The objective was to determine the relationship of early hypothermia to multiple organ failure and mortality in severely injured trauma patients.
This prospective observational study was performed at seven Level I trauma centers over 16 months. Severely injured patients with hypoperfusion and a need for blood transfusion during the early hospital course were followed with near-infrared spectroscopy-derived tissue oxygen saturation (StO2) and clinical variables. Outcomes including multiple organ dysfunction syndrome (MODS) and 28-day mortality were evaluated. Hypothermia was defined as temperature < 35°C within the first 6 hours.
Hypothermia was common (43%, 155/359). Hypothermic patients were more likely than normothermic patients to develop MODS (21% vs 9%, P = 0.003), but did not have increased mortality rates (16% vs 12%, P = 0.28). The maximum base deficit (Max BD) in hypothermic patients did not discriminate between those who did or did not develop MODS (9.8 ± 4.6 mEq/l vs 9.4 ± 4.4 mEq/l, P = 0.56) but had good discrimination for mortality in both hypothermic and normothermic patients. Significant predictors of MODS using multivariate analysis included minimum StO2 (P = 0.0002) and hypothermia (P = 0.01), but not Max BD (P = 0.09). Predictors for mortality with multivariate analysis included minimum StO2 (P = 0.0004) and Max BD (P = 0.01), but not hypothermia (P = 0.74). Hypothermia remained a significant risk factor for MODS when fluid/blood infusion volumes were included in the multivariate model.
Hypothermia is common in severely injured trauma patients and is a risk factor for MODS but not mortality. Minimum StO2 predicts MODS and mortality in normothermic and hypothermic patients, while the predictive effect of BD for MODS is blunted in the presence of hypothermia.