The coagulative and cardiorespiratory responses to reamed intramedullary nailing of isolated fractures

We measured the changes during operation in seven markers of coagulation in a prospective series of 84 patients with fractures of the tibia or femur w ho were undergoing reamed intramedullary nailing. All patients were also co ntinually monitored using transoesophageal echocardiography to assess marro w embolism. In a subset of 40 patients, intraoperative cardiopulmonary func tion was monitored, using pulmonary and systemic arterial catheterisation. The procedure produced a significant increase in prothrombin time, activate d partial thromboplastin time, the level of prothrombin fragments F1+2 and D-dimers, and a decrease in the fibrinogen level, suggesting activation of both the coagulation and fibrinolytic pathways. There was evidence of both platelet hyper-reactivity and depletion, as estimated by an increase in bet a -thromboglobulin levels and a decrease in the platelet count. In the pati ents who had invasive monitoring there was an incremental increase in mean pulmonary arterial pressure, with the changes being greatest during inserti on of the guide-wire and reaming. The change in markers of coagulation, pulmonary artery pressure and arteria l oxygen partial pressures correlated with the intraoperative embolic respo nse. Greater changes in these parameters were observed during stabilisation of pathological fractures and in those patients in whom surgery bad been d elayed for more than 48 hours. Seven patients with pathological fractures developed more severe hypoxic ep isodes during reaming, which were associated with significantly greater art erial hypoxaemia, a fall in the right ventricular ejection fraction and an increase in the mean pulmonary artery pressure, pulmonary capillary wedge p ressure, central venous pressure and the pulmonary vascular resistance inde x. These changes suggested that the patients had transient intraoperative r ight heart strain. Eight patients developed significant postoperative respiratory compromise. They all had severe intraoperative embolic responses and, in the three who had invasive monitoring, there was a significantly greater increase in pulm onary artery pressure and alveolar-arterial oxygen gradient, and a fall in the ratio of arterial partial pressure of oxygen to the inspired oxygen con centration. Operative delay, intraoperative paradoxical embolisation and th e scores for the severity of the coagulative and embolic responses were pre dictive of the development of postoperative respiratory complications on un ivariate logistic regression analysis. On multivariate analysis, however, o nly the embolic and coagulative scores were significant independent predict ors of respiratory complications.