Calculated parenteral initial treatment of bacterial infections: Respiratory infections

Ciprofloxacin in Patients Undergoing Extracorporeal Membrane Oxygenation (ECMO): A Population Pharmacokinetic Study

Extracorporeal membrane oxygenation (ECMO) is utilized to temporarily sustain respiratory and/or cardiac function in critically ill patients. Ciprofloxacin is used to treat nosocomial infections, but data describing the effect of ECMO on its pharmacokinetics is lacking. Therefore, a prospective, observational trial including critically ill adults (n = 17), treated with ciprofloxacin (400 mg 8–12 hourly) during ECMO, was performed. Serial blood samples were collected to determine ciprofloxacin concentrations to assess their pharmacokinetics. The pharmacometric modeling was performed (NONMEM^®) and utilized for simulations to evaluate the probability of target attainment (PTA) to achieve an AUC_0–24/MIC of 125 mg·h/L for ciprofloxacin. A two-compartment model most adequately described the concentration-time data of ciprofloxacin. Significant covariates on ciprofloxacin clearance (CL) were plasma bicarbonate and the estimated glomerular filtration rate (eGFR). For pathogens with an MIC of ≤0.25 mg/L, a PTA of ≥90% was attained. However, for pathogens with an MIC of ≥0.5 mg/L, plasma bicarbonate ≥ 22 mmol/L or eGFR ≥ 10 mL/min PTA decreased below 90%, steadily declining to 7.3% (plasma bicarbonate 39 mmol/L) and 21.4% (eGFR 150 mL/min), respectively. To reach PTAs of ≥90% for pathogens with MICs ≥ 0.5 mg/L, optimized dosing regimens may be required.

Spectrum of Microorganisms, Antibiotic Resistance Pattern, and Treatment Outcomes Among Patients With Empyema Thoracis: A Descriptive Cross-Sectional Study From the Bahawal Victoria Hospital Bahawalpur, Punjab, Pakistan

Background: This study involves the analysis of spectrum of microorganisms, antibiotic resistance pattern, and treatment outcomes among empyema thoracis patients. This study also analyzes the factors associated with unsuccessful treatment outcome and duration of hospital stay among the patients.

Methods: This was a descriptive, cross-sectional study carried out in the Pulmonology Ward of the Bahawal Victoria hospital, Bahawalpur, Pakistan. All patients with empyema thoracis registered at the study site during the period of 1 year were included in the study. Multivariate regression analysis was used to analyze the factors associated with duration of hospital stay and unsuccessful treatment outcome among the patients.

Results: A total 110 patients were included in the study. Most of the patients (n = 73, 66.4%) were treated with piperacillin/tazobactam alone and in combination with either one or more than one antibiotics as an empiric therapy. Culture was positive in 58 (52.7%) patients and the most commonly identified organisms included, gram-negative Pseudomonas aeruginosa (n = 20; 18.8%) and Klebsiella sp. (n = 11, 10%) followed by same proportion of E. coli. The most commonly identified bacterial isolates showed high level of resistance against antibiotics used as an empiric therapy, while these showed low level of resistance against amoxicillin, clarithromycin, ertapenem, colistin, tigecycline, fosfomycin, rifampicin, and vancomycin. In this study, 82 (74.5%) patients successfully completed the treatment, while 12 (11%) showed no clinical improvement, 5 (4.5%) lost to follow up and 11 (10%) died. In multivariate binary logistic regression analysis, none of the patient attributes were significantly associated with unsuccessful treatment outcome, while in multivariate linear regression analysis, the factors which were significantly associated with duration of hospital stay included; duration of symptoms <2 weeks prior to admission (p = 0.008, beta = −0.247) and resistance to five antibiotic classes (p = 0.02, beta = 0.280).

Conclusion: Close to 25% of the patients did not complete the treatment successfully. Most of the common bacterial isolates showed high level of resistance against the broad-spectrum antibiotics used as an empiric therapy. This is alarming. However, better sensitivity of common bacterial isolates against standardized first line treatment for empyema thoracis is promising.