Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Multicenter Study Clinical TrialInterscalene brachial plexus anesthesia and analgesia for open shoulder surgery: a randomized, double-blinded comparison between levobupivacaine and ropivacaine.
We compared the onset time and quality of interscalene brachial plexus block produced with levobupivacaine and ropivacaine in 50 patients undergoing open shoulder surgery randomly allocated to receive 30 mL of 0.5% levobupivacaine (n = 25) or 0.5% ropivacaine (n = 25) injected through a 20-gauge catheter placed into the interscalene sheath using a 18-gauge insulated and stimulating Tuohy introducer. The block was also prolonged after surgery using a patient-controlled interscalene analgesia with 0.125% levobupivacaine or 0.2% ropivacaine, respectively (basal infusion rate, 6 mL/h; bolus, 2 mL; lockout period, 15 min; maximum boluses per hour, three). Three patients (two with levobupivacaine [8%] and one with ropivacaine [4%]) failed to achieve surgical block within 45 min after the injection and were excluded. The onset time of surgical block was 20 min (10-40 min) with levobupivacaine and 20 min (5-45 min) with ropivacaine (P = 0.53). Rescue intraoperative analgesia (0.1 mg of fentanyl IV) was required in eight patients in each group (34%) (P = 0.99). Forty-two patients completed the 24-h postoperative infusion (22 with levobupivacaine and 20 with ropivacaine). Postoperative analgesia was similarly effective in both groups. Total consumption of local anesthetic infused during the first 24 h was 147 mL (144-196 mL) with levobupivacaine and 162 mL (144-248 mL) with ropivacaine (P = 0.019), with a ratio between boluses received and requested of 0.8 (0.4-1.0) and 0.7 (0.4-1.0), respectively (P = 0.004). The degree of motor block of the operated limb was deeper with levobupivacaine than ropivacaine when starting postoperative analgesia; however, no further differences in degree of motor function were observed between the two groups. We conclude that 30 mL of levobupivacaine 0.5% induces an interscalene brachial plexus anesthesia of similar onset and intensity as the one produced by the same volume and concentration of ropivacaine. Postoperative interscalene analgesia with 0.125% levobupivacaine results in similar pain relief and recovery of motor function with less volume of local anesthetic than with 0.2% ropivacaine. ⋯ This prospective, randomized, double-blinded study demonstrates that 30 mL of 0.5% levobupivacaine produces an interscalene brachial plexus block of similar onset and quality as the one produced by the same volume of 0.5% ropivacaine. When prolonging the block after surgery, 0.125% levobupivacaine provides adequate pain relief and recovery of motor function after open shoulder surgery, with less volume infused during the first 24 h after surgery than 0.2% ropivacaine.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialTarget-controlled infusion for remifentanil in vascular patients improves hemodynamics and decreases remifentanil requirement.
Remifentanil is a potent ultra-short-acting opioid, which permits rapid emergence. However, remifentanil is expensive and may have detrimental effects on hemodynamics in case of overdose. Target-controlled infusion (TCI) permits adapting infusion to pharmacokinetic models. In this prospective randomized study, we compared intra- and postoperative hemodynamics, remifentanil requirement during anesthesia, and postoperative morphine requirement in patients scheduled for carotid surgery, and receiving either continuous IV weight-adjusted infusion of remifentanil (RIVA) or TCI for remifentanil (TCIR). Forty-six patients were enrolled in this study: all were anesthetized by using TCI for propofol. Twenty-three received RIVA (0.5 micro g. kg(-1) x min(-1)) for the induction of anesthesia and endotracheal intubation, with the infusion rate decreased to 0.25 micro g x kg(-1) x min(-1) after intubation, then adapted by step of 0.05 micro g x kg(-1) x min(-1) according to hemodynamics. Twenty-three patients received TCIR (Minto model, Rugloop), with an effect-site concentration at 4 ng/mL during induction, then adapted by step of 1 ng/mL according to hemodynamics. All patients received atracurium and a 50% mixture of N(2)O/O(2). Hemodynamic variables were recorded each minute. The number and duration of hemodynamic events were collected, and total doses of anesthetics (remifentanil and propofol) and vasoactive drugs were noted in both groups of patients. Data were analyzed by using unpaired t-tests. RIVA was significantly associated with more frequent episodes of intraoperative hypotension (16 versus 6, P < 0.001) and more frequent episodes of postoperative hypertension and/or tachycardia requiring more frequent administration of beta-adrenergic blockers (16 vs 10, P < 0.04) in comparison with TCIR. The need for morphine titration was not significantly different between groups. TCIR led to a significantly smaller requirement of remifentanil (700 +/- 290 versus 1390 +/- 555 micro g, P < 0.001) without difference in propofol requirement. This prospective randomized study demonstrated that, during carotid endarterectomy, in comparison with patients receiving remifentanil using continuous RIVA, TCI results in less hypotensive episodes during the induction of anesthesia, in fewer episodes of tachycardia and/or hypertension and a smaller beta-adrenergic blocker requirement during recovery, and a decrease in remifentanil requirement. Recommendations to prefer TCI for remifentanil administration during carotid endarterectomy may be justified. ⋯ Remifentanil for intraoperative analgesia in carotid artery surgery is associated with a better stability in perioperative hemodynamics when administered in target-controlled infusion compared with continuous weight-adjusted infusion. This may be related to a smaller requirement of this drug when using target-controlled infusion, as well as a smooth mode of administration.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialThe effects of clonidine premedication on the blood pressure and tachycardiac responses to ephedrine in elderly and young patients during propofol anesthesia.
