Abstract 13737: Enhanced Prehospital End-Tidal CO2 Monitor Data Analysis for Intubated Severe Traumatic Brain Injury: Striking Findings From the EPIC Study

Abstract

Background: Studies show that EMS patients are often inadvertently hyperventilated (HV), resulting in hypocapnia. In TBI, HV markedly increases mortality. We evaluated continuous prehospital ETCO2 data in intubated TBI patients. Methods: Analysis of monitor data files (Philips MRx™) from a sample of intubated TBI cases in the EPIC Study (NIH-R01NS071049). Results: Among hundreds of cases, graphical display of continuous ETCO2 from 3 subjects dramatically exemplified commonly-occurring inadvertent HV. Fig 1 shows unrecognized HV lasting nearly 15 min. Fig 2 reveals nearly 14 min of increasing ventilatory rate and progressively worsening hypocapnia. Fig 3 shows nearly 4 min of HV that ends abruptly with clear, sudden recognition and slowing of ventilatory rate that leads to restoration of normal ETCO2 in only a few breaths. The corresponding EMS patient care records (PCR) failed to document the presence, severity, and duration of HV. Conclusions: In a study emphasizing prevention of HV, subsequent evaluation of continuous ETCO2 data revealed many cases of unintentionally rapid manual ventilation and severe hypocapnia, often occurring for long periods. These findings, even in the face of explicit guideline-based training, demonstrate a clear need for routine access to continuous monitor data among intubated patients for quality improvement and in clinical studies. Review of PCRs does not reliably identify mismanagement of ventilation. Furthermore, these findings make it likely that real-time audiovisual feedback technology would improve ventilatory management by alerting providers to unidentified HV that results from the frequent distractions occurring during EMS care.