Anesthesia and analgesia
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyStimulating popliteal catheters for postoperative analgesia after hallux valgus repair.
Stimulating catheters have been recently introduced in clinical practice. We assessed the efficacy of stimulating and nonstimulating catheter placement for pain control and local anesthetic requirements after hallux valgus repair with continuous sciatic popliteal nerve block in this comparative, randomized, blinded-to-observer study of 48 patients. A stimulating catheter was placed in groups S-125 and S-0625. ⋯ Lower median (range) VAS scores for pain (0-100 points) were found in group S-125 at 6-8 h postoperatively when compared with groups S-0625 and NS-125: 5 (0-17.5) versus 60 (15-80) and 70 (25-80), respectively (P < 0.05); and lower VAS scores for pain were also found in group S-125 at 19-23 h when compared with group NS-125: 0 (0-0) and 7.5 (0-10), respectively (P < 0.05). Fewer patients required IV opioid analgesia in group S-125 than in groups S-0625 and NS-125: 0, 5, and 7 patients, respectively (P < 0.05). We conclude that efficacy in pain control was increased with stimulating catheter placement.
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Anesthesia and analgesia · Jan 2006
Comparative StudyTotal knee arthroplasty as an overnight-stay procedure using continuous femoral nerve blocks at home: a prospective feasibility study.
The average duration of hospitalization after total knee arthroplasty (TKA) in the United States is 4-5 days. In this two-phase study we investigated the feasibility of converting TKA into an overnight-stay procedure using a continuous femoral nerve block provided at home through postoperative day 4. ⋯ Pain was well controlled, opioid requirements and sleep disturbances were minimal, and patient satisfaction was high. Additional research is required to replicate these results in a controlled trial, define the appropriate subset of patients, and assess the incidence of complications associated with this practice before its mainstream use.
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Anesthesia and analgesia · Jan 2006
Comparative StudyThe effects of sevoflurane and propofol on QT interval and heterologously expressed human ether-a-go-go related gene currents in Xenopus oocytes.
Sevoflurane can induce prolongation of the cardiac QT interval by inhibiting the repolarization phase of the action potential. This may occur as a result of inhibition of the human ether-a-go-go related gene (HERG) channel. To clarify the mechanisms of anesthetics on HERG channels, we monitored the electrocardiogram and measured QT intervals in the guinea pig in the presence of sevoflurane and propofol. ⋯ The time constant of the converging current was decreased in the presence of sevoflurane, but the inactivation and activation curves were not shifted. Propofol did not affect these currents within the clinically relevant concentration. In conclusion, compared with steady-state currents, sevoflurane was more potent in inhibiting the outward tail currents, suggesting that sevoflurane may modulate the HERG channel kinetics in its inactivated state.
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Anesthesia and analgesia · Jan 2006
Case ReportsPartial sensory and motor deficit of ipsilateral lower limb after continuous interscalene brachial plexus block.
We describe a partial sensory and motor block of the ipsilateral lower limb after interscalene infusion. After and injection of 20 mL of ropivacaine through the needle, the catheter was advanced 5 cm, and an infusion of ropivacaine 0.2% 5 mL/h commenced. ⋯ We conclude that the neurological symptoms were caused by an injection of local anesthetic via an interscalene catheter placed in proximity to the epidural space. To avoid this complication, we recommend advancing the catheter no more than 2-3 cm and performing frequent neurological evaluation of patients.
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Anesthesia and analgesia · Jan 2006
Randomized Controlled Trial Comparative StudyThe analgesic effect of tramadol after intravenous injection in healthy volunteers in relation to CYP2D6.
Tramadol analgesia results from a monoaminergic effect by tramadol itself and an opioid effect of its metabolite (+)-M1 formed by O-demethylation of tramadol by CYP2D6. In this study we sought to determine the impact of (+)-M1 on the analgesic effect of tramadol evaluated by experimental pain models. The effect of an IV injection of 100 mg tramadol on experimental pain was studied 15-90 min after dosing in volunteers, 10 extensive metabolizers with CYP2D6 and 10 poor metabolizers without CYP2D6 in 2 placebo-controlled trials. ⋯ In extensive metabolizers, tramadol reduced discomfort experienced during the cold pressor test (P = 0.002). In poor metabolizers, the pain tolerance thresholds to sural nerve stimulation were increased (P = 0.04). (+)-M1 could be detected in the serum samples from all extensive metabolizers except one, but (+)-M1 was below the limit of determination in all poor metabolizers. The opioid effect of (+)-M1 appears to contribute to the analgesic effect of tramadol, but the monoaminergic effect of tramadol itself seems to create an analgesic effect.