Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1994
Randomized Controlled Trial Clinical TrialSystemic opioids enhance the spread of sensory analgesia produced by intrathecal lidocaine.
The effect of different doses of fentanyl and nalbuphine on the spread of spinal analgesia produced by lidocaine was studied in 68 patients undergoing transurethral resection of the prostate (TURP) under spinal anesthesia. Patients were randomly assigned to six groups: fentanyl A, B, or C (FA, FB, FC) or nalbuphine A, B, or C (NA, NB, NC), which received intravenous (i.v.) 50, 100, or 150 micrograms of fentanyl or 10, 15, or 20 mg of nalbuphine, respectively, 20 min after spinal anesthesia with lidocaine. We tested the level of spinal analgesia with pinprick sensation 20 min after spinal anesthesia and 10 min after the opioid administration, when 0.4 mg of naloxone was administered i.v. ⋯ Ten minutes after fentanyl or nalbuphine, the level of analgesia increased (1.8 +/- 1.7, 3.1 +/- 1.2, and 4.1 +/- 1.5 cm, in the FA, FB, and FC groups and 1.9 +/- 0.9, 2.6 +/- 1.4, and 3.7 +/- 2.2 cm in the NA, NB, and NC groups, respectively). The increases in the level of analgesia differed significantly between the fentanyl groups (F = 8.0939; df = 2.35; P < 0.001), the increase produced by 150 micrograms being significantly higher than produced by 50 micrograms of fentanyl (limits of confidence -4.236809 and -0.4431909; P < 0.01). Naloxone reversed the effect of fentanyl and 10 min after its administration the fentanyl groups did not differ with regard to the level of spinal analgesia.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Jul 1994
Histopathology after repeated intrathecal injections of preservative-free ketamine in the rabbit: a light and electron microscopic examination.
Epidural and spinal administration of ketamine has been used in humans. Single-dose studies have shown that preservative-free ketamine lacks neurotoxic effects, but there are no studies after repeated administrations. The aim of this study was to examine the effects of daily administration of preservative-free ketamine. ⋯ Light microscopic, electron microscopic, and morphometric examinations showed no differences between the spinal cords from the rabbits injected with ketamine versus saline. Intrathecal ketamine produced motor impairment for a period of 15 min. We conclude that repeated intrathecal administration of preservative-free ketamine confirms the lack of neurotoxicity from single-dose studies.
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Anesthesia and analgesia · Jul 1994
Comparative StudyComparison of high-dose thrombin time with activated clotting time for monitoring of anticoagulant effects of heparin in cardiac surgical patients.
The activated clotting time (ACT) is routinely used for monitoring of heparin effects during cardiopulmonary bypass (CPB). However, ACT is not a specific assay for heparin and may be influenced by several other factors, which may be misleading with regard to the proper administration of heparin and protamine. In this pilot study, we compared a new test, the high-dose thrombin time (HiTT), with the conventional ACT test for both in vitro and in vivo heparin-induced anticoagulation. ⋯ Hypothermia and hemodilution occurring during CPB did not alter HiTT results. ACT also correlated well with both heparin concentration and HiTT before CPB, but the linear relationship was lost during CPB. Our results suggest that HiTT is a useful assay for monitoring heparin effects during cardiac surgery, even during hypothermia and hemodilution.
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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.