Inflammation and the coagulation system

Advances in cardiopulmonary bypass circuitry

PURPOSE OF REVIEW

The purpose of this review is to present developments in cardiopulmonary bypass circuitry, and to give the authors' opinions on the causes of the potentially harmful processes that are initiated by cardiopulmonary bypass, and how they may be attenuated.

RECENT FINDINGS

Much of the recently published work investigates the effect of various forms of biocompatible circuitry, either heparin bonded, or polymer coated. The increasing number of patients having off-pump coronary surgery allows comparison of such patients with those that have had surgery using the various forms of cardiopulmonary bypass circuitry.

SUMMARY

Recent developments of biocompatible circuits are promising in terms of their potential for reducing the perioperative inflammatory response. The use of such circuitry, however, is likely to be of benefit only when included as part of an overall strategy to control triggers of the inflammatory response during and after cardiac surgery, particularly in the high-risk patient.

Universal changes in biomarkers of coagulation and inflammation occur in patients with severe sepsis, regardless of causative micro-organism [ISRCTN74215569]

INTRODUCTION

PROWESS (Recombinant Human Activated Protein C Worldwide Evaluation in Severe Sepsis) was a phase III, randomized, double blind, placebo controlled, multicenter trial conducted in patients with severe sepsis from 164 medical centers. Here we report data collected at study entry for 1690 patients and over the following 7 days for the 840 patients who received placebo (in addition to usual standard of care).

METHODS

Nineteen biomarkers of coagulation activation, anticoagulation, fibrinolysis, endothelial injury, and inflammation were analyzed to determine the relationships between baseline values and their change over time, with 28-day survival, and type of infecting causative micro-organism.

RESULTS

Levels of 13 of the 19 biomarkers at baseline correlated with Acute Physiology and Chronic Health Evaluation II scores, and nearly all patients exhibited coagulopathy, endothelial injury, and inflammation at baseline. At study entry, elevated D-dimer, thrombin-antithrombin complexes, IL-6, and prolonged prothrombin time were present in 99.7%, 95.5%, 98.5%, and 93.4% of patients, respectively. Markers of endothelial injury (soluble thrombomodulin) and deficient protein C, protein S, and antithrombin were apparent in 72%, 87.6%, 77.8%, and 81.7%, respectively. Impaired fibrinolysis (elevated plasminogen activator inhibitor-1) was observed in 44% of patients. During the first 7 days, increased prothrombin time (which is readily measurable in most clinical settings) was highly evident among patients who were not alive at 28 days.

CONCLUSION

Abnormalities in biomarkers of inflammation and coagulation were related to disease severity and mortality outcome in patients with severe sepsis. Coagulopathy and inflammation were universal host responses to infection in patients with severe sepsis, which were similar across causative micro-organism groups.