Please see Bibliography of References for a list of abstracts, manuscripts and posters.
Guyette F, Gomez H, Suffoletto B, Quintero J, Mesquida J, Kim HK, Hostler D, Puyana J, Pinsky M. Crit Care Med. 2009;37(12, Suppl):A28.
Introduction: Traditional vital signs fail to recognize occult shock or “compensated” shock in trauma patients. Near infrared tissue oximetry (StO2) in combination with a vascular occlusion test (VOT) is predictive of mortality and may improve prehospital identification and treatment of shock.
Hypothesis: Dynamic tissue oxygen saturation response during a vascular occlusion test (VOT) in the prehospital environment is feasible and predicts in-hospital mortality in trauma patients.
Methods: We enrolled a convenience sample of 93 trauma patients flown to a single academic Level I trauma center serving western Pennsylvania between April and July 2009. Of the 93 patients, we excluded 30 due to data integrity/loss. Using a wide gap near-infrared spectrometer(InSpectra 650, Hutchinson, 15 mm), thenar StO2 kinetics were recorded during VOT of stagnant forearm ischemia to StO2 <40%. We recorded baseline StO2 as well as the deoxygenation (StO2de)and reoxygenation (StO2re) slopes (%/min) during a VOT. We use the paired Wilcoxon Sign-Rank test to compare baseline StO2, StO2de, and StO2re slopes with mortality.
Results: Baseline StO2 measurements did not differ between survivors 78 (IQR 66,88) and non-survivors 70 (IQR 63,84) p=0.64. The StO2de and StO2re slopes were different between survivors and nonsurvivors (StO2de 11 (IQR -7.4, -13) v. 5.2 (IQR -3.9,-9.3) p<0.05; StO2re144 (IQR 78, 215) v. 48 (IQR 20,56), p=0.01). Among the three deaths in this 63 patient sample, only one had prehospital vitals signs that would have met our protocolized criteria for resuscitation (HR>120,SBP<90). There was no difference in the patients enrolled compared to those undergoing the VOT with respect to age, sex, weight, vital signs, shock index,injury severity score (ISS), prehospital
lactate, or prehospital fluid resuscitation.
Conclusions: Performing a StO2 VOT is feasible during prehospital air trauma transport. Prehospital dynamic tissue O2 saturation deoxygenation and reoxygenation identifies patients at risk of death in our trauma population.