[Incidence and characteristics of perioperative pulmonary thromboembolism in Japan from 2005 through 2007--results of research by Japanese Society of Anesthesiologists, Committee on Patient Safety and Risk Management, Perioperative Pulmonary Thromboembolism Working Group].

Background: This study aimed to investigate the annual incidence and characteristics of perioperative pulmonary thromboembolism (PTE) in Japan from 2005 through 2007, and to compare the current trend with that observed in our previous studies conducted since 2002.

Methods: In the 3-year study period, a questionnaire was annually mailed to every institution certified as a training hospital for anesthesiologists by the Japanese Society of Anesthesiologists (JSA). The survey included the parameters of age, sex, type of surgery, and the risk factors in patients who were operated upon.

Results: The average rate of effective responses was 55.1%, and a total of 825 cases of perioperative PTE were registered in the 3-year study period. The incidence of perioperative PTE was 2.79 per 10,000 cases in 2005, 2.25 per 10,000 cases in 2006, and 2.57 per 10,000 cases in 2007. The incidence of PTE in all the 3 years was significantly lower than that observed in 2002-03 (P < 0.01). In addition, the incidence of fetal PTE in 2006 and 2007 was also significantly lower than that in 2002-03. The incidence of PTE in older persons (66-85 years) was approximately twice (4.70 per 10,000 cases) and that in the oldest persons (> 86 years) was approximately thrice (6.28 per 10,000 cases) the incidence in middle-aged individuals (2.17 per 10,000 cases). PTE was found to be more frequent in females than in males (males, 1.89 per 10,000 cases; females, 3.75 per 10,000 cases). The types of surgery that most commonly resulted in perioperative PTE were limb and/or hip joint surgery (5.57 per 10,000 cases), thoracotomy with laparotomy (5.19 per 10,000 cases), and spinal surgery (4.49 per 10,000 cases). Perioperative PTE was fatal in 185 patients (22.4%), and the mortality rate of patients who had not received prophylaxis was significantly higher (37.8%) than that of patients who received anticoagulant drugs (20.8%). Guidelines for prevention of perioperative PTE were accepted by 58% of all training institutions.

Conclusions: The incidence of perioperative PTE and fetal PTE has currently decreased; however, prophylaxis with anticoagulant drugs may have reduced the mortality in some cases.