml of 5% albumin solution or 2 units of packed red blood cells were given over a 60-min period. During the 2-h period after volume loading, significant increases in mean arterial pressure (MAP), pulmonary capillary wedge pressure (WP), central venous pressure (CVP), and oxygen consumption (VO2) were observed. One hour after fluid administration MAP had risen from 72 +/- 16 (SD) at baseline to 78 +/- 17 mm Hg (p less than .01), WP from 9 +/- 5 to 16 +/- 7 mm Hg (p less than .05), CVP from 7 +/- 4 to 9 +/- 4 mm Hg (p less than .05) and VO2 from 132 +/- 19 to 148 +/- 31 ml/min X m2 (p less than .01). Improvement in VO2 after volume loading is consistent with the concept that circulatory problems in sepsis result in less VO2 than is needed and that intravascular volume expansion in normovolemic septic patients may improve peripheral perfusion as measured by oxygen uptake.