Extravasation of intravenous computed tomography scan contrast in blunt abdominal and pelvic trauma.

BACKGROUND: Intravenous contrast extravasation (CE) on computed tomography (CT) scan in blunt abdominal trauma is generally regarded as an indication for the need for invasive intervention (either angiography or laparotomy). More recently, improvements in CT scan technology have increased the sensitivity in detecting CE, and, thus, we postulate that not all patients with this finding require intervention. METHODS: This study is a retrospective review of all patients who underwent a CT scan for blunt abdominal trauma between January 1999 and September 2003. Patterns of injury, associated injuries, management, and outcomes were examined for patients with CE. RESULTS: Seventy of 1,435 patients (4.8%) demonstrated CE. Mean age was 44 years and mean Injury Severity Score was 39. The location of CE was intra-abdominal in 25, pelvis/retroperitoneum in 39, and both areas in 3 patients. Six patients received supportive treatment for nonsurvivable head injury and were excluded from further analysis. Overall, 30 (47%) patients underwent immediate intervention (angiography or laparotomy) and 34 (53%) were managed nonoperatively. Of those who had initial nonoperative management, overall seven (20.5%) underwent intervention, with the remainder being managed without intervention. The success for nonoperative management was greater for those with pelvic/retroperitoneal CE (4 of 7: 57%) than for intra-abdominal extravasation (23 of 27: 85%). CONCLUSION: Although evidence of CE may suggest significant vascular injury, our data suggest that not all patients require invasive intervention. Further studies are needed to better define criteria for nonoperative management in patients with CE identified on their initial CT scan.

Association between alcohol and mortality in patients with severe traumatic head injury.

HYPOTHESIS: Admission blood alcohol concentration (BAC) is associated with in-hospital death in patients with severe brain injury from blunt head trauma. DESIGN: Retrospective cohort study. SETTING: Academic level I trauma center in Toronto, Ontario. PATIENTS: Using trauma registry data, between January 1, 1988, and December 31, 2003, we identified 1158 consecutive patients with severe brain injury from blunt head trauma. INTERVENTION: There was no active intervention. The primary exposure of interest was the BAC at admission, stratified into the following 3 levels: 0, no BAC; 0 to less than 230 mg/dL, low to moderate BAC; and 230 mg/dL or greater, high BAC. MAIN OUTCOME MEASURE: In-hospital death. RESULTS: In patients with severe brain injury, low to moderate BAC was associated with lower mortality than was no BAC (27.9% vs 36.3%; P = .008). High BAC was associated with higher mortality than was no BAC (44.7% vs 36.3%), although this was not statistically significant (P = .10). These associations were all statistically significant after adjusting for demographic data and injury factors using logistic regression analysis. The odds ratio for death was 0.76 (95% confidence interval, 0.52-0.98) for low to moderate BAC compared with no BAC. The odds ratio for death was 1.73 (95% confidence interval, 1.05-2.84) for high BAC compared with no BAC. CONCLUSIONS: Low to moderate BAC may be beneficial in patients with severe brain injury from blunt head trauma. In contrast, high BAC seems to have a deleterious effect on in-hospital death in these patients, which may be related to its detrimental hemodynamic and physiologic effects. Alcohol-based fluids may have a role in the management of patients with severe brain injury after they have been well resuscitated.

Preventable deaths from hemorrhage at a level I Canadian trauma center.

BACKGROUND: Studies of trauma deaths have had a tremendous impact on the quality of contemporary trauma care. We studied causes of trauma death at a Level I Canadian trauma center, and tabulated preventable deaths from hemorrhage using explicit criteria. METHODS: Trauma registry data were used to identify all trauma deaths at our institution from January 1, 1999 to December 31, 2003. Demographics, mechanism, and time or location of death were recorded. Registry data analysis and selective chart or autopsy review were then performed to assign causes of death. RESULTS: A total of 558 consecutive trauma deaths were reviewed. Mean age was 48.7 (46.7-50.6), and mean Injury Severity Score was 38.8 (37.6-40.0); 29% were females. Blunt trauma represented 87% of all cases; penetrating injuries were only 13%. Central nervous system (CNS) injuries were the most frequent cause of death (60%), followed by hemorrhage (15%), and then combination CNS and hemorrhagic injuries (11%). Multiple organ failure caused 5% of deaths and 9% of deaths were from other causes. Of hemorrhagic deaths, 48% (n = 41) were from blunt injury, and 52% (n = 45) were from a penetrating mechanism. Of these hemorrhagic deaths, 16% were judged to be preventable because of significant delays in identifying the major source of hemorrhage. Hemorrhage from blunt pelvic injury was the major cause of exsanguination in 12 of 14 of these preventable deaths. CONCLUSIONS: Blunt injury is the major mechanism leading to trauma deaths. Massive bleeding from blunt pelvic injury is the major cause of preventable hemorrhagic deaths in our study.

