M.B. Singer

IL6 Deficiency Affects Function After Traumatic Brain Injury

OBJECTIVEnInterleukin-6 (IL6) is a major inflammatory mediator and one of the first cytokines produced after traumatic brain injury (TBI). This study evaluates early behavioral changes and acute inflammation after TBI in IL6 knock-out mice using electromagnetic controlled cortical impact.nnnMETHODSnIL6 knock-out (KO) and C57BL/6 (WT) male mice were subjected to TBI or sham injury (n = 6 mice per group) using electromagnetic controlled cortical impact. Behavioral deficits were tested by standard performance tests. Brain IL1β expression was measured by ELISA and HSP70 expression was measured by Western blot.nnnRESULTSnAfter TBI, KO showed reduced performance on the neuroscreen compared with wild type (KO 3.2 ± 0.7 versus WT 4.7 ± 0.2 points, P = 0.007), less exploratory activity in the open field test (KO 1090.2 ± 1799.2 versus WT 5636.8 ± 1291.8 regions explored per hour, P = 0.003) less rearing behavior in the open field test (KO 36.4 ± 79.2 versus WT 346.5 ± 18.5 rearing per hour, P = 0.0006), reduced travel on the rotarod (KO 3.5 ± 4.0 versus WT 13.0 ± 4.0 cm, P = 0.0109), and reduced time balanced on the rotarod (KO 15.0 ± 11.5 versus WT 36.2 ± 5.9 s, P = 0.0109). After TBI, IL6 knock-out mice had significantly elevated IL1β (KO 58.16 ± 17.54 versus WT 14.98 ± 8.33 pg/mL, P = 0.003 and nonsignificantly increased HSP70 levels (KO 0.93xa0± 0.96 versus WT 0.68 ± 0.97, P = 0.77).nnnCONCLUSIONnIL6 deficiency after TBI is associated with poor behavior performance, and appears to affect expression of IL1β and, possibly, HSP70.

Admission heart rate is a predictor of mortality.

BACKGROUND: The association between admission heart rate (AHR) and mortality after trauma can assist initial emergency department triage and resuscitation. In addition, increased AHR is often associated with sympathetic hyperactivity which may require targeted treatment. We determined whether AHR was a predictor for mortality in trauma patients. METHODS: The Los Angeles County Trauma System Database was queried for all injured patients admitted between 1998 and 2005 (n = 147,788). Traumatic brain injury (TBI) patients (head Abbreviated Injury Scale score ≥3) were excluded. Demographics were compared at various AHR subgroups (<50, 50–59, 60–69, 70–79, 80–89, 90–99, 100–109, and ≥110). Mortality was compared at various AHR ranges, and logistic regression was performed to determine significance. RESULTS: After exclusions, 103,799 trauma patients requiring admission were identified; overall mortality was 1.4%. AHR 80 to 89 demonstrated a statistically significant lower mortality (0.5%) compared with all other AHR ranges, except AHR 70 to 79 (0.6%). In trauma patients who required admission, AHR 70 to 79 and 80 to 89 were predictors of lower mortality. Mortality for 22,232 moderate to severely injured patients was 5.5% and AHR 80 to 89 demonstrated a statistically lower mortality (2.0%) than all other AHR ranges, except AHR 70 to 79 (1.9%). After moderate to severe trauma, AHR <60 and ≥100 were associated with significantly higher mortality. CONCLUSION: Mortality after trauma increases outside the AHR range of 70 to 89 beats per minute. AHR ranges previously considered “normal” were associated with significantly increased mortality. Prospective research is required to evaluate if resuscitation goals should target heart rate at the 70 to 89 range. LEVEL OF EVIDENCE: III, prognostic study.

Insulin-dependent diabetes and serious trauma

PurposeTrauma patients with diabetes mellitus (DM) represent a unique population as the acute injury and the underlying disease may both cause hyperglycemia that leads to poor outcomes. We investigated how insulin-dependent DM (IDDM) and noninsulin-dependent DM (NIDDM) impact mortality after serious trauma without brain injury.MethodsThe National Trauma Data Bank (NTDB) version 7.0 was queried for all patients with moderate to severe traumatic injury [injury severity score (ISS)xa0>9]. Patients were excluded if missing data, agexa0<10xa0years, severe brain injury [head abbreviated injury scale (AIS)xa0>3], dead on arrival or any AISxa0=xa06. Logistic regression modeled the association between DM and mortality as well as IDDM, NIDDM and mortality.ResultsOverall 166,103 trauma patients without brain injury were analyzed. Mortality was 7.6 and 4.4xa0% in patients with and without DM, respectively (pxa0<xa00.01). Mortality was 9.9xa0% for patients with IDDM and 6.7xa0% for NIDDM (pxa0<xa00.01). The increased mortality associated with DM was only significantly higher for DM patients in their forties (5.6 vs. 3.3xa0%, pxa0<xa00.01). Regression analyses demonstrated that DM (AOR 1.14, pxa0=xa00.04) and IDDM (AOR 1.46, pxa0<xa00.01) were predictors of mortality compared to no DM, but NIDDM was not (AOR 1.02, pxa0=xa00.83).ConclusionsWhile DM was a predictor for higher mortality after serious trauma, this increase was only observed in IDDM and not NIDDM. Our findings suggest IDDM patients who present after serious trauma are unique and attention to their hyperglycemia and related insulin therapy may play a critical role in recovery.