Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1995
Randomized Controlled Trial Comparative Study Clinical TrialSpinal anesthesia in outpatient knee surgery: 22-gauge versus 25-gauge Sprotte needle.
Spinal anesthesia in day-care surgery is still controversial because of the possibility of postdural puncture headache (PDPH). The use of the Sprotte needle with a conical tip that spreads the dural fibers may reduce the incidence of PDPH. The aim of this study was to compare the 22-gauge and 25-gauge Sprotte needles with respect to PDPH and postoperative complaints in out-patients undergoing arthroscopy. ⋯ The failure rate was 0.8%. Unilateral anesthesia was achieved in 88% of 213 patients. Our data indicate that the use of spinal block is a suitable technique in the ambulatory setting, with a low rate of unplanned hospital admission.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jul 1995
The reliability of quantitative electroencephalography as an indicator of cerebral ischemia.
The electroencephalogram (EEG) has been used to detect episodes of cerebral ischemia during various surgical procedures. Recently, computerized systems for recording and interpreting the quantitative EEG (QEEG) have been used by anesthesiologists because of their ease of application, clarity of display, and reported ability to identify ischemic EEG changes. However, the extent to which automated techniques of QEEG interpretation reliably differentiate cerebral ischemia from the confounding effects of anesthetics and other sources of "artifact" is not completely established. ⋯ The CIMON technique identified episodes which met previously defined criteria for QEEG cerebral dysfunction and ischemic pattern in both groups, despite the presumed absence of cerebral ischemia in the control patients. Since there was no evidence of cerebral ischemia in the raw EEGs of either the ICD patients or the controls, these QEEG changes were not confirmed by conventional techniques of EEG interpretation. Our results suggest that caution is warranted when using automated systems for intraoperative interpretation of EEG.
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Anesthesia and analgesia · Jul 1995
Comparative StudyPropofol concentration monitoring in plasma or whole blood by gas chromatography and high-performance liquid chromatography.
We compared the measurement of propofol concentrations in plasma or whole blood by high-performance liquid chromatography (HPLC) to that of gas chromatography (GC). Blood samples were collected from patients who had received bolus injection or continuous infusion of propofol. The results showed that the two methods correlated well both in plasma and whole blood samples. ⋯ This discrepancy in concentrations resulted from the infusion or clearance of propofol, and the lag of redistribution across blood cell membranes. In conclusion, monitoring of propofol concentrations by the methods of GC and HPLC gives equivalent results. For propofol concentration monitoring, plasma samples are preferred, but immediate centrifugation is needed.
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To verify a safe location of the endotracheal tube (ETT), palpation of the ETT at the sternal notch is a time-honored technique: After anesthetic induction and confirmation of orotracheal intubation, the patient's head is placed in a neutral position. The ETT is withdrawn or advanced while gentle, repetitive pressure is applied with the fingers at the level of the suprasternal notch. Simultaneously, the pilot balloon is held in the other hand. ⋯ Average distance to the carina in women was 3 cm (range, 2-5) and in men 3.4 cm (range, 2-6). In this study, palpation of the ETT cuff effectively confirmed ETT location. The technique, which should not be used to verify endotracheal rather than bronchial intubation, should decrease the risk of bronchial intubation or impingement on the carina.
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Anesthesia and analgesia · Jul 1995
Ketamine does not increase cerebral blood flow velocity or intracranial pressure during isoflurane/nitrous oxide anesthesia in patients undergoing craniotomy.
Ketamine's effect on cerebral hemodynamics is controversial. We hypothesized that ketamine would not increase intracranial pressure (ICP) and cerebral blood flow (CBF) velocity in anesthetized, ventilated patients. Twenty patients requiring craniotomy for brain tumor or cerebral aneurysm were studied. ⋯ ICP decreased from 16 +/- 1 mm Hg to 14 +/- 1 mm Hg (mean +/- SE; P < 0.001) and VMCA decreased from 44 +/- 4 cm/s to 39 +/- 4 cm/s (P < 0.001). Total EEG power decreased (P < 0.02). These results suggest that ketamine can be used in anesthetized, mechanically ventilated patients with mildly increased ICP without adversely altering cerebral hemodynamics.