ABSTRACT
BACKGROUND: The long-term outcome of patients with pyogenic vertebral osteomyelitis (PVO) has not been fully assessed. METHODS: We conducted a retrospective cohort study to describe the long-term outcome of PVO and to assess risk factors for treatment failure in patients evaluated at our institution between 1994 and 2002. Patients were observed until July 1, 2013. RESULTS: Two hundred sixty patients with PVO were included in this study. Twenty-seven percent (70) of patients developed their infection after an invasive spinal procedure. Staphylococcus aureus accounted for 40% (103) of infections. Forty-nine percent (128) of patients underwent spinal surgery as part of their initial therapy. The median duration of parenteral antimicrobial therapy was 42 days (interquartile range, 38-53). The estimated 2-, 5-, and 10-year cumulative probability of treatment failure-free survival was 72%, 69%, and 69%, respectively. Seventy-five percent of patients who developed treatment failure did so within 4.7 months of diagnosis. Residual neurological defects and persistent back pain were seen in 16% and 32% of patients, respectively. In a multivariate analysis, longer duration of symptoms before diagnosis and having an infection with S. aureus were associated with increased risk of treatment failure. CONCLUSIONS: Increasing duration of symptoms and infection with S. aureus were associated with treatment failure in patients with PVO. Most treatment failures occurred early after initiation of treatment. Pyogenic vertebral osteomyelitis is associated with a high 2-year failure rate. Persistent neurological deficits and back pain are common after therapy.
ABSTRACT
OBJECTIVE: The potassium channel opener, pinacidil, has been shown to be an effective cardioplegic agent over short periods of ischemia. However, clinical settings typically involve longer ischemic periods. This study tested the hypothesis that myocardial protection with a potassium channel opener is feasible during prolonged periods of arrest and is comparable with the traditional St. Thomas' Hospital solution. METHODS: With a blood-perfused, isolated rabbit heart model, hearts underwent 1 hour of global normothermic ischemia followed by 30 minutes of reperfusion. During ischemia, three different cardioplegic solutions were administered either intermittently by infusion every 20 minutes or as continuous low-flow cardioplegia (150 ml total volume in all groups): (1) Krebs-Henseleit solution alone (control), (2) Krebs-Henseleit solution + pinacidil (50 micromol/L), or (3) St. Thomas' Hospital solution. Initial potassium channel opener infusions contained 5 mmol/L procaine. Postreperfusion systolic function (percent of developed pressure) was measured. Compliance changes were integrated from the end-diastolic pressure/volume relationships. RESULTS: For intermittent cardioplegia, only St. Thomas' Hospital solution improved function (62.5% +/- 4.0%) versus control (43.6% +/- 3.3%,p < 0.001). However, with continuous cardioplegia, only pinacidil (75.6% +/- 4.8%) exceeded control (62.7% +/- 2.2%, p < 0.001) and was significantly better than St. Thomas' Hospital solution. Compared with the intermittent control group, all other groups showed significant preservation of preischemic diastolic properties. CONCLUSIONS: Myocardial protection during a longer, more clinically relevant ischemic period is feasible with a potassium channel opener only when it is given continuously. Continuous low-flow pinacidil cardioplegia was superior to St. Thomas' Hospital solution given either as an intermittent or continuous infusion.
