Base deficit-based predictive modeling of outcome in trauma patients admitted to intensive care units in Dutch trauma centers.

BACKGROUND: Worldwide, the base deficit is available as an objective indicator of acid base status. We used the base deficit as a measure of physiologic derangement in a Trauma and Injury Severity Score (TRISS)-like model as a predictor for outcome in trauma patients. METHODS: We prospectively recorded data of 349 consecutive trauma patients admitted to the intensive care unit and calculated Revised Trauma Score, Injury Severity Score and Abbreviated Injury Scale, and TRISS and correlated them with the simultaneously determined base deficit value. The delta base deficit is introduced, which is the absolute difference of the base deficit from its normal range (-2 to 2). A statistical model analogous to the TRISS model was designed in which the physiologic disturbance reflected by the Revised Trauma Score was replaced by the delta base deficit [Base Excess Injury Severity Scale (BISS) model]. Calculating the area under the curve (AUC) of the respective receiver operating characteristic curve compared these two models. Finally, the BISS model was validated in a patient group from another tertiary referral hospital in which similar data were recorded prospectively. RESULTS: We demonstrated a significant correlation between the delta base deficit and the calculated trauma scoring systems. Moreover, the delta base deficit is significantly correlated with mortality. The BISS performed better than the TRISS did when evaluated by the AUC of the receiver operating characteristic curves (AUC 0.806 vs. 0.803, respectively). Validation in an independent prospectively compiled dataset from another referral center showed comparable and even better results (AUC 0.891 vs. 0.885, respectively). CONCLUSIONS: The performance of our proposed BISS model was superior to that of the TRISS model in the populations under investigation. Nevertheless, given the ease of assessment and the objective value of the base deficit, it may be considered as a good method to predict outcome and evaluate care of trauma patients. Whether this can be translated to trauma patients in general needs further investigation.

Prevalence and determinants of disabilities and return to work after major trauma.

OBJECTIVE: The purpose of this study was to assess the prevalence and determinants of disabilities and return to work after severe injury in a Dutch, Level I trauma center. METHODS: We prospectively included 295 patients with an Injury Severity Score > or = 16 treated between January 1996 and January 1999. All survivors received a mailed questionnaire in 2000, at least 1 year after their initial hospital admission. Health status was measured by the EuroQol-5D instrument, and the Glasgow Outcome Scale. Additional questions were asked about cognitive functioning and return-to-work rates. Regression analyses was conducted to explore the associations between these functional outcome measures and patient characteristics. RESULTS: Of the 295 patients included, 99 (34%) died in hospital or during follow-up. From the 196 survivors, a response was obtained from 166 (85%). Of the survivors, 33% had to change their work or daily activity as a result of their injuries. Of the 127 patients of working age (18-65 years), 33 (26%) were unable to work and depended on social security. Problems with mobility, self-care, daily activities, pain/discomfort, anxiety/depression, and cognitive ability were found in 34%, 15%, 51%, 58%, 37%, and 57%, respectively. The EuroQol-5D summary score (0.76) was far below that of the general population norms. The number of body areas affected, injury severity (Injury Severity Score > or = 25), and gender (female) were significant independent predictors of worse long-term functional outcome. CONCLUSION: Severe trauma has a substantial impact on long-term functioning. Empiric quantitative data, as presented in this study, enable us to estimate the burden of injury and to evaluate the quality of trauma care programs.

Advanced trauma life support study: quality of diagnostic and therapeutic procedures.

BACKGROUND: The introduction of the ATLS course in The Netherlands in 1995 provided for an opportunity to compare data of trauma patients between a pre-ATLS and a post-ATLS period. MATERIALS AND METHODS: Over a 3-year period (May 1996 - September 1997 pre ATLS; December 1997-April 1999 post ATLS) 63 trauma patients with an AIS-ISS > or = 16 (n = 31, pre-ATLS and n = 32, post-ATLS) were prospectively studied in two community residency training (ACS Level III) hospitals. All diagnostic and therapeutic procedures were recorded by a video-camera and evaluated by a neutral faculty of six experienced ATLS trained specialists. RESULTS: Ten out of 14 interventions were performed qualitatively better in the post-ATLS group, while also the overall score was highly significantly better (4.2 pre-ATLS and 5.8 post-ATLS, p < 0.0001). CONCLUSION: Using the opinion of an expert team, this study identified a significantly lower number of patients with inadequate management.

Pre-hospital trauma care: a proposal for more efficient evaluation.

