Anesthesia and analgesia
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Anesthesia and analgesia · Mar 2006
Comparative StudyAnesthetic complications of awake craniotomies for epilepsy surgery.
Awake craniotomies are often performed for resection of epileptogenic foci close to vital areas of the brain. For awake craniotomies at our institution, propofol is infused during local anesthetic injection and craniotomy, spontaneous ventilation is preserved, and no endotracheal tube or laryngeal mask airway is used. Propofol is discontinued for language, motor, and/or sensory mapping and for electrocorticography. ⋯ We compared the incidence of intraoperative respiratory and hemodynamic complications and incidence of seizures, nausea, brain swelling, patient movement, bleeding, aspiration, air embolism, and death. Airway compromise was uncommon in AAA cases and although incidences of hypertension, hypotension, and tachycardia were statistically increased in AAA versus general anesthesia craniotomy, these were treated appropriately. In only one patient the use of our AAA technique may have contributed to a poor clinical outcome.
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Anesthesia and analgesia · Mar 2006
Case ReportsUnanticipated difficult endotracheal intubations in patients with cervical spine instrumentation.
We present two cases of unanticipated difficult airway in patients requiring reoperation after cervical spine instrumentation. In both cases, the upper airway examination was normal, and fiberoptic-guided intubation proceeded with the patient sedated and breathing spontaneously. ⋯ Later review of radiographs showed the previously unrecognized protrusion of cervical hardware into the meso- and hypopharynx. We recommend that anesthesiologists review recent radiographic studies for potential airway compromise before approaching the airway of patients presenting for revision of cervical instrumentation.
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Anesthesia and analgesia · Mar 2006
Comparative StudyIntravenous anesthetics are more effective than volatile anesthetics on inhibitory pathways in rat hippocampal CA1.
In this study, we have examined the effects of both volatile and IV general anesthetics on excitatory synaptic transmission, with and without recurrent inhibition, to clarify whether excitatory or inhibitory synapses are the major targets of action. Field population spike amplitudes (fPSs) of CA1 pyramidal neurons were recorded in rat hippocampal slices. Schaffer-collateral-commissural fibers (Sch) were stimulated orthodromically, and the evoked fPSs (PS[Sch]) in CA1 area were measured. ⋯ The effects of the IV anesthetics with recurrent inhibition were antagonized in the presence of the gamma-aminobutyric acid-A-receptor antagonist bicuculline methiodide. In addition, all anesthetics prolonged recurrent inhibition from 100 ms (sevoflurane and isoflurane) to 400 ms (propofol). The results suggest that sevoflurane and isoflurane inhibit mainly on glutamate-mediated orthodromic pathways, whereas thiopental and propofol enhance gamma-aminobutyric acid-A-mediated recurrent inhibitory pathways in CA1 neurons, thus providing further evidence that the mechanisms of general anesthetics are drug- and pathway-specific.