Systemic Absorption Resulting from Tobramycin-Loaded Antibiotic Cement Spacers Used in the Treatment of Prosthetic Joint Infection.

Purpose: Antimicrobial cement spacer (ACS) placement has been a cornerstone of two-stage management of prosthetic hip and knee infection. Pharmacokinetic modelling has described peak systemic antibiotic concentrations within the first 24-48 h post-operatively, followed by rapid clearance. A few studies have, however, identified detectable tobramycin levels in patients with a post-operative decline in creatinine clearance. Our study sought to determine how frequently detectable serum tobramycin levels occurred within the first 72 h following ACS placement in all patients regardless of baseline or subsequent changes in renal function, whether these levels correlated with tobramycin spacer dosage, creatinine clearance, or potential nephrotoxicity risk factors, and whether any patients developed acute kidney injury within the 14-day post-operative period. Methods: We prospectively enrolled patients with prosthetic hip or knee infections and subsequent ACS placement from October 2017 to February 2020. Patient comorbidities (chronic kidney disease, diabetes mellitus, chronic liver disease, chronic obstructive pulmonary disease, and atrial fibrillation), Charleston Comorbidity Index score, risk factors for post-operative nephrotoxicity (perioperative hypotension and nephrotoxic agent receipt), total tobramycin dosage, post-operative days 1 and 3 serum tobramycin concentrations, and serum creatinine and creatinine clearance throughout a 14-day post-operative period were recorded. Results: A total of 20 patients were enrolled, comprising 20 spacers with a median total tobramycin dosage of 4.80 g with an interquartile range (IQR) of 4.13-7.20 g. Thirteen patients had a median detectable post-operative day 1 serum tobramycin concentration of 0.80 (IQR 0.50-1.60) mcg/mL. Five of these 13 patients had a median detectable post-operative day 3 serum tobramycin concentration of 0.80 (IQR 0.50-1.10) mcg/mL. A correlation was not found between serum tobramycin drug levels and patient comorbidities, receipt of nephrotoxic medications, or baseline and subsequent post-operative creatinine clearance up to day 14. Conclusion: The majority of patients who underwent tobramycin ACS placement had detectable serum tobramycin levels in the immediate post-operative period, but most reached undetectable levels within 72 h. There were no reliable perioperative predictors of detectable drug levels.

Utility of Direct Specimen Sequencing in Addition to Conventional Testing in Management of Infections in an Urban Referral Health Center.

BACKGROUND: Direct specimen sequencing (DSS) offers the promise of enhanced pathogen detection and disease diagnosis. METHODS: A single healthcare network, retrospective chart review over a 3-year period was completed for all cases in which DSS was submitted, in addition to conventional testing (CT) for workup of an infectious disease. We sought to compare results (concordance and discordance) from these 2 techniques in order to evaluate any additional yield from DSS over CT. Additionally, we calculated mean turnaround time (TAT) and average cost for obtaining DSS on all specimens. RESULTS: A total of 23 patients' specimens were sent for DSS. DSS and CT concordance occurred in 91% (21/23) of cases. DSS testing was able to identify specific pathogens in 17.4% (4/23) of patients, out of which 4% (1/23) were discordant. The respective mean TAT and total cost per specimen for DSS were 6 days and $821.52 (range $573-$1590), respectively. CONCLUSIONS: In our limited cohort of patients, there was significant concordance between the 2 testing modalities primarily due to negative tests. DSS did not provide significant additional yield in the infectious diagnosis in our cohort compared to CT. Short TAT may provide advantage in the detection of fastidious organisms, but high cost remains a limitation. Larger sample size may reveal a clinically meaningful difference.

Impact of Procalcitonin Guidance on Management of Adults Hospitalized with Chronic Obstructive Pulmonary Disease Exacerbations.

BACKGROUND: Antibiotics are often prescribed for hospitalized patients with chronic obstructive pulmonary disease (COPD) exacerbations. The use of procalcitonin (PCT) in the management of pneumonia has safely reduced antibiotic durations, but limited data on the impact of PCT guidance on the management of COPD exacerbations remain. OBJECTIVE: To determine the impact of PCT guidance on antibiotic utilization for hospitalized adults with exacerbations of COPD. DESIGN: A retrospective, pre-/post-intervention cohort study was conducted to compare the management of patients admitted with COPD exacerbations before and after implementation of PCT guidance. The pre-intervention period was March 1, 2014, through October 31, 2014, and the post-intervention period was March 1, 2015, through October 31, 2015. PARTICIPANTS: All patients with hospital admissions during the pre- and post-intervention period with COPD exacerbations were included. Patients with concomitant pneumonia were excluded. INTERVENTION: Availability of PCT laboratory values in tandem with a PCT guidance algorithm and education. MAIN MEASURES: The primary outcome was duration of antibiotic therapy for COPD. Secondary objectives included duration of inpatient length of stay (LOS) and 30-day readmission rates. KEY RESULTS: There were a total of 166 and 139 patients in the pre- and post-intervention cohorts, respectively. There were no differences in mean age (66.2 vs. 65.9; P = 0.82) or use of home oxygenation (34% vs. 39%; P = 0.42) in the pre- and post-intervention groups, respectively. PCT guidance was associated with a reduced number of antibiotic days (5.3 vs. 3.0; p = 0.01) and inpatient LOS (4.1 days vs. 2.9 days; P = 0.01). Respiratory-related 30-day readmission rates were unaffected (10.8% vs. 9.4%; P = 0.25). CONCLUSIONS: Utilizing PCT guidance in the management of COPD exacerbations was associated with a decreased total duration of antibiotic therapy and hospital LOS without negatively impacting hospital readmissions.

