Anesthesia and analgesia
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Comparative Study Clinical TrialA double-blinded, randomized comparison of either 0.5% levobupivacaine or 0.5% ropivacaine for sciatic nerve block.
To compare intraoperative and postoperative clinical properties of levobupivacaine and ropivacaine for sciatic nerve block, 50 ASA physical status I and II patients undergoing hallux valgus repair received a femoral nerve block with 15 mL of 2% mepivacaine. They were then randomly allocated in a double-blinded fashion to receive a sciatic nerve block with either 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25). An independent blinded observer evaluated the onset time of surgical anesthesia as well as the quality of the surgical block and postoperative analgesia. The median (range) onset time of surgical block at the sciatic nerve distribution was 30 min (5-60 min) with levobupivacaine and 15 min (5-60 min) with ropivacaine (P = 0.63). Four patients (two patients in each group) received a supplementary ankle block by the surgeon just before the beginning of surgery. All four patients also received IV fentanyl supplementation, but in three of them, propofol infusion was required to complete surgery (two in the Levobupivacaine group [8%] and one in the Ropivacaine group [4%]; P = 0.99). In six patients of the Levobupivacaine group (24%) and five patients of the Ropivacaine group (20%), IV fentanyl supplementation was required to complete surgery (P = 0.99). No differences in the time to recovery of sensory and motor function were observed between the two groups, whereas median (range) duration of postoperative analgesia was 16 h (8-24 h) with levobupivacaine and 16 h (8-24 h) with ropivacaine (P = 0.83). We conclude that 0.5% levobupivacaine and 0.5% ropivacaine provide comparable surgical anesthesia and postoperative analgesia. ⋯ No studies have compared the clinical properties of levobupivacaine with those of ropivacaine when providing sciatic nerve block for hallux valgus repair. Results from this prospective, randomized, double-blinded study demonstrate that 20 mL of either 0.5% levobupivacaine or 0.5% ropivacaine provide comparable surgical block with prolonged postoperative analgesia.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialPerioperative small-dose S(+)-ketamine has no incremental beneficial effects on postoperative pain when standard-practice opioid infusions are used.
Several studies report that when small-dose racemic ketamine, an N-methyl-D-aspartate receptor antagonist, is administered perioperatively, opioid consumption is reduced postoperatively. S(+)-ketamine has a higher affinity for the N-methyl-D-aspartate receptor and less-serious side effects than racemic ketamine. Thirty patients scheduled for elective arthroscopic anterior cruciate ligament repair were enrolled in this randomized, double-blinded clinical trial designed to determine the preemptive effect of S(+)-ketamine on postoperative analgesia requirements in a setting of clinically relevant perioperative analgesia. Total IV anesthesia was induced and maintained with remifentanil (0.125-1.0 microg x kg(-1) x min(-1)) and a propofol target-controlled infusion (target 2-4 microg/mL). The Ketamine group received a bolus of 0.5 mg/kg S(+)-ketamine before incision, followed by a continuing infusion of 2 microg x kg(-1) x min(-1) until 2 h after emergence from anesthesia. The Control group received NaCl in the same sequence. After IV morphine provided pain relief down to < or =3 on a visual analog scale scored from 0 to 10, patients were connected to a patient-controlled analgesia device. There were no significant differences between the two groups in terms of total morphine consumption or VAS scores, either at rest or with movement. In our study, S(+)-ketamine did not contribute to postoperative pain reduction, possibly because of the clinically routine perioperative opioid analgesia. ⋯ Small-dose S(+)-ketamine had no positive effect on postoperative analgesia when administered perioperatively for elective arthroscopic anterior cruciate ligament repair. Unlike investigations of the racemic mixture of ketamine, our study methods included timely standard-practice perioperative opioid analgesia, which seems to make supplemental analgesia unnecessary.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialA study of lidocaine iontophoresis for pediatric venipuncture.
