Objective: To determine the clinical significance of serum myoglobin (Mb) in the evaluation of severity and prognosis of non-cardiogenic critically ill patients by comparing with acute physiology and chronic health evaluation II (APACHE II) score.
Methods: One hundred and thirty patients admitted consecutively to emergency intensive care unit (EICU) from April to December in 2005 were enrolled for the study. Determination of serum Mb content, routine serum biochemical tests and APACHE II scoring were performed simultaneously. The serum Mb was measured with the use of chemoluminescence and solid-chromatography. All the patients were followed up till recovery/discharge or death.
Results: APACHE II score, white blood cell count and mortality were significantly different between the two groups classified by the content of serum Mb [Mb < 140 microg/L (76 patients) and Mb > or = 140 microg/L (55 patients)]. When Mb rose, diseases aggravated, APACHE II score and mortality went up (both P < 0.01). APACHE II score, Mb and neutrophil were remarkably higher in the death group (45 patients) than the recovery group (86 patients, all P < 0.01). Stepwise Cox Regression showed that Mb and APACHE II score were the parameters that related to the survival rate, while Mb was the main option. When Mb > 500 microg/L, the mortality rate was 82% (23/28); when APACHE II score > 20, the mortality rate was 85% (23/27); the morality rate went up to 95% (19/20) in the patients with Mb > 500 microg/L and APACHE II score > 20, suggesting that a combination of Mb determination and APACHE II score would raise the accuracy of evaluation of the prognosis of critically ill patients.
Conclusion: Compares with APACHE II score for evaluation of critical illness, Mb can also be considered as a significant biomarker to evaluate the seriousness of the ailment in the critically ill and to judge the effect of the treatment.Therefore, it could be used as a prospective and meaningful biomarker for a quick evaluation of the disease severity in the ICU, so it is worth for further study.