Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2009
Comparative StudyA comparison of dexmedetomidine with propofol for magnetic resonance imaging sleep studies in children.
Magnetic resonance imaging (MRI) sleep studies can be used to guide management of children with obstructive sleep apnea (OSA) refractory to conservative therapy. Because children with OSA are sensitive to the respiratory-depressant effects of sedatives and anesthetics, provision of anesthesia for imaging studies in this patient population can be challenging. Dexmedetomidine has been shown to have pharmacological properties simulating natural sleep with minimal respiratory depression. We hypothesized that, compared with propofol, dexmedetomidine would have less effect on upper airway tone and airway collapsibility, provide more favorable conditions during dynamic MRI airway imaging in children with OSA, have fewer scan interruptions, and require less aggressive airway interventions. ⋯ Dexmedetomidine provided an acceptable level of anesthesia for MRI sleep studies in children with OSA, producing a high yield of interpretable studies of the patient's native airway. The need for artificial airway support during the MRI sleep study was significantly less with dexmedetomidine than with propofol. Dexmedetomidine may be the preferred drug for anesthesia during MRI sleep studies in children with a history of severe OSA and may offer benefits to children with sleep-disordered breathing requiring anesthesia or anesthesia for other diagnostic imaging studies.
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Anesthesia and analgesia · Sep 2009
Low tidal volume ventilation in a porcine model of acute lung injury improves cerebral tissue oxygenation.
In study, we investigated the effects of different tidal volumes on cerebral tissue oxygenation and cerebral metabolism in a porcine model of acute lung injury (ALI). We hypothesized that mechanical ventilation with low tidal (LT) volumes improves cerebral tissue oxygenation and metabolism after experimentally induced ALI. ⋯ Protective ventilation with LT yielded a significant improvement in cerebral tissue oxygenation and metabolism compared to HT ventilation in a porcine model of ALI. There was dissociation between arterial and cerebral tissue oxygenation. Cerebral oxygenation and metabolism might have possibly been impaired by a more distinctive inflammatory response in the HT group.
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Anesthesia and analgesia · Sep 2009
The diagnostic value of the upper lip bite test combined with sternomental distance, thyromental distance, and interincisor distance for prediction of easy laryngoscopy and intubation: a prospective study.
Accuracy of upper lip bite test (ULBT) has been compared with the Mallampati classification. In this study, we investigated whether the combination of the ULBT classification with sternomental distance (SMD), thyromental distance (TMD), and interincisor distance (IID) or a composite score can improve the ability to predict easy laryngoscopy and intubation compared with each test alone. ⋯ We conclude that the specificity and accuracy of the ULBT is significantly higher than the other tests and is more accurate in airway assessment. However, the ULBT in conjunction with the other tests could more reliably predict easy laryngoscopy or intubation.
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Approximately 25% of initial arteriovenous fistula (AVF) placements will fail as a result of thrombosis or failure to develop adequate vessel size and blood flow. Fistula maturation is impacted by patient characteristics and surgical technique, but both increased vein diameter and high fistula blood flow rates are the most important predictors of successful AVFs. Anesthetic techniques used in vascular access surgery (monitored anesthesia care, regional blocks, and general anesthesia) may affect these characteristics and fistula failure. ⋯ Use of regional blocks may improve the success of vascular access procedures by producing significant vasodilatation, greater fistula blood flow, sympathectomy-like effects, and decreased maturation time. However, a large-scale, prospective, clinical trial comparing the different anesthetic techniques is still needed to verify these findings.