Subpulmonary haemothorax: 387 cases.

The diagnostic features of subpulmonary haemothorax (SH) are often overlooked. A retrospective review of 399 consecutive patients discharged with diagnoses of post-traumatic haemo- or haemopneumothorax yielded 51 (12.8 per cent) instances of SH on the initial radiographs. In 24 (47.1 per cent) of these initial diagnosis of SH had been missed. A concerted teach-in followed in order to reduce the rate of error. In a subsequent prospective study of 1773 consecutive patients with haemothorax (510) or haemopneumothorax (1263), mostly due to penetrating injuries, and who had undergone pre-interventional erect chest radiography, 336 (19.0 per cent) had the blood confined to the subpulmonary position; 156 (12.4 per cent) of the haemopneumothoraces and 180 (35.3 per cent) of the pure haemothoraces presented in this way. Confirmatory lateral decubitus radiography was necessary in 141 (42.0 per cent) of the SHs but initial diagnostic errors were confined to six cases (1.8 per cent). Comparison of the 336 SH patients and the 1437 presenting with more florid radiological signs showed only one significant difference in management and outcome: emergency thoracotomy rates of, respectively, 0.9 per cent and 9.2 per cent (P less than 0.0005). We conclude that SH is a common and normal presentation of less than massive haemothorax and we stress the diagnostic radiological features.