Biomedical subjects

Eric Bergeron

Publications and source records attributed to Eric Bergeron.

23 records · Page 2Linked to original sources

PubMed2004

Preinjury warfarin use among elderly patients with closed head injuries in a trauma center.

BACKGROUND: This study aimed to determine the impact of warfarin use on the severity of injury among elderly patients presenting with closed head injuries. METHODS: A cohort of patients 55 years of age or older with closed head injuries taken to a tertiary trauma center between April 1993 and March 2001 was retrospectively identified. Patient characteristics, mechanism of injury, type and severity of injury, and hospital survival data were obtained from the trauma registry. Each case then was reviewed for completeness of information, assessment of preinjury warfarin use, and comorbidity. RESULTS: Among the 384 patients presenting with closed head injuries, 35 (9%) were receiving warfarin before their trauma. As compared with nonusers, anticoagulated patients had a higher frequency of isolated head trauma (54% vs. 32%; p = 0.008), more severe head injuries (65.7% vs. 44.1%; p = 0.02), and a higher rate of mortality (40% vs. 21%, p = 0.01). These associations remained evident even after population differences in age, gender, comorbidities, and mechanism of injury were taken into account. Indeed, according to multivariate logistic regression models, warfarin use was associated with a statistically significant risk of death (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.22-6.12), statistically significant odds for more severe head injury (OR, 2.39; 95% CI, 1.10-5.17), and odds for isolated head injury that almost reached statistical significance (OR, 1.79; 95% CI, 0.82-3.90). CONCLUSIONS: Among patients 55 years of age or older who present with closed head injury, the use of warfarin before trauma appears to be associated with a higher frequency of isolated head trauma, more severe head trauma, and a higher likelihood of death. The findings of this retrospective study support the concern about the adverse effects of anticoagulants in cases of head trauma.

Aged↗

PubMed2004

Improving the TRISS methodology by restructuring age categories and adding comorbidities.

BACKGROUND: The Trauma and Injury Severity Score (TRISS) methodology was developed to predict the probability of survival after trauma. Despite many criticisms, this methodology remains in common use. The purpose of this study was to show that improving the stratification for age and adding an adjustment for comorbidity significantly increases the predictive accuracy of the TRISS model. METHODS: The trauma registry and the hospital administrative database of a regional trauma center were used to identify all blunt trauma patients older than 14 years of age admitted with International Classification of Diseases, Ninth Revision codes 800 to 959 from April 1993 to March 2001. Each individual medical record was then reviewed to ascertain the Revised Trauma Score, the Injury Severity Score, the age of the patients, and the presence of eight comorbidities. The outcome variable was the status at discharge: alive or dead. The study population was divided into two subsamples of equal size using a random sampling method. Logistic regression was used to develop models on the first subsample; a second subsample was used for cross-validation of the models. The original TRISS and three TRISS-derived models were created using different categorizations of Revised Trauma Score, Injury Severity Score, and age. A new model labeled TRISSCOM was created that included an additional term for the presence of comorbidity. RESULTS: There were 5,672 blunt trauma patients, 2,836 in each group. For original TRISS, the Hosmer-Lemeshow statistic (HL) was 179.1 and the area under the receiver operating characteristic (AUROC) curve was 0.873. Sensitivity and specificity were 99.0% and 27.8%, respectively. For the best modified TRISS model, the HL statistic was 20.35, the AUROC curve was 0.902, the sensitivity was 99.0%, and the specificity was 27.8%. For TRISSCOM, the HL statistic was 14.95 and the AUROC curve was 0.918. Sensitivity and specificity were 99.0% and 29.7%, respectively. The difference between the two models almost reached statistical significance (p = 0.086). When TRISSCOM was applied to the cross-validation group, the HL statistic was 10.48 and the AUROC curve was 0.914. The sensitivity was 98.6% and the specificity was 34.9%. CONCLUSION: TRISSCOM can predict survival more accurately than models that do not include comorbidity. A better categorization of age and the inclusion of comorbid conditions in the logistic model significantly improves the predictive performance of TRISS.

Adolescent↗

PubMed2003

Processing of alpha4 integrin by the proprotein convertases: histidine at position P6 regulates cleavage.