Although mortality is an important outcome parameter for pre-hospital trauma care, it is influenced by many factors other than pre-hospital trauma care alone. We therefore studied an alternative method to evaluate pre-hospital trauma care by calculating the change in probability of survival (Ps) according to the TRISS methodology, before and directly after the pre-hospital trauma care. Correlations between patient characteristics and a change in Ps were assessed. Further, required sample sizes were calculated for an 80% power to detect a hypothetical 3% reduction in mortality and the corresponding change in Ps. In 140 of 191 patients with an Injury Severity Score > or =16, the Ps did not change. In 36, the Ps increased and in 15 patients, the Ps decreased. Between these three groups, significant differences were found in Revised Trauma Score and age, but no clear differences in Injury Severity Score or mortality. A 3% difference in mortality would require 6800 patients, in contrast to 3500 when the change in Ps was the primary outcome parameter. A change in Ps is a promising outcome parameter for a more efficient evaluation of pre-hospital trauma care. A good collaboration is, however, required between ambulance services and the trauma center for reliable registration.

Clinical impact of advanced trauma life support.

The Advanced Trauma Life Support (ATLS) course sponsored by the American College of Surgeons Committee On Trauma (ACSCOT) presents a standardized method of initial trauma care. This study attempted to measure any changes in morbidity and mortality in trauma patients after the introduction of ATLS training. Over a 3-year period (May 1996 to September 1997-pre-ATLS period; December 1997 to April 1999-post-ATLS period), 63 trauma patients with an Injury Severity Scale (ISS) > or =16 (n = 31, pre-ATLS and n = 32, post-ATLS) were prospectively studied in two community teaching hospitals. There was no significant difference in mortality rate between groups (48% [15 of 31] pre-ATLS vs. 30% [10 of 32] post-ATLS; P = .203, Fisher exact test). Mortality rates within the ISS range of 16 to 25 were 64% (nine of 14 pre-ATLS) versus 29% (five of 17 post-ATLS), and for the ISS 26 to 35 subgroup, 40% (four of 10 pre-ATLS) versus 25% (two of eight post-ATLS), and within the ISS 36 to 75 subgroup, 29% (two of seven pre-ATLS) versus 43% (three of seven post-ATLS). There was a significant difference in mortality during the first 60 minutes after admission: 0.0% post-ATLS versus 24.2% pre-ATLS (P = .002, Fisher exact test (95% confidence interval ranged from 12-45% in the pre-ATLS group and 0-11% in the post-ATLS group). According to the TRISS methodology (a worldwide-accepted mathematical method to calculate chances of survival through logistical regression),ATLS improved outcome from sub-"Major Trauma Outcome Study" (MTOS) standard results (z = -2.9 to a MTOS standard result z = -0.49). Our data demonstrate that introduction of the ATLS program significantly improved trauma patient outcome in the first hour after admission, as well as improvement from sub-MTOS standard to MTOS standard levels.

Consequences of delayed diagnoses in trauma patients: a prospective study.

BACKGROUND: The approach to trauma care has improved in recent decades but delayed diagnoses still occur. This study aimed to analyze the prevalence and consequences of delayed diagnoses in a single European trauma center. The effect of a systematic reexamination of the patient (tertiary survey) and reevaluation of x-rays and CT scans was evaluated. STUDY DESIGN: We prospectively registered complications among all trauma patients admitted to our hospital from January 1, 1996, to January 1, 2000. All relevant trauma and patient-related data were added by the physician to a hospital-wide trauma database with client server architecture. Complications including delay in diagnosis were subsequently added to this database. Admitted trauma patients underwent a tertiary survey and all x-rays and CT scans were reevaluated within 24 hours after admission. RESULTS: A total of 3,879 patients were studied and 1,016 complications were registered. Of all complications 55 concerned delayed diagnoses detected in 49 patients (1.3%). In 28 of these patients (57.1%) the tertiary survey (20 of 49; 40.8%) and reevaluation of x-rays and CT scans (8 of 49; 16.3%) resulted in detection of delayed diagnoses within 24 hours. Detection of the remaining 21 delayed diagnoses occurred after more than 24 hours. Delayed diagnoses resulted in delayed treatment in 27 of the 49 patients (55.1%) and surgery was necessary in 12 patients (24.5%). None of the delayed diagnoses resulted in death. CONCLUSIONS: A prospective trauma and complication registration enables evaluation of the delays in diagnosis. In our study population more than half of the delayed diagnoses could be detected by a tertiary survey and reevaluation of x-rays and CT scans. Attempts to decrease the number of delayed diagnoses should prevent delays in treatment and improve the quality of trauma care.