We studied the pressor and tachycardiac responses to ephedrine in elderly and young patients given either clonidine or midazolam during propofol anesthesia. In the first experiment, elderly (>60 yr) and young (20-45 yr) patients were randomly allocated to one of four groups according to age and premedicated regimens (n = 16 each; elderly-clonidine [EC], elderly-midazolam [EM], young-clonidine [YC], and young-midazolam [YM]). Under propofol anesthesia, ephedrine was injected, and hemodynamic measurements were made. In the second experiment, with clonidine premedication, elderly patients (n = 16) were given a reduced dose of propofol (EC-LP) and young patients (n = 16) were given an increased dose of propofol (YC-HP). Ephedrine was injected, and he- modynamic measurements were performed. The in-creases in mean blood pressure and heart rate were larger in the EC group than in the EM, YM, and EC-LP groups (P < 0.05). In the YC-HP group, the pressor response to ephedrine tended to be augmented as compared with the YC group but was not statistically significant. These results suggest that clonidine premedication augmented the pressor and tachycardiac responses to ephedrine, especially in elderly patients during a standard dose of propofol anesthesia, and that clonidine, age, and propofol could be involved in the augmentation of the blood pressure and tachycardiac responses to ephedrine. ⋯ Clonidine premedication augments the pressor and tachycardiac responses to ephedrine in elderly patients during standard or large doses of propofol anesthesia but does not augment during small doses of propofol anesthesia. Clonidine, age, and propofol could be involved in the augmentation of the pressor and tachycardiac responses to ephedrine.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Comparative Study Clinical TrialAdvancing the tracheal tube over a flexible fiberoptic bronchoscope by a sleeve mounted on the insertion cord.
The advancement of an endotracheal tube (ETT) over a flexible fiberoptic bronchoscope (FOB) is often impeded at the glottis. This is attributed to the creation of a cleft by the difference in the outer diameter of the fiberscope and the internal diameter of the tube. We designed a conical-shaped polyvinyl chloride sleeve to fit the insertion cord. This report compares the ease of advancement of the tube over a sleeved versus a nonsleeved bronchoscope. General anesthesia was induced, and one anesthesiologist introduced the FOB (a 3.8-mm Olympus LF2). Patients were randomly assigned to undergo tracheal intubation with the regular bronchoscope (25 patients) or the sleeved bronchoscope (25 patients). The FOB was advanced to approximately 1 cm above the carina. A blinded operator advanced the tube over the bronchoscope. The ETT was successfully advanced over the nonsleeved bronchoscope into the trachea on the first attempt in 64% of the patients, whereas tracheal intubation succeeded from the first attempt in 96% of patients when the sleeved FOB was used (P < 0.05). Advancement of the ETT over the fiberscope can be facilitated by using a conically shaped sleeve mounted on the insertion cord. ⋯ This report shows that a conical sleeve mounted on the insertion cord of a fiberoptic bronchoscope will facilitate advancing the endotracheal tube into the trachea.
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Anesthesia and analgesia · Jan 2003
Randomized Controlled Trial Clinical TrialA needle-free jet-injection system with lidocaine for peripheral intravenous cannula insertion: a randomized controlled trial with cost-effectiveness analysis.
Insertion of a peripheral IV cannula is a common, although painful, procedure. We tested the analgesic efficacy, adverse effects, and cost-effectiveness of a needle-free intradermal drug delivery system (Jet) with lidocaine for the insertion of an IV cannula (18-gauge; dorsum of hand). Four-hundred patients were randomly allocated to one of four groups: (a) no treatment, (b) Jet (J-Tip), National Medical Products Inc, CA; $3.0 per device) with 0.5 mL of saline, (3) Jet with 0.5 mL of lidocaine 1%, and (4) Jet with 0.5 mL of lidocaine 2%. Pain was evaluated using a numerical verbal scale (NVS 0-10). A NVS < or =3 was considered as acceptable in this context. Incremental cost-effectiveness ratios were calculated. Without treatment, 42.4% of patients had a NVS < or = 3, 39.3% with saline, 60.7% with 1% lidocaine (relative risk [RR] compared with no treatment, 0.70; 95% confidence interval [CI], 0.53-0.93), and 86.7% with 2% lidocaine (RR, 0.49; 95% CI, 0.38-0.62). Nineteen and one-half percent of patients had a NVS >3 because of Jet treatment, 13.5% had local hyperemia, and 16.9% had minor local bleeding. Of all Jet treatments, 10.5% were technical failures, and there were 17.6% cannula insertion failures (10.1% without treatment [RR, 1.74; 95% CI, 0.92-3.32]). Compared with no treatment, costs to generate one additional patient with a NVS < or =3 were $23 with lidocaine 1% and $10 with lidocaine 2%. On insertion of an IV cannula on the back of the hand, 58% of patients report at least moderate pain. Lidocaine-Jet is analgesic; there is dose-responsiveness. However, Jet treatment is not painless, and costs incurred to achieve one success compared with doing nothing are not negligible. ⋯ Insertion of an IV cannula is painful. Four-hundred patients were randomly allocated to test the analgesic efficacy, adverse effects, and cost-effectiveness of the needle-free intradermal drug delivery system (J-Tip); Jet). Jet with lidocaine is effective, but its application is not painless. Costs to achieve one patient with no more than moderate pain (numerical verbal scale < or =3 of 10) on insertion of an IV cannula are $10.