Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Russi CS, Berns K, Hankins J. NAEMSP 2009 Annual Meeting; January 22-24, 2009; Jacksonville, FL.
Introduction: In December 2006, Hutchinson Technologies began marketing the InSpectra™ Tissue Oxygen Monitor. This non-invasive technology relies on optical light measurements (near-infrared spectroscopy) to observe and trend a patient’s tissue oxygen level using a skeletal muscle bed (thenar eminence). As a result, it is felt that NIRS provides real-time feedback of a patient’s oxygen delivery to consumption – a critical piece of information in shock states. There exists several large trauma center trials evaluating the monitor but there lacks any EMS use data. We aim to demonstrate the feasibility of using the InSpectra in patients transported by a HEMS system as part of an ongoing trauma trial.
Methods: A prospective, observational cohort of adult (>18 years) trauma patients flown by a busy three-site HEMS system. Our system uses 2 BK-117s and 1 EC-145 aircraft. All adult trauma patients flown were monitored using the InSpectra™ StO2 monitor. Crew members were blinded to the graph and StO2 level as part of an ongoing study. Following the flight, monitor data was downloaded to a protected central server for review. All data was collected and analyzed using Microsoft Excel and JMP software. This project was approved by the Mayo Clinic IRB.
Results: There have been 107 flights using the InSpectra™ with complete data. Of those, 99 (92.5%) had successful downloads of monitoring graphic trends for review. The average patient age was 42.3 years (range: 19 – 91). Eighty-four (78.5%) were male. Fifty-one (47.6%) were scene flights. Once the patient was loaded, the mean initial StO2 was 83.2% (CI: 81.5% - 84.9%). Average minimum StO2 during flight was 73.6% (CI: 71.4% - 75.8%). Minimum SBP averaged 119.4 mmHg (CI: 114.6 – 124.2). Twenty-two patients required intubation and had a mean StO2 level of 76.9% (CI: 72.0 – 81.8).
Conclusions: Near-infrared spectroscopy appears to be a usable technology in the austere HEMS environment. Patients were successfully monitored using NIRS for variable lengths of time and with no interference from the aircraft. Further prehospital HEMS studies are ongoing to evaluate the potential impact of StO2 on protocols and correlation to specific outcomes.