Anesthesia and analgesia
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Anesthesia and analgesia · Oct 1994
Randomized Controlled Trial Comparative Study Clinical TrialComparative vascular effects of midazolam and lorazepam administered during cardiopulmonary bypass.
We studied the comparative vascular effects of midazolam and lorazepam in 52 patients undergoing elective cardiac surgery procedures. After administration of fentanyl, 100 micrograms/kg intravenously, the patients were randomized to receive either midazolam 0.1 mg/kg (M high), midazolam 0.05 mg/kg (M low), lorazepam 0.1 mg/kg (L high), lorazepam 0.05 mg/kg (L low), or placebo during cardiopulmonary bypass (CPB). Compared to the placebo and L-low groups, the high-dose midazolam group had more effect on systemic vascular resistance (SVR) starting at 5 min after study drug administration (P < 0.02). ⋯ In the first 12 h of the postoperative period, the M-high group required phenylephrine (PHE) infusion for hypotension associated with decreased SVR more often than placebo (8/10 vs 1/11 patients, P < 0.008, chi 2). In conclusion, midazolam more effectively attenuated the increase in SVR that occurred during CPB than patients receiving either placebo or lorazepam. The hemodynamic effects from a single dose of 0.1 mg/kg midazolam administered at the start of CPB may persist into the postoperative period.
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Anesthesia and analgesia · Oct 1994
Body position does not affect the hemodynamic response to venous air embolism in dogs.
Current therapy for massive venous air embolism (VAE) includes the use of the left lateral recumbent (LLR) position. This recommendation is based on animal studies, conducted 50 yr ago, which looked primarily at survival. Little is known, however, about the concomitant hemodynamic response after VAE in various body positions. ⋯ The acute hemodynamic changes occurring during the first 5-15 min after VAE recovered to 80% of control within 60 min. Our data suggest that body repositioning does not influence the cardiovascular response to VAE. Specifically, our data do not support the recommendation of repositioning into the LLR position for the treatment of VAE.
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Anesthesia and analgesia · Oct 1994
Prevention of occupational transmission of human immunodeficiency virus and hepatitis B virus among anesthesiologists: a survey of anesthesiology practice.
In light of the increasing prevalence of the human immunodeficiency virus (HIV) and hepatitis B virus (HBV), anesthesiologists are now likely to see more patients who are at high risk for these viruses. Therefore, it is important that they adopt infection control policies aimed at preventing occupational transmission of these and other pathogens during their clinical practice. This study was designed, using a questionnaire format, to evaluate anesthesiologist compliance with Centers for Disease Control (CDC) guidelines for the prevention of occupational transmission of HIV and HBV. ⋯ However, anesthesiologists who reported recapping needles using the one-handed technique were less likely to sustain a needlestick injury than those who recapped using the two-handed technique. Thirty-one percent and 72% of respondents respectively reported a clean or contaminated needlestick within the preceeding 12 mo. Only 45.4% of those receiving a contaminated needlestick sought treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
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Anesthesia and analgesia · Oct 1994
Comparative StudyComparison of the force required for dural puncture with different spinal needles and subsequent leakage of cerebrospinal fluid.
An in vitro model was used to determine the force required to pierce bovine dura with a range of new spinal needles and to measure the subsequent leakage rate of cerebrospinal fluid (CSF). A significantly greater force was required to pierce the dura with pencil-point style needles compared to Quincke needles of the same size. ⋯ The results suggest that there is not likely to be a significant reduction in postdural puncture headache (PDPH) using a 27-gauge pencil-point needle compared to a 25-gauge needle that may be easier to use. Different makes of the same design and gauge of needle showed significant differences in the amount of CSF leakage, which may influence the clinician's choice of needle.
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Anesthesia and analgesia · Oct 1994
The difference of isoflurane and halothane in ventriculoarterial coupling in dogs.
Effective arterial elastance (Ea) and left ventricular end-systolic elastance (Ees) are used as indices of cardiac afterload and cardiac contractility, respectively. We compared the effects of two volatile anesthetics, halothane and isoflurane, on ventriculoarterial coupling using an index of Ea/Ees in 20 mongrel dogs. Ees was obtained using a single-beat estimation technique. ⋯ The decreases in cardiac output and Ees were not significantly different between halothane and isoflurane. Halothane increased Ea/Ees from 0.83 +/- 0.05 to 1.22 +/- 0.13, whereas isoflurane maintained the Ees/Es at a constant level. Our results suggest that mechanical efficiency is well maintained during isoflurane anesthesia because it has an equivalent effect on left ventricular contractility and arterial properties, whereas halothane can impair mechanical efficiency by depressing left ventricular contractility more than the arterial system.