Anesthesia and analgesia
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The purpose of this study was to gain new insights in the role of succinylcholine in the initiation of malignant hyperthermia (MH). The intravenous (i.v.) administration of succinylcholine (2.0 mg/kg) induced fasciculations and masseter spasm in both normal swine and those susceptible to MH. However, the amplitudes and durations of generalized fasciculations were significantly greater in the susceptible animals that subsequently developed a fulminant episode of MH: succinylcholine induced not only tachycardia, hyperthermia, contractures, and increases in PaCO2 and lactate, all classic indicators of an episode, but also an initial severe hypotension. ⋯ In the pretreated and untreated susceptible swine, dantrolene was an equally effective treatment. Plasma catecholamine levels after succinylcholine administration were increased only in the susceptible swine without the pancuronium pretreatment. We concluded that the effects of succinylcholine on skeletal muscle and/or on other tissues play a significant role in the initiation of a MH episode in swine with this genetic disorder, and that these effects are not dependent on an abnormal sensitivity for succinylcholine-induced skeletal muscle fasciculations in these animals.
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Anesthesia and analgesia · Jul 1994
The use of Quincke and Whitacre 27-gauge needles in orthopedic patients: incidence of failed spinal anesthesia and postdural puncture headache.
This study examined the incidence of failed spinal anesthesia and postdural puncture headache using a 27-gauge Whitacre and a 27-gauge Quincke needle in patients undergoing elective inpatient orthopedic procedures. The overall rate of failed spinal anesthesia was 8.5% [95% confidence interval (CI) = 4.6%-12.4%] (n = 17) in the Quincke group (n = 199) and 5.5% [95% CI = 2.3%-8.7%] (n = 11) in the Whitacre group (n = 199). This difference was not statistically significant. ⋯ The mean time for withdrawal of the stylet to appearance of cerebrospinal fluid was 10.8 +/- 6.9 s in the Quincke (n = 31) and 10.7 +/- 6.8 s in the Whitacre group (n = 33). These differences were not statistically significant. Our results suggest that both needles are associated with a very low incidence of PDPH and an incidence of failed anesthesia of 5.5%-8.5%.
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Anesthesia and analgesia · Jul 1994
Postoperative epidural analgesia and oral anticoagulant therapy.
The relative safety of epidural catheter placement with subsequent heparinization has been well documented. However, what is the risk of neurologic sequelae in such patients who receive warfarin perioperatively? This study retrospectively evaluates the risk of spinal hematoma in patients receiving postoperative epidural analgesia while receiving low-dose warfarin after total knee replacement. All patients received low-dose warfarin to prolong the prothrombin time (PT) to 15.0-17.3 s (normal 10.9-12.8 s). ⋯ Mean PT at the time of epidural catheter removal was 13.4 +/- 2 s. There were no signs of spinal hematoma. Although epidural catheter placement and subsequent anticoagulation with warfarin appears relatively safe, there is a large variability in patient response to warfarin; therefore, coagulation status should be monitored to avoid excessive prolongation of the PT, and the patient should be watched closely for evidence of spinal hematoma.