Anesthesiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Lumbar plexus block reduces pain and blood loss associated with total hip arthroplasty.
The usefulness of peripheral nerve blockade in the anesthetic management of hip surgery has not been clearly established. Because sensory afferents from the hip include several branches of the lumbar plexus, the authors hypothesized that a lumbar plexus block could reduce pain from a major hip procedure. ⋯ Posterior lumbar plexus block provides effective analgesia for total hip arthroplasty, reducing intra- and postoperative opioid requirements. Moreover, blood loss during and after the procedure is diminished. Epidural anesthetic distribution should be anticipated in a minority of cases.
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Randomized Controlled Trial Clinical Trial
Regulation of proprioceptive memory by subarachnoid regional anesthesia.
Patient perception of limb position during regional anesthesia is frequently incorrect. The existing model ascribes this misperception, or phantom sensation, as a reversion to a fixed, slightly flexed, body schema. A model was developed to evaluate the influence of limb position changes on the incidence of incorrect or phantom sensations during regional anesthesia. ⋯ Proprioceptive memory involves a dynamic neuroplastic imprinting process that is influenced by limb or joint position prior to onset of regional anesthesia. This contrasts with previously held beliefs of a purely fixed body schema.
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Randomized Controlled Trial Clinical Trial
Differences in cardiovascular response to airway stimulation at different sites and blockade of the responses by lidocaine.
Mechanical stimulation of the airways elicits abrupt cardiovascular responses (CVR) in anesthetized humans. We examined a potential difference in such responses by comparing changes in heart rate (HR) and arterial blood pressure (AP) responses to mechanical stimulation of three different parts of the airways, as well as the effects of localized airway anesthesia with lidocaine on these responses. ⋯ We found that CVRs to tactile stimulation differ in their magnitude at three different sites within the airways, and localized anesthesia with lidocaine can abolish these responses in humans. The inhibition of lidocaine could be mainly due to direct blockade of the mechanoreceptors of the airways and partly to its systemic effect.
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Although the use of external positive end-expiratory pressure (PEEP) is recommended for patients with intrinsic PEEP, no simple method exists for bedside titration. We hypothesized that the occlusion pressure, measured from airway pressure during the phase of ventilator triggering (P0.1t), could help to indicate the effects of PEEP on the work of breathing (WOB). ⋯ These results show that P0.1t may help to assess the effects of PEEP in patients with intrinsic PEEP.