Anesthesia and analgesia
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We studied the relationship between the timing of discontinuing chronic angiotensin-converting enzyme inhibitors (ACEI) and angiotensin II receptor subtype 1 antagonists (ARA) and hypotension after the induction of general anesthesia in a general surgical population. We retrospectively studied 267 hypertensive patients receiving chronic ACEI/ARA therapy undergoing elective noncardiac surgery under general anesthesia. During preoperative visits, patients were asked to either take their last ACEI/ARA therapy on the morning of surgery or withhold it up to 24 h before surgery. ⋯ During the 31-60 min after induction, the incidence of either moderate (P = 0.43) or severe (P = 0.97) hypotension was similar in the two groups. No differences in postoperative complications were found between groups. In conclusion, discontinuation of ACEI/ARA therapy at least 10 h before anesthesia was associated with a reduced risk of immediate postinduction hypotension.
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Anesthesia and analgesia · Mar 2005
The effects of propofol or sevoflurane on the estimated cerebral perfusion pressure and zero flow pressure.
The zero flow pressure (ZFP) is the pressure at which blood flow ceases through a vascular bed. Using transcranial Doppler ultrasonography, we investigated the effects of propofol or sevoflurane on the estimated cerebral perfusion pressure (eCPP) and ZFP in the cerebral circulation. Twenty-three healthy patients undergoing nonneurosurgical procedures under general anesthesia were studied. ⋯ The eCPP decreased significantly in the propofol group (median, from 58 to 41 mm Hg) but not in the sevoflurane group (from 60 to 62 mm Hg). Correspondingly, ZFP increased significantly in the propofol group (from 25 to 33 mm Hg) and it decreased significantly in the sevoflurane group (from 27 to 7 mm Hg). Hypocapnia did not change eCPP or ZFP in the propofol group, but it significantly decreased eCPP and increased ZFP in the sevoflurane group.
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Anesthesia and analgesia · Mar 2005
Case ReportsThe use of a laryngeal mask airway for emergent airway management in a prone child.
A 5-yr-old girl with Arnold-Chiari Malformation, Type 1, was accidentally tracheally extubated while positioned prone in a Mayfield neurosurgical headrest during a decompressive craniectomy and cervical laminectomy. While preparations were being made to return the patient to the supine position for reintubation, we placed a laryngeal mask airway (LMA) without difficulty. The child was kept in the prone position with the LMA in place using positive-pressure ventilation for the remainder of the operation. This case report emphasizes the practical, emergent use of a LMA to secure the airway of a pediatric patient in the prone position after accidental extubation.
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Anesthesia and analgesia · Mar 2005
Cardiac arrest during neuraxial anesthesia: frequency and predisposing factors associated with survival.
The frequency and predisposing factors associated with cardiac arrest during neuraxial anesthesia remain undefined, and the survival outcome data are contradictory. In this retrospective study, we evaluated the frequency of cardiac arrest, as well as the association of preexisting medical conditions and periarrest events with survival after cardiac arrest during neuraxial anesthesia between 1983 and 2002. To assess whether survival after cardiac arrest differs for patients who arrest during neuraxial versus general anesthesia, data were also obtained for patients who experienced cardiac arrest under general anesthesia during similar surgical procedures during the same time interval. ⋯ Hospital survival was significantly improved for patients who arrested during neuraxial anesthesia versus general anesthesia (65% vs 31%; P = 0.013). The association of improved survival with neuraxial anesthesia remained statistically significant after adjusting for all patient/procedural characteristics, with the exception of ASA classification and emergency procedures. We conclude that a cardiac arrest during neuraxial anesthesia is associated with an equal or better likelihood of survival than a cardiac arrest during general anesthesia.
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Anesthesia and analgesia · Mar 2005
Case ReportsEpidural hematoma unrelated to combined spinal-epidural anesthesia in a patient with ankylosing spondylitis receiving aspirin after total hip replacement.
Although rare, major complications after spinal and epidural anesthesia do occur. The safety of spinal and epidural anesthesia has been well established. This is a report of an epidural hematoma in a patient with ankylosing spondylitis who received aspirin for thromboprophylaxis after total hip replacement that was unrelated to the combined spinal-epidural anesthetic. Most epidural hematomas are spontaneous and idiopathic.