• The ionized calcium (IC) and parathyroid hormone response to polymicrobial intra-abdominal sepsis and the relationship between IC and hemodynamic alterations with and without crystalloid resuscitation were investigated. Thirty swine underwent cecal ligation and incision (n = 19) or sham laparotomy (n = 11), with seven animals that had cecal ligation and incision administered Ringer's solution (50 mL/kg) after each set of measurements recorded on days 0,1,2,4, and 8. An early decrease in mean arterial pressure and cardiac index in animals that had cecal ligation and incision reversed with resuscitation. The IC also fell early and parathyroid hormone level increased in both the unresuscitated and resuscitated septic groups. However, correlation coefficients of mean arterial pressure and cardiac index with IC ranged from .034 to .287 in the septic animals and were lower in the group that had sham laparotomy. We conclude that polymicrobial intra-abdominal sepsis results in decreased IC and an elevated parathyroid hormone level. Hemodynamics do not correlate with IC levels, and resuscitation can be achieved without calcium administration.
(Arch Surg. 1992;127:265-272)