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

Recent Advances in Monoclonal Antibody-Based Approaches in the Management of Bacterial Sepsis

Sepsis is a life-threatening condition characterized by an uncontrolled inflammatory response to an infectious agent and its antigens. Immune cell activation against the antigens causes severe distress that mediates a strong inflammatory response in vital organs. Sepsis is responsible for a high rate of morbidity and mortality in immunosuppressed patients. Monoclonal antibody (mAb)-based therapeutic strategies are now being explored as a viable therapy option for severe sepsis and septic shock. Monoclonal antibodies may provide benefits through two major strategies: (a) monoclonal antibodies targeting the pathogen and its components, and (b) mAbs targeting inflammatory signaling may directly suppress the production of inflammatory mediators. The major focus of mAb therapies has been bacterial endotoxin (lipopolysaccharide), although other surface antigens are also being investigated for mAb therapy. Several promising candidates for mAbs are undergoing clinical trials at present. Despite several failures and the investigation of novel targets, mAb therapy provides a glimmer of hope for the treatment of severe bacterial sepsis and septic shock. In this review, mAb candidates, their efficacy against controlling infection, with special emphasis on potential roadblocks, and prospects are discussed.

Long noncoding RNA MALAT1 inhibition attenuates sepsis-induced acute lung injury through modulating the miR-129-5p/PAX6/ZEB2 axis

This research aimed to investigate the role of the long noncoding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/microRNA-129-5p (miR-129-5p)/paired box gene 6 (PAX6) axis in sepsis-induced acute lung injury (ALI). MLE-12 cells and C57BL/6 mice were induced by LPS to establish lung injury in in vitro and in vivo models. Cell viability and apoptosis were measured by cell counting kit-8 assay and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) staining, respectively. Levels of inflammatory cytokines in cell supernatants and bronchoalveolar lavage fluid (BALF) were detected by ELISA. Lung injury was evaluated by lung wet weight-to-dry weight ratio and hematoxylin-eosin staining. MALAT1, PAX6, and zinc finger E-box-binding homeobox 2 (ZEB2) expression was elevated and miR-129-5p expression was reduced in the serum of patients with sepsis-induced ALI, LPS-induced MLE-12 cells, and lung tissues of ALI mice. MALAT1 interference delayed the LPS-induced cell proliferation decrease, apoptosis increase, and inflammatory factor increase. miR-129-5p inhibition could reverse the delaying effect of MALAT1 interference on LPS-induced lung cell injury. PAX6 overexpression (oe) reversed the inhibitory effect of miR-129-5p oe on LPS-induced lung cell injury. Downregulating MALAT1 reduced pulmonary edema, inflammatory cytokine levels, lung injury, and apoptosis in ALI mice. Moreover, miR-129-5p suppression or PAX6 oe reversed the delaying effect of MALAT1 interference on sepsis-induced ALI. MALAT1 aggravates sepsis-induced ALI via the miR-129-5p/PAX6/ZEB2 axis.

Pharmacokinetic study of high-dose oral rifampicin in critically Ill patients with multidrug-resistant Acinetobacter baumannii infection

PURPOSE

Although rifampicin (RIF) is used as a synergistic agent for multidrug-resistant Acinetobacter baumannii (MDR-AB) infection, the optimal pharmacokinetic (PK) indices of this medication have not been studied in the intensive care unit (ICU) settings. This study aimed to evaluate the PK of high dose oral RIF following fasting versus fed conditions in terms of achieving the therapeutic goals in critically ill patients with MDR-AB infections.

METHODS

29 critically ill patients were included in this study. Under fasting and non-fasting conditions, RIF was given at 1200 mg once daily through a nasogastric tube. Blood samples were obtained at seven time points: exactly before administration of the drug, and at 1, 2, 4, 8, 12, and 24 h after RIF ingestion. To quantify RIF in serum samples, high-performance liquid chromatography (HPLC) was used. The MONOLIX Software and the Monte Carlo simulations were employed to estimate the PK parameters and describe the population PK model.

RESULTS

The mean area under the curve over the last 24-h (AUC0-24) value and accuracy (mean ± standard deviation) in the fasting and fed states were 220.24 ± 119.15 and 290.55 ± 276.20 μg × h/mL, respectively. There was no significant difference among AUCs following fasting and non-fasting conditions (P > 0.05). The probability of reaching the therapeutic goals at the minimum inhibitory concentration (MIC) of 4 mg/L, was only 1.6%.

CONCLUSION

In critically ill patients with MDR-AB infections, neither fasting nor non-fasting administrations of high-dose oral RIF achieve the therapeutic aims. More research is needed in larger populations and with measuring the amount of protein-unbound RIF levels.

