Anesthesia and analgesia
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The cardiovascular actions of three concentrations of desflurane (formerly I-653), a new inhalation anesthetic, were examined in 12 unmedicated normocapnic, normothermic male volunteers. We compared the effects of 0.83, 1.24, and 1.66 MAC desflurane with measurements obtained while the same men were conscious. Desflurane caused a dose-dependent increase in right-heart filling pressure and a decrease in systemic vascular resistance and mean systemic arterial blood pressure. ⋯ During the seventh hour of desflurane anesthesia, heart rate and cardiac index were higher at both anesthetic concentrations than during the first 90 min of anesthesia. Left ventricular ejection fraction and velocity of fiber shortening did not change with duration of desflurane anesthesia. Oxygen consumption, oxygen transport, the ratio of the two, mixed venous PO2, and mixed venous oxyhemoglobin saturation (SO2) increased late in the anesthetic in comparison with the first 90 min.
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Anesthesia and analgesia · Aug 1991
Hemodynamic effects of desflurane/nitrous oxide anesthesia in volunteers.
We determined the cardiovascular effects of 0.91, 1.34, and 1.74 MAC of desflurane/nitrous oxide anesthesia (60% inspired nitrous oxide contributed 0.5 MAC at each level) in 12 healthy, normocapnic male volunteers. Desflurane/nitrous oxide anesthesia decreased systemic blood pressures, cardiac index, stroke volume index, systemic vascular resistance, and left ventricular stroke work index, and increased pulmonary arterial pressures and central venous pressure in a dose-dependent fashion, while heart rate was 10%-12% and mixed venous oxygen tension was 2-4 mm Hg higher at all MAC levels than at baseline (awake). Desflurane/nitrous oxide anesthesia modestly increased left ventricular end-diastolic cross-sectional area (preload) and decreased velocity of left ventricular circumferential fiber shortening, systolic wall stress (afterload), and area ejection fraction; this combination of changes indicates myocardial depression. ⋯ After 7 h of anesthesia, regardless of the background gas, somewhat less cardiovascular depression and/or modest stimulation was apparent: cardiac index, area ejection fraction, and velocity of left ventricular circumferential fiber shortening recovered to or toward awake values, whereas heart rate was further increased. Evidence of circulatory insufficiency did not develop in any volunteers during the study. Segmental left ventricular function was normal at baseline, and no segmental wall-motion abnormalities, ST-segment change, or dysrhythmias developed.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Aug 1991
Clinical Trial Controlled Clinical TrialEffect of prior anesthetic solution on epidural morphine analgesia.
The quality and duration of analgesia and incidence of side effects following epidurally administered morphine after cesarean section are highly variable. Two suggested sources of this variability are prior use of epinephrine-containing solutions, which may enhance both analgesia and side effects of morphine, and prior use of 2-chloroprocaine, which may inhibit epidural morphine analgesia. To examine these proposed sources of this variability we performed two studies. ⋯ In the second study, designed to test the effect of 2-chloroprocaine, 30 women received 7 mL of either 2% 2-chloroprocaine or lidocaine for epidural catheter testing, followed by 0.5% bupivacaine for epidural anesthesia. Compared to lidocaine testing, 2-chloroprocaine decreased the duration of epidural morphine analgesia (median 16 h with 2-chloroprocaine vs 24 h with lidocaine; P less than 0.05) without altering the incidence of side effects. The authors conclude that addition of epinephrine to local anesthetic does not increase the incidence of side effects or the analgesic effect from epidurally administered morphine. 2-Chloroprocaine, even when administered in small doses remote to the time of morphine injection, interferes with the duration of epidural morphine analgesia.
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Anesthesia and analgesia · Aug 1991
A survey of 800 patients' knowledge, attitudes, and concerns regarding anesthesia.
The present study was undertaken to assess patients' knowledge, attitudes, and concerns regarding anesthetic management. A survey of 34 items was developed and administered preoperatively to 800 consecutive patients. Included were 303 men and 497 women with a mean age 52 yr and a mean educational level of 12 yr. ⋯ Issues of least concern included disclosure of personal matters during anesthesia, experiencing impaired judgment postoperatively, and being asleep or bedridden for a prolonged period of time. It is suggested that anesthesiologists address significant patient concerns during the preoperative visit to enhance their effectiveness in patient care. Efforts to educate the public on the anesthesiologist's role in perioperative care should improve patient confidence.