Charles W. Mains

A retrospective analysis of geriatric trauma patients: venous lactate is a better predictor of mortality than traditional vital signs

BackgroundTraditional vital signs (TVS), including systolic blood pressure (SBP), heart rate (HR) and their composite, the shock index, may be poor prognostic indicators in geriatric trauma patients. The purpose of this study is to determine whether lactate predicts mortality better than TVS.MethodsWe studied a large cohort of trauma patients age ≥ 65 years admitted to a level 1 trauma center from 2009-01-01 - 2011-12-31. We defined abnormal TVS as hypotension (SBP < 90 mm Hg) and/or tachycardia (HR > 120 beats/min), an elevated shock index as HR/SBP ≥ 1, an elevated venous lactate as ≥ 2.5 mM, and occult hypoperfusion as elevated lactate with normal TVS. The association between these variables and in-hospital mortality was compared using Chi-square tests and multivariate logistic regression.ResultsThere were 1987 geriatric trauma patients included, with an overall mortality of 4.23% and an incidence of occult hypoperfusion of 20.03%. After adjustment for GCS, ISS, and advanced age, venous lactate significantly predicted mortality (OR: 2.62, p < 0.001), whereas abnormal TVS (OR: 1.71, p = 0.21) and SI ≥ 1 (OR: 1.18, p = 0.78) did not. Mortality was significantly greater in patients with occult hypoperfusion compared to patients with no sign of circulatory hemodynamic instability (10.67% versus 3.67%, p < 0.001), which continued after adjustment (OR: 2.12, p = 0.01).ConclusionsOur findings demonstrate that occult hypoperfusion was exceedingly common in geriatric trauma patients, and was associated with a two-fold increased odds of mortality. Venous lactate should be measured for all geriatric trauma patients to improve the identification of hemodynamic instability and optimize resuscitative efforts.

The impact of the AIS 2005 revision on injury severity scores and clinical outcome measures

BACKGROUND The abbreviated injury scale (AIS) was updated in 2005 from the AIS 1998 version. The purpose of this study is to describe the effects of this change on injury severity scoring and outcome measures. MATERIALS AND METHODS Analyses were performed on all trauma patients consecutively admitted over a 6-month period at two geographically separate Level I trauma centers. Injuries were manually double-coded according to the AIS 05 and the AIS 98. Changes in AIS, ISS, and new ISS (NISS) were analysed using paired t-tests. Apparent differences in outcome by ISS strata (<16, 16-24, >24) were compared for AIS 05 versus AIS 98 using the Wald-type statistic. Lastly, the percent of patients with a change in ISS strata are reported. RESULTS There were 2250 patients included in the study. Nearly half (46.4%) of AIS codes changed, resulting in a different AIS score for 18.9% of all codes. The mean ISS was significantly lower using the AIS 05 (11.7) versus the AIS 98 (13.3, p<0.001). Similarly, the mean NISS was significantly lower (16.3 versus 18.7, p<0.001). In the ISS strata 16-24 an apparent increase in mortality, length of stay, and percent of patients not discharged home was observed for the AIS 05 versus AIS 98. Changes in outcome measures for this stratum were as follows (AIS 98 versus AIS 05): mortality, 4.3% versus 7.7% (p=0.002); hospital length of stay, 5.2 days versus 7.3 days (p<0.001); percent of patients not discharged home, 39.2% versus 49.3% (p<0.001). Finally, there was a 20.5% reduction in patients with an ISS>or=16 and a 26.2% reduction in patients with an ISS>or=25 using the AIS 05. CONCLUSIONS The AIS revision had a significant impact on overall injury severity measures, clinical outcome measures, and percent of patients in each ISS strata. Therefore, the AIS revision affects the ability to directly compare data generated using AIS 05 and AIS 98 which has implications in trauma research, reimbursement and ACS accreditation.

