Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2011
Randomized Controlled Trial Comparative StudyValue of single-injection or continuous sciatic nerve block in addition to a continuous femoral nerve block in patients undergoing total knee arthroplasty: a prospective, randomized, controlled trial.
Continuous femoral nerve block in patients undergoing total knee arthroplasty (TKA) improves and shortens postoperative rehabilitation. The primary aim of this study was to investigate whether the addition of sciatic nerve block to continuous femoral nerve block will shorten the time-to-discharge readiness. ⋯ A single-injection or continuous sciatic nerve block in addition to a femoral nerve block did not influence time-to-discharge readiness. A single-injection sciatic nerve block can reduce severe pain on the day of the surgery, whereas a continuous sciatic nerve block reduces moderate pain during mobilization on the first 2 postoperative days.
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Reg Anesth Pain Med · Sep 2011
Randomized Controlled Trial Comparative StudyCatheter orifice configuration influences the effectiveness of continuous peripheral nerve blockade.
We investigated perineural catheter threading distance and orifice configuration during continuous interscalene analgesia. ⋯ These results suggest that multiorifice catheters provide superior intermittent bolus continuous peripheral nerve blockade compared with end-hole catheters. For anterolateral approach interscalene catheter placement, there is minimal benefit, either way, to 2.5- or 5-cm blind catheter advancement.
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Reg Anesth Pain Med · Sep 2011
Comparative StudyLocal anesthetic Schwann cell toxicity is time and concentration dependent.
Peripheral nerve blocks with local anesthetics (LAs) are commonly performed to provide surgical anesthesia or postoperative analgesia. Nerve injury resulting in persistent numbness or weakness is a potentially serious complication. Local anesthetics have previously been shown to damage neuronal and Schwann cells via several mechanisms. We sought to test the hypothesis that LAs are toxic to Schwann cells and that the degree of toxicity is directly related to the concentration of LA and duration of exposure. Intraneural injection of LAs has been shown to produce nerve injury. We sought to test the hypothesis that a prolonged extraneural infusion of LA can also produce injury. ⋯ Local anesthetics induce Schwann cell death in a time- and concentration-dependent manner. Bupivacaine and ropivacaine have greater toxicity at intermediate concentrations, and prolonged exposure to bupivacaine produces significant toxicity even at low concentrations. Brief exposure to high concentrations of bupivacaine damages Schwann cells. Prolonged extraneural infusion of bupivacaine results in nerve injury.
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Reg Anesth Pain Med · Sep 2011
Patient experiences as knowledge for the evidence base: a qualitative approach to understanding patient experiences regarding the use of regional anesthesia for hip and knee arthroplasty.
It is reported that patients continue to have misgivings about regional anesthesia (RA) despite strong evidence to support its use for hip and knee replacement surgery. To date, no one has had an opportunity to study the experiences of patients who have undergone both types of anesthesia for these procedures. ⋯ These findings have important implications. First, many patients were surprisingly neutral about the procedure and seemed more fearful of anesthesia in general rather than of either technique specifically. This finding, combined with patient's influence by clinician preference, underscores the importance of physician support for RA. Some participants identified one of their misgivings about RA as being fear of being awake, which is consistent with the medical literature. Our findings also support the idea that from a patient's perspective, appropriate sedation while undergoing RA may be important.