Placement of cardiac electrodes: written, simulated, and actual accuracy.

BACKGROUND: Research has shown that critical care nurses show low accuracy on written tests of placement of electrodes, yet it is unknown how this low accuracy translates into placement of electrodes on actual patients. OBJECTIVES: To determine if accuracy scores differ between three methods (written knowledge, simulated clinical practice, actual clinical practice) of evaluating placement of continuous ECG electrodes by a group of cardiac care nurses. METHODS: A standardized scoring diagram was used with three different methods of measuring the accuracy of 44 nurses who worked on a telemetry unit or medical ICU in placing continuous ECG electrodes. The three methods were (1) written knowledge--placement of stickers on a diagram of a torso, (2) simulated clinical practice--placement of electrodes on a human model, and (3) actual clinical practice--placement of electrodes on an assigned patient. RESULTS: For the total diagram score (maximum score = 11), no significant differences among groups were found. For the V1 subscale score (maximum score = 4), a significant difference among groups was found: Scheffé's test showed that the significant difference was between simulated and actual clinical practice. Percentages of nurses achieving the maximum, or accurate, score were 18% for written knowledge, 25% for simulated clinical practice, and 9% for actual clinical practice. CONCLUSIONS: Although total scores did not differ among groups, the mean scores indicate that placement of electrodes was not accurate by any method. This finding has implications for how electrode placement is taught to nurses and for the accountability of nurses for placement of electrodes on their patients.

Combined chromatographic-isotopic dilution analysis of fecapentaenes in human feces.

Fecapentaene-12 (FP-12) and fecapentaene-14 (FP-14) are genotoxic unsaturated ether lipids produced by colonic bacteria in man. We have developed and applied to feces collections from normal volunteers direct isotopic dilution procedures using tritium-labeled (at C5) FP-12 and FP-14 for measuring these compounds. FPs were recovered from feces by solvent extraction, silica cartridge clean-up, and analytical liquid chromatography. Low levels of FP-12 and FP-14 (less than 0.1 to 2.4 micrograms/g of freeze-dried feces) were observed. Identity of chromatographic peaks was established by co-elution and by ultraviolet absorption spectra obtained via photodiode array scanning. Two unknown peaks were tentatively identified from absorption spectra as closely related compounds with increased (hexane?) or decreased (tetraene?) number of double bonds. Levels of FPs increased after incubation of feces at 37 degrees C for 96 h under anaerobic conditions and pre-FP-12 and pre-FP-14 peaks were observed, which showed identical spectra with authentic FPs. These were interpreted to be isomeric forms of the all-trans-[3H]FPs used for the isotopic dilution analysis. Total FPs (including pre-FP) yielded a range of 0.3-80 micrograms FP-12 and 2.8-44 micrograms FP-14 per g of freeze-dried feces from the study group.