Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1998
Randomized Controlled Trial Comparative Study Clinical TrialPreemptive caudal bupivacaine and morphine for postoperative analgesia in children.
We designed this double-blind study to evaluate the efficacy of preemptive epidural bupivacaine and small-dose morphine for postoperative analgesia in children after herniorraphy. Sixty children, ASA physical status I or II, who were undergoing elective hernia repair under general anesthesia were randomly allocated into two groups. Group I (preemptive group) received 0.66 mL/kg 0.25% bupivacaine with morphine 0.02 mg/kg caudally after the induction of anesthesia but 15 min before surgery. Group II (postincisional group) received the same drug mixture after surgery. Pain was assessed using an objective pain scale (OPS). Time to first postoperative analgesics (TFA), the number of supplementary analgesic used, and the amount of morphine consumed over the ensuing 24-h period were noted. The OPS score was significantly less in Group I at 0.5, 4, and 8 h (P < 0.05) than in Group II after surgery. The median OPS score recorded over 24 h was 0 for Group I and 2 for Group II, which was significantly different (P < 0.05). The TFA in Group I (12.55 +/- 3.06 h) was significantly (P < 0.05) prolonged compared with Group II (10.62 +/- 3.18 h). The total postoperative morphine consumption in Group I (2.24 +/- 1.4 mg) was significantly (P < 0.05) less than that in Group II (3.34 +/- 2.29 mg). Nevertheless, the incidence of nausea and vomiting was not significantly different between the groups. In this study, we demonstrated that preemptive epidural bupivacaine and small-dose morphine administration is superior to the same mixture given at the conclusion of surgery for pain relief. ⋯ This study was performed on two groups of 30 children undergoing hernia repair. Group I received a bupivacaine-morphine mixture caudally before surgery, and Group II received the same drugs caudally at the completion of surgery. Postoperative assessment demonstrated longer and better pain relief in Group I.
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Anesthesia and analgesia · Jul 1998
Randomized Controlled Trial Comparative Study Clinical TrialThe placement of the cuffed oropharyngeal airway with sevoflurane in adults: a comparison with the laryngeal mask airway.
We sought to determine the anesthetic duration of sevoflurane required to achieve good conditions for placement of a cuffed oropharyngeal airway (COPA) or a laryngeal mask airway (LMA). Forty adult ASA physical status I or II patients presenting for elective surgery received single-breath vital capacity inhaled induction with 5% sevoflurane via face mask; thereafter, ventilation was manually assisted. The patients were randomized to receive either a COPA or LMA placement. The time of anesthetic exposure was varied for consecutive patients using the staircase method. The mean (95% confidence interval) anesthetic time required for acceptable COPA placement (100 [55-145] s) was significantly shorter than that for LMA (160 [101-219] s). The 50% and 95% effective doses (from logistic analyses) for acceptable conditions associated with COPA or LMA placement were 90 s and 145 s or 164 s and 261 s, respectively. These findings suggest that COPA insertion is less stimulating than the LMA. ⋯ The cuffed oropharyngeal airway is a new airway device that is similar to a laryngeal mask airway in many ways. However, it requires shorter anesthetic duration for successful placement, which suggests that it can be placed with less stimulation. It may be an alternative to a laryngeal mask airway.
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Anesthesia and analgesia · Jul 1998
Randomized Controlled Trial Clinical TrialVisual evaluation of residual curarization in anesthetized patients using one hundred-hertz, five-second tetanic stimulation at the adductor pollicis muscle.
We were looking for a clinical test to indicate a train-of-four (TOF) ratio of approximately 0.9. We compared the adductor pollicis muscle (AP) visually evaluated response to ulnar nerve 100-Hz, 5-s tetanus (RF100 Hz) with the measured AP TOF ratio in 30 ASA physical status I or II adult anesthetized (propofol, sufentanil, N2O/O2) patients. After the induction of anesthesia, the left ulnar nerve was stimulated at the wrist (single twitch and TOF) and the resultant isometric force was measured. When TOF was assessed, the independent investigators, unaware of the left AP-measured TOF ratios, visually evaluated the presence or absence of AP fading elicited by right ulnar nerve 100-Hz, 5-s tetanus. The 30 patients were randomly allocated to receive either 0.5 mg/kg atracurium (n = 15) or 0.1 mg/kg vecuronium (n = 15). The neuromuscular blockade was allowed to resolve spontaneously. A multiple logistic regression analysis was performed by computing the 771 visual observations. The probabilities of success of 100-Hz, 5-s tetanus to detect TOF ratios of 0.8, 0.85, and 0.9 were 99%, 96%, and 67%, respectively. The sensitivity and specificity of 100-Hz, 5-s tetanus as an indicator of TOF ratios of 0.85 and 0.9 are 100% and 75%, 54% and 67%, respectively. We conclude that RF100 Hz visual assessment seems to be highly sensitive in evaluating residual paralysis, as the absence of RF100 Hz visual fading at the AP is compatible with a TOF ratio > 0.85. ⋯ After the administration of muscle relaxants, the absence of visual fading at the adductor pollicis, elicited in anesthetized patients by 100-Hz, 5-s tetanus, is compatible with a train-of four ratio > 0.85. Therefore, clinical observation of fading after 100-Hz, 5-s tetanus seems to be a highly sensitive test in evaluating residual paralysis.
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Anesthesia and analgesia · Jul 1998
Randomized Controlled Trial Clinical TrialMagnesium sulfate reduces intra- and postoperative analgesic requirements.
In a randomized, double-blind study with two parallel groups, we assessed the analgesic effect of perioperative magnesium sulfate administration in 46 ASA physical status I or II patients undergoing arthroscopic knee surgery with total i.v. anesthesia. The patients received either magnesium sulfate 50 mg/kg preoperatively and 8 mg.kg-1.h-1 intraoperatively or the same volume of isotonic sodium chloride solution i.v. Anesthesia was performed with propofol (2 mg/kg for induction, 6-8 mg.kg-1.h-1 for maintenance), fentanyl (3 micrograms/kg for induction), and vecuronium (0.1 mg/kg for intubation). Intraoperative pain was defined as an increase of mean arterial blood pressure and heart rate of more than 20% from baseline values after the induction of anesthesia and was treated with bolus fentanyl (1-2 micrograms/kg). Postoperative analgesia was achieved with fentanyl (0.5 microgram/kg) and evaluated using the pain visual analog scale for 4 h. During the intraoperative and postoperative periods, patients in the magnesium group required significantly less fentanyl than those in the control group (control group 0.089 +/- 0.02 microgram.kg-1.min-1 versus magnesium group 0.058 +/- 0.01 microgram.kg-1.min-1; P < 0.05 and control group 0.021 +/- 0.013 microgram.kg-1.min-1 and magnesium group 0.0031 +/- 0.0018 microgram.kg-1.min-1; P < 0.01 for intraoperative and postoperative periods, respectively). We conclude that, in a clinical setting with almost identical levels of surgical stimulation, i.v. magnesium sulfate administration reduces intraoperative and postoperative analgesic requirements compared with isotonic sodium chloride solution administration. ⋯ The perioperative administration of i.v. magnesium sulfate reduces intra- and postoperative analgesic requirements in patients with almost identical levels of surgical stimulus. Our results demonstrate that magnesium can be an adjuvant to perioperative analgesic management.