Articles: anesthesia.
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Randomized Controlled Trial Comparative Study Clinical Trial
The thermoregulatory threshold in humans during nitrous oxide-fentanyl anesthesia.
Narcotics and nitrous oxide (N2O) inhibit thermoregulatory responses in animals. The extent to which N2O/fentanyl anesthesia lowers the thermoregulatory threshold in humans was tested by measuring peripheral cutaneous vasoconstriction using skin-surface temperature gradients (forearm temperature-fingertip temperature) and the laser Doppler perfusion index. Fifteen unpremedicated patients were anesthetized with N2O (70%) and fentanyl (10 micrograms/kg iv bolus followed by 4 micrograms.kg-1.h-1 infusion) during elective, donor nephrectomy. ⋯ Four hypothermic patients developed a passive thermal steady state without becoming sufficiently cold to trigger vasoconstriction. Thus, active thermoregulation occurs during N2O/fentanyl anesthesia but does not occur until core temperatures are approximately 2.5 degrees C lower than normal. The thermoregulatory threshold during N2O/fentanyl anesthesia is similar to that previously determined during halothane (34.4 +/- 0.2 degrees C).(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Maximum FIO2 during caesarean section.
Forty patients undergoing elective and emergency Caesarean section (excluding severe fetal distress) were divided into four groups to receive 50% oxygen, 50% nitrous oxide, and 0.5% halothane (group 1, controls) or 100% oxygen supplemented by 1.5 x MAC of halothane, enflurane or isoflurane (groups 2,3,4, respectively) reducing to 1.0 x MAC 5 min after induction. The umbilical venous PO2 in the oxygen-only groups was higher than in the oxygen-nitrous oxide groups, this difference reaching statistical significance when the patients in the oxygen-only groups were combined. ⋯ Improved cardiovascular stability was demonstrated in the elective high-oxygen groups. The technique is safe and warrants further study, since there are no important ethical objections.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Etomidate versus etomidate and hydrocortisone for anesthesia induction in abdominal surgical interventions].
The imidazole derivative etomidate has been shown to block (reversibly) adrenocortical steroid synthesis. Long-term sedation with etomidate has been associated with adrenocortical insufficiency and increased mortality in severely ill patients. The significance of adrenocortical blockade after a single induction dose of etomidate remains a matter of debate. ⋯ At the end of surgery patients were extubated after oxygenation. In all patients blood pressure, heart rate, central venous pressure, and ECG were monitored continuously, both intra- and postoperatively. During induction, patients received 1,000 ml 0.9% NaCl, followed by continuous administration of 0.9% NaCl, 6 ml/kg per hour intraoperatively and 40 ml/kg per 24 hours post-operatively.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Clinical Trial
Epidural fentanyl for shaking in obstetrics.
This study assesses the efficacy of epidural fentanyl in the relief of shaking associated with epidural analgesia. Fifty mothers whose shaking was sufficient to cause distress were divided randomly to receive either fentanyl 25 micrograms in 5 ml sterile normal saline or 5 ml of saline through their in-situ epidural. Shaking stopped within 15 minutes in 18 out of 25 (72%) of those given fentanyl but in only 4 out of 25 (16%) of the saline group and this is statistically significant (p less than 0.01). Fentanyl can be recommended in this context.
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Anesthesia and analgesia · Sep 1988
Randomized Controlled Trial Clinical TrialTourniquet pain during spinal anesthesia: a comparison of plain solutions of tetracaine and bupivacaine.
The incidence of tourniquet pain was evaluated in 40 patients having orthopedic surgery of the lower extremities during spinal anesthesia using 15 mg of a plain solution of either 0.5% tetracaine or 0.5% bupivacaine. The drugs were administered in a randomized fashion, and measurement of the levels of sensory anesthesia to pinprick and motor blockade as well as the occurrence of tourniquet pain were made by an independent blinded observer. The onset and maximum cephalad spread of sensory anesthesia and the onset and degree of motor block were similar in both groups of patients. ⋯ The occurrence of tourniquet pain was not related to the level of sensory anesthesia, because patients in the tetracaine group had a higher level of sensory anesthesia (mean T6) than did patients in the bupivacaine group (mean T10) at the onset of tourniquet pain. It is speculated that during spinal anesthesia both A and C fibers (mediating fast and slow pain, respectively) are initially equally inhibited. However, as the concentration of local anesthetic in the cerebrospinal fluid declines, C fibers may become unblocked earlier with tetracaine than A fibers, resulting in tourniquet pain in the presence of an otherwise satisfactory spinal anesthetic.