SYSTEMIC INFLAMMATORY RESPONSE SYNDROME AFTER CARDIAC OPERATIONS

Background. A systemic inflammatory response after a open heart operat ion may be responsible for hyperdynamic circulatory instability and or gan dysfunction. To what extent mediator release is involved needs to be clarified. Methods. Ten patients with postoperative hyperdynamic ci rculatory dysregulation (group I) requiring application of alpha-const rictors and 10 patients with routine cardial procedures and stable pos toperative hemodynamic indices (group II) were analyzed for mediator r elease and metabolic and hemodynamic changes until the third postopera tive day. Results. Group I patients showed a significantly increased c ardiac index and decreased systemic vascular resistance after bypass ( cardiac index, group I: 5.2 +/- 1.2 L . min(-1) . m(-2), group II: 2.5 +/- 1.6 L . min(-1) . m(-2); systemic vascular resistance, group I: 4 95 +/- 204 dyne . s . cm(-5), group II: 1,356 +/- 466 dyne . s . cm(-5 )) and at 3 hours (cardiac index, group I: 4.4 +/- 0.8 L . min(-1) . m (-2), group II: 2.9 +/- 0.6 L . min(-1) . m(-2); systemic vascular res istance, group I: 567 +/- 211 dyne . s . cm(-5), group II: 1,053 +/- 2 73 dyne . s . cm(-5)). Significantly higher serum levels of interleuki n-6 were assessed in group I (post-bypass, group I: 6,812 +/- 9,293 pg /mL, group II: 295 +/- 303 pg/mL; 3 hours, group I: 3,474 +/- 5,594 pg /mL, group II: 286 +/- 296 pg/mL). Concentrations of elastase, tumor n ecrosis factor, soluble tumor necrosis factor receptor, and interleuki n-8 were elevated in group I (not significant). Early postoperative le vels of soluble E-selectin and soluble intercellular adhesion molecule were also higher in group I (not significant). Continuously increased levels of endotoxin could be detected in only 3 of 10 patients in gro up I. Severe lactic acidosis (greater than or equal to 5 mmol/L) occur red in group I only. Conclusions. Postoperative hyperdynamic instabili ty after open heart operations appears to be associated with a certain pattern of mediator release. In particular, interleukin-6 arrears to be involved in circulatory dysregulation and metabolic derangement.