Kinked rib

There have been several inhalational studies on benzene in the rat. In an unpublished study summarized by Murray et al., teratogenie effeets were observed at 500 ppm when rats were exposed to 0, 10, 50 or 500 ppm benzene for 7 hr/day on days 6-15 of pregnaney and a low ineidenee of exeneephaly, kinked ribs and abnormal ossifieation of the forepaws was noted at 500 ppm. In another unpublished study quoted by Murray et al. no teratoge-nieity but inereased embryoloethality was seen after exposure to 10 or 40 ppm for 6 hours/day on days 6-15 of pregnaney in the rat. 

Fracture of a central venous catheter due to compression between the clavicle and the adjacent first rib has been reported (5). A pinched-off sign on X-ray indicates the need to remove the catheter, because of a significant risk of subsequent fracture, which has an incidence of 0.9%. Catheters lying anterior to the subclavian vein between the clavicle and the first rib are hable to be compressed and to fracture subsequently. This is a potentially life-threatening complication that can be averted by correct placing of the central venous catheter and by immediate chest radiography to search for evidence of catheter kinking or compression. 

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