Plasma cholinesterase correlations in acute surgical and critical illness

AIM. The properties of plasma cholinesterase (CHE) are partly undiscovered. Equally unknown are the correlations between changes in CHE and other blood variables during the acute phase response related to acute surgical and critical illness. METHODS. Data from 432 measurements of CHE and other variables performed in 92 patients were systematically evaluated and processed by regression analysis. RESULTS. There was a strong direct correlation between CHE and albumin (r=0.77, p<0.0001). CHE was also directly correlated to cholesterol, iron binding capacity, hematocrit, prothrombin activity, and inversely correlated to bilirubin and to presence of sepsis and liver dysfunction (p<0.0001 for all). Postoperatively CHE decreased to about 60% of the preoperative value, remaining directly related to it (r=0.69, p<0.0001), and decreasing further in the presence of sepsis or liver dysfunction, with slow reversal of the decrease during recovery from illness. In parenterally fed septic patients the decrease in CHE was moderated by increasing the amino acid dose (p<0.0001). CONCLUSION. In acute surgical and critical illness CHE mostly behaves as a negative acute phase reactant, independently of the modifications related to other already known factors. This should be taken into account when interpreting the implications of decreased CHE in the clinical setting.