Characterization and identification of na-cl sources in ground water.

Elevated concentrations of sodium (Na+) and chloride (Cl-) in surface and ground water are common in the United States and other countries, and can serve as indicators of, or may constitute, a water quality problem. We have characterized the most prevalent natural and anthropogenic sources of Na+ and Cl- in ground water, primarily in Illinois, and explored techniques that could be used to identify their source. We considered seven potential sources that included agricultural chemicals, septic effluent, animal waste, municipal landfill leachate, sea water, basin brines, and road deicers. The halides Cl-, bromide (Br), and iodide (I) were useful indicators of the sources of Na+-Cl- contamination. Iodide enrichment (relative to Cl-) was greatest in precipitation, followed by uncontaminated soil water and ground water, and landfill leachate. The mass ratios of the halides among themselves, with total nitrogen (N), and with Na+ provided diagnostic methods for graphically distinguishing among sources of Na+ and Cl- in contaminated water. Cl/Br ratios relative to Cl- revealed a clear, although overlapping, separation of sample groups. Samples of landfill leachate and ground water known to be contaminated by leachate were enriched in I and Br; this provided an excellent fingerprint for identifying leachate contamination. In addition, total N, when plotted against Cl/Br ratios, successfully separated water contaminated by road salt from water contaminated by other sources.

13-Year experience in external fixation of the pelvis: complications, reduction and removal.

PURPOSE: To evaluate the complications associated with anterior pelvic external fixation and the success of this device in maintaining reduction when used in conjunction with sacroiliac screws. METHODS: Through a retrospective clinical study at an academic Level I Trauma Center, 129 patients fit the criteria for inclusion with a mean duration of anterior pelvic external fixation of 62 days and mean follow-up of 360 days. Charts were reviewed for complications postoperatively. The symphysis diastasis, vertical displacement and posterior displacement of each hemipelvis were quantified from pelvic radiographs. RESULTS: Of the 129 patients receiving anterior pelvic external fixation, 14 (10.9 %) presented to an emergency department for problems with their anterior pelvic external fixation. Of these 14 patients, 7 (5.4 %) required readmission, all for infectious concerns necessitating IV antibiotics. 6 (4.7 %) required formal operative debridement and device removal. 13 patients (10.1 %) had superficial pin site infections successfully treated with oral antibiotics. Reduction was maintained (rated as fair, good or excellent) in all patients with radiographic follow-up (n = 74, average radiographic follow-up of 216 days) following removal of their anterior pelvic external fixation. 38 patients (30.4 %) had their anterior pelvic external fixation removed in clinic, while 87 (69.6 %) had formal removal in the operating room. CONCLUSION: While previous data suggest high complication rates in definitive anterior pelvic external fixation, we present the largest cohort of patients receiving anterior pelvic external fixation and sacroiliac screws, demonstrating a low complication rate while maintaining reduction of the pelvic ring. In addition, we found that these devices could be reliably removed in a clinic setting.

Open distal tibial shaft fractures: a retrospective comparison of medial plate versus nail fixation.

PURPOSE: Studies comparing open reduction internal fixation (ORIF) vs. intramedullary nailing (IMN) for distal tibia shaft fractures focus upon closed injuries containing small patient series with open fractures. As such, complication rates for open fractures are unknown. To characterize complications associated with ORIF vs. IMN, we compared complications based on surgical approach in a large patient series of open distal tibia shaft fractures. METHODS: Through retrospective analysis at an urban level I trauma center, 180 IMN and 36 ORIF patients with open distal tibia fractures from 2002 to 2012 were evaluated. Patient charts were reviewed to identify patient demographics, fracture grade (G), patient comorbidities, and postoperative complications including nonunion, malunion, infection, hardware-related pain, and wound dehiscence. Fisher's exact tests compared complications between ORIF and IMN groups. Multivariate regression identified risk factors with statistical significance for the development of a postoperative complication. RESULTS: One hundred and eighty IMN (G1 22, G2 79, and G3 79) and 36 ORIF (G1 10, G2 16, and G3 10) patients were included for analysis. ORIF patients had a higher rate of nonunion (25.0 %, n = 9) compared with IMN patients (10.6 %, n = 20, p = 0.03). No additional complication had a significant statistical difference between groups. Multivariable analysis shows only surgical method influenced the development of complications: ORIF patients had 2.52 greater odds of developing complications compared with IMN patients (95 % CI 1.05-6.02; p = 0.04). CONCLUSIONS: ORIF leads to higher rates of nonunion and significantly increases the odds of developing a complication compared with IMN for open distal tibia fractures. This is the first study investigating complication rates based on surgical approach in a large cohort of patients with exclusively open distal tibia fractures.