Anesthesia and analgesia
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Anesthesia and analgesia · May 1997
The threshold for thermoregulatory vasoconstriction during nitrous oxide/sevoflurane anesthesia is reduced in the elderly.
Elderly patients become more hypothermic during surgery, shiver less postoperatively, and take longer to rewarm than younger patients. Similarly, the vasoconstriction threshold (triggering core temperature) is reduced approximately 1 degree C in elderly patients during nitrous oxide/isoflurane anesthesia. Accordingly, we tested the hypothesis that the vasoconstriction threshold in the elderly is also reduced approximately 1 degree C during nitrous oxide and sevoflurane anesthesia. ⋯ The data from five patients who did not vasoconstrict at minimum core temperatures of 33-34 degrees C were eliminated, leaving 10 patients in each group. The vasoconstriction threshold was significantly less in the elderly (35.0 +/- 0.8 degrees C) than in younger patients (35.8 +/- 0.3 degrees C), despite similar mean skin temperatures (mean +/- SD, P < 0.01, Student's t-test). Age dependence of thermoregulatory vasoconstriction during nitrous oxide/sevoflurane anesthesia is similar to that previously observed during nitrous oxide/isoflurane anesthesia.
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This investigation analyzed the changes in inspiratory airway pressures during transition from two-lung to one-lung ventilation in patients tracheally intubated with a double-lumen endotracheal tube (DLT) using a classical method of intubation without fiberoptic bronchoscopy. All patients were anesthetized in a standardized fashion. Ventilation was accomplished with the Siemens 900 constant-flow mechanical ventilator (Solna, Sweden). ⋯ When the DLT was in a correct position, Ppeak increased by a mean of 55.1% and Pplateau increased by a mean of 41.9%. When the DLT was malpositioned, this increase was significantly larger (74.9% and 68.8%, respectively). Three tests commonly used as markers of malpositioned DLTs were evaluated based on the data of this study, and it was established that, although the pressure differences related to position are statistically significant, as a single value, they cannot be used for clinical decision making.
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Anesthesia and analgesia · May 1997
Neurologic complications of 603 consecutive continuous spinal anesthetics using macrocatheter and microcatheter techniques. Perioperative Outcomes Group.
Recent case reports of cauda equina syndrome after continuous spinal anesthesia have led to a reevaluation of the indications and applications of this regional anesthetic technique. However, few large studies have formally investigated the frequency of neurologic complications using macro- and microcatheter (smaller than 24 gauge) techniques. This retrospective review examines 603 continuous spinal anesthetics, including 127 administered through a 28-gauge microcatheter, performed between June 1987 and May 1992. ⋯ An epidural blood patch was performed in 41 (6.8%) patients. The frequency of neurologic complications, excluding PDPH, is similar to those in published reviews. However, PDPH in microcatheter patients is more frequent than previously reported.
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Anesthesia and analgesia · May 1997
Duration of intrathecal labor analgesia: early versus advanced labor.
Early first-stage labor pain is primarily visceral in origin. Increasing pain intensity and transition to somatic nociceptive input characterizes late first- and second-stage labor pain. The effect of this change in nociceptive input on the duration of intrathecal labor analgesia has not been well studied. ⋯ Duration of analgesia was defined as the lesser of time until the pain score exceeded 5 or until a request for supplemental epidural analgesia was made. The duration of spinal analgesia was significantly less when intrathecal injection was made in advanced labor (120 +/- 26 min) compared with early labor (163 +/- 57 min, P < 0.01). We conclude that cervical dilation and stage of labor significantly impact the effective duration of intrathecal sufentanil/ bupivacaine labor analgesia.