Are injuries spatially related? Join-count spatial autocorrelation for small-area injury analysis.

OBJECTIVE: To present a geographic information systems (GIS) method for exploring the spatial pattern of injuries and to demonstrate the utility of using this method in conjunction with classic ecological models of injury patterns. DESIGN: Profiles of patients' socioeconomic status (SES) were constructed by linking their postal code of residence to the census dissemination area that encompassed its location. Data were then integrated into a GIS, enabling the analysis of neighborhood contiguity and SES on incidence of injury. SETTING: Data for this analysis (2001-2006) were obtained from the British Columbia Trauma Registry. Neighborhood SES was calculated using the Vancouver Area Neighborhood Deprivation Index. Spatial analysis was conducted using a join-count spatial autocorrelation algorithm. PATIENTS: Male and female patients over the age of 18 and hospitalized from severe injury (Injury Severity Score >12) resulting from an assault or intentional self-harm and included in the British Columbia Trauma Registry were analyzed. RESULTS: Male patients injured by assault and who resided in adjoining census areas were observed 1.3 to 5 times more often than would be expected under a random spatial pattern. Adjoining neighborhood clustering was less visible for residential patterns of patients hospitalized with injuries sustained from self-harm. A social gradient in assault injury rates existed separately for men and neighborhood SES, but less than would be expected when stratified by age, gender, and neighborhood. No social gradient between intentional injury from self-harm and neighborhood SES was observed. CONCLUSIONS: This study demonstrates the added utility of integrating GIS technology into injury prevention research. Crucial information on the associated social and environmental influences of intentional injury patterns may be under-recognized if a spatial analysis is not also conducted. The join-count spatial autocorrelation is an ideal approach for investigating the interconnectedness of injury patterns that are rare and occur in only a small percentage of the population.

Hand-held thoracic sonography for detecting post-traumatic pneumothoraces: the Extended Focused Assessment with Sonography for Trauma (EFAST).

BACKGROUND: Thoracic ultrasound (EFAST) has shown promise in inferring the presence of post-traumatic pneumothoraces (PTXs) and may have a particular value in identifying occult pneumothoraces (OPTXs) missed by the AP supine chest radiograph (CXR). However, the diagnostic utility of hand-held US has not been previously evaluated in this role. METHODS: Thoracic US examinations were performed during the initial resuscitation of injured patients at a provincial trauma referral center. A high frequency linear transducer and a 2.4 kg US attached to a video-recorder were used. Real-time EFAST examinations for PTXs were blindly compared with the subsequent results of CXRs, a composite standard (CXR, chest and abdominal CT scans, clinical course, and invasive interventions), and a CT gold standard (CT only). Charts were reviewed for in-hospital outcomes and follow-up. RESULTS: There were 225 eligible patients (207 blunt, 18 penetrating); 17 were excluded from the US examination because of battery failure or a lost probe. Sixty-five (65) PTXs were detected in 52 patients (22% of patients), 41 (63%) being occult to CXR in 33 patients (14.2% whole population, 24.6% of those with a CT). The US and CXR agreed in 186 (89.4%) of patients, EFAST was better in 16 (7.7%), and CXR better in 6 (2.9%). Compared with the composite standard, the sensitivity of EFAST was 58.9% with a likelihood ratio of a positive test (LR+) of 69.7 and a specificity of 99.1%. Comparing EFAST directly to CXR, by looking at each of 266 lung fields with the benefit of the CT gold standard, the EFAST showed higher sensitivity over CXR (48.8% versus 20.9%). Both exams had a very high specificity (99.6% and 98.7%), and very predictive LR+ (46.7 and 36.3). CONCLUSION: EFAST has comparable specificity to CXR but is more sensitive for the detection of OPTXs after trauma. Positive EFAST findings should be addressed either clinically or with CT depending on hemodynamic stability. CT should be used if detection of all PTXs is desired.

Randomized clinical trial of intermittent pneumatic compression and low molecular weight heparin in trauma.

BACKGROUND: After trauma, up to 60 per cent of immobilized patients have been reported to develop a silent deep vein thrombosis (DVT). No large, prospective randomized trials have tested the efficacy of intermittent pneumatic compression (IPC) devices in these patients. METHODS: A prospective randomized trial was performed of 442 patients who received thromboprophylaxis using either an IPC device or low molecular weight heparin (LMWH). Duplex imaging was performed on both legs on admission, and was repeated weekly thereafter until discharge, at 30 days or when there was a thrombotic event, whichever occurred first. RESULTS: There were no significant differences in time spent in intensive care, or the proportion of patients with pelvic fractures, spinal cord or head injuries between the two groups. Six patients (2.7 per cent) developed a DVT in the IPC group and one (0.5 per cent) in the LMWH group (P = 0.122). Pulmonary embolism occurred in one patient in each group. There were 13 minor bleeding episodes (four in the IPC group and nine in the LMWH group) and eight major bleeding episodes (four in each group), none of which required operative intervention. CONCLUSION: The low rate of thromboembolic complications and the cost savings suggest that IPC might be used safely and effectively for thromboprophylaxis in trauma patients.

Gram positive infection in trauma patients: new strategies to decrease emerging Gram-positive resistance and vancomycin toxicity.

Bacterial resistance to antibiotics has become a serious problem in medicine. Particularly worrisome is the increasing incidence of multi-resistant organisms such as methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). Not surprisingly, in view of the high incidence of life-threatening infections and heavy antibiotic use, resistance has become very frequent and problematic in intensive care units. The standard approach for the treatment of MRSA is vancomycin or teicoplanin. Long-term therapeutic and unrestricted prophylactic use of vancomycin has given rise to VRE which in turn may lead to the emergence of vancomycin-resistant S. aureus (VRSA) through plasmid mediated transmission. In order to reduce the incidence of VRE and to avoid the emergence of VRSA, vancomycin use should be restricted and alternative antibiotic strategies should be developed. Using those antibiotics to which MRSA are still generally sensitive, perhaps in combination with new ones, such as, quinupristin/dalfopristin, should be entertained. We performed a retrospective review of the Gram-positive infections in our Level 1 Trauma Center Intensive Care Unit, and an analysis of the resistance patterns of the NMSA infections showed that additional resistance rarely develops within less than 5 days. We then designed a new strategy for the treatment of MRSA infections. This strategy consists of the sequential use of a range of antibiotics with activity against MRSA in short 5-7 day pulses until the full clinical course is completed. Studies validating the benefit of this approach are currently in preparation.