Residual Neuromuscular Blockade.

This article provides an update on residual neuromuscular blockade for nurse anesthetists. The neuromuscular junction, pharmacology for producing and reversing neuromuscular blockade, monitoring sites and methods, and patient implications relating to incomplete reversal of neuromuscular blockade are reviewed. Overall recommendations include using multiple settings when employing a peripheral nerve stimulator for monitoring return of neuromuscular function and administering pharmacologic reversal when the train-of-four ratio is below 0.9.

Taste + odor interactions in compound aversion conditioning.

In three experiments with rats, taste + odor interactions in compound aversion conditioning were investigated. In Experiment 1, two odors (0.02% almond and 0.02% orange) were compared on single-element odor aversions, taste (denatonium) potentiated odor aversions, and potentiated odor aversions following taste extinction. Although no odor differences were seen following single-element conditioning, both types of potentiated orange odor aversions were stronger than their almond odor counterparts. These data show that odors of similar conditionability are differentially potentiated by the same taste. To determine whether these differences were due to unique perceptual representations, the effects of elemental extinction or compound extinction on aversions to the compound were investigated in Experiments 2 and 3. In Experiment 2, orange odor extinction weakened responding to the compound significantly more than taste extinction did. In contrast, almond odor extinction and taste extinction produced similar decrements in responding to the compound in Experiment 3. These results suggest that the perceptual representation of these specific taste + odor compounds are different, and they are discussed in regard to configural and within-compound association accounts of potentiation.

Effects of postconditioning inflation on odor + taste compound conditioning.

The within-compound association approach has been proposed as an account of synergistic conditioning in flavor aversion learning. One prediction from the within-compound association approach is that following taste + odor compound conditioning, postconditioning inflation of one element of the compound should increase responding to the second element. In four experiments with rats, the AX+/A+ design was used to determine whether postconditioning inflation of A would increase responding to X. In Experiments 1 and 3, responding to X was significantly stronger after AX+/A+ conditioning, as compared with AX+ conditioning. In Experiments 2 and 4, the specificity of the inflation effect was demonstrated, because AX+/A+ conditioning produced a stronger aversion to X than did AX+/B+ conditioning. Furthermore, it appears that the taste + odor association is symmetrical because inflation of the taste aversion increased responding to the odor (Experiments 1 and 2) and inflation of the odor aversion increased responding to the taste (Experiments 3 and 4).