Anesthesia and analgesia
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Perioperative bleeding is a major challenge particularly because of increasing clinical use of potent antithrombotic drugs. Understanding current concepts of coagulation is important in determining the preoperative bleeding risk of patients, and in managing hemostatic therapy perioperatively. The serine protease thrombin plays pivotal roles in the activation of additional serine protease zymogens (inactive enzymatic precursors), cofactors, and cell-surface receptors. ⋯ However, a limitation of current treatment is that conventional clotting tests do not reflect the entire physiological processes of coagulation making optimal pharmacologic therapy difficult. Understanding the in vivo regulatory mechanisms and pharmacologic modulation of thrombin generation may help control bleeding without potentially increasing prothrombotic risks. In this review, we focus on the regulatory mechanisms of hemostasis and thrombin generation using multiple, simplified models of coagulation.
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Anesthesia and analgesia · May 2009
ReviewGreater trochanteric pain syndrome: a review of anatomy, diagnosis and treatment.
Greater trochanteric pain syndrome (GTPS) is a term used to describe chronic pain overlying the lateral aspect of the hip. This regional pain syndrome, once described as trochanteric bursitis, often mimics pain generated from other sources, including, but not limited to myofascial pain, degenerative joint disease, and spinal pathology. The incidence of greater trochanteric pain is reported to be approximately 1.8 patients per 1000 per year with the prevalence being higher in women, and patients with coexisting low back pain, osteoarthritis, iliotibial band tenderness, and obesity. ⋯ Most cases of GTPS are self-limited with conservative measures, such as physical therapy, weight loss, nonsteroidal antiinflammatory drugs and behavior modification, providing resolution of symptoms. Other treatment modalities include bursa or lateral hip injections performed with corticosteroid and local anesthetic. More invasive surgical interventions have anecdotally been reported to provide pain relief when conservative treatment modalities fail.
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Anesthesia and analgesia · May 2009
ReviewOptimal perfusion during cardiopulmonary bypass: an evidence-based approach.
In this review, we summarize the best available evidence to guide the conduct of adult cardiopulmonary bypass (CPB) to achieve "optimal" perfusion. At the present time, there is considerable controversy relating to appropriate management of physiologic variables during CPB. Low-risk patients tolerate mean arterial blood pressures of 50-60 mm Hg without apparent complications, although limited data suggest that higher-risk patients may benefit from mean arterial blood pressures >70 mm Hg. ⋯ Similarly, no distinct clinical benefits have been observed when open venous reservoirs have been compared to closed systems. In conclusion, there are currently limited data upon which to confidently make strong recommendations regarding how to conduct optimal CPB. There is a critical need for randomized trials assessing clinically significant outcomes, particularly in high-risk patients.
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Anesthesia and analgesia · May 2009
ReviewTranscatheter aortic valve implantation: anesthetic considerations.
Aortic valvular stenosis remains the most common debilitating valvular heart lesion. Despite the benefit of aortic valve (AV) replacement, many high-risk patients cannot tolerate surgery. AV implantation treats aortic stenosis without subjecting patients to sternotomy, cardiopulmonary bypass (CPB), and aorta cross-clamping. ⋯ Transcatheter AV implantation relies on intraoperative hemodynamic manipulation for success. Transfemoral and transapical approaches pose unique management challenges, but both require rapid ventricular pacing, the management of hypotension and arrhythmias during beating-heart valve implantation, and TEE. Anesthesiologists will care for debilitated patients with aortic stenosis receiving transcatheter AV implantation.
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Amniotic fluid embolism is one of the most catastrophic complications of pregnancy. First described in 1941, the condition is exceedingly rare and the exact pathophysiology is still unknown. The etiology was thought to be embolic in nature, but more recent evidence suggests an immunologic basis. ⋯ Early recognition of amniotic fluid embolism is critical to a successful outcome. However, despite intensive resuscitation, outcomes are frequently poor for both infant and mother. Recently, aggressive and successful management of amniotic fluid embolism with recombinant factor VIIa and a ventricular assist device, inhaled nitric oxide, cardiopulmonary bypass and intraaortic balloon pump with extracorporeal membrane oxygenation have been reported and should be considered in select cases.