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The ideal time interval for critical care severity-of-illness assessment
Murray M Pollack1, J Michael Dean, Jerry Butler
1Department of Child Health, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA. mpollack@phoenixchildrens.com
Insights
A shorter 6-hour window for collecting laboratory data in pediatric critical care accurately estimates illness severity using the Pediatric Risk of Mortality III score. This method avoids institutional bias and captures most relevant patient data.
Area of Science:
- Pediatric Critical Care Medicine
- Clinical Informatics
- Healthcare Analytics
Background:
- Accurate assessment of illness severity is crucial for pediatric critical care.
- The Pediatric Risk of Mortality III (PRISM III) score relies on laboratory variables to estimate baseline severity.
- Optimizing data collection intervals can improve efficiency without compromising accuracy.
Purpose of the Study:
- To determine if a shorter sampling interval for laboratory variables is as sensitive as the standard 0-12 hour period for estimating baseline illness severity in pediatric critical care.
- To assess for site-specific bias when using a reduced data collection window.
- To confirm if the shorter interval captures the majority of relevant dysfunction compared to the standard PRISM III score.
Main Methods:
- Prospective random patient selection in general/medical and cardiac/cardiovascular Pediatric Intensive Care Units (PICUs) across eight hospitals.
- Inclusion of patients younger than 18 years admitted to the PICU.
- Analysis of Pediatric Risk of Mortality III laboratory variables (e.g., pH, glucose, creatinine) collected during a -2 to 4-hour interval compared to the standard 0-12 hour period.
Main Results:
- A reduced observation period from 0-12 hours to -2 to 4 hours resulted in only a 3.4% loss of measured Pediatric Risk of Mortality III laboratory variables.
- Similar trends were observed for individual laboratory variables.
- The distribution of PRISM III points within the -2 to 4-hour period closely matched the standard period, with no detected institutional bias.
Conclusions:
- Laboratory data collected within the -2 to 4-hour interval post-PICU admission captures the majority of dysfunction relevant to PRISM III scores.
- This shorter sampling period is prognostically important and equivalent in sensitivity to the standard 0-12 hour period.
- No institutional bias was associated with the use of the -2 to 4-hour sampling period.
Objective:
Determine if the shortest sampling interval for laboratory variables used to estimate baseline severity of illness in pediatric critical care is equivalently sensitive across multiple sites without site-specific bias, while accounting for the vast majority of dysfunction compared with the standard 0- to 12-hour Pediatric Risk of Mortality III score.
Design:
Prospective random patient selection.
Setting:
General/medical and cardiac/cardiovascular PICUs in eight hospitals.
Patients:
Patients younger than 18 years admitted to the PICU.
Interventions:
None.
Measurements And Main Results:
A total of 376 patients were included. Measurements for Pediatric Risk of Mortality III laboratory variables (pH, PCO2, total CO2, PaO2, glucose, potassium, blood urea nitrogen, creatinine, total WBC count, platelet count, and prothrombin time/partial thromboplastin time) were recorded from 2 hours prior to PICU admission through 12 hours of PICU care except for data in the operating room. Decreasing the observation period from 0 to 12 hours post-PICU admission resulted in progressive decreases in the Pediatric Risk of Mortality III laboratory variables measured. However, allowing the observation period to start 2 hours prior to PICU admission to 4 hours reduced this loss to only 3.4%. Similar trends existed for each of the individual laboratory Pediatric Risk of Mortality III variables. There was a nearly identical distribution of laboratory Pediatric Risk of Mortality III points within the -2- to 4-hour period compared with the standard period. We did not detect any institutional bias using the -2- to 4-hour time period compared with the baseline.
Conclusions:
Prognostically important laboratory physiologic data collected within the interval from 2 hours prior to PICU to admission through 4 hours after admission account for the vast majority of dysfunction that these variables would contribute to Pediatric Risk of Mortality III scores. There was no institutional bias associated with this sampling period.
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