Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2008
Increased oxygen administration improves cerebral oxygenation in patients undergoing awake carotid surgery.
During regional anesthesia for carotid endarterectomy (CEA), 10% to 15% of patients develop signs of cerebral hypoxia after cross-clamping, manifested as changes in speech, cerebration or contralateral motor power. Reversal of such neurological deficits using administration of 100% O2 has been described. We used near-infrared cerebral oximetry to assess whether 100% O2 reliably improves regional cerebral oxygenation (rSO2) during carotid cross-clamping. ⋯ With the carotid cross-clamped, ipsilateral rSO2 was reliably increased by the administration of 100% O(2) compared with 28% O2. The etiology of this increase is unclear, but may relate to the associated increase in O2 content of the blood or to an improvement in cerebral blood flow. Thus administration of 100% O2 during carotid cross-clamping may be beneficial for all patients undergoing CEA.
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Anesthesia and analgesia · Nov 2008
The influence of age on the dynamic relationship between end-tidal sevoflurane concentrations and bispectral index.
Age is an important determinant of the pharmacokinetic profile of inhaled anesthetics. The influence of age on the dynamic profile of sevoflurane's effect has not been well described. We performed this study to characterize the influence of age and other covariates on the dynamic relationship between sevoflurane end-tidal concentration (C(ET)) and its effect measured by bispectral index (BIS). ⋯ Age significantly affects the dynamic relationship between sevoflurane C(ET) and its effect measured with BIS.
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Anesthesia and analgesia · Nov 2008
Emergency airway management with fiberoptic intubation in the prone position with a fixed flexed neck.
We describe emergency airway management with fiberoptic intubation in a patient in the prone position with her neck flexed by a head pin holder during a neurosurgical procedure. Laryngeal mask airway is suggested in emergency difficult airway algorithms; however, this was not feasible in this patient because of her edematous upper airway and limited mouth opening resulting from extreme neck flexion by a head pin holder. The case illustrates the role of fiberoptic intubation in emergency airway management in this critical situation. Maneuvers to facilitate fiberoptic technique are also described.
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Anesthesia and analgesia · Nov 2008
Case ReportsEndobrochial blockade through a tracheostomy tube for lung isolation.
We present an alternative technique for one-lung ventilation as safe way of treating patients with tracheostomy using a fiberoptic bronchoscope and a Fogarty catheter.
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Anesthesia and analgesia · Nov 2008
The effects of volatile aromatic anesthetics on voltage-gated Na+ channels expressed in Xenopus oocytes.
Many inhaled anesthetics inhibit voltage-gated sodium channels at clinically relevant concentrations, and suppression of neurotransmitter release by these anesthetics results, at least partly, from decreased presynaptic sodium channel activity. Volatile aromatic anesthetics can inhibit N-methyl-D-aspartate (NMDA) receptor function and enhance gamma-amino butyric acid A receptor function, but these effects depend strongly on the chemical properties of the aromatic compounds. In the present study we tested whether diverse aromatic anesthetics consistently inhibit sodium channel function. ⋯ Aromatic compounds vary in their actions on the kinetics of sodium channel gating and this may underlie their variable inhibition. The range of inhibition produced by minimum alveolar anesthetic concentration concentrations of inhaled anesthetics indicates that sodium channel inhibition may underlie the action of some of these anesthetics, but not others.