Antimicrobial dosing in critically ill patients with sepsis-induced acute kidney injury

Inhibition of histone methyltransferase G9a effectively protected the kidney against ischemia-reperfusion injury

This study examined whether BIX01294, a histone methyltransferase G9a inhibitor, effectively preserves the renal function following acute kidney ischemia-reperfusion (AKIR) injury. Adult-male-SD rats (n = 24) were equally categorized into Group 1 (sham-operated control), Group 2 (AKIR + 1.0 cc N/S I.P. injection), and Group 3 (AKIR + BIX01294/5 mg/Kg by I.P. administration at 3 h after the procedure) and the kidneys were harvested at day-3 post-IR procedure. The results showed that by day 3, the levels of creatinine and the blood urea nitrogen (BUN) were significantly higher in group 3 and more significantly higher in group 2 than in group 1 (all P < 0.0001). The protein expression of upstream (TLR-2/TLR-4/MyD88/TRAF6/p-NF-κB) and downstream (IL-1ß/IL-6/TNF-α) inflammatory signaling molecules exhibited a pattern identical to that of creatinine levels among the groups (all P < 0.0001). The protein expression of oxidative stress (NOX-1/NOX-2), MAP kinase family members (ASK1/MKK4/MKK7/JNK/p-38/p-ERK1/2), apoptosis (cleaved-caspase3/cleaved-caspase8/cleaved-PARP/mitochondrial-Bax), fibrosis (Smad3/TGF-ß), and mitochondrial-damaged markers (cyclophilin D/cytosolic-cytochrome-C) displayed a pattern identical to that of creatinine levels among the groups (all P < 0.0001). The kidney injury score, fibrosis, cellular expression of inflammation (CD68+cells), and glomerulus/renal-tubular damaged markers (Snail/KIM-1/WT-1) exhibited an identical pattern, whereas the cellular expression of podocyte component (synaptopodin) displayed an opposite pattern of creatinine levels among the groups (all P < 0.0001). Therefore, the G9a inhibitor effectively protected kidneys against IR injury.

The impact of continuous renal replacement therapy on antibiotic pharmacokinetics in critically ill patients

Introduction: Mortality due to severe infections in critically ill patients undergoing continuous renal replacement therapy (CRRT) remains high. Nevertheless, rapid administration of adequate antibiotic therapy can improve survival. Delivering optimized antibiotic therapy can be a challenge, as standard drug regimens often result in insufficient or excessive serum concentrations due to significant changes in the volume of distribution and/or drug clearance in these patients. Insufficient drug concentrations can be responsible for therapeutic failure and death, while excessive concentrations can cause toxic adverse events.Areas covered: We performed a narrative review of the impact of CRRT on the pharmacokinetics of the most frequently used antibiotics in critically ill patients. We have provided explanations for the changes in the PKs of antibiotics observed and suggestions to optimize dosage regimens in these patients.Expert opinion: Despite considerable efforts to identify optimal antibiotic dosage regimens for critically ill patients receiving CRRT, adequate target achievement remains too low for hydrophilic antibiotics in many patients. Whenever possible, individualized therapy based on results from therapeutic drug monitoring must be given to avoid undertreatment or toxicity.

Antibiotic therapy in sepsis: No next time for a second chance!

WHAT IS KNOWN AND OBJECTIVE

Sepsis is a life-threatening organ dysfunction associated with a high rate of morbidity and mortality. Appropriate antibiotic therapy remains the cornerstone of sepsis and septic shock management.

COMMENT

Although the early initiation of antimicrobial agents in the treatment of sepsis is widely acknowledged, the selection and adjustment to optimal dosage can be equally important. Since significant pathophysiological changes in the critically ill patients lead to altered pharmacokinetics of antibiotics, early consideration of pharmacokinetic/pharmacodynamic (PK/PD) properties is necessary for optimal antibiotic dosing in sepsis and should be integrated in practice.

WHAT IS NEW AND CONCLUSION

Where possible, an individualized antibiotic dosing approach through the application of therapeutic drug monitoring (TDM) service should replace the conventional dosing in critically ill patients with sepsis. Finally, antimicrobial stewardship can help improve clinical outcomes.

Optimal levofloxacin dosing regimens in critically ill patients with acute kidney injury receiving continuous renal replacement therapy

PURPOSES

To determine appropriate dosing of levofloxacin in critically ill patients receiving continuous renal replacement therapy (CRRT).

METHODS

All necessary pharmacokinetic and pharmacodynamic parameters from critically ill patients were obtained to develop mathematical models with first order elimination. Levofloxacin concentration-time profiles were calculated to determine the efficacy based on the probability of target attainment (PTA) of AUC_24h/MIC ≥50 for Gram-positive and AUC_24h/MIC ≥125 for Gram-negative infections. A group of 5000 virtual patients was simulated and tested using Monte Carlo simulations for each dose in the models. The optimal dosing regimens were defined as the dose achieved target PTA at least 90% of the virtual patients.

RESULTS

No conventional, FDA approved regimens achieved at least 90% of PTA for Gram-negative infection with Pseudomonas aeruginosa at MIC of 2 mg/L. The successful dose (1750 mg on day 1, then 1500 mg q 24 h) was far exceeded the maximum FDA-approved doses. For Gram-positive infections, a levofloxacin 750 mg q 24 h was sufficient to attain PTA target of ~90% at the MIC of 2 mg/L for Streptococcus pneumoniae.

