Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Comparative Study
Estimation of equivalent threshold currents using different pulse widths for the epidural stimulation test in a porcine model.
The epidural stimulation test can help detect if a catheter is correctly positioned in the epidural space. Previous studies showed that a current of up to 16 mA was required to elicit a motor response, but few peripheral nerve stimulators can produce a current this high. Manipulating pulse width can produce a positive response at a lower current. To clarify the effects of pulse width on the epidural stimulation test, we performed a single-blinded study in a porcine model to estimate the equivalent current needed at varying pulse widths. ⋯ In situations where different pulse widths are needed, the nomograms presented here may be useful to estimate the equivalent threshold current which is required to elicit a motor response according to previously published criteria for epidural stimulation tests.
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Randomized Controlled Trial
Transesophageal echocardiography simulation is an effective tool in teaching psychomotor skills to novice echocardiographers.
Performance of transesophageal echocardiography (TEE) requires the psychomotor ability to obtain interpretable echocardiographic images. The purpose of this study was to determine the effectiveness of a simulation-based curriculum in which a TEE simulator is used to teach the psychomotor skills to novice echocardiographers and to compare instructor-guided with self-directed online delivery of the curriculum. ⋯ High-fidelity TEE simulators are an effective training adjunct for the acquisition of basic TEE psychomotor skills. There was no difference in improvement between the different modalities of instruction. Further research will examine the need for a faculty resource for a curriculum in which a simulator is used as an adjunct.
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Brain imaging studies suggest that loss of consciousness induced by general anesthetics is associated with impairment of thalamic function. There is, however, limited information on the time course of these changes. We recently obtained intracranial electroencephalogram (EEG) recordings from the ventroposterolateral (VPL) nucleus of the thalamus and from the motor cortex during induction of anesthesia in three patients to study the time course of the alterations of cortical and thalamic function. ⋯ We conclude that induction of anesthesia with propofol in these patients was associated with concurrent alterations of cortical and sensory thalamic activity.