Arterial base deficit (ABD) represents occult hypoperfusion (OH) in trauma patients and has been recommended as an endpoint of resuscitation. The time to correct OH (TC) correlates with mortality in these patients and the early identification and correction of occult hypoperfusion has been shown to improve survival and decrease complication rates. The TC does not, however, directly take into account the magnitude ABD, which may have an impact on these outcomes.
149 blunt abdominal trauma patients with an ICU stay of at least 48 hours were reviewed. 21 additional non-survivors were also reviewed. The magnitude of the ABD was combined with the TC by using linear regression analysis of the base deficit vs. time plot and calculating the area underneath the curve for each patient. This was termed the oxygen debt exposure (ODE). Both the time of TC and the ODE were compared with the development of hypoxemia (pO2/FiO2 <250) and mortality.
Among the 33 patients in the initial group with OH, there were 7 deaths (21%). The addition of the 21 non-survivors resulted in a total of 45 patients with OH. There were 27 patients with a TC<24 hours with 7 deaths (26%) and 22 patients with hypoxemia (81%). There were 18 patients with a TC >24 hours with 9 deaths (50%) and 18 patients with hypoxemia (100%). There were 35 patients with an ODE of <5000 with 9 deaths (26%) and 31 patients with hypoxemia (89%). There were 10 patients with an ODE >5000 with 7 deaths (70%) and 10 patients with hypoxemia (100%).CONCLUSIONS: An ODE of >5000 is a better predictor of mortality than persistent OH.
Mathematical modeling of ABD clearance with calculation of ODE may be useful in predicting hypoxemia and mortality in blunt abdominal trauma patients.
J.P. Kepros, None.