[Mortality in an intensive care unit: predictive value of APACHE II severity score versus maximum APACHE]

Area of Science:

• Critical Care Medicine
• Health Outcomes Research

Background:

• Patients in intensive care units (ICUs) exhibit dynamic physiological changes.
• The Acute Physiology and Chronic Health Evaluation (APACHE) score, typically assessed on admission, may not accurately reflect a patient's evolving severity.
• A single early assessment might underestimate the prognostic significance of a patient's overall ICU trajectory.

Purpose of the Study:

• To evaluate the prognostic value of daily APACHE scores in ICU patients.
• To compare the predictive accuracy of the maximum APACHE score attained during hospitalization against the admission APACHE score for mortality.

Main Methods:

• Daily APACHE scores were recorded for 314 patients admitted to the Hospital Clínico UC ICU.
• Statistical analysis was performed to compare the predictive performance of admission APACHE scores versus maximum APACHE scores for mortality outcomes.
• Patient mortality rates during ICU stay and post-discharge hospitalization were documented.

Main Results:

• The mean maximum APACHE score (18.6 +/- 9.7) was significantly higher than the mean admission score (17.5 +/- 9.3).
• A substantial proportion of patients (21.7%, and 33% excluding those with <1 day ICU stay) achieved their maximum APACHE score after the initial 24 hours.
• The maximum APACHE score demonstrated superior predictive capability for mortality compared to the admission score.

Conclusions:

• Daily monitoring and assessment of the maximum APACHE score provide a more accurate prognosis for ICU patients than relying solely on the admission score.
• Clinical practice should consider the dynamic nature of patient severity by evaluating peak APACHE scores throughout the ICU stay.
• The findings suggest a need to re-evaluate standard protocols for severity assessment in ICUs.