Anesthesia and analgesia
-
Anesthesia and analgesia · May 1996
Comparative Study Clinical Trial Controlled Clinical TrialThe effects of transnasal butorphanol on mood and psychomotor functioning in healthy volunteers.
Transnasal butorphanol is effective in relieving migraine and postoperative pain. The extent to which this drug preparation impacts on cognitive and psychomotor performance, as well as mood, has not been examined. Accordingly, the cognitive and psychomotor, subjective, and physiological effects of two clinically relevant doses of transnasal butorphanol (1 and 2 mg) were compared to that of placebo, and a common analgesic drug combination given for pain relief in ambulatory settings, 600 mg of acetaminophen and 60 mg of codeine, in healthy volunteers (n = 10). ⋯ The smaller dose had no psychomotor-impairing effects, but had subjective effects (including increased ratings of "sleepy"). All three active drug conditions including miosis. These laboratory results suggest that patients should use caution when using the 1-mg dose of transnasal butorphanol, and should curtail certain activities if they administer the 2-mg dose of transnasal butorphanol for analgesia.
-
Anesthesia and analgesia · May 1996
Randomized Controlled Trial Clinical TrialEpidural test dose: isoproterenol is a reliable marker for intravascular injection in anesthetized adults.
Epidural test doses containing more than 15 micrograms epinephrine are reliable for the detection of intravascular injection based on the conventional systolic blood pressure (SBP) criterion (positive if > or = 15 mm Hg increase) but not on the heart rate (HR) criterion (positive if > or = 20 bpm increase) in adult patients anesthetized with isoflurane. The present study was designed to test whether isoproterenol could be used as a reliable marker. Thirty adult patients were randomly assigned to one of two groups, each of which was anesthetized with 1% end-tidal isoflurane and nitrous oxide after endotracheal intubation. ⋯ On the other hand, 12 of 15 patients in the isoproterenol group and none in the saline group exhibited SBP increases > or = 15 mm Hg, resulting in 80% sensitivity and 83% negative predictive value. In the isoproterenol group, however, transient systolic hypotension ( < 80% of the preinjection value) occurred in five patients without untoward clinical sequelae. These results indicate that, based on the peak HR response, the epidural test dose containing 3 micrograms isoproterenol is a reliable marker for intravascular injection in adult patients during isoflurane anesthesia.
-
Anesthesia and analgesia · May 1996
Rapid core-to-peripheral tissue heat transfer during cutaneous cooling.
Perioperative thermal manipulations are usually directed at the skin surface because methods of directly warming the core are invasive or ineffective. However, inadequate heat flow between peripheral and core compartments will decrease the rate at which core temperature changes. We therefore determined whether core hypothermia is delayed after initiation of surface cooling. ⋯ There was no delay between initiation of active cooling and the decrease in core temperature. Furthermore, peripheral (arm and leg) and core (trunk and head) tissue heat contents decreased at virtually the same rates: approximately 50 kcal/h and approximately 47 kcal/h, respectively. These data indicate that there is little restriction of heat flow between peripheral and core tissues in vasodilated, anesthetized subjects.
-
Anesthesia and analgesia · May 1996
Randomized Controlled Trial Comparative Study Clinical TrialVideo as a patient teaching tool: does it add to the preoperative anesthetic visit?
-
Anesthesia and analgesia · May 1996
Comparative StudyThe use of a circumferential cathode improves amplitude of intraoperative electrical transcranial myogenic motor evoked responses.
Measurement of motor evoked responses to transcranial electrical stimulation (tc-MER) is a technique for intraoperative monitoring of motor pathways. Since most anesthetics significantly reduce motoneuronal excitability, optimal stimulation paradigms should be sought. We compared the efficiency of stimulus delivery using two different configurations of the cathode component of the stimulating electrode pair (circumferential: Fz, F3, F4, A1, and A2 versus a single cathode at Fz). ⋯ There was no significant difference in onset latency between electrode configurations. The observed tc-MER amplitude augmentation with the use of a circumferential cathode might allow tc-MER monitoring in those patients who do not have sufficiently reproducible responses when a single cathode is used. A possible explanation is that the circumferential cathode alters the direction of the electrical currents in the cortex, resulting in more efficient depolarization of cortical motor neurons.