Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2010
Perioperative pulmonary circulatory changes during bilateral total hip arthroplasty under regional anesthesia.
The transient and rarely clinically relevant effect of bone and cement embolization during unilateral joint arthroplasty is a known phenomenon. However, available studies do not address events surrounding bilateral total hip arthroplasties, during which embolic load is presumably doubled. To elucidate events surrounding this increasingly used procedure and assess the effect on the pulmonary hemodynamics in the intraoperative and postoperative periods, we studied 24 subjects undergoing cemented bilateral total hip arthroplasty during the same anesthetic session. ⋯ The embolization of material during bilateral total hip arthroplasty is associated with prolonged increases in pulmonary artery pressures and vascular resistance, particularly after completion of the second side. Performance of bilateral procedures should be cautiously considered in patients with diseases suggesting decreased right ventricular reserve.
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Reg Anesth Pain Med · Sep 2010
Subepineurial injection in ultrasound-guided interscalene needle tip placement.
The neural elements of the brachial plexus between the anterior and middle scalene muscles are readily visible by ultrasound. However, the epineurium of these nerve structures is difficult to discern on ultrasound imaging because of the proximity of the scalene muscles to the nerve elements, and this may lead to unintentional subepineurial injection (SEI). To evaluate whether typical needle tip placement under ultrasound guidance results in SEI, as opposed to extraneural injection, we undertook this cadaver study. ⋯ In a cadaver model of needle tip placement for ultrasound-guided interscalene block, we found that SEI occurred more frequently than expected.
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Reg Anesth Pain Med · Sep 2010
Comparative StudyPerineural dexmedetomidine provides an increased duration of analgesia to a thermal stimulus when compared with a systemic control in a rat sciatic nerve block.
The present study was designed to test the hypothesis that perineural dexmedetomidine provides a longer duration of analgesia than the same dose given subcutaneously in a peripheral nerve block in rats. ⋯ Sensory analgesia provided by dexmedetomidine added to ropivacaine for peripheral nerve blocks in rat is a peripherally mediated effect.
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Reg Anesth Pain Med · Sep 2010
Ultrasound-guided continuous oblique subcostal transversus abdominis plane blockade: description of anatomy and clinical technique.
Recently, ultrasound-guided transversus abdominis plane blockade for abdominal wall analgesia has been described, and it involves injection of local anesthetic into the transversus abdominis plane. The posterior approach involves injection of local anesthetic in the lateral abdominal wall between the costal margin and the iliac crest and is suitable for postoperative analgesia after surgery below the umbilicus. The subcostal approach is suitable after abdominal surgery in the periumbilical region. The subcostal block can be modified, and the needle can be introduced along the oblique subcostal line from the xyphoid process toward the anterior part of the iliac crest. ⋯ A catheter can be placed along the oblique subcostal line in the transversus abdominis plane for continuous infusion of local anesthetic. Multimodal analgesia and intravenous opioid are used in addition because visceral pain is not blocked. Continuous oblique subcostal transversus abdominis plane block is a new technique and requires both a detailed knowledge of sonographic anatomy and technical skill for it to be successful.