Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialPostoperative nausea and vomiting after sevoflurane with or without ondansetron compared with propofol in female patients undergoing breast surgery.
We studied 180 female patients undergoing breast surgery. The patients were randomly allocated to receive one of three anesthetic techniques. Compared with either propofol or sevoflurane alone, sevoflurane with ondansetron resulted in a decreased incidence of postoperative nausea and vomiting. Sevoflurane with ondansetron prophylaxis is a good alternative to propofol with respect to avoiding postoperative nausea and vomiting.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Clinical TrialThe efficacy of hemodynamic and T wave criteria for detecting intravascular injection of epinephrine test doses in anesthetized adults: a dose-response study.
Recent studies have shown that an epidural test dose containing 15 microg of epinephrine has a sensitivity and specificity of 100% for detecting intravascular injection based on the systolic blood pressure (SBP) (positive if > or =15-mm Hg increase) and the T wave criteria (positive if > or =0.1 mV and 25% decrease in amplitude), whereas the modified heart rate (HR) criterion (positive if > or =10-bpm increase) produced uncertain results in sevoflurane-anesthetized adults. Because a fractional dose of the test dose may be injected intravascularly in actual clinical situations, we designed this study to determine, in a dose-related manner, the efficacy and minimum effective dose of epinephrine based on those hemodynamic and the T wave criteria. Eighty healthy adult patients were randomly assigned to one of four groups according to a simulated IV test dose under 2% end-tidal sevoflurane and nitrous oxide anesthesia after endotracheal intubation (n = 20 each). The saline group received 3 mL of normal saline IV; the epinephrine-15 group received 3 mL of 1.5% lidocaine containing 15 microg of epinephrine (1); and the epinephrine-10 and -5 groups received 2 and 1 mL of the test dose of the identical components, respectively. HR, SBP, and lead II of the electrocardiograph were recorded continuously for 5 min after the IV injection of the study drug. Sensitivities and specificities of 100% were obtained based on the HR and the SBP criteria only if 15 microg of epinephrine was injected IV, whereas sensitivities and specificities of 100% were obtained based on both T wave criteria after 15 and 10 microg of epinephrine was injected IV. Two blinded observers were able to detect all T wave changes in patients who received 15, 10, and 5 microg of epinephrine IV, resulting in 100% efficacy (P: < 0.05 versus HR and SBP criteria). We conclude that minimum effective epinephrine doses for detecting accidental intravascular injection are 15 microg on the HR and the SBP criteria, and 10 microg on both T wave criteria, and that observing T wave changes may detect even smaller (5 microg) doses of epinephrine injected IV in adult patients anesthetized with sevoflurane and nitrous oxide. ⋯ To determine whether an epidural catheter is in a blood vessel, an epidural test dose containing 15 microg of epinephrine is used. We found that a decrease in T wave amplitude appears to be more sensitive than heart rate and systolic blood pressure change for detecting accidental intravascular injection of a small dose of epinephrine-containing test dose in sevoflurane-anesthetized patients.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialRecovery from neuromuscular blockade after either bolus and prolonged infusions of cisatracurium or rocuronium using either isoflurane or propofol-based anesthetics.
We examined the recovery characteristics of cisatracurium or rocuronium after bolus or prolonged infusion under either isoflurane or propofol anesthesia. Sixty patients undergoing neurosurgical procedures of at least 5 h were randomized to receive either isoflurane with fentanyl (Groups 1 and 2) or propofol and fentanyl (Groups 3 and 4) as their anesthetic. Groups 1 and 3 received cisatracurium 0.2 mg/kg IV bolus, spontaneously recovered, after which time an infusion was begun. Groups 2 and 4 received rocuronium 0.6 mg/kg IV, spontaneously recovered, and an infusion was begun. Before the end of surgery, the infusion was stopped and recovery of first twitch (T(1)), recovery index, clinical duration, and train-of-four (TOF) recovery was recorded and compared among groups by using appropriate statistical methods. Clinical duration was shorter for rocuronium compared with cisatracurium using either anesthetic. Cisatracurium T(1) 75% recovery after the infusion was shorter with propofol compared with isoflurane. Cisatracurium TOF 75% recovery was similar after either bolus or infusion, but rocuronium TOF 75% recovery after the infusion was delayed. Infusion rates decreased for cisatracurium but remained relatively constant for rocuronium regardless of the anesthetic used. Isoflurane enhances the effect of both muscle relaxants but prolonged cisatracurium recovery more than rocuronium. Of the two muscle relaxants studied, rocuronium's recovery was most affected by length of the infusion. Cisatracurium may be a more desired muscle relaxant for prolonged procedures because recovery was least affected by prolonged infusion. ⋯ This study describes the effect of different anesthetic techniques on the recovery of two different muscle relaxants, cisatracurium and rocuronium, when administered as either a single bolus or prolonged infusion during neurosurgery. This study demonstrates the feasibility of using these relaxants for these prolonged procedures.
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialPatient-controlled analgesia with tramadol versus tramadol plus lysine acetyl salicylate.
By using a patient-controlled analgesia (PCA) delivery system, we compared the clinical advantages and disadvantages of PCA with tramadol and PCA with a mixture of tramadol plus lysine acetyl salicylate (a soluble aspirin). Fifty adult patients who had undergone major orthopedic surgeries were enrolled into a prospective, randomized, and double-blinded study. The general anesthesia was performed in a standard manner. At the beginning of wound closure, an equal volume dose of either tramadol 2.5 mg/kg (Group 1) or tramadol 1.25 mg/kg + lysine acetyl salicylate 12.5 mg/kg mixture (Group 2) was administered slowly IV. These solutions were continued postoperatively for IV PCA. Pain control, patient satisfaction, vital signs, and adverse effects were assessed for 48 h. Visual Analog Scale
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Anesthesia and analgesia · Nov 2000
Randomized Controlled Trial Comparative Study Clinical TrialA comparison of the effects of propofol and midazolam on memory during two levels of sedation by using target-controlled infusion.
We examined memory during sedation with target-controlled infusions of propofol and midazolam in a double-blinded five-way, cross-over study in 10 volunteers. Each active drug infusion was targeted to sedation level 1 (asleep) and level 4 (lethargic) as determined with the Observer Assessment of Alertness/Sedation scale. At the target level of sedation, drug concentration was clamped for 30 min, during which time neutral words were presented. After 2 h, explicit memory was assessed by recall, and implicit memory by using a wordstem completion test. Venous drug concentrations (mean +/- SD) were 1350 ng/mL (+/-332 ng/mL) for propofol and 208 ng/mL (+/-112 ng/mL) for midazolam during Observer Assessment of Alertness/Sedation scale level 4; and 1620 ng/mL (+/-357 ng/mL) and 249 ng/mL (+/-82 ng/mL) respectively during level 1. The wordstem completion test frequencies at low level sedation were significantly higher than spontaneous frequencies (8.7% + 2.4%; P: < 0.05 in all cases), and lower than during placebo (33.6% + 23%) (P: < 0.05 in all cases, except P: = 0.076 for propofol at level 4). Clinically distinct levels of sedation were accompanied by small differences in venous propofol or midazolam concentrations. This indicates steep concentration-effect relationships. Neutral information is still memorized during low-level sedation with both drugs. The memory effect of propofol and midazolam did not differ significantly. ⋯ Implicit memory can occur during different states of consciousness and might lead to psychological damage. In 10 volunteers, implicit memory was investigated during sedation with propofol and midazolam in a double-blinded, placebo-controlled study. To compare the effects of both drugs, they were titrated using a computer-controlled infusion system to produce similar high and low levels of sedation.