Anesthesia and analgesia
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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 =3 could be achieved with either group. Total tramadol consumption was significantly less in Group 2 than in Group 1 (614 +/- 259 mg vs 923 +/- 354 mg) (P: < 0.05). Patients in Group 2 were more alert (P: < 0.05). Blood loss from the surgical drain was similar, 865 +/- 275 mL (Group 1) vs 702 +/- 345 mL (Group 2). We conclude that aspirin can be used as an effective and safe adjuvant to tramadol for PCA after orthopedic surgery. ⋯ Injectable aspirin can be used as an effective and safe adjuvant to tramadol for patient-controlled analgesia (PCA) in orthopedic patients. The tramadol requirement is therefore reduced. This combination supports the concept that drugs other than opioids can be used for PCA.
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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.