Impact of Procalcitonin Guidance with an Educational Program on Management of Adults Hospitalized with Pneumonia.

BACKGROUND: Community-acquired pneumonia and healthcare-associated pneumonia are often treated with prolonged antibiotic therapy. Procalcitonin (PCT) has effectively and safely reduced antibiotic use for pneumonia in controlled studies. However, limited data exist regarding PCT guidance in real-world settings for management of pneumonia. METHODS: A retrospective, preintervention/postintervention study was conducted to compare management for patients admitted with pneumonia before and after implementation of PCT guidance at 2 teaching hospitals in Pittsburgh, Pennsylvania. The preintervention period was March 1, 2014 through October 31, 2014, and the postintervention period was March, 1 2015 through October 31, 2015. RESULTS: A total of 152 and 232 patients were included in the preintervention and postintervention cohorts, respectively. When compared with the preintervention group, mean duration of therapy decreased (9.9 vs 6.0 days; P < .001). More patients received an appropriate duration of 7 days or less (26.9% vs 66.4%; P < .001). Additionally, mean hospital length of stay decreased in the postintervention group (4.9 vs 3.5 days; P = .006). Pneumonia-related 30-day readmission rates (7.2% vs 4.3%; P = .26) were unaffected. In the postintervention group, patients with PCT levels <0.25 µg/L received shorter mean duration of therapy compared with patients with levels >0.25 µg/L (4.6 vs 8.0 days; P < .001), as well as reduced hospital length of stay (3.2 vs 3.9 days; P = .02). CONCLUSIONS: In this real-world study, PCT guidance led to shorter durations of total antibiotic therapy and abridged inpatient length of stay without affecting hospital readmissions.

Adenoviral nephritis in a renal transplant recipient: Case report and literature review.

Adenovirus (AdV) infections in transplant recipients may cause invasive disease. We present a case of granulomatous interstitial nephritis secondary to AdV infection in a renal transplant recipient that was initially interpreted as acute graft rejection on histopathology. Specific testing based on clinical suspicion, however, aided in making an accurate diagnosis. We present a retrospective review of all cases of AdV infection in renal transplant recipients to date, and analyze outcomes based on different treatment modalities for this disease.

Propionibacterium acnes: Time-to-Positivity in Standard Bacterial Culture From Different Anatomical Sites.

BACKGROUND: Propionibacterium acnes infections are likely under-recognized and underreported. This is partly because of low clinical suspicion, perceived non-pathogenicity, or lack of adequate culture incubation time. We conducted a study to assess the optimal incubation period to recover P. acnes from specimens acquired during the workup of suspected clinical infections. METHODS: A 5-year retrospective chart review was conducted between January 2010 and December 2014 at a single tertiary-care hospital. All patient cases from which P. acnes was recovered were included for analysis. Source of infection, antibiotic use, and culture time-to-positivity (TTP) were recorded. RESULTS: Implanted devices comprised the single most common source of P. acnes infection. In the majority of cases, P. acnes was the only organism identified. The mean incubation TTP for all isolates was 5.73 days. CONCLUSIONS: Standard 5-day culture incubation periods are insufficient to recover P. acnes. As a result, P. acnes is likely a much more common etiology of a variety of clinical infections than previously reported.

Brain abscess induced by Propionibacterium acnes in a patient with severe chronic sinusitis.

Propionibacterium acnes has long been considered a contaminant organism. However, recently the isolation of this emerging pathogen has become a more difficult clinical challenge. Infections of the central nervous system caused by P. acnes have been strongly associated with neurosurgical procedures. We describe a patient with Propionibacterium acnes cerebral abscess developed as consequence of a severe chronic sinus disease.

Good outcome is possible after months of refractory convulsive status epilepticus: lesson learned.

Determining a prognosis for functional recovery after prolonged status epilepticus can be difficult. Prior case studies have shown that despite seizure control, functional outcomes are typically poor unless a reversible cause is identified. Herein we present a case of idiopathic status epilepticus with a surprisingly good outcome after a 125-day drug-induced coma.