Abstract 13835: Accuracy of Prehospital Documentation of Hypoxia Compared to Continuous Non-Invasive Monitor Data Tracking in Major Traumatic Brain Injury

Abstract

Background: It is well established that prehospital hypoxia dramatically increases mortality in Traumatic Brain Injury (TBI). Thus, in EMS TBI research, case ascertainment and risk-adjustment are highly dependent upon documentation of in-field O 2 saturation. Objective: To compare the rate of hypoxia identified by EMS personnel and documented in EMS patient care records (PCR) vs the actual rate of hypoxia recorded by continuous, non-invasive monitor in TBI. Methods: A subset of major TBI cases (moderate/severe) in the EPIC EMS TBI Study (NIH 1R01NS071049) were evaluated (3/30/13-6/26/15). Cases from 4 EMS agencies that report continuous monitor data (Philips MRx™) as part of EPIC were included. All monitor data available for post-hoc review were displayed and accessible to the providers during EMS care. We compared PCR documentation of hypoxia (O 2 sat <90%) to actual recorded monitor data on each patient (Fisher’s Exact Test; α=0.05). Results: 77 cases were included [median age: 52; 65% male]. The monitors displayed and recorded 16 hypoxic cases (20.8%), but only 6 (37.5%) were documented. Thus, while the rate of actual hypoxia was 20.8%, the case ascertainment was only 7.8% (6/77) when PCR documentation alone was used (p=0.036). Conclusion: Among patients with major TBI, monitor-identified hypoxia occurred much more frequently (20.8%) than was documented (7.8%). Only 37.5% of cases with actual hypoxia were recorded in the PCRs. This may be explained, in part, by the fact that pulse oximetry occurs continuously. Thus, ongoing care responsibilities and scene distractions may cause providers to miss low readings as they fluctuate moment-by-moment. This has significant clinical implications as a potential hidden contributor to poor outcomes if hypoxia goes unrecognized (and untreated) rather than simply not being documented. Furthermore, these findings have important implications for case ascertainment, confounding, and risk-adjustment in EMS TBI studies. Whenever possible, quality improvement and research projects should utilize continuous non-invasive monitor data to identify and evaluate hypoxic patients in the setting of TBI. These findings may also have implications for identifying hypoxia in EMS patients with other critical conditions.