The proprotein convertases (PCs) participate in the limited proteolysis of integrin alpha4 subunit at the H(592)VISKR(597) downward arrow ST site (where underlined residues indicate positively charged amino acids important for PC-mediated cleavage and downward arrow indicates the cleavage site), since this cleavage is inhibited by the serpin alpha1-PDX (alpha1-antitrypsin Portland). Co-expression of alpha4 with each convertase in LoVo (furin-deficient human colon carcinoma) cells revealed that furin and proprotein convertase 5A (PC5A) are the best pro-alpha4 convertases. In agreement, processing of endogenous pro-alpha4 in human lymphoblastoid CEM-T4 cells was enhanced greatly in stable transfectants overexpressing either enzyme. In many leucocyte cell lines, the expression of furin closely correlated with the endogenous processing efficacy, suggesting that furin is a candidate pro-alpha4 convertase. Mutational analysis showed that replacement of P1 Arg(597) with alanine (R597A) abrogated cleavage, whereas the P6 mutant H592R is even better processed by the endogenous convertases of Chinese-hamster ovary CHO-K1 cells. In vitro kinetic studies using synthetic peptides confirmed the importance of a positively charged residue at P6 and showed that wild-type alpha4 processing is performed best by furin and PC5A at acidic and neutral pHs, respectively. Biosynthetic analysis of pro-alpha4 and its H592R and H592K mutants in the presence or absence of the weak base, NH(4)Cl, revealed that the P6 histidine residue renders its processing by furin sensitive to cellular pH. This suggests that pro-alpha4 cleavage occurs preferentially in acidic compartments. In conclusion, although the accepted furin processing motif is Arg-Xaa-(Lys/Arg)-Arg downward arrow, our data further extend it to include a regulatory histidine residue at P6 in precursors that lack a basic residue at P4.

Amino Acids↗

PubMed2003

Elderly trauma patients with rib fractures are at greater risk of death and pneumonia.

BACKGROUND: The purpose of this study was to show that elderly patients admitted with rib fractures after blunt trauma have increased mortality. METHODS: Demographic, injury severity, and outcome data on a cohort of consecutive adult trauma admissions with rib fractures to a tertiary care trauma center from April 1, 1993, to March 31, 2000, were extracted from our trauma registry. RESULTS: Among 4,325 blunt trauma admissions, there were 405 (9.4%) patients with rib fractures; 113 were aged > or = 65. Injuries were severe, with Injury Severity Score (ISS) > or = 16 in 54.8% of cases, a mean hospital stay of 26.8 +/- 43.7 days, and 28.6% of patients requiring mechanical ventilation. Mortality (19.5% vs. 9.3%; p < 0.05), presence of comorbidity (61.1% vs. 8.6%; p < 0.0001), and falls (14.6% vs. 0.7%; p < 0.0001) were significantly higher in patients aged > or = 65 despite significantly lower ISS (p = 0.031), higher Glasgow Coma Scale score (p = 0.0003), and higher Revised Trauma Score (p < 0.0001). After adjusting for severity (i.e., ISS and Revised Trauma Score), comorbidity, and multiple rib fractures, patients aged > or = 65 had five times the odds of dying when compared with those < 65 years old. CONCLUSION: Despite lower indices of injury severity, even after taking account of comorbidities, mortality was significantly increased in elderly patients admitted to a trauma center with rib fractures.

Aged↗

PubMed2002

Impact of deferred treatment of blunt diaphragmatic rupture: a 15-year experience in six trauma centers in Quebec.

BACKGROUND: The purpose of this study was to show that blunt diaphragmatic rupture does not require immediate emergency operation in the absence of other indications. METHODS: We reviewed all patients with blunt diaphragmatic rupture admitted within 24 hours of injury to one of six university trauma centers providing trauma care for the province of Quebec from April 1, 1984, to March 31, 1999. Multivariate analysis of demographic profiles, severity indices, indications for operation, and preoperative delays was performed. RESULTS: There were 160 patients (91 men and 69 women) with blunt diaphragmatic rupture. Mean age was 40.1 +/- 16.2 years. Mean Injury Severity Score was 26.9 +/- 11.5 and mortality was 14.4%. Patients undergoing emergency surgery for indications other than diaphragmatic rupture had a significantly higher Injury Severity Score than those undergoing surgery for repair of diaphragmatic rupture alone (34.7 +/- 10.7 vs. 22.0 +/- 9.0, p < 0.001). In patients undergoing surgery for diaphragmatic rupture alone, delay before repair of the diaphragmatic hernia did not lead to an increased mortality compared with patients undergoing immediate surgery (3.4% vs. 5.0%, p = NS). CONCLUSION: Blunt diaphragmatic rupture in the absence of other surgical injuries carries low mortality. Operative repair of diaphragmatic rupture can be deferred without appreciable increased mortality if no other indication mandates immediate surgery.

Adult↗