Cardiopulmonary Monitors and Clinically Significant Events in Critically Ill Children

Abstract

Cardiopulmonary monitors (CPMs) generate false alarm rates ranging from 85%-99% with few of these alarms actually representing serious clinical events. The overabundance of clinically insignificant alarms in hospitals desensitizes the clinician to true-positive alarms and poses significant safety issues. In this IRB-approved externally funded study, we sought to assess the clinical conditions associated with true and false-positive CPM alarms and attempted to define optimal alarm parameters that would reduce false-positive alarm rates (as they relate to clinically significant events) and thus improve overall CPM performance in critically ill children. Prior to the study, clinically significant events (CSEs) were defined and validated. Over a seven-month period in 2009, critically ill children underwent evaluation of CSEs while connected to a CPM. Comparative CPM and CSE data were analyzed with an aim to estimate sensitivity, specificity, and positive and negative predictive values for CSEs. CPM and CSE data were evaluated in 98 critically ill children. Overall, 2,245 high priority alarms were recorded with 68 CSEs noted in 45 observational days. During the course of the study, the team developed a firm understanding of CPM functionality, including the pitfalls associated with aggregation and analysis of CPM alarm data. The inability to capture all levels of CPM alarms represented a significant study challenge. Selective CPM data can be easily queried with standard reporting, however the default settings with this reporting exclude critical information necessary in compiling a coherent study denominator database. Although the association between CPM alarms and CSEs could not be comprehensively evaluated, preliminary analysis reflected poor CPM alarm specificity. This study provided the necessary considerations for the proper design of a future study that improves the positive predictive value of CPM alarms. In addition, this investigation has resulted in improved awareness of CPM alarm parameter settings and associated false-positive alarms. This information has been incorporated into nursing educational programs.