Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2006
Case ReportsCauda equina syndrome and profound hearing loss after spinal anesthesia with isobaric bupivacaine.
A 33-yr-old man undergoing anorectal surgery developed cauda equina syndrome and bilateral profound hearing loss after single-injection spinal anesthesia with isobaric bupivacaine. There was no pain on needle placement. ⋯ Although hearing impairment can occur with cerebrospinal fluid leakage, the etiology of cauda equina syndrome is uncertain. The simultaneous occurrence of these events has not been previously reported.
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Anesthesia and analgesia · Jun 2006
The effects of indomethacin on intracranial pressure and cerebral hemodynamics during isoflurane or propofol anesthesia in sheep with intracranial hypertension.
The effect of indomethacin in reducing intracranial pressure (ICP) may be dependent on the choice of anesthetic regimen. We studied the effects of indomethacin on ICP and cerebral blood flow (CBF) during isoflurane or propofol anesthesia in a sheep model of intracranial hypertension. A crossover design was applied in which six sheep were anesthetized with isoflurane and propofol in a random order. ⋯ The reduction in CBF was significantly more pronounced for propofol (P = 0.02). The effect on ICP, however, was most pronounced during isoflurane anesthesia. We suggest that the effect of indomethacin is partly mediated by an autoregulatory response.
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Anesthesia and analgesia · Jun 2006
The implications of arterial Po2 oscillations for conventional arterial blood gas analysis.
In a surfactant-depletion model of lung injury, tidal recruitment of atelectasis and changes in shunt fraction lead to large Pao2 oscillations. We investigated the effect of these oscillations on conventional arterial blood gas (ABG) results using different sampling techniques in ventilated rabbits. In each rabbit, 5 different ventilator settings were studied, 2 before saline lavage injury and 3 after lavage injury. ⋯ After saline lavage, when Po2 fluctuations measured by the indwelling arterial Po2 probe confirmed tidal recruitment, Pao2 by ABG was significantly higher at peak (295 +/- 130 mm Hg) compared with trough (74 +/- 15 mm Hg) or mean (125 +/- 75 mm Hg). In early, mild lung injury after saline lavage, Pao2 can vary markedly during the respiratory cycle. When atelectasis is recruited with each breath, interpretation of changes in shunt fraction, based on conventional ABG analysis, should account for potentially large respiratory variations in arterial Po2.
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Anesthesia and analgesia · Jun 2006
The usefulness of transesophageal echocardiography during intraoperative cardiac arrest in noncardiac surgery.
According to guidelines established by the American Society of Anesthesiologists and the Society of Cardiovascular Anesthesiologists, life-threatening hemodynamic disturbances are classified as a category I indication for the intraoperative use of transesophageal echocardiography (TEE). However, the usefulness of TEE during intraoperative cardiac arrest and its impact on patient management have not been rigorously investigated. Using our departmental TEE database, we identified a population of 22 patients who underwent noncardiac surgical procedures and experienced unexpected intraoperative hemodynamic collapse requiring the initiation of Advanced Cardiac Life Support procedures between the time of induction of general anesthesia and the termination of the surgical procedure. ⋯ In 18 patients, TEE guided specific management beyond implementation of Advanced Cardiac Life Support protocols, including the addition of surgical procedures in 12 patients. Fourteen patients survived to leave the operating room, and 7 of these patients were eventually discharged from the hospital. Thus, TEE may provide additional diagnostic information in patients with intraoperative cardiac arrest and may directly guide specific, potentially life-saving therapy.
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Anesthesia and analgesia · Jun 2006
Video assessment of supraglottic airway orientation through the perilaryngeal airway in pediatric patients.
The COBRA perilaryngeal airway (PLA) is a new supraglottic airway device available for use in children. We studied the orientation of the larynx as viewed through the PLA using video obtained with a fiberoptic bronchoscope in 45 infants and children. Laryngeal view was scored, and position of the grill bars of the PLA and the epiglottis was assessed. ⋯ This was uncommon in larger children. The grill bars of the PLA were closely opposed to the epiglottis and supraglottic structures in nearly all subjects. We conclude that 1) the PLA provides an acceptable airway in infants and children, but infolding of the epiglottis with obstruction of the view of the glottic opening is common in infants, 2) extra vigilance for airway obstruction in this age group is necessary, and 3) the PLA's close opposition to the supraglottic structures suggests that removal in a deeper plane of anesthesia might minimize laryngeal stimulation.