Anesthesiology
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Long-acting local anesthetics cause muscle damage. Moreover, long-acting local anesthetics act as uncoupler of oxidative phosphorylation in isolated mitochondria and enhance sarcoplasmic reticulum Ca(2+) release. The aim of the study was to evaluate effects of perineural injections of local anesthetics on mitochondrial energetic metabolism and intracellular calcium homeostasis in vivo. ⋯ Bupivacaine, levobupivacaine, and ropivacaine injected via femoral nerve block catheters induce a deleterious effect in mitochondrial energy, whereas only levobupivacaine disturbs calcium homeostasis.
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The true incidence of serious neuraxial complications such as epidural hematoma or abscess after postoperative epidural infusions is still uncertain, in part due to inconsistencies in multicenter data collection. ⋯ Spinal hematoma was very rare (< 0.05%). Epidural abscess was also rare (< 0.1%) but remains a potentially serious complication. Early diagnosis, using magnetic resonance imaging in patients with appropriate clinical indicators, before the onset of neurologic signs, enables conservative therapy in many cases and may help to prevent the development of serious neurologic sequelae.
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The cardiac safety of droperidol given at antiemetic doses is a matter of debate. Although droperidol potently inhibits human ether-a-go-go-related gene (HERG) channels, the molecular mode of this interaction is unknown. The role of amino acid residues typically mediating high-affinity block of HERG channels is unclear. It is furthermore unresolved whether droperidol at antiemetic concentrations induces action potential prolongation and arrhythmogenic early afterdepolarizations in cardiac myocytes. ⋯ Droperidol is a high-affinity blocker of HERG channels. Amino acid residues typically involved in high-affinity block mediate droperidol effects. Patch clamp results and computational modeling allow the hypothesis that interaction with calcium currents may explain why droperidol at antiemetic concentrations prolongs the action potential without inducing early afterdepolarizations.
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Alveolar fluid clearance is impaired in the majority of patients with acute respiratory distress syndrome (ARDS). Experimental studies have shown that a reduction of tidal volume increases alveolar fluid clearance. This study was aimed at assessing the impact of the response to a recruitment maneuver (RM) on net alveolar fluid clearance. ⋯ In the absence of alveolar recruitment and improvement in arterial oxygenation, RM decreases the rate of alveolar fluid clearance, suggesting that lung overinflation may be associated with epithelial dysfunction.
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Some patients develop recrudescence after a malignant hyperthermia (MH) reaction, but it is not clear which patients are at risk. The authors analyzed clinical variables associated with recrudescence after a clinical MH episode. ⋯ Recrudescence occurred in 20% of patients. Muscular body types had a higher rate of recrudescence, perhaps associated with increased muscle mass. The risk of recrudescence increased as time from induction to the initial MH reaction increased, perhaps as a result of greater muscle exposure to triggering agents.