Hypocholesterolemia and risk of death in the critically ill surgical patient.

OBJECTIVE

To evaluate the additional information provided by the determination of cholesterolemia to the Acute Physiology and Chronic Health Evaluation (APACHE) II score.

DESIGN

Retrospective evaluation of patients admitted to the intensive care unit (ICU).

SETTING

ICUs in a university hospital.

PATIENTS

638 consecutive critically ill surgical patients.

INTERVENTIONS

Surgical and medical therapy according to clinical status.

MEASUREMENTS AND MAIN RESULTS

Two indices were devised: DELCUPOS and DELCUNEG (cubed absolute value of the difference between measure cholesterol and the value of 190 mg/dl when cholesterolemia was, respectively, over and under 190 mg). The first estimation of cholesterolemia was taken upon admission to the ICU. The APACHE II score was computed from teh worst values obtained during the first 24h of the ICU stay, including the pre-operative period for patients transferred from the operating theatre. Mortality (24.4%) over the whole time of hospitalization has been considered. A stepwise linear logistic regression on APACHE II, DELCUPOS, DELCUNEG, and on interactions among these three factors has been carried out. A U-shaped relationship between cholesterolemia and morality was demonstrated. The significance of DELCUPOS (p = 0.0021) and DELCUNEG (p = 0.0002), considered together with the APACHE II score, has demonstrated an additive information content with respect to the APACHE score for the prediction of mortality.

CONCLUSION

Both hyper- and hypocholesterolemia have a highly significant relationship to mortality. Cholesterolemia improves the prognostic power of the APACHE II score. This result could be used to create a more powerful prognostic index.