CONCLUSIONS

Levofloxacin cannot be recommended as an empiric monotherapy for serious Gram-negative infections in patients receiving CRRT due to suboptimal efficacy.

Currently used dosage regimens of vancomycin fail to achieve therapeutic levels in approximately 40% of intensive care unit patients

Objective:

This study aimed to assess whether currently used dosages of vancomycin for treatment of serious gram-positive bacterial infections in intensive care unit patients provided initial therapeutic vancomycin trough levels and to examine possible factors associated with the presence of adequate initial vancomycin trough levels in these patients.

Methods:

A prospective descriptive study with convenience sampling was performed. Nursing note and medical record data were collected from September 2013 to July 2014 for patients who met inclusion criteria. Eighty-three patients were included. Initial vancomycin trough levels were obtained immediately before vancomycin fourth dose. Acute kidney injury was defined as an increase of at least 0.3mg/dL in serum creatinine within 48 hours.

Results:

Considering vancomycin trough levels recommended for serious gram-positive infection treatment (15 - 20µg/mL), patients were categorized as presenting with low, adequate, and high vancomycin trough levels (35 [42.2%], 18 [21.7%], and 30 [36.1%] patients, respectively). Acute kidney injury patients had significantly greater vancomycin trough levels (p = 0.0055, with significance for a trend, p = 0.0023).

Conclusion:

Surprisingly, more than 40% of the patients did not reach an effective initial vancomycin trough level. Studies on pharmacokinetic and dosage regimens of vancomycin in intensive care unit patients are necessary to circumvent this high proportion of failures to obtain adequate initial vancomycin trough levels. Vancomycin use without trough serum level monitoring in critically ill patients should be discouraged.

DPP-4 enzyme deficiency protects kidney from acute ischemia-reperfusion injury: role for remote intermittent bowel ischemia-reperfusion preconditioning

We analyzed the effects of acute ischemia-reperfusion (KIR) injury on the status of kidney function and architecture in dipeptidyl peptidase4-difficient (DPP4^D) rats and the effect of remote small bowel ischemia-reperfusion (BIR) preconditioning. DPP4-deficient (DPP4^D) and normal Fischer344 (F344) rats were divided into 6 groups: (1) sham-F344, (2) sham-DPP4^D, (3) KIR-F344 (4) KIR-DPP4^D, (5) DPP4^D-KIR-extendin-9-39 and (6) BIR-KIR-F344. Blood creatinine and urea nitrogen levels and the urinary protein-to-creatinine ratio was higher in KIR-F344 rats than BIR-KIR-F344 or KIR-DPP4^D rats 72 h after acute KIR. Conversely, the circulating glucagon-like peptide 1 (GLP-1) levels were higher in BIR-KIR-F344 and KIR-DPP4^D than KIR-F344 rats after acute KIR. KIR-F344 rats showed greater inflammation, oxidative stress, apoptosis, DNA damage and kidney injury than other rat groups. Damage to the kidney architecture in KIR-F344 rats was greater than in BIR-KIR-F344 or KIR-DPP4^D rats. Expression of antioxidant proteins and GLP-1 receptor was higher in kidneys from KIR-DPP4^D and BIR-KIR-F344 than KIR-F344 rats, which suggests better intrinsic responses. We therefore suggest that elevated circulating GLP-1 levels due to DPP4 deficiency and BIR preconditioning protect kidney function and architecture during acute IR injury.

Management of ventilator-associated pneumonia in intensive care units: a mixed methods study assessing barriers and facilitators to guideline adherence

Background

Guidelines from the Infectious Diseases Society of America/The American Thoracic Society (IDSA/ATS) provide recommendations for diagnosis and treatment of ventilator-associated pneumonia (VAP). However, the mere presence of guidelines is rarely sufficient to promote widespread adoption and uptake. Using the Systems Engineering Initiative for Patient Safety (SEIPS) model framework, we undertook a study to understand barriers and facilitators to the adoption of the IDSA/ATS guidelines.

Methods

We conducted surveys and focus group discussions of different health care providers involved in the management of VAP. The setting was medical-surgical ICUs at a tertiary academic hospital and a large multispecialty rural hospital in Wisconsin, USA.

Results

Overall, we found that 55 % of participants indicated that they were aware of the IDSA/ATS guideline. The top ranked barriers to VAP management included: 1) having multiple physician groups managing VAP, 2) variation in VAP management by differing ICU services, 3) physicians and level of training, and 4) renal failure complicating doses of antibiotics.

Facilitators to VAP management included presence of multidisciplinary rounds that include nurses, pharmacist and respiratory therapists, and awareness of the IDSA/ATS guideline. This awareness was associated with receiving effective training on management of VAP, keeping up to date on nosocomial infection literature, and belief that performing a bronchoscopy to diagnose VAP would help with expeditious diagnosis of VAP.

Conclusions

Findings from our study complement existing studies by identifying perceptions of the many different types of healthcare workers in ICU settings. These findings have implications for antibiotic stewardship teams, clinicians, and organizational leaders.

High-resolution mass spectrometry for exploring metabolic signatures of sepsis-induced acute kidney injury

Sepsis is a commonly encountered scenario in an intensive care unit (ICU), and the kidney is one of the organs frequently affected.