Case 155: Diabetic Foot: Failure Associated with Resistant Pseudomonas Infection

This 67 year old diabetic male was still an active smoker. He had had a left BK amputation in 1982 and recurrent myocardial infarctions. One of the latter delayed his consideration for bypass surgery in the Virginia Veterans Administration Hospital where his right leg was followed from July 1985 for a toe ulcer. The fifth toe and then the fourth toe were removed there and his foot gradually deteriorated, in spite of multiple courses of antibiotics, to the state shown in his admission photograph in 1987. A strain of Pseudomonas aeruginosa resistant to all antibiotics was cultured from the necrotic material in his arch.

He was advised that his best outcome might follow an open transtarsal amputation of his foot. His second toe and his 3rd, 4th and 5th metatarsals were largely debrided and removed in his room in hopes of leaving a small shell of necrotic material that could be managed with local soaks and antibiotic injections while boot therapy re-established some blood flow. Again, it was hoped that the extraordinary tissue concentrations of antibiotic obtained by local injections might overcome the resistance of his Pseudomonas. Persistent pain, likely from his infection, led to a vascular surgical consultation and an arteriogram.

An eight inch segment of tibial vessel was seen in the mid-calf (arrows) but had no runoff. Multiple small collateral vessels were seen in the calf (a common development in patients undergoing boot therapy). The surgeon reported that the severe small vessel disease with lack of runoff into the foot did not allow bypass surgery. A transtarsal amputation was performed.

The patient continued to receive local antibiotic injections and his Mini-Boot treatments with his foot immersed in Sea Soaks again containing antibiotics. While the skin rounded the upper portion of his wound, the lower segment continued to grow resistant Pseudomonas. In addition to his antibiotics, attempts were made to rid the foot of the infection with ultraviolet light, dilute silver nitrate and Silvadene cream.

Outpatient care was attempted for a few weeks with no success in controlling his heel pain. He was re-admitted to the hospital and necrotic material was debrided from his plantar flap both on April 29th and June 5th, 1987. The dorsal aspect of his foot continued to heal while the infection in his plantar flap persisted. He was transferred back to his Virginia VA hospital for leg amputation.

Comments: This was a difficult case: advanced vascular disease associated with insulin-dependent diabetes and years of smoking and years of continued use of antibiotics successfully selecting out a very resistant organism. The success in healing the non-infected portions of his wound suggests that our ultimate failure was due to his resistant Pseudomonas. The emergence of resistant organisms should be a great concern for all physicians and patients. Without effective antibiotics, many if not most of the leg salvage procedures attempted in our hospitals today would fail. This man had years of exposure to antibiotics. We would like to feel that if we were able to apply our techniques two years earlier in his case that his organisms might have been eliminated, his foot cured and need for almost three years of hospitalization avoided. Of course, stopping smoking would have helped also.