A case of tracheobronchomalacia due to relapsing polychondritis treated with Montgomery T-tube.

Relapsing polychondritis is a rare and multi-system autoimmune disease of unknown etiology characterized by inflammation and destruction of cartilaginous structures. Its clinical manifestations include recurrent chondritis of the ears, nose, pinna, peripheral joints, and laryngotracheobronchial tree and can be life-threatening in advanced cases of laryngotracheal stenosis. Because of the rarity of relapsing polychondritis and lack of understanding of its pathogenesis, there is no standard medical therapy, and treatment is tailored according to disease activity and site of organ involvement. In respiratory failure due to laryngotracheal involvement, which has been reported in up to 50% of relapsing polychondritis patients and is a major cause of death, immediate procedures such as stenting and tracheostomy are very important. This report describes a 70-year-old male patient suffering from tracheobronchomalacia due to relapsing polychondritis who was treated with Montgomery T-tube insertion.

Rapidly Fatal Emphysematous Osteomyelitis with Multiple Septic Emboli and Liver Abscess Caused by Klebsiella pneumoniae.

Emphysematous osteomyelitis, characterized by intraosseous gas, is a rare but potentially fatal condition that requires prompt diagnosis and aggressive therapy. Causative organisms are members of the bacterial family Enterobacteriaceae or anaerobes in most cases and significant comorbidities such as diabetes mellitus and malignancy, may predispose an individual to the development of emphysematous osteomyelitis. We report a case of extensive emphysematous osteomyelitis via hematogenous spread from Klebsiella pneumoniae liver abscess, complicated by gas-containing abscesses in adjacent soft tissues and epidural space, and multiple systemic septic emboli in a diabetic patient.

Population Pharmacokinetic Analysis of Meropenem After Intravenous Infusion in Korean Patients With Acute Infections.

PURPOSE: The aim of this study was to investigate the population pharmacokinetic (PK) profile of meropenem in Korean patients with acute infections. METHODS: The study included 37 patients with a creatinine clearance ≤50 or >50 mL/min who received a 500- or 1000-mg dose of meropenem, respectively, infused intravenously over 1 hour every 8 hours. Blood samples were collected before and at 1, 1.5, and 5 hours after the start of the fourth infusion. The population PK analysis was conducted by using nonlinear mixed effect modeling software (NONMEM). Monte-Carlo simulations were performed to identify optimal dosing regimens. FINDINGS: Thirty-seven subjects completed the study. Meropenem PK variables were well described by using a one-compartment model. The typical values (relative SE) for weight-normalized clearance (CL) and Vd were 0.266 L/h/kg (12.29%) and 0.489 L/kg (11.01%), respectively. Meropenem CL was significantly influenced by the serum creatinine level, which explained 11% of the interindividual CK variability. The proposed equation to estimate meropenem CL in Korean patients was as follows: CL (L/h) = 0.266 × weight × [serum creatinine/0.74]-1.017. The simulation results indicate that the current meropenem dosing regimen may be suboptimal in patients infected with normal or augmented renal function. IMPLICATIONS: Prolonged infusions of meropenem over at least 2 hours should be considered, especially in patients with augmented renal function and those infected with pathogens for which the minimum inhibitory meropenem concentration is >1 µg/mL. Our results suggest an individualized meropenem dosing regimen for patients with abnormal renal function and those infected with pathogens with decreased in vitro susceptibility.

Efficacy of nebulized colistin-based therapy without concurrent intravenous colistin for ventilator-associated pneumonia caused by carbapenem-resistant Acinetobacter baumannii.

BACKGROUND: Although there have been studies regarding the role of nebulized colistin as adjunctive therapy of ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Acinetobacter baumannii (CRAB), a paucity of information on the efficacy of nebulized colistin as monotherapy is available. METHODS: We retrospectively reviewed 219 patients with VAP caused by CRAB treated with either intravenous (n=93) or nebulized colistin (n=126), from March 2010 to November 2015. Factors related to clinical failure was assessed using propensity-score-matched analysis. RESULTS: Of 219 patients, 39 patients from each group (n=78) were matched after covariate adjustment using propensity score. There were no significant differences in baseline characteristics as well as the rates of clinical failure between the propensity-score-matched groups [Odds ratio (OR), 0.48; 95% confidence interval (CI), 0.19-1.19; P=0.11], while a significantly lower rate of acute kidney injury (AKI) during colistin therapy (18% vs. 49%, P=0.004) was observed in nebulized colistin group. In addition, multivariable analysis revealed that nebulized colistin did not significantly alter the rate of clinical failure [adjusted odds ratio (aOR), 0.36; 95% CI, 0.12-1.09; P=0.070]. Instead, medical intensive care unit (ICU) admission (aOR, 7.14; 95% CI, 1.60-32.00; P=0.010), and septic shock (aOR, 3.93; 95% CI, 1.27-12.17; P=0.018) were independent risk factors for clinical failure. CONCLUSIONS: Our findings suggest that nebulized colistin-based therapy, even without concurrent administration of intravenous colistin, may be an effective and safe treatment option for VAP caused by CRAB.

Population pharmacokinetics of levofloxacin in Korean patients.

Levofloxacin (LVFX) has different effects depending on the area under the concentration-time curve (AUC)/minimum inhibitory concentration (MIC) ratio. While AUC can be expressed as dose/clearance (CL), we measured serial concentrations of LVFX in Koreans and tried to set a Korean-specific equation, estimating the CL of the antibiotic. In total, 38 patients, aged 18-87 years, received once daily intravenous LVFX doses of 500 mg or 250 mg, depending on their renal function. Four plasma samples were obtained according to a D optimal sampling design. The population pharmacokinetic (PK) parameters of LVFX were estimated using non-linear mixed-effect modeling (NONMEM, ver. 7.2). The CL of LVFX was dependent on creatinine clearance (CLCR) as a covariate. The mean population PK parameters of LVFX in Koreans were as follows: CL (l/hour) = 6.19 × (CLCR/75)(1.32). The CL of LVFX in Koreans is expected to be lower than that in Western people.