The Effect of Age on Glasgow Coma Scale Score in Patients With Traumatic Brain Injury

IMPORTANCE The Glasgow Coma Scale (GCS) is used frequently to define the extent of neurologic injury in patients with a traumatic brain injury (TBI). Whether age affects the predictive ability of the GCS for severity of TBI (determined by the Abbreviated Injury Scale [AIS] score) remains unknown. OBJECTIVE To investigate the effect of age on the association between the GCS and anatomic TBI severity. DESIGN, SETTING, AND PARTICIPANTS We examined all patients with a TBI, defined by diagnostic codes 850 to 854 from the International Classification of Diseases, Ninth Revision, Clinical Modification, who were admitted to 2 level I trauma centers from January 1, 2008, through December 31, 2012. EXPOSURES We compared elderly (≥65 years) and younger (18-64 years) adults with TBI. MAIN OUTCOMES AND MEASURES We examined differences by age in GCS category (defined by emergency department GCS as severe [3-8], moderate [9-12], or mild [13-15]) at each level of TBI severity (head AIS score, 1 [minor] to 5 [critical]). Cochran-Armitage χ² trend tests and stepwise multivariate linear and logistic regression models were used. RESULTS During the study period, 6710 patients had a TBI (aged <65 years, 73.17%). Significant differences in GCS category by age occurred at each AIS score (P ≤ .01 for all). In particular, among patients with an AIS score of 5, most of the elderly patients (56.33%) had a mild neurologic deficit (GCS score, 13-15), whereas most of the younger patients (63.28%) had a severe neurologic deficit (GCS score, 3-8). After adjustment, the younger adults had increased odds of presenting with a severe neurologic deficit (GCS score, 3-8) at each of the following AIS scores: 1, 4.2 (95% CI, 1.0-17.6; P = .05); 2, 2.0 (1.0-3.7; P = .04); 3, 2.0 (1.2-3.5; P = .01); 4, 4.6 (2.8-7.5; P < .001); and 5, 3.1 (2.1-4.6; P < .001). The interaction between age and GCS for anatomic TBI severity remained significant after adjustment (estimate, -0.11; P = .005). CONCLUSIONS AND RELEVANCE Age affects the relationship between the GCS score and anatomic TBI severity. Elderly TBI patients have better GCS scores than younger TBI patients with similar TBI severity. These findings have implications for TBI outcomes research and for protocols and research selection criteria that use the GCS.

Pharmacologic thromboprophylaxis is a risk factor for hemorrhage progression in a subset of patients with traumatic brain injury.

BACKGROUND Pharmacologic thromboprophylaxis (PTP) may exacerbate intracranial hemorrhage (ICH) in patients with traumatic brain injury (TBI). We examined risk factors for hemorrhage progression in patients with blunt TBI and hypothesized that PTP would increase ICH progression in a subset of these patients. METHODS We retrospectively studied patients with TBI admitted to our level I trauma center during 19 months. Progression of hemorrhage was examined in two populations: patients with a stable initial follow-up (F/U) computed tomography (CT) and patients with hemorrhage progression on initial F/U CT. Risk factors potentially associated with hemorrhage progression were analyzed using logistic regression. Timing of PTP was defined two ways: exposed to PTP versus not exposed; early (<72 hours), late (>or=72 hours), or no PTP. RESULTS Three hundred forty patients with TBI were reviewed and hemorrhage progression occurred in 32.4% (n = 110) of patients of which 59.1% were considered clinically significant. In patients with ICH progression on initial F/U CT, predictors of subsequent hemorrhage progression include exposure to PTP (odds ratio [OR]: 13.07, p = 0.01), extradural/subdural hemorrhage (OR: 5.15, p = 0.03), Glasgow Coma Score 3-8 (OR: 4.64, p = 0.03), and body mass index >or=25 (OR = 4.32, p = 0.03). PTP was not significantly associated with hemorrhage progression in patients with a stable initial F/U CT. CONCLUSIONS These findings suggest that PTP use is associated with a 13-fold increased odds of further hemorrhage progression in patients whose F/U CT within 1 day of admission showed ICH progression; 16% of this risk can be attributed to receiving PTP. Conversely, PTP may be safe in a subgroup of patients with TBI with no ICH progression on initial F/U CT.

The effect of storage on the accumulation of oxidative biomarkers in donated packed red blood cells.

