Assuring process safety in the transfer of hydrogen cyanide manufacturing technology.

This paper outlines the critical issues to be addressed in the transfer of hydrogen cyanide (HCN) manufacturing technology to a licensee. Process safety management (PSM) is of critical importance because of the toxicity, flammability and reactivity of HCN. The critical issues are based on experience that DuPont has gained (1) while safely manufacturing hydrogen cyanide for over 50 years, and (2) while DuPont has safely licensed HCN technology to other firms at locations around the world. DuPont's HCN experience has been combined with Aker Kvaerner's project engineering experience to insure the safe transfer of HCN technology to a licensee.

A preliminary investigation of balloon angioplasty versus surgical treatment of thrombosed dialysis access grafts.

It has been estimated that 180,000 patients in the United States have end-stage renal disease requiring hemodialysis, and this number is currently increasing at a rate of 10 per cent per year. With the growing number of patients requiring hemodialysis the insertion and maintenance of dialysis access has become a common task for vascular surgeons. In fact dialysis access is now the most common vascular operation and may account for as much as 40 to 50 per cent of the practice of a busy vascular surgeon. The two major techniques for repairing thrombosed dialysis access grafts are open surgical revision and balloon angioplasty. Surgical revisions of access sites include patch angioplasty and interposition jump grafts. Balloon angioplasty involves declotting the graft mechanically or chemically followed by dilation of the stenotic segment by an angioplasty balloon under fluoroscopy. Few studies have compared the two methods of repair, and the studies that have been done reveal conflicting results. A retrospective chart review of patients treated at the New Hanover Regional Medical Center for repair of thrombosed dialysis access grafts was conducted. The final sample available for analysis consisted of 16 patients with balloon angioplasty and 44 patients with surgical revision. These two groups were compared in terms of demographics, past medical history, surgery time, complications, length of stay, length of graft patency, and typical costs. Overall balloon angioplasty as compared with surgical revision was associated with longer patency (5.5 vs 3.2 months), shorter surgical time (43.9 vs 64.5 minutes), shorter length of hospital stay (less than one day vs one day or more), and fewer complications (12% vs 30% of the patients). We concluded from this analysis that endovascular treatment of thrombosed dialysis grafts is an acceptable alternative to surgical revision and should be the first option after primary failure of the grafts caused by stenotic lesions.