Remdesivir Administration in COVID-19 Patients With Renal Impairment: A Systematic Review

BACKGROUND

Remdesivir (RDV) is the main antiviral for the treatment of moderate to severe forms of Coronavirus disease 2019 (COVID-19). Several studies revealed a shortening time to clinical improvement of COVID-19 and mortality benefits in patients receiving RDV. The patients with renal disease were excluded from large clinical trials of RDV, and the probable nephrotoxicity of the drug, its metabolites, and the vehicle (sulfobutylether-β-cyclodextrin) have led to the recommendation against using RDV in patients with an estimated glomerular filtration rate of <30 mL/min.

AREAS OF UNCERTAINTY

This systematic review aimed to collect data about the necessity and safety administration of RDV in the setting of renal impairment.

DATA SOURCES

Search through databases including MEDLINE, ScienceDirect, Cochrane Library, and PubMed was performed. The studies were carried out in adults and enrolled patients with different types of renal impairment (ie, acute kidney injury, chronic kidney disease, kidney transplant, and renal replacement therapy) were included. Eligible studies were assessed, and required data were extracted.

RESULTS

Twenty-two cross-sectional studies, cohorts, case reports, and case series were included in this review. The mortality rate was between 7.3% and 50%, and various severity of COVID-19 was included in the studies. None of them reported an increase in adverse effects attributed to RDV administration. A decrease in inflammatory mediators and other benefits were obvious.

CONCLUSIONS

Although the manufacturer's labeling does not recommend RDV administration in patients with severe renal impairment, it seems that nephrotoxicity is less concerning in the population of these patients. Moreover, RDV may be helpful in acute kidney injury induced by the viral invasion of COVID-19. To the best of our knowledge, this is the first systematic review of the use of RDV in kidney failure. Larger, well-designed, and pharmacokinetic studies are required to have a safe and logical recommendation about the use of RDV in patients with renal disorders.

Pulsed Electromagnetic Field (PEMF) Treatment Reduces Lipopolysaccharide-Induced Septic Shock in Mice

Despite advances in medicine, mortality due to sepsis has not decreased. Pulsed electromagnetic field (PEMF) therapy is emerging as an alternative treatment in many inflammation-related diseases. However, there are few studies on the application of PEMF therapy to sepsis. In the current study, we examined the effect of PEMF therapy on a mouse model of lipopolysaccharide (LPS)-induced septic shock. Mice injected with LPS and treated with PEMF showed higher survival rates compared with the LPS group. The increased survival was correlated with decreased levels of pro-inflammatory cytokine mRNA expression and lower serum nitric oxide levels and nitric oxide synthase 2 mRNA expression in the liver compared with the LPS group. In the PEMF + LPS group, there was less organ damage in the liver, lungs, spleen, and kidneys compared to the LPS group. To identify potential gene targets of PEMF treatment, microarray analysis was performed, and the results showed that 136 genes were up-regulated, and 267 genes were down-regulated in the PEMF + LPS group compared to the LPS group. These results suggest that PEMF treatment can dramatically decrease septic shock through the reduction of pro-inflammatory cytokine gene expression. In a clinical setting, PEMF may provide a beneficial effect for patients with bacteria-induced sepsis and reduce septic shock-induced mortality.

Adherence to practice guidelines for the management of febrile neutropenia in patients undergoing hematopoietic stem cell transplantation: An observational study in a referral center in Iran

INTRODUCTION

Patients undergoing hematopoietic stem cell transplantation (HSCT) are suspected to develop febrile neutropenia (FN) and severe infections. Therefore, appropriate prescription of antibiotics in these patients is crucial to reduce the rates of morbidity, mortality, and antimicrobial resistance. The present study aimed to evaluate the physicians' prescription and adherence to the FN clinical guidelines among patients undergoing HSCT.

METHODS

This prospective observational single-center study was conducted during a 15-month period in a tertiary referral hospital in Iran. The patients with at least one episode of FN following HSCT were included in the current study. The physicians' adherence to the Infectious Diseases Society of America (IDSA) and National Comprehensive Cancer Network (NCCN) clinical guidelines for the management of FN was evaluated using prescription data and medical record reviews.

RESULTS

Two hundred and fifteen patients with 297 FN episodes were evaluated. The timing of antibiotics and the selection of the initial regimen were considered guideline-based therapy. However, antibiotic dosing and initial regimen modification were not followed in terms of the guideline recommendations in 58.1% of the patients. In particular, vancomycin was inappropriately given in 83.1% of patients. The overall adherence of physicians to the guidelines was 35.8%.

CONCLUSION

Non-adherence to clinical guidelines is high particularly in initial regimen modification and administration of vancomycin, which affects hospital stay and patient's outcome. Implementation of guideline-review sessions to raise the awareness of the physicians and to improve the rational use of antimicrobial agents may be crucial.

