Sterility and efficiency of two methods of cardiac output determination: closed loop and capped syringe methods

A prospective randomized study was done to compare the fluid contamination rates of two methods used to determine cardiac output by thermodilution under in-use conditions. Fifty patients were randomly assigned to have cardiac output measured by the capped syringe or closed loop method, and were followed with quantitative cultures of fluid and catheter. The two treatment groups (n = 25 each) were comparable in terms of age, sex, intensive care unit location, underlying diagnosis, and mean number of cardiac output determinations performed in the first 24 hours after placement of the catheter line. No differences in the rates of fluid contamination were seen at any time between the two groups. The overall fluid contamination rate was 2/124 cultures (1.8% with 95% confidence interval +/- 4.1%) with one colony of Staphylococcus epidermidis from a closed loop sample and one colony of Pseudomonas maltophilia in a capped syringe sample. Although no difference in contamination rates was documented, the closed loop system required less nursing time and effort.     

Electrolyte imbalances in cardiovascular disease: the forgotten factor

Hypomagnesemia is not an infrequent finding in diuretic-induced hypokalemia. Potassium replacement therapy in these cases may be ineffective in raising serum potassium levels unless normal magnesium concentrations are restored.     

Localization of arboviral antigen in brain tissues from patients with encephalitis

Brain tissues from 38 patients with a clinical suspicion of encephalitis or encephalopathy were examined by two immunoenzymatic techniques for the detection of arboviral antigen. Group B arboviral antigen was identified in 23 of these tissues. This simple method could be used for the diagnosis of the causal agent of encephalitis.