Articles: general-anesthesia.
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Comparative Study
Pharmacokinetics of alfentanil in children undergoing surgery.
Alfentanil pharmacokinetics and protein binding were determined in 20 children aged 10 months-6.5 yr. The data were compared with those from 10 adult patients. ⋯ The degree of plasma protein binding was also similar in children and adults with mean free fractions of 11.5 +/- 0.9% (+/- SD) and 11.8 +/- 3.9%, respectively. There were marked differences in the elimination half-life of alfentanil (63 +/- 24 min in children; 95 +/- 20 min in adults (P less than 0.001] and plasma clearance of alfentanil (11.1 +/- 3.9 ml min-1 kg-1 in children and 5.9 +/- 1.6 ml min-1 kg-1 in adults (P less than 0.001].
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Improvement in postoperative pulmonary mechanics with epidural analgesia has been described. Data on the hemodynamic effects of this technique are absent from the surgical literature. To provide such data we have evaluated two groups of patients undergoing aortic reconstruction: group I (n = 25), general anesthesia and group II (n = 6), general anesthesia with adjunctive epidural analgesia. ⋯ Postoperatively there were no significant differences in the pressure-related parameters; however, rate-related factors including heart rate and double product were significantly decreased in group II with no reduction in cardiac index. Postoperative increases in total body oxygen consumption were also markedly attenuated by epidural analgesia. Epidural analgesia reduces the hemodynamic demands on the heart after major surgery and is a useful adjunct, especially in patients with coronary artery disease.
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Randomized Controlled Trial Comparative Study Clinical Trial
[Comparative hemodynamic study of anesthesia induction with propofol (Diprivan), thiopental, methohexital, etomidate and midazolam in patients with coronary disease].
In patients undergoing cardiac surgery, the induction of anesthesia is not without risk because of specific cardiovascular effects of the anesthetic and the preoperative state of the patient. The hemodynamic effects of etomidate, midazolam, thiopental, and methohexital are well known: etomidate is an anesthetic that induces only minor cardiovascular changes; its influence on the endocrine system, however, has reduced its clinical indication. Barbiturates such as thiopental and methohexital produce negative inotropic effects in combination with an increase in heart rate and myocardial oxygen consumption; midazolam reduces pre- and afterload in patients with poor left ventricular function. Propofol, a new short-acting induction agent with good anesthetic properties, is said to diminish arterial pressure as well as myocardial oxygen consumption. ⋯ In a randomized study we investigated the hemodynamic effects of intravenous induction with propofol (2 mg/kg body wt.), thiopental (5 mg/kg), methohexital (1 mg/kg), etomidate (0.3 mg/kg), and midazolam (0.15 mg/kg) in 50 patients undergoing coronary artery bypass grafting. All patients were premedicated with flunitrazepam (0.03 mg/kg up to 2 mg) and morphine hydrochloride (0.2 mg/kg up to 15 mg) 100 min before the investigation. After 0.003 mg/kg fentanyl the patients received the induction agent in the above-mentioned dosage within 40 s followed by 0.1 mg/kg pancuronium bromide. Hemodynamic measurements were performed 1, 3, and 5 min after the end of the injection as well as 1 and 5 min after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)
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The use of pulse oximetry as a noninvasive method to assess intravascular volume status is described. Pulse oximeters providing a continuous display of the pulse waveform offer a new method of estimating relative volume status during positive-pressure ventilation. ⋯ A significant correlation (r = 0.61) was seen between pulse waveform variation and systolic pressure variation, which has previously been shown to be a sensitive indicator of hypovolemia. When data from individual patients were analyzed separately, the correlation between pulse waveform variation and systolic pressure variation was as high as 0.88.