Acute infection in ventilated patients in the intensive care unit: Association between resting energy expenditure and C-reactive protein

Background: Sepsis is a common cause of hospitalization, particularly in intensive care units (ICUs), and is a major cause of morbidity and mortality. Diagnosis is often difficult due to the absence of characteristic clinical signs (e.g., fever and leukocytosis); therefore, additional markers, in addition to C-reactive protein (CRP) and white blood cell (WBC) count, are needed. Objectives: To prospectively link resting energy expenditure (REE) with CRP, WBC count, and sequential organ failure assessment (SOFA) scores in ICU patients. Such a correlation may suggest REE measurement as an additional parameter for sepsis diagnosis. Methods: Our study comprised 41 ventilated consecutive patients > 18 years of age. Patient demographic data, height, actual body weight, and SOFA scores were collected at admission. REE was measured by indirect calorimetry. REE, CRP, and WBC measurements were collected at admission, on day three after admission, and 1 week later or as clinically indicated. Results: Comparison of the REE and CRP changes revealed a significant correlation between REE and CRP changes (r = 0.422, P = 0.007). In addition, CRP changes also correlated with the changes in REE/REEp (r = 0.36, P = 0.02). Although no significant correlations in REE, WBC count, and SOFA score were found, a strong trend was observed. Conclusions: To the best of our knowledge, this is the first study to link REE and CRP levels, indicative of severe infection. Further study is needed to establish these findings.