In this randomized, double-blinded, placebo-controlled study, we evaluated the safety and efficacy of lidocaine iontophoresis for the prevention of pain associated with venipuncture in 59 children aged 6-17 yr. Children received either lidocaine HCl 2% with epinephrine 1:100,000 (Active) or the same formulation without lidocaine (Placebo) via a 20 mA/min iontophoretic treatment. Pain during venipuncture was assessed by the subject, parent, and nurse using a 100-mm visual analog scale. Median (interquartile range) visual analog scale scores were significantly lower in the Active versus Placebo groups: subject, 7.0 (2.0-20.8) versus 31.0 (12.0-48.0), P < 0.001; nurse, 5.0 (2.2-10.8) versus 24.0 (9.0-47.0), P < 0.001; and parent, 3.0 (0.8-7.2) versus 20.0 (4.5-43.0), P < 0.002, respectively. Similarly, higher median satisfaction scores were given to the Active versus Placebo group by the three evaluators. Of the 59 subjects completing the study, 10 subjects experienced a total of 12 adverse events that were all graded as mild. In conclusion, lidocaine iontophoresis is safe in children, reduces discomfort associated with venipuncture, and increases satisfaction when compared with the placebo. ⋯ In this randomized, double-blinded, placebo-controlled study, we found that dermal anesthesia with lidocaine HCl 2% combined with epinephrine 1:100,000 administered via iontophoresis in children is achieved in 8.8 +/- 2.1 min, reduces discomfort associated with venipuncture, is safe, and increases satisfaction when compared with the placebo.
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Anesthesia and analgesia · Apr 2002
Randomized Controlled Trial Clinical TrialIntubating laryngeal mask airway size selection: a randomized triple crossover study in paralyzed, anesthetized male and female adult patients.
We determined the optimal size of intubating laryngeal mask airway (ILM) for ventilation and blind tracheal intubation in men and women. We also determined the distance the tracheal tube needs to protrude beyond the distal aperture to ensure that the cuff is through the vocal cords. Fifty male and 50 female anesthetized, paralyzed patients (ASA physical status I or II, aged 18-80 yr) were studied. Three operators (A, B, and C) were involved for the purposes of blinding. The size 3, 4, or 5 ILM was inserted into each patient in random order by Operator A, and the quality of ventilation was scored (adequate, suboptimal, or failed) by Operator B. The fiberoptic position (correct, too shallow, or too deep) and the distance between the distal aperture and the vocal cords was determined by Operator B. A single attempt at blind intubation was made by Operator C. Operators B and C were blinded to the size of the ILM. Operator C was also blinded to the information recorded by Operator B. All ILMs were inserted into the laryngopharynx at the first attempt. For men and women, the ventilation score was smaller for the Size 3 than the Size 4 or 5 (all: P < 0.002). For men, correct positioning was less common with the Size 3 than the Size 4 or 5 (both: P < 0.02). For women, correct positioning was similar among sizes. For men, tracheal intubation was successful less frequently with the Size 3 (84%) than the Size 4 (100%) or 5 (98%) (both: P < or = 0.01). For women, tracheal intubation success was similar among sizes (Size 3, 4, and 5: 86%, 96%, and 92%, respectively). Intubation was always successful if the ILM was correctly positioned and always failed if it was too shallow or deep. In both male and female patients, the distance between the distal aperture and the vocal cords increased with increasing ILM size (all: P < 0.04) and patient height (P < 0.0001) and was always longer for men (all: P < 0.0001). The overall mean distance (95% confidence interval) that the tracheal tube needed to protrude was 10-12 cm (8-13 cm) in men and 8-11 cm (8-12 cm) in women. We conclude that for men, the Size 4 and 5 ILMs are better than the Size 3 for ventilation and blind intubation. For women, the Size 4 and 5 ILMs are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on ILM size, the tracheal tube size, and the sex and height of the patient. ⋯ For men, the Size 4 and 5 intubating laryngeal mask airways are better than the Size 3 for ventilation and blind tracheal intubation. For women, the Size 4 and 5 are better than the Size 3 for ventilation, but there is no difference among sizes for blind intubation. The length the tracheal tube must protrude from the distal aperture of the intubating laryngeal mask airway to ensure that the cuff is completely through the vocal cords is 8-13 cm, depending on the size of the mask and tracheal tube and on the sex and height of the patient.