Radiation exposure from diagnostic imaging in severely injured trauma patients.

BACKGROUND: Trauma patients often require multiple imaging tests, including computed tomography (CT) scans. CT scanning, however, is associated with high-radiation doses. The purpose of this study was to measure the radiation doses trauma patients receive from diagnostic imaging. METHODS: A prospective cohort study was conducted from June 1, 2004 to March 31, 2005 at a Level I trauma center in Toronto, Canada. All trauma patients who arrived directly from the scene of injury and who survived to discharge were included. Three dosimeters were placed on each patient (neck, chest, and groin) before radiologic examination. Dosimeters were removed before discharge. Surface doses in millisieverts (mSv) at the neck, chest, and groin were measured. Total effective dose, thyroid, breast, and red bone marrow organ doses were then calculated. RESULTS: Trauma patients received a mean effective dose of 22.7 mSv. The standard "linear no threshold" (LNT) model used to extrapolate from effects observed at higher dose levels suggests that this would result in approximately 190 additional cancer deaths in a population of 100,000 individuals so exposed. In addition, the thyroid received a mean dose of 58.5 mSv. Therefore, 4.4 additional fatal thyroid cancers would be expected per 100,000 persons. In all, 22% of all patients had a thyroid dose of over 100 mSv (mean, 156.3 mSv), meaning 11.7 additional fatal thyroid cancers per 100,000 persons would result in this subgroup. CONCLUSION: Trauma patients are exposed to significant radiation doses from diagnostic imaging, resulting in a small but measurable excess cancer risk. This small individual risk may become a greater public health issue as more CT examinations are performed. Unnecessary CT scans should be avoided.

Traumatic abdominal wall hernia: epidemiology and clinical implications.

BACKGROUND: Traumatic abdominal wall hernias (TAWHs) are uncommon, and it remains controversial whether such patients require urgent laparotomy. As such, this study was undertaken to assess the clinical sequelae of operative versus nonoperative management of TAWH, and whether certain patient or injury characteristics are predictive of the need for early surgery. METHODS: Retrospective review of all patients presenting acutely with a TAWH at a Regional Trauma Center from January 2000 to December 2004. RESULTS: Thirty-four patients were identified (age 39 +/- 12 years; Injury Severity Score 31 +/- 13). The most frequent mechanism of injury was motor vehicle collision (MVC; 24 cases), followed by motorcycle collision (6) and falls (4). The diagnosis of a TAWH was made primarily by computed tomography scan. Overall, 19 patients underwent urgent laparotomy or laparoscopy (56%) and 15 patients required bowel resection (44%). TAWH secondary to a MVC more frequently required urgent laparotomy and bowel resection than other mechanisms (p < 0.05). All three patients with clinically apparent anterior TAWH had intra-abdominal injuries and required urgent laparotomy. Only eight patients (24%) had their TAWH repaired acutely. At follow-up, two patients managed nonoperatively had symptomatic hernias, and three patients that had had an early repair had developed recurrent hernias. CONCLUSIONS: First, the mechanism of injury should be considered when deciding if a patient with a TAWH needs an urgent laparotomy. Clinically apparent anterior TAWHs appear to have a high rate of associated injuries requiring urgent laparotomy. Finally, occult TAWHs diagnosed only by computed tomography may not require urgent laparotomy or hernia repair.

Recombinant activated coagulation factor VII and bleeding trauma patients.

