Do C-reactive protein and body mass index predict duration of mechanical ventilation in critically ill trauma patients?

BACKGROUND

The predictive ability of body mass index (BMI) or C-reactive protein (CRP) as a simple, inexpensive, and dynamic marker of critical illness in patients requiring mechanical ventilation (MV) is unknown. This study was thus conducted to determine the incidence and presence of a relationship between the predictors of BMI or CRP and duration of MV in trauma patients admitted to the intensive care unit (ICU).

METHODS

This prospective observational study included 72 critically ill trauma patients. Admitted patients were categorized by duration of MV to Group A (< or =7 days) and Group B (>7 days). The biological status of patients was assessed by the serial measurement of CRP on admission to the ICU (T1), at 48 and 72 hours after admission, and on the day of beginning (T2) or discontinuation (T3) of MV. Data on BMI, serum albumin, and the Sequential Organ Failure Assessment (SOFA) score were also collected at T2 or T3.

RESULTS

At T3, the SOFA score, BMI, albumin, and CRP were significantly higher in patients in Group B compared with Group A (p<0.01). The incidence of low BMI (< or =20 kg/m2) or high CRP (>10 mg/L) in patients in Group B was significantly higher at T2 or T3 compared with Group A (p<0.05). At T3, CRP was determined as the most powerful predictor of >7 days of MV followed by BMI.

CONCLUSION

Both BMI and CRP, comparable with the SOFA score, can be used in estimating the risk of prolonged MV.