Regional anesthesia and pain medicine
-
Reg Anesth Pain Med · Mar 2010
Randomized Controlled TrialUltrasound-guided continuous femoral nerve block for analgesia after total knee arthroplasty: catheter perpendicular to the nerve versus catheter parallel to the nerve.
This study tested the hypothesis that, in continuous femoral nerve block (CFNB) under ultrasound guidance, placing a catheter perpendicular to the nerve can shorten the time of catheter insertion while providing a similar quality of analgesia compared with placing a catheter parallel to the nerve. ⋯ In CFNB under ultrasound guidance, using the catheter perpendicular to the nerve technique can shorten the time of catheter insertion while providing a similar quality of analgesia after total knee arthroplasty as compared with the catheter parallel to the nerve technique.
-
Although new drugs and techniques may improve outcomes when unintended high blood levels of local anesthetics occur, the primary focus of daily practice should remain the prevention of such events. Although adoption of no single "safety step" will reliably prevent systemic toxicity, the combination of several procedures seems to have reduced the frequency of systemic toxicity since 1981. These include the use of minimum effective doses, careful aspiration, and incremental injection, coupled with the use of intravascular markers when large doses are used. ⋯ Fentanyl has also been confirmed to produce sedation in pregnant women when used as an alternative. The use of ultrasound observation of needle placement and injection may be useful, but has also been reported as not completely reliable. Constant vigilance and suspicion are still needed along with a combination of as many of these safety steps as practical.
-
Reg Anesth Pain Med · Mar 2010
ReviewModels and mechanisms of local anesthetic cardiac toxicity: a review.
Cardiovascular collapse, even death, may occur after intoxication with bupivacaine or related amide local anesthetic agents. The problem has been studied in myriad laboratories for more than 20 years. Nevertheless, there is consensus neither regarding which animal model best mimics this clinical catastrophe nor as to which ion channel, enzyme, or other local anesthetic binding site represents the point of initiation for the process. This review aimed to define the various credible mechanisms that have been proposed to explain cardiovascular collapse and death after administration of local anesthetics, particularly after bupivacaine and related agents.
-
Reg Anesth Pain Med · Mar 2010
Comparative StudySonographic identification of needle tip by specialists and novices: a blinded comparison of 5 regional block needles in fresh human cadavers.
Needle visibility using ultrasound remains problematic at steep insertion angles. Despite modified techniques, steep approaches are still needed, particularly in the obese, neuraxial anesthesia or pain blocks around the spine. We describe a novel technique for objective assessment of needle-tip identification and present data on a new needle. ⋯ Needle T demonstrated good properties even at steep insertion angles. Tip location was accurate, and observers rated it highly visible. Ability to identify needle-tip position can be objectively assessed.
-
Reg Anesth Pain Med · Mar 2010
In-plane ultrasound-guided thoracic paravertebral block: a preliminary report of 36 cases with radiologic confirmation of catheter position.
Thoracic paravertebral block (TPVB) can be used for unilateral surgical procedures. Modifications of the classic approach have been proposed to minimize the risk of pleural puncture. In this study, we evaluated the feasibility and success rate of a transverse in-plane ultrasound (US)-guided TPVB with radiologic confirmation of catheter position. ⋯ An in-plane transverse US-guided TPVB using the described technique is feasible and has a high success rate. In all patients, correct catheter position in the thoracic paravertebral space was radiologically confirmed.