Parmet J L, Horrow J C, Pharo G, Collins L, Berman A T, Rosenberg H
Department of Anesthesiology, Medical College of Pennsylvania, Philadelphia, USA.
Anesth Analg. 1995 Oct;81(4):757-62. doi: 10.1097/00000539-199510000-00017.
During total knee arthroplasty (TKA), instrumentation of the marrow cavity with an intramedullary guide appears responsible for fatal intraoperative pulmonary embolism. Transesophageal echocardiography demonstrates venous emboli (VE) after tourniquet deflation during intramedullary guided TKA. Extramedullary guides avoid manipulating the marrow cavity. We determined the incidence of VE in 20 patients undergoing extramedullary guided TKA. Recordings of hemodynamic variables, mixed venous oximetry, end-tidal CO2 and N2 tensions, and echocardiograph images occurred after induction of anesthesia, after tourniquet inflation, during cementing, and for 15 min after tourniquet deflation. Large VE appeared in 14 patients and small VE in the other 6 patients. Large VE occurred only after deflation of the tourniquet. Beginning 3 min after tourniquet deflation, mean pulmonary arterial pressures increased from the baseline of 21 +/- 1.0 to 30 +/- 1.3 mm Hg and remained increased for the duration of the procedure. The incidence of large VE with extramedullary guided TKA did not differ compared to the previously reported incidence with intramedullary guided TKA. These data suggest that VE might arise from a thrombogenic effect of the tourniquet rather than from manipulation of the marrow cavity.
在全膝关节置换术（TKA）中，使用髓内导向器对骨髓腔进行器械操作似乎是导致术中致命性肺栓塞的原因。经食管超声心动图显示，在髓内导向TKA过程中止血带放气后出现静脉栓子（VE）。髓外导向器可避免对骨髓腔进行操作。我们确定了20例行髓外导向TKA患者的VE发生率。在麻醉诱导后、止血带充气后、骨水泥固定期间以及止血带放气后15分钟记录血流动力学变量、混合静脉血氧饱和度、呼气末二氧化碳和氮气分压以及超声心动图图像。14例患者出现大的VE，另外6例患者出现小的VE。大的VE仅在止血带放气后出现。止血带放气后3分钟开始，平均肺动脉压从基线的21±1.0 mmHg升至30±1.3 mmHg，并在手术过程中持续升高。髓外导向TKA中大VE的发生率与先前报道的髓内导向TKA的发生率相比无差异。这些数据表明，VE可能源于止血带的血栓形成作用，而非骨髓腔的操作。
