SLR - October 2016 - Yerusalem Lanier

Risk Factors for Foot Amputation in Patients Hospitalized for Diabetic Foot Infection

Reference: Quilici MT, Del Fiol Fde S, Vieira AE, and Toledo MI: Risk Factors for Foot Amputation in Patients Hospitalized for Diabetic Foot Infection. J Diabetes Res: 2016; 2016:8931508.

Scientific Literature Review

Reviewed By:
Yerusalem Lanier, DPM
Residency Program: St. Vincent Hospital

Podiatric Relevance: Patients with diabetes have increased risk of foot amputations, and the main cause is diabetic peripheral arterial disease accelerated by the direct damage to the nerves and blood vessels by high blood glucose levels. Most interesting to me initially was that prior antibiotic treatment is correlated with increased risk of amputation, as I thought this suggested antibiotics were counterproductive. However, this likely means that patients who have already failed outpatient antibiotics are less likely to respond to inpatient antibiotics. This is the most relevant helpful takeaway from this article to my podiatric practice. I will expect those who have previously been given antibiotics who are then admitted are more likely to end with amputation than patients who are admitted with diabetic foot infections who are antibiotic naive. The final finding is also relevant: those who underwent debridement or other nonsurgical treatment of their wounds had lower incidence of amputation. This supports aggressive outpatient interventions like debridement, but it is not possible to determine based on the article how helpful it is or in which patient it is most effective as details are lacking.

Method: This was a cross-sectional study of 100 patients from a vascular hospital who were diabetic and had an ulcer of their lower extremity. The patients had to be 18 years and older. Patients responded to a questioner about their sociodemographic status, knowledge of the disease, previous antibiotic use and compliance with diabetes treatment. All foot ulcers were graded according to Wagner criteria, and data analysis was based on debridement, revascularization and amputation outcomes. Compliance with outpatient treatment for diabetes was evaluated using the Moresby test, which consisted of four simple questions. These questions were: Do you ever forget to take medication? When you feel better, do you sometimes stop taking your medication? Sometimes, if you feel worse when you take your medication, do you stop taking it? Each negative answer is assigned one point. The higher the score, the more adherent the patient.

Results: In most patients, diabetes was being monitored 79 percent. Seventy-three percent of patients attended medical appointments over the past year, 67 percent had attended more than three appointments and 86 percent were tested for blood glucose levels. The most frequent chronic complications were neuropathy (91 percent), hypertension (72 percent), vascular peripheral disease (63 percent), retinopathy (42 percent), dyslipidemia (41 percent) and nephropathy (26 percent). Forty-five percent had undergone a prior nonsurgical procedure (debridement). Thirty-two percent underwent an amputation, and 74 percent of the patients were in their first hospitalization for complications of diabetes. Eighty-four percent had an ulcer of less than 2cm. Seventy-six percent had gangrene, and 86 percent had neuroischemic diabetic foot. Eighty-nine percent showed signs of inflammation, and 52 percent had osteomyelitis. Compliance with treatment was poor in 72 percent of patients, while 27 percent were considered compliant.

The authors conclude that antimicrobial protocols for diabetic feet in outpatients should be reviewed, as control prior to hospitalization is helpful. I would conclude that, except in isolated cases, we should generally initiate antibiotic treatment of diabetic foot infections in the hospital. We may lose our one final chance to avoid amputation if inadequate antibiotics are given outpatient; by the time they fail, we may have no further chance to avoid amputation.

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