CHANGES IN PLASMA CALCIUM DURING SEPTIC SHOCK

Previous studies have documented a decrease in plasma calcium occurrin g early after trauma, haemorrhage and cardiac arrest. Therefore, chang es in plasma calcium in an ovine experimental model of septic shock du e to intraperitoneal sepsis were investigated. Subjects were volume-lo aded with Ringer's lactate solution. Plasma calcium and albumin were m easured before and 24h after surgical induction of sepsis. Subjects we re divided into two groups according to the severity of shock. Group 1 (n = 8) developed severe hyperdynamic sepsis with renal failure. Grou p 2 (n = 8) showed no change in blood pressure, cardiac output or rena l function. Plasma calcium fell significantly in both groups, and was lower in Group 1 during sepsis (Group 1: 2.36 +/- 0.19 to 1.84 +/- 0.1 4 mmoll-1; Group 2: 2.34 +/- 0.12 to 2.01 +/- 0.13 mmoll-1; mean +/- S D; both P < 0.001). Plasma albumin fell during sepsis, and the reducti on was greater in Group 1. The plasma calcium, corrected for albumin, was still significantly reduced and was similar in each group during s epsis (Group 1: 2.55 +/- 0.13 to 2.23 +/- 0.12 mmoll-1; Group 2: 2.50 +/- 0.08 to 2.27 +/- 0.09 mmoll-1; both P < 0.001). In this large anim al model of septic shock, which reproduces the important features of c linical sepsis, there were significant decrements in uncorrected and c orrected plasma calcium 24 h after the surgical induction of intraperi toneal sepsis. These changes may contribute to the pathophysiology of this condition.