BACKGROUND: Recombinant activated coagulation factor VII (rFVIIa) is increasingly being administered to massively bleeding trauma patients. rFVIIa has been shown to correct coagulopathy and to decrease transfusion requirements. However, there is no conclusive evidence to suggest that rFVIIa improves the survival of these patients. The purpose of this study was to determine whether or not rFVIIa has an effect on the in-hospital survival of massively bleeding trauma patients. METHODS: A retrospective cohort study was conducted from January 1, 2000 to January 31, 2005, at a Level I trauma center in Toronto, Canada. Inclusion criteria included trauma patients requiring transfusion of 8 or more units of packed red cells within the first 12 hours of admission. The primary exposure of interest was the administration of rFVIIa. Primary outcome was a 24-hour survival and secondary outcome was overall in-hospital survival. RESULTS: There were 242 trauma patients identified who met inclusion criteria; 38 received rFVIIa. rFVIIa patients were younger, had more penetrating injuries, and fewer head injuries. However, rFVIIa patients required more red cell transfusions initially, and were more acidotic. Administering rFVIIa was associated with improved 24-hour survival, after adjusting for baseline demographics and injury factors. The odds ratio (OR) for survival was 3.4 (1.2-9.8). Furthermore, there was a strong trend toward increased overall in-hospital survival. The OR of in-hospital survival was 2.5 (0.8-7.6). Also, subgroup analysis of rFVIIa patients showed that 24-hour survivors required a slower initial rate of red cell transfusion (4.5 vs. 2.9 units/hr, p = 0.002), had higher platelet counts (175 vs. 121 [x10(-9)/L], p = 0.05) and smaller base deficits (7.1 vs. 14.3, p = 0.001) compared with rFVIIa patients who died during the first 24 hours. CONCLUSION: rFVIIa may be able to improve the early survival of massively bleeding trauma patients. However, surgical control of massive hemorrhage still has primacy, as rFVIIa did not appear efficacious if extremely high red cell transfusion rates were required. Also, correction of acidosis and thrombocytopenia may be important for rFVIIa efficacy. Prospective studies are required.

Noncompliance with seat-belt use in patients involved in motor vehicle collisions.

BACKGROUND: Seat-belt compliance in trauma patients involved in motor vehicle collisions (MVCs) appears low when compared with compliance of the general public. In this study we wished to define the relative frequency of seat-belt use in injured Canadian drivers and passengers and to determine if there are risk factors particular to seat-belt noncompliance in this cohort. METHODS: We identified trauma patients who were involved in MVCs over a 24-month period and contacted them 2-4 years after the injury by telephone to administer a standardized survey. Potential determinants of seat-belt noncompliance were compared with the occurrence of an MVC by multiple logistic regression. RESULTS: Seat-belt noncompliance in 386 MVC patients was associated with drinking and driving, youth, speeding, male sex, being a passenger, smoking, secondary roads, rural residence, low level of education, overnight driving, having no dependents, licence demerit points, previous collisions, unemployment and short journeys. There was an increase in seat-belt awareness and a decrease in self-rated driving ability after the MVC. CONCLUSIONS: Factors that indicate poor driving habits (alcohol, speeding, previous MVCs and driving offences) also predict seat-belt noncompliance. Injury prevention programs should selectively target these high-risk drivers to improve seat-belt compliance and limit associated injury and consumption of health care resources.

The increasing incidence of severe pelvic injury in motor vehicle collisions.

BACKGROUND: Pelvic fractures constitute a major cause of death and residual disability in motor vehicle collisions (MVC). To date there has been poor documentation of the epidemiology of severe pelvic injuries. A detailed retrospective examination of all abbreviated injury score (AIS) > or = 4 pelvic fractures sustained in occupants of MVCs seen at this lead trauma hospital over the last 12 years and in the province of Ontario over the last 6 years was completed. METHODS: The regional trauma centre registry and provincial database were used to obtain demographics, injuries, course in hospital and crash data on patients sustaining AIS > or = 4 pelvic injuries between May 1988 and April 2000. Data was analysed for drivers (D), front (FP) and rear (RP) passengers in 4-year blocks. Means (S.D.) with t-test for continuous and chi2 for categorical data were used for analysis. RESULTS: AIS > or = 4 pelvic fractures increased significantly in D and FP over 12 years and in RP over the last 8 years. Similar significant increases were seen throughout the province over the last 6 years. No significant change in age, sex, ISS or referral patterns was seen. Lateral impact collisions also increased over the study duration. Occupants with pelvic injury compared to all MVC survivors ISS > or = 16 during the same study period had a higher ISS (P < 0.001), utilised more blood in 24h and in total (P < 0.001) and died more frequently (P < 0.001). However, significantly fewer required ICU support (P < 0.01) which may reflect the associated injuries. Patients with pelvic fractures had significantly fewer head and chest injuries as well as fewer face and neck injuries. They did have significantly more injuries in the region of the pelvis including lumbar and sacral spine fractures, genitourinary, liver, spleen and lower extremity blood vessel, nerve and bone injuries. CONCLUSION: This study documented an increasing incidence of severe pelvic injury resulting from MVCs. This may be related to an associated increase in the incidence of lateral impact collisions. The role of side impact protection and side airbags, introduced to decrease injury severity in lateral impact collisions will require further study.