Anesthesia and analgesia
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Anesthesia and analgesia · Mar 1993
Comparative StudyComplications and fiberoptic assessment of size 1 laryngeal mask airway.
In pediatric practice, complications due to the laryngeal mask airway (LMA) have been studied with size 2 LMA, but not with size 1 LMA. We, therefore, compared prospectively the complications induced by LMA size 1 and 2 in 141 children aged 21 days to 11 yr. Intraoperative and lowest SpO2 values after removal of LMA were recorded. ⋯ The number of attempts, complications, intraoperative SpO2, and lowest SpO2 values were similar when using size 1 and size 2 LMA. Fiberoptic examination of size 1 LMA showed a high incidence of impinging of the epiglottis in the LMA bars without airway obstruction. In conclusion, there was no difference in the complication rate between the two pediatric sizes of LMA when used in pediatric patients.
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Anesthesia and analgesia · Mar 1993
Randomized Controlled Trial Comparative Study Clinical TrialThe effect of two levels of hypotension on intraoperative blood loss during total hip arthroplasty performed under lumbar epidural anesthesia.
The degree of induced hypotension necessary to achieve a significant reduction in intraoperative blood loss has never been defined. Forty patients undergoing primary total hip arthroplasty during epidural anesthesia by a single surgeon were randomly assigned to have mean arterial pressure maintained at 50 +/- 5 mm Hg or 60 +/- 5 mm Hg throughout surgery. ⋯ No difference in transfusion requirements, postoperative hematocrit, or duration of surgery was noted. A difference in mean arterial blood pressure of 10 mm Hg from 50 to 60 mm Hg during surgery for total hip arthroplasty under epidural anesthesia has a measurable effect on intraoperative blood loss.
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Frequently fluid may be aspirated from epidural catheters during epidural anesthesia/analgesia. This fluid may be either cerebrospinal fluid or local anesthetic. Several methods for differentiation of the two fluids have been recommended. ⋯ When the glucose-positive aspirates were subjected to immunoelectrophoresis, 6 of 7 aspirates revealed a prealbumin band. In conclusion, the glucose test for cerebrospinal fluid may be misleading. The source of this glucose may be normal cerebrospinal fluid drainage into the epidural space.
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Anesthesia and analgesia · Mar 1993
Comparative StudyToxicity of bupivacaine encapsulated into liposomes and injected intravenously: comparison with plain solutions.
The acute central nervous system and cardiac toxicities of 0.25% bupivacaine, without adrenalin, encapsulated in multilamellar liposomes were compared with 0.25% plain solutions with and without adrenalin after intravenous infusion at a rate of 0.15 mg.kg-1 x min-1 with an increase of 0.036 mg.kg-1 x min-1 every 10 min. Three groups of six anesthetized, unventilated rabbits were studied. The doses of bupivacaine (in mg.kg-1) which produced seizure, ventricular tachycardia, and asystole were determined. ⋯ A statistical comparison of the cumulative lethal doses of bupivacaine 0.25% with adrenalin and of liposomal bupivacaine led to a P = 0.06. Adrenalin did not modify the systemic toxicity of the local anesthetic. This study showed a reduction of nervous and cardiac toxicity of bupivacaine encapsulated in multilamellar liposomes when infused intravascularly.
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Anesthesia and analgesia · Mar 1993
The effect of head-down tilt on arterial blood pressure after spinal anesthesia.
We examined the usefulness of 10 degrees head-down tilt for hypotension after spinal block. Two different investigations were performed, one employing head-down tilt after arterial blood pressure had decreased (n = 40), and the other using a prophylactic tilt (n = 50). When the head-down tilt was applied to treat hypotension after spinal block (n = 40), arterial blood pressure increased only in patients whose systemic blood pressure decreased more than 30% from the control (severe hypotension group, n = 11). ⋯ When the head-down tilt was performed immediately after spinal block (n = 24), the changes in systolic blood pressure were the same as in the horizontal group (n = 26). The cephalad spread of analgesia at 20 min after spinal block was higher, however, in the head-down tilt group (T3.8 +/- 1.6) than the horizontal group (T5.2 +/- 1.9). From these results we conclude that head-down tilt for hypotension after spinal block increases arterial blood pressure only for severe hypotension, and that prophylactic head-down tilt has no effect in maintaining blood pressure.