Daily estimation of the severity of multiple organ dysfunction syndrome in critically ill children

Abstract

Background: Daily evaluation of multiple organ dysfunction syndrome has been performed in critically ill adults. We evaluated the clinical course of multiple organ dysfunction over time in critically ill children using the Pediatric Logistic Organ Dysfunction (PELOD) score and determined the optimal days for measuring scores.

Methods: We prospectively measured daily PELOD scores and calculated the change in scores over time for 1806 consecutive patients admitted to seven pediatric intensive care units (PICUs) between September 1998 and February 2000. To study the relationship between daily scores and mortality in the PICU, we evaluated changes in daily scores during the first four days; the mean rate of change in scores during the entire PICU stay between survivors and nonsurvivors; and Cox survival analyses using a change in PELOD score as a time-dependent covariate to determine the optimal days for measuring daily scores.

Results: The overall mortality among the 1806 patients was 6.4%. A high PELOD score (>or=20 points) on day 1 was associated with an odds ratio (OR) for death of 40.7 (95% confidence interval [CI] 20.3-81.4); a medium score (10-19 points) on day 1 was associated with an OR for death of 4.2 (95% CI 2.0-8.7). Mortality was 50% when a high score on day 1 increased on day 2. The course of daily PELOD scores differed between survivors and nonsurvivors. A set of seven days (days 1, 2, 5, 8, 12, 16 and 18) was identified as the optimal period for measurement of daily PELOD scores.

Interpretation: PELOD scores indicating a worsening condition or no improvement over time were indicators of a poor prognosis in the PICU. A set of seven days for measurement of the PELOD score during the PICU stay provided optimal information on the progression of multiple-organ dysfunction syndrome in critically ill children.

Figure 1

Selection of critically ill children for the study population. PICU = pediatric intensive care unit.

Figure 2

Calculation of the daily PELOD (Pediatric Logistic Organ Dysfunction) score. Each organ dysfunction receives points for the variable associated with the highest points. For example, if the worst heart rate of the day was 200 beats/min (10 points) and the systolic blood pressure remained at 30 mm Hg (20 points), then 20 points is assigned. When a variable is measured more than once in the 24 hours, the most severe value is used in calculating the score. The maximum number of points for an organ is 20, and the maximum daily PELOD score is 71. Adapted, with permission, from Leteurtre et al (Copyright © 1999 SAGE Publications).

Figure 3

Serial evaluation of the change in the daily PELOD (Pediatric Logistic Organ Dysfunction) score from day 1, adjusted for baseline value (PELOD score on day 1). *Hazard ratio (HR) of death and 95% confidence interval (CI) are reported per point increase in the change in score. The cumulative HR of death was calculated as follows: (HR of PELOD score on day 1) × (HR of change in score from day 1 to specified day). For example, for a child whose score is 23 on day 1 and 13 on day 5, the change in score is −10; the HR for death would be 21.48 [61.55 × (1.11⁻¹⁰) = 61.55 × 0.35]. For a child whose score is 12 on day 1 and 32 on day 16, the change in score is 20; in this instance, the HR for death would be 98.37 [6.12 × (1.1520) = 6.12 × 16.08].