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KEY CONCEPTS
Clinical manifestations of bone cement implantation syndrome include hypoxia (increased pulmonary shunt), hypotension, arrhythmias (including heart block and sinus arrest), pulmonary hypertension (increased pulmonary vascular resistance), and decreased cardiac output.
The use of a pneumatic tourniquet on an extremity creates a bloodless field that may facilitate surgery. However, tourniquets can produce potential problems of their own, including hemodynamic changes, pain, metabolic alterations, arterial thromboembolism, and pulmonary embolism.
Fat embolism syndrome classically presents within 72 h following long-bone or pelvic fracture, with the triad of dyspnea, confusion, and petechiae.
Deep vein thrombosis and pulmonary embolism can cause morbidity and mortality during and following orthopedic operations, particularly those procedures involving the pelvis and lower extremities.
Neuraxial anesthesia alone or combined with general anesthesia may reduce thromboembolic complications by several mechanisms, including sympathectomy-induced increases in lower extremity venous blood flow, systemic anti-inflammatory effects of local anesthetics, decreased platelet reactivity, attenuated postoperative increase in factor VIII and von Willebrand factor, attenuated postoperative decrease in antithrombin III, and alterations in stress hormone release.
Preoperatively, neuraxial techniques may be performed after waiting at least 12 h after a prophylactic low-molecular-weight heparin (LMWH) dose. Postoperatively, neuraxial catheters may be maintained in patients who receive once-daily prophylactic dosing, and catheters should be removed at least 12 h after the previous dose. Following catheter removal, the next dose may be given after a 4 h delay. For postoperative patients who receive twice-daily prophylactic dosing, neuraxial catheters should not be left in situ and should be removed 4 or more hours before the first dose of LMWH. For therapeutic dosing of LMWH, a longer wait time of 24 h after the previous dose is recommended prior to any neuraxial technique.
Flexion and extension lateral radiographs of the cervical spine should be obtained preoperatively in patients with rheumatoid arthritis severe enough to require steroids, immune therapy, or methotrexate. If atlantoaxial instability is present, intubation should be performed with in-line stabilization utilizing video or fiberoptic laryngoscopy.
Effective communication between the anesthesia practitioner and surgeon is essential during bilateral hip arthroplasty. If major hemodynamic instability occurs during the first hip replacement procedure, the second arthroplasty should be postponed.
Adjuvants such as opioids, clonidine, ketorolac, and neostigmine, when added to local anesthetic solutions for intraarticular injection, have been used in various combinations to extend analgesic duration following knee arthroscopy.
Effective postoperative multimodal analgesia facilitates early physical rehabilitation to maximize postoperative range of motion and prevent joint adhesions following knee replacement.
Interscalene brachial plexus block with or without a perineural catheter is ideally suited for shoulder procedures. Even when general anesthesia is employed, a peripheral nerve or brachial plexus block can supplement intraoperative anesthesia and provide effective postoperative analgesia.
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Orthopedic surgery provides many anesthetic challenges. Patients may present as neonates with congenital limb deformities, as teenagers with sports-related injuries, as adults for procedures ranging from excision of a minor soft-tissue mass to joint replacement, or at any age with bone ...