Impact of land-use on macroinvertebrate communities in the Zwalm river basin.

For determining the impact of land-use on the aquatic ecosystem in a river basin, a Geographic Information System (GIS) has been used to integrate the main impact factors at different scales. The headwaters and streams of the Zwalm River basin (Flanders, Belgium), which is part of the Scheldt river basin, were selected as study site. A river ecological database was developed based on physical-chemical and biological monitoring. The research focussed on three zones within this Zwalm River basin, each characterized by different land-uses and by consequence different types of pollution, mainly of diffuse origin. The impact was measured by means of the biological diversity, the Belgian Biotic Index and a key macroinvertebrate taxon. For measuring, assessing and managing the impact of land-use on biological communities, an integrated and multidisciplinary approach will be necessary.

Granulocyte elastase compared to C-reactive protein for early diagnosis of septicemia in critically ill patients.

Plasma levels of granulocyte elastase and C-reactive protein were measured 0, 12, 24 and 48 h after suspicion of septicemia in 64 critically ill patients. Initial elastase levels were higher in 16 bacteremic patients (mean 773 micrograms/l) than in 48 non-bacteremic patients (mean 341 micrograms/l, p less than 0.01), whereas C-reactive protein levels were similar in both groups. At a level of 100% sensitivity for the early detection of septicemia, increased elastase was less than 50% specific, indicating limited diagnostic usefulness in this setting.

Calcium chloride in experimental electromechanical dissociation: a placebo-controlled trial in dogs.

While calcium administration has been recommended in CPR, its beneficial effects have been challenged. The effectiveness of calcium chloride was evaluated and compared with epinephrine during successive episodes of electromechanical dissociation (EMD) after ventricular fibrillation in closed-chest dogs. Each of three successive episodes of CPR was randomly and blindly treated by repeated (every 2 min) injections of 5 ml H2O plus either 500 mg of calcium chloride (CaCl2), 1 mg of epinephrine (Epi), or 5% dextrose (D5W). Of 42 CPR attempts performed on 16 dogs, 16 were reversed by only chest compression and artificial ventilation. For the 26 CPR with pharmacologic intervention, recovery was obtained after one injection in 5 of 6 Epi but only in 4 of 11 CaCl2 and 4 of 9 D5W. Only four CPR attempts were ultimately unsuccessful, all in CaCl2 group. During recovery, the Epi group showed significantly higher arterial pressures and heart rates but less severe acidemia. In this model, calcium chloride alone is ineffective during EMD.

Fluid resuscitation with hypertonic saline in endotoxic shock.

Hypertonic saline has been used in the treatment of hypovolemic or burn shock for its rapid volemic effects. Hypertonic solutions could also improve cardiac performance and protect cellular metabolism in acute circulatory failure. We therefore studied the hemodynamic effects of continuous hypertonic saline infusion in the treatment of severe endotoxic shock in the dog. Thirty minutes after slow injection of 3 mg/kg of Escherichia coli endotoxin, fluid resuscitation with either hypertonic saline containing 1,200 mOsm of NaCl/liter (eight dogs) or normotonic saline solution (eight dogs) was started and titrated to maintain left-sided filling pressures at control level. For the next 210 min, the total amount of fluid administered was 64.5 +/- 7.8 ml/kg in the hypertonic group and 83.6 +/- 10.3 ml/kg in the normotonic group. These differences were not statistically significant. Intravascular pressures were similar in the two groups, but cardiac output, stroke volume, and oxygen consumption were significantly higher in the hypertonic group. These results therefore indicate that hypertonic saline can rapidly restore oxygen transport and tissue oxygen consumption in septic shock. The duration of these hemodynamic effects, however, remains to be determined.