BACKGROUND Transfusion-related acute lung injury (TRALI) is a life-threatening condition characterized by oxidative stress. Longer storage times of packed red blood cells (PRBC) and other blood products have been implicated with an increased risk in developing TRALI in transfused patients. METHODS A total of 10 units of blood containing PRBC stored in citrate-phosphate-dextrose buffer at 4 degrees C were included in the study. At Bonfils Blood Center (Denver, CO), samples were collected on storage day 1 and day 42. Samples were immediately centrifuged, and the supernatants were collected and stored at -80 degrees C until further analysis. Oxidation-reduction potential and protein oxidation were measured in both the day 1 and day 42 samples. RESULTS Oxidation-reduction potential significantly increased (p < 0.05) in the day 42 sample (98.1 mV +/- 21.9 SD) versus the day 1 sample (62.6 mV +/- 21.5 SD). The oxidation of human serum albumin increased by 63.6% during the storage time. Other serum proteins such as apolipoprotein A1 and transthyretin demonstrated similar increases in oxidation. Also, proteins with a cleaved C-terminal amino acid were observed indicating the presence of carboxypeptidase activity, a marker of inflammation. CONCLUSIONS The presence of an oxidative environment in transfused PRBC increases with storage time. This could partially explain the increased risk of developing TRALI related to the transfusion of older blood products.

Interrupted pharmocologic thromboprophylaxis increases venous thromboembolism in traumatic brain injury.

BACKGROUND Pharmacologic thromboprophylaxis (PTP) is frequently withheld, begun late, or interrupted in patients with traumatic brain injury (TBI). The purpose of this study was to analyze whether late or interrupted PTP increases the risk of venous thromboembolism (VTE) after TBI. METHODS We retrospectively studied patients with blunt TBI and stable head computed tomography (CT) scans who were admitted to two Level I trauma centers. PTP use was analyzed as an independent risk factor for VTE using separate logistic regression models for each definition of PTP use: (1) administration of PTP; (2) timing of PTP (early [<72 hours] vs. late [≥72 hours]); and (3) continuous versus interrupted use of PTP. RESULTS Four hundred eighty patients with TBI were identified. VTE occurred in 15 patients (3.13%). VTE developed in six patients despite early PTP (5.56%), four patients with late PTP (2.72%), and five with no PTP (2.22%). Neither administration of PTP nor timing of PTP was independent predictor of developing a VTE (PTP vs. none: odds ratio [OR]=0.36, p=0.18; early PTP vs. late PTP: OR=2.00, p=0.41). PTP was administered continuously in 188 patients (73.7%). Patients with interrupted PTP had a significant increased odds of developing VTE compared with patients with continuous PTP (OR=7.07, p=0.04). Walking before discharge significantly decreased the odds of developing a VTE (OR=0.19, p=0.02). CONCLUSIONS Interrupted administration of PTP in patients with TBI is associated with significantly increased risk of VTE. These findings underscore the importance of continuous PTP administration, and every effort should be made to avoid interruption if possible.

Current utilization and radiation dose from computed tomography in patients with trauma

Objective: To quantify the cumulative effective dose of radiation received during hospitalization after traumatic injury and to compare the computed tomography (CT) utilization practices for two time periods in patients with trauma. Design: A retrospective analysis of radiologic and medical data. Setting: A level I trauma center. Patients: Consecutively admitted adult patients with trauma with moderate to severe injuries (injury severity score >8), an intensive care unit (ICU) length of stay of one or more days, who were directly admitted and not transferred to another acute care center. Measurements and Main Results: CT examination means and utilization were compared for April through August, 2003 and April to August, 2007. Cumulative effective doses were calculated for the 2007 period, and patients with a high radiation dose (>100 mSv) were identified. One hundred sixty-five adult patients with trauma were included. An increase in mean CT examinations per patient was observed in the 2007 period compared with the 2003 period, overall (4.41 vs. 3.44, p = 0.002) and among subsets of patients. The overall increase remained significant after adjustment for patient demographics (p = 0.05). The mean cumulative effective dose per patient was 11.13 mSv in 2007; 9% of patients received a dose ≥100 mSv. Conclusions: Patients with trauma are at an increased risk of adverse effects from CT studies, because they receive high doses of radiation, and the number of CT examinations that patients receive is increasing with time. We recommend that risk of radiation be prospectively monitored and estimated by hospitals through the use of CT examination count per patient.

