Prevalence of endotoxemia after surgery and its association with ICU length of stay.

Introduction: The aim of this observational study was to investigate the prevalence of endotoxemia after surgery and its association with ICU length of stay.
Methods: 102 patients admitted to a university ICU after surgery were recruited. Within four hours of admission, functional data were collected and APACHE II severity score calculated. Arterial blood samples were taken and endotoxemia was measured by chemiluminescence (Endotoxin Activity (EA)). Patients were stratified according to their endotoxin levels (low, intermediate and high) and according to their surgical procedures. Differences between endotoxin levels were assessed by ANOVA, accepting P < 0.05 as significant. Data are expressed as mean +/- SD.
Results: EA levels were low in 68 (66%) patients, intermediate in 17 (17%) and high in 17 (17%). Age (61 +/- 17 years) and APACHE II score 8.3 +/- 3.7 (P = 0.542) were not significantly different in the three EA groups. Functional parameters on admission were similar between EA groups: white blood cells 11093 +/- 4605 cells/mm3 (P = 0.385), heart rate 76 +/- 16 bpm (P = 0.898), mean arterial pressure 88.8 +/- 13.6 mmHg (P = 0.576), lactate 1.18 +/- 0.77 mmol/L (P = 0.370), PaO2/FiO2 383 +/- 109 mmHg (P = 0.474). Patients with high levels of EA were characterized by longer length of stay in the ICU: 1.9 +/- 3.0 days in the low EA group, 1.8 +/- 1.4 days in intermediate and 5.2 +/- 7.8 days in high group (P = 0.038).
Conclusions: 17% of our patients were characterized by high levels of endotoxemia as assessed by EA assay, despite their low level of complexity on admission. High levels of endotoxin were associated with a longer ICU length of stay.