Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1996
Comparative Study Clinical TrialEpiduroscopic changes in patients undergoing single and repeated epidural injections.
Using a superfine fiberscope with an outer diameter of 0.75 mm, the effect of repeated injections through a single epidural catheter on the epidural space was examined in 18 patients. The subjects were divided into a control group of 10 patients who had not previously received epidural anesthesia (EA) and an EA group of 8 patients who had received repeated EA with 4-6 mL 0.25% bupivacaine through an epidural catheter, two to three times per day for 7-14 days. The epidural space was observed through a fiberscope passed through a 17-gauge Tuohy needle. ⋯ Five patients in the EA group experienced pain when the fiberscope was inserted into the epidural space. These investigations show that continuous EA might be followed by a high incidence of nonspecific epidural changes. Superfine fiberscope may be useful in the detection or diagnosis of local epidural reaction.
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Anesthesia and analgesia · Jan 1996
Comparative Study Clinical TrialNeostigmine reversal of vecuronium neuromuscular block and the influence of renal failure.
The duration of clinical relaxation induced by vecuronium and reversal by neostigmine was studied in 40 patients with renal failure (RF) and 40 patients with normal renal function (NL) under general anesthesia. Patients were premedicated with flunitrazepam, and anesthesia commenced with fentanyl 1-2 micrograms/kg, thiopental 5-8 mg/kg, and vecuronium 0.1 mg/kg. Anesthesia was maintained with 60% nitrous oxide in oxygen, isoflurane 0.3%-1.0% end-tidal concentration, and 1 microgram/kg fentanyl every 20-30 min. ⋯ Spontaneous recovery time, reversal time, and the time to recovery of TOF ratio to 0.7 were recorded. RF did not prolong the vecuronium neuromuscular blocking effect, reversal was achieved at the same rate in NL as in RF, and the duration of reversal of neuromuscular blocking effect of vecuronium was not influenced by the time of administration of neostigmine. Therefore, the neuromuscular blocking effect of a tracheal intubating dose of vecuronium can be reversed at the same rate in patients with end-stage RF as in patients with normal kidney function.
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Anesthesia and analgesia · Jan 1996
Clinical TrialThe analgesic response to intravenous lidocaine in the treatment of neuropathic pain.
This study was performed in order to determine concentration-effect, and graded and quantal dose-response relationships for the clinical administration of intravenous (IV) lidocaine to patients with neuropathic pain. Thirteen patients were administered 500 mg of IV lidocaine at a rate of 8.35 mg/min over 60 min. Visual analog pain scores and venous blood samples were obtained concomitantly at 10 min intervals for 60 min. ⋯ Interestingly, the free concentration of lidocaine had no better correlation with the onset of analgesia or the attainment of complete analgesia than the serum concentration of lidocaine. This suggests that the mechanism of analgesia to IV lidocaine may not be based upon a conventional concentration-effect relationship. In conclusion, the results of this study suggest that the analgesic response to IV lidocaine is best characterized by a precipitous "break in pain" over a narrow dosage and concentration range.
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Anesthesia and analgesia · Jan 1996
Comparative StudyCoronary perfusion pressure during cardiopulmonary resuscitation after spinal anesthesia in dogs.
Cardiac arrest during spinal anesthesia is a rare event, but when it does happen cardiopulmonary resuscitation (CPR) is often ineffectual. This study examines the effect of spinal anesthesia on coronary perfusion pressure (CPP) during CPR and the subsequent response of CPP to epinephrine administration. Twenty mongrel dogs were anesthetized, and randomly assigned to a spinal injection with either 0.5 mg/kg bupivacaine or with an equivalent volume of normal saline. ⋯ Epinephrine is effective in increasing CPP during CPR above the critical threshold. These data suggest that if cardiac arrest occurs during spinal anesthesia, epinephrine should be given in doses of 0.01-0.02 mg/kg IV initially and then increasing to 0.1 mg/kg IV. When this does not work, and ineffective CPR is suspected, alternative resuscitative measures should be considered.
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Anesthesia and analgesia · Jan 1996
Head rotation during internal jugular vein cannulation and the risk of carotid artery puncture.
We undertook a prospective laboratory study to examine the effect of head position on the relative positions of the carotid artery and the internal jugular vein (IJV). Volunteers (n = 12) from departmental staff, 18-60 yr of age, who had never undergone cannulation of the IJV underwent imaging of their IJV and carotid artery. With the subject in a 15 degrees Trendelenburg position, two-dimensional ultrasound images of the IJV and the carotid artery were obtained on the left and right sides of the neck at 2 and 4 cm from the clavicle along the lateral border of the sternal head of the sternocleidomastoid muscle at 0 degrees, 40 degrees, and 80 degrees of head rotation from the midline. ⋯ The IJV frequently collapses with needle insertion. This may result in puncture of the posterior wall of the vessel, and thus of the carotid artery when the two vessels overlap. To decrease this risk, the head should be kept in as neutral a position as possible, that is < 40 degrees rotation, during IJV cannulation.