Clinical Utility of the Cobalt-Albumin Binding Assay in the Diagnosis of Intestinal Ischemia

Currently, the rapid diagnosis of mesenteric ischemia is problematic because of the nonspecificity of most laboratory assays and the unreliability of physical examinations. The evaluation of the cobalt-albumin binding assay (CABA) as a diagnostic marker for short-term risk stratification of emergency department patients presenting with symptoms of intestinal ischemia is reported. This preliminary study includes patients scheduled for exploratory laparotomy with symptoms of ischemic bowel and/or bowel obstruction. Approximately 10 mL of blood was drawn from each patient 1 hour preoperatively into a serum separator gel tube. After 30 minutes of clotting time, serum was collected and frozen at -80 degrees C. The CABA test was performed on the samples by an investigator blinded to the patients condition, and values were compared with the clinical and pathologic diagnosis of ischemic bowel postoperatively. CABA test values are reported as absorbance units (ABSU) at 470 nm. Of the 26 patients enrolled in the study, 12 were clinically diagnosed with intestinal ischemia. These patients had significantly higher CABA test values (0.52 ABSU +/- 0.04 SEM) than patients without intestinal ischemia (0.31 ABSU +/- 0.02 SEM, p = 0.00023). Only two false-positives and no false-negatives were recorded. This resulted in a sensitivity of 100% and a specificity of 85.7% for the CABA test for these particular samples. The CABA test could be a useful tool for clinicians in the risk stratification of intestinal ischemia.

Injury severity and serum amyloid A correlate with plasma oxidation-reduction potential in multi-trauma patients: a retrospective analysis

BackgroundIn critical injury, the occurrence of increased oxidative stress or a reduced antioxidant status has been observed. The purpose of this study was to correlate the degree of oxidative stress, by measuring the oxidation-reduction potential (ORP) of plasma in the critically injured, with injury severity and serum amyloid A (SAA) levels.MethodsA total of 140 subjects were included in this retrospective study comprising 3 groups: healthy volunteers (N = 21), mild to moderate trauma (ISS < 16, N = 41), and severe trauma (ISS ≥ 16, N = 78). For the trauma groups, plasma was collected on an almost daily basis during the course of hospitalization. ORP analysis was performed using a microelectrode, and ORP maxima were recorded for the trauma groups. SAA, a sensitive marker of inflammation in critical injury, was measured by liquid chromatography/mass spectrometry.ResultsORP maxima were reached on day 3 (± 0.4 SEM) and day 5 (± 0.5 SEM) for the ISS < 16 and ISS ≥ 16 groups, respectively. ORP maxima were significantly higher in the ISS < 16 (-14.5 mV ± 2.5 SEM) and ISS ≥ 16 groups (-1.1 mV ± 2.3 SEM) compared to controls (-34.2 mV ± 2.6 SEM). Also, ORP maxima were significantly different between the trauma groups. SAA was significantly elevated in the ISS ≥ 16 group on the ORP maxima day compared to controls and the ISS < 16 group.ConclusionThe results suggest the presence of an oxidative environment in the plasma of the critically injured as measured by ORP. More importantly, ORP can differentiate the degree of oxidative stress based on the severity of the trauma and degree of inflammation.

The relationship between patient volume and mortality in American trauma centres: A systematic review of the evidence

OBJECTIVE To synthesise published and unpublished findings examining the relationship between institutional trauma centre volume or trauma patient volume per surgeon and mortality. BACKGROUND Evidence on the relationship between patient volume and survival in trauma patients is inconclusive in the literature and remains controversial. METHODS A literature search was performed to identify studies published between 1976 and 2013 via MEDLINE (Pubmed) and the Cumulative Index to Nursing and Allied Health Literature (EbscoHost) as well as footnote chasing. Abstracts from appropriate conferences and ProQuest Dissertations and Theses were also searched. Inclusion criteria required studies to be original research published in English that examined the relationship between mortality and either institutional or per surgeon volume in American trauma centres. We employed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement checklist and flowchart. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach was employed to rate the quality of the evidence. RESULTS Of 1392 studies reviewed, 19 studies met defined inclusion criteria; all studies were retrospective. The definition of volume was heterogeneous across the studies. Patient population and analysis methods also varied across the studies. Sixteen studies (84%) examined the relationship between institutional trauma centre volume and mortality. Of the 16 studies, 12 examined the volume of severely injured patients and eight examined overall trauma patient volume. High institutional volume was associated with at least somewhat improved mortality in ten of 16 studies (63%); however, nearly half of these studies found only some subpopulations experienced benefits. In the remaining six studies, volume was not associated with any benefits. Four studies (25%) analysed the impact of surgeon volume on mortality. High volume per surgeon was associated with improved mortality in only one of four studies (25%). CONCLUSIONS The studies were extremely heterogeneous, thus definitive conclusions cannot be drawn regarding optimal volume before a clear advantage in survival is observed. A prospective study defining volume as a continuous variable is warranted to support current admission criteria for American trauma patients.