Tissue Oxygen Saturation Predicts the Development of Organ Dysfunction During Traumatic Shock Resuscitation
Cohn SM, Nathens AB, Moore FA, Rhee P, Puyana JC, Moore EE, Beilman GJ.
Presented at the American Association for the Surgery of Trauma Annual Meeting, September 2006.
A prospective observational clinical study was conducted over a 15-month period to identify the role that tissue oxygen saturation (StO2) monitoring with the InSpectra™ StO2 System could play in hemorrhagic shock and resuscitation. The study was designed to determine if StO2 measurements on the thenar eminence are an indicator of hypoperfusion. Multiple organ dysfunction syndrome (MODS) was chosen as the measure of hypoperfusion because it is generally accepted that early hypoperfusion is associated with later development of organ dysfunction. The study also assessed StO2’s ability to monitor tissue oxygenation changes during resuscitation. Seven Level I trauma centers enrolled a total of 383 severely injured patients.
Introduction
Near-infrared spectroscopy (NIRS) permits continuous, noninvasive measurement of tissue hemoglobin oxygen saturation and has been evaluated in a wide range of conditions.1,2 In a porcine shock model, peripheral muscle StO2 was more reliable than base deficit and SvO2 as an index of hemorrhagic shock.3 In a 1998 pilot study, McKinley et al demonstrated that skeletal muscle StO2 correlated with DO2I (r=0.95, p<0.05), base deficit (r=0.83, p<0.05) and lactate (r=0.82, p<0.05), suggesting that it may have potential value as a noninvasive indicator of resuscitation status.4 Crookes and colleagues measured thenar muscle StO2 in 145 individuals undergoing evaluation and treatment in a Level I trauma center resuscitation area to determine whether NIRS could identify severity of shock in trauma patients. StO2 discriminated normal and no-shock patients from those with severe shock (p<0.05).5
Study objectives
In order to determine if StO2 measurements on the thenar eminence indicate hypoperfusion in trauma patients, the study objectives included:
- Determine the ability of StO2 to predict the development of MODS.
- Determine the ability of StO2 to predict mortality, red blood cell transfusion, and coagulopathy.
- Determine if a predictive relationship exists between StO2 or base deficit, and ventilator-free days, ICU-free days, and/or LOS
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Compare the area under the ROC curves of base deficit and StO2 to predict MODS and mortality.
Methods
Over a 15-month period, seven Level I trauma centers in the USA enrolled 383 patients, 50 of whom developed MODS. Patients who had sustained major blunt and/or penetrating trauma and required blood transfusion within six hours of admission were enrolled. StO2 monitoring was started on the thenar eminence within 30 minutes of ED arrival and recorded continuously for 24 hours. Clinicians were blinded to StO2 results. Additionally, standard hemodynamic parameters recorded as part of patient care were collected for the first 24 hours. These included base deficit and clinical outcomes.
Conclusions
Among the study’s conclusions:
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StO2 below 75% may indicate serious hypoperfusion in trauma patients. In the trial, 78% of patients who developed MODS, and 91% of patients who died, had StO2 below 75% in the first hour of arrival in the emergency department (ED).
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StO2 above 75% indicates adequate perfusion. Trauma patients who maintained StO2 above 75% within the first hour of ED arrival had an 88% chance of MODS-free survival. StO2 was significantly different during the course of resuscitation for patients who developed MODS compared to those who did not.
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StO2 functions as well as base deficit in indicating hypoperfusion in trauma patients, with the added benefits of being continuous, direct and noninvasive. The results for minimum StO2 within the first hour after ED arrival compared favorably for both the MODS and mortality outcomes when compared to maximum base deficit collected within the first hour.
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No device-related adverse events were observed during the study.
Principal Investigators
Avery B. Nathens, MD, PhD, MPH – University of Washington, Harborview Medical Center
Frederick A. Moore, MD – University of Texas, Houston, Memorial Hermann Hospital
Peter Rhee, MD, MPH – Los Angeles County, University of Southern California
Juan Carlos Puyana, MD – University of Pittsburgh, UPMC Presbyterian
Gregory J. Beilman, MD – University of Minnesota, North Memorial Medical Center
Ernest E. Moore, MD – University of Colorado, Denver Health Medical Center
Stephen M. Cohn, MD – University of Texas, Health Science Center at San Antonio
References
1 Cohn SM, Crookes BA, Proctor KG. Near-infrared spectroscopy in resuscitation. J Trauma. 2003;54:S199-S202.
2 Taylor DE, Simonson SG. Use of near-infrared spectroscopy to monitor tissue oxygenation. New Horiz. 1996;4:420-425.
3 Beilman GJ, Groehler KE, Lazaron V, Ortner JP. Near-infrared spectroscopy measurement of regional tissue oxyhemoglobin saturation during hemorrhagic shock. Shock. 1999;12:196-200.
4 McKinley BA, Marvin RG, Cocanour CS, Moore FA. Tissue hemoglobin O2 saturation during resuscitation of traumatic shock monitored using near infrared spectrometry. J Trauma. 2000;48:637-642.
5 Crookes BA, Cohn SM, Bloch S, et al. Can near-infrared spectroscopy identify the severity of shock in trauma patients? J Trauma. April 2005; 58(4):806-813; discussion 813-816.
