Anesthesia and analgesia
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Anesthesia and analgesia · Jun 1996
Comparative Study Clinical TrialUnilateral spinal anesthesia using low-flow injection through a 29-gauge Quincke needle.
Restriction of sympathetic denervation during spinal anesthesia may minimize hemodynamic alterations. Theoretically, the use of nonisobaric anesthetics may allow unilateral anesthesia and thus restrict sympathetic denervation to one side of the body. The present prospective study investigates the incidence of unilateral spinal anesthesia using hyperbaric bupivacaine 0.5% (1.4 mL, 1.6 mL, 1.8 mL, or 2.0 mL) injected via a 29-gauge Quincke needle with a pump-controlled injection flow of 1 mL/min. ⋯ Twenty minutes after injection of the local anesthetic, mean arterial blood pressure decreased significantly in patients with bilateral sympathetic blockade from 87 +/- 8 to 83 +/- 8 mm Hg (P < 0.01) but not in patients with unilateral sympathetic blockade (from 87 +/- 11 to 85 +/- 10 mm Hg). In conclusion, low-flow injection (1 mL/min) of hyperbaric bupivacaine 0.5% via a 29-gauge Quincke needle prevented bilateral sympathetic blockade in more than 69% of the patients. The data further suggest that loss of temperature discrimination alone is not a reliable estimation of sympathetic block.
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Anesthesia and analgesia · Jun 1996
Comparative Study Clinical TrialTransesophageal echocardiography in myocardial revascularization: I. Accuracy of intraoperative real-time interpretation.
Transesophageal echocardiography (TEE) is increasingly used intraoperatively as a monitor of ventricular function and volume. Despite its increasing use, whether data from TEE monitoring can be interpreted accurately on-line in real-time is unknown. We studied the performance of five community-based, full-time cardiac anesthesiologists during 75 surgical procedures in which biplane TEE monitoring was used. ⋯ Recognition of normal and severe regional wall-motion abnormality, such as akinesis, had more concordance between real-time and off-line analysis, 93% and 79%, respectively, than recognition of mild regional wall-motion abnormalities. Anesthesiologists can estimate EFA in real-time to within +/-10% of off-line values in 75% of all cases. Real-time identification of normal regional function is more accurate than identification of abnormal function, i.e., there is variability in quantifying the severity of regional dysfunction.
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Anesthesia and analgesia · Jun 1996
Randomized Controlled Trial Clinical TrialOral clonidine premedication enhances the quality of postoperative analgesia by intrathecal morphine.
Since clonidine potentiates the analgesia by morphine, the current study was performed to investigate whether oral clonidine premedication would enhance the postoperative analgesia by intrathecal morphine. Twenty-six patients, aged 37-60 yr, schedule for abdominal total hysterectomy under spinal anesthesia, were studied. Patients were randomly allocated to one of two groups; the clonidine group (n = 13) received oral clonidine approximately 5 micrograms/kg, and the control group (n = 13) received no clonidine. ⋯ Although there was no difference in the total number of injections of supplemental analgesics (1.1 +/- 0.4 and 2.2 +/- 0.3 in the clonidine and control groups, respectively), the number of patients not requiring supplemental analgesics during the entire study period was larger in the clonidine group than the control group (six patients versus one patient; P < 0.05). There were no differences at any observation point between groups in visual analog pain scores, or the incidence of nausea and pruritus. Oral clonidine preanesthetic medication enhances the postoperative analgesia of intrathecal morphine plus tetracaine without increasing the intensity of side effects from morphine.