Selection and application of a rainbow trout toxicity testing procedure for screening Sacramento River Watershed, California samples.

A number of procedures have been developed to assess toxic effects on the early life stages of salmonid fish. In this study 13 rainbow trout embryo development relatively short-term (7 to 90 day) procedures were reviewed. Three 7-day methods from the published literature and three modifications developed at AQUA-Science (A-S) were evaluated in the laboratory. Based on that evaluation, A-S methods were selected for screening surface water samples (A-S 1) collected in the Sacramento River watershed (California) and for conducting toxicity identification evaluations (TIE) to identify cause(s) of toxicity. Test control performance, test sensitivity, and reference toxicant response variability in the A-S 1 were superior to those in commonly used freshwater toxicity testing methods. The incidence of Sacramento River watershed samples resulting in a notable decrease in embryo development was very low. Of 260 samples screened only 16 (6%) resulted in statistically significant inhibition of embryo development. Of the 16 toxic samples, nine caused minimal (less than 20% abnormal development) and four marginal (less than 30%) toxicity. Samples collected from the agriculture-dominated Colusa Basin Drain and rangeland/forest-dominated Battle Creek on June 16, 2005 caused significant toxicity. TIE procedures indicated that cationic chemicals were the primary cause of toxicity. Metals analysis did not reveal concentrations sufficient to inhibit embryo development, so the most probable cause of toxicity in the two samples was cationic chemicals (perhaps surfactants?) or metals that were not included in the analytical screening.

Superior Mesenteric Artery Syndrome with Abdominal Compartment Syndrome.

Superior Mesenteric Artery (SMA) syndrome is a condition in which the duodenum becomes compressed between the SMA and the aorta, resulting in bowel obstruction which subsequently compresses surrounding structures. Pressure on the inferior vena cava (IVC) and aorta decreases cardiac output which compromises distal blood flow, resulting in abdominal compartment syndrome with ischemia and renal failure. A 15-year-old male with SMA syndrome presented with 12 hours of pain, a distended, rigid abdomen, mottled skin below the waist, and decreased motor and sensory function in the lower extremities. Exploratory laparotomy revealed ischemic small bowel and stomach with abdominal compartment syndrome. Despite decompression, the patient arrested from hyperkalemia following reperfusion.