Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1997
Randomized Controlled Trial Comparative Study Clinical TrialPropofol sedation during awake craniotomy for seizures: electrocorticographic and epileptogenic effects.
This prospective study evaluated the effects of propofol sedation on the incidence of intraoperative seizures and the adequacy of electrocorticographic (ECoG) recordings during awake craniotomy performed for the management of refractory epilepsy. Thirty patients scheduled for temporal or frontal lobectomy for epilepsy under bupivacaine scalp block were randomized to receive patient-controlled propofol sedation (PCS) combined with a basal infusion of propofol (n = 15) or neurolept analgesia using an initial bolus dose of fentanyl (0.7 microg/kg) and droperidol (0.04 mg/kg) followed by a fentanyl infusion (n = 15). Propofol administration was suspended 15 min before ECoG recording in the PCS group. ⋯ Evidence of low spike activity on ECoG did not correlate with the type of sedation administered. Higher frequency background ECoG activity was noted among patients who received propofol, but this did not interfere with ECoG interpretation. The use of propofol sedation does not appear to interfere with ECoG during epilepsy surgery, provided administration is suspended at least 15 min before recording.
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Anesthesia and analgesia · Jun 1997
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of multiport and uniport epidural catheters in laboring patients.
The relative incidence of technical difficulties associated with multiport (three lateral ports) and uniport (single distal port) epidural catheters remains controversial. As part of a continuing institutional evaluation of epidural catheter insertion, 500 parturients were randomized to have either a multiport or a uniport epidural catheter inserted 6 cm into the epidural space. ⋯ No multiport epidural catheter was associated with multicompartment placement. We conclude that multiport epidural catheters are preferable for use in laboring patients since they reduce the incidence of inadequate epidural analgesia.
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Anesthesia and analgesia · Jun 1997
Clinical TrialDynamic ventilatory characteristics during weaning in postoperative critically ill patients.
Postoperative patients occasionally require more than 48 h of mechanical ventilation. This study examined whether there were distinct differences in dynamic respiratory variables between patients who successfully weaned from mechanical ventilation and those who failed. Forty general and thoracic surgery patients underwent a standardized weaning sequence: 25 min of synchronous intermittent mandatory ventilation (SIMV) at 8 bpm plus 5 cm H2O pressure support ventilation (PSV), then SIMV at 4 bpm plus 5 cm H2O PSV, followed by continuous positive airway pressure (CPAP) plus 5 cm H2O PSV and, finally, CPAP without PSV. ⋯ P0.1 (threshold 4.5 cm H2O, sensitivity 1.00, specificity 1.00), patient work of breathing (threshold 1.3 J/L, sensitivity 0.92, and specificity 0.98), and the sRR/sV(T) ratio (threshold 65 bpm/L, sensitivity 0.90, specificity 0.80) were distinctive. Most unique was the analysis of spontaneous breaths during low SIMV rates. This appears to permit an early determination of whether weaning would succeed.
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Anesthesia and analgesia · Jun 1997
Cerebral hemoglobin and optical pathlength influence near-infrared spectroscopy measurement of cerebral oxygen saturation.
Near-infrared spectroscopy (NIRS) is a noninvasive optical technique to monitor cerebral oxygen saturation at the bedside. Despite its applicability, NIRS has had limited clinical use because of concerns about accuracy, noted by intersubject variability in slope and intercept of the line between NIRS- and weighted-average arterial-cerebrovenous saturation (SMO2). This study evaluated transcranial optical pathlength and cerebral hemoglobin concentration as sources for this intersubject variability. ⋯ By adjusting the NIRS algorithm with the cerebral hemoglobin measurements, slope and intercept remained unchanged by hemodilution. These data indicate that intersubject variability in NIRS originates, in part, from biologic variations in transcranial optical pathlength and cerebral hemoglobin concentration. Instruments to account for these factors may improve NIRS cerebral oxygen saturation measurements.