Protocol management of late-stage pressure ulcers: a 5-year retrospective study of 101 consecutive patients with 179 ulcers.

BACKGROUND: Despite a 12 to 82 percent pressure ulcer recurrence rate, no standard protocol exists for postoperative management. The authors reviewed a single surgeon's experience using a standard protocol: surgery and immediate reconstruction regardless of nutrition, intraoperative bone culture guiding postoperative antibiotic use, and hospital admission for 3 weeks of flat bedrest before graduated sitting. METHODS: A 5-year retrospective chart review was performed on consecutive surgically treated pressure ulcers. A search of billing records identified 101 patients with 179 ulcers. Data abstracted included demographics, comorbidities, location and stage of ulcers, treatment history with outcomes, and laboratory data. RESULTS: Seventy-nine percent of the patients were men with a mean age of 49.4 years. Of 179 ulcers, 49.7 percent were ischial, 26.8 percent were sacral, and 19 percent were trochanteric; 87.7 percent of ulcers were stage 4. Primary closure was performed on 45.8 percent; others underwent flap closure. There was no correlation between positive bone cultures and recurrence or complications. The overall recurrence rate was 16.8 percent at a mean period of 435.9 days. New ulcer occurrence was 14.5 percent and the complication rate was 17.3 percent. Admission prealbumin and albumin did not correlate with recurrence or complication. Mean follow-up was 629 days. CONCLUSIONS: A standard clinical pathway for pressure ulcer treatment improves long-term outcomes; the authors' protocol's validity is supported by low recurrence and complication rates. Nutritional data do not predict outcome. Intraoperative bone cultures are the most valid method of diagnosing osteomyelitis; results should not delay definitive treatment. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Is there a simple, definitive, and cost-effective way to diagnose osteomyelitis in the pressure ulcer patient?

BACKGROUND: Despite advances in managing pressure ulcers, there is still no definitive way to diagnose bone infection (osteomyelitis) short of open biopsy. An effective, less invasive diagnostic method might result in cost savings and improved care; however, needle aspiration, computed tomography scan, magnetic resonance imaging, ultrasound, and bone scans have proven unsatisfactory in predicting osteomyelitis. The authors reviewed preoperative radiologic studies of stage IV pressure ulcer patients and their bone biopsy results to determine which radiologic studies are most diagnostic for osteomyelitis. METHODS: Patients (n = 44) having surgical débridement of stage IV ulcers with open bone biopsy after prior radiographic imaging (plain films, ultrasound, computed tomography, magnetic resonance imaging, and/or nuclear bone scans) were included. Studies were interpreted by a single musculoskeletal radiologist blinded to information from the medical record and following standard radiologic criteria for the diagnosis of osteomyelitis. RESULTS: The percentage of patients with biopsy-proven osteomyelitis identified with imaging was 50 percent using a computed tomography scan and 88 percent using a plain film of the bony area of involvement. The overall sensitivity of either radiologic study was 61 percent. The percentage of patients without osteomyelitis identified as not having the condition by imaging was 85 percent for the computed tomography scan and 32 percent for the plain film. Overall specificity of both studies was 69 percent. CONCLUSION: Preoperative radiologic studies for osteomyelitis in a pressure ulcer are far from definitive; however, if a radiologic study is used to make that diagnosis in a stage IV pressure ulcer, it would appear that a plain film would suffice.

Comparative evolutionary genetics of spontaneous mutations affecting fitness in rhabditid nematodes.

Deleterious mutations are of fundamental importance to all aspects of organismal biology. Evolutionary geneticists have expended tremendous effort to estimate the genome-wide rate of mutation and the effects of new mutations on fitness, but the degree to which genomic mutational properties vary within and between taxa is largely unknown, particularly in multicellular organisms. Beginning with two highly inbred strains from each of three species in the nematode family Rhabditidae (Caenorhabditis briggsae, Caenorhabditis elegans, and Oscheius myriophila), we allowed mutations to accumulate in the relative absence of natural selection for 200 generations. We document significant variation in the rate of decay of fitness because of new mutations between strains and between species. Estimates of the per-generation mutational decay of fitness were very consistent within strains between assays 100 generations apart. Rate of mutational decay in fitness was positively associated with genomic mutation rate and negatively associated with average mutational effect. These results provide unambiguous experimental evidence for substantial variation in genome-wide properties of mutation both within and between species and reinforce conclusions from previous experiments that the cumulative effects on fitness of new mutations can differ markedly among related taxa.