Relationship between amikacin pharmacokinetics and biological parameters associated with organ dysfunction: a case series study of critically ill patients with intra-abdominal sepsis

OBJECTIVES

This study aimed to evaluate the relationship between amikacin pharmacokinetics and the biomarkers associated with organ dysfunction in critically ill patients with intra-abdominal sepsis.

METHODS

A case series involving critically ill patients with intra-abdominal sepsis who received an amikacin loading dose of 20-25 mg/kg intravenous infusion was studied. The 1-, 2-, 4-, 6- and 24-hour amikacin serum concentrations were measured to calculate the pharmacokinetic parameters. The Sequential Organ Failure Assessment (SOFA) score, white blood cells, neutrophil to lymphocyte ratio, platelet count, serum creatinine, creatinine clearance, bilirubin, partial pressure of oxygen to fraction of inspired oxygen ratio, serum albumin, procalcitonin, lactate level, erythrocyte sedimentation rate (ESR) and C-reactive protein were recorded. A linear regression analysis was performed to examine the relationship between the amikacin pharmacokinetics and the biological parameters.

RESULTS

Twenty-one patients were studied. A significant correlation was found between the volume of distribution and ESR (p<0.05, r=0.844). Moreover, drug clearance had a significant inverse correlation with serum lactate (p<0.05, r=-0.603). No other significant correlations were found.

CONCLUSIONS

ESR and serum lactate were identified as useful predictors of amikacin pharmacokinetics in critically ill patients with intra-abdominal sepsis and may help guide the selection of appropriate empirical dosing.

Evaluation of amikacin dosing schedule in critically ill elderly patients with different stages of renal dysfunction

OBJECTIVES

Amikacin is still a widely used aminoglycoside for the treatment of life-threatening infections. The pharmacokinetic parameters of this antibiotic may be altered in critically ill conditions. Moreover, in the elderly population, pathophysiological changes affect these pharmacokinetic variables, making it difficult to predict the appropriate dose and dosing schedule for amikacin. This study aimed to characterise the pharmacokinetics of amikacin in critically ill elderly patients with renal dysfunction, and to evaluate if the available dose adjustment schedules dependent on renal function would be appropriate for empirical dosing.

METHODS

Critically ill patients aged >60 years with a creatinine clearance of >20 mL/min in need of treatment with amikacin were randomly enrolled. All the patients received approximately 25 mg/kg amikacin. The patients were then divided into three groups according to the stages of their renal dysfunction based on creatinine clearance, and the optimum time to re-dosing was calculated for each group. The pharmacokinetic parameters of the patients were calculated and estimated as population pharmacokinetic data.

RESULTS

Of 30 patients, only 20% attained the target peak levels of amikacin of >64 mg/L. In addition, the mean volume of distribution was 0.47 L/kg. There was a poor correlation between amikacin clearance and creatinine clearance. The difference in amikacin half-life was not statistically significant among any of the stages of renal impairment.

CONCLUSIONS

The initial dosing of amikacin in critically ill elderly patients should not be reduced, even in the context of renal impairment. Regarding the dose adjustment in renal impairment, dosing intervals estimation, no decision can be made based on the creatinine clearance and the first dose individualisation method in terms of the two-sample measurements may be considered as an appropriate strategy.

Management of a critically ill patient with COVID-19-related fulminant myocarditis: A case report

A 78-year-old man with COVID-19 infection was admitted. Initial echocardiography indicated left ventricular ejection fraction (LVEF) of 15%, high pulmonary arterial pressure, severe left ventricular dysfunction, mild diastolic dysfunction, mild regurgitation mitral valve, and normal septal thickness. Considering the probable diagnosis of COVID-19-related myocarditis, the patient was early managed with the antivirals, immunomodulatory agents, a high dose of ascorbic acid, melatonin, and immunoglobulin therapy. His clinical condition was improved and his last echocardiography revealed LVEF of 40% and improvement in systolic and diastolic dysfunction. The clinicians should be aware of the potentially lethal cardiac complication of COVID-19, especially in geriatrics.

An UPLC-PDA assay for simultaneous determination of seven antibiotics in human plasma

Appropriate antibiotic dosing in critically ill patients requires concentration monitoring due to the occurrence of pathophysiological changes and frequent extracorporeal therapy that could significantly alter the normal pharmacokinetics of drugs. Herein, we describe an ultra-performance liquid chromatography with photodiode array (UPLC-PDA) for the simultaneous concentration determination of seven frequently used antibiotics (meropenem, cefotaxime, cefoperazone, piperacillin, linezolid, moxifloxacin, and tigecycline) in plasma from critically ill patients. The analytes were extracted from 200 μL human plasma by the addition of methanol for protein precipitation. The chromatographic separation was achieved using an ACQUITY UPLC HSS T3 column (2.1 × 50 mm, 1.8 µm) with a water (containing 0.1% trifluoroacetic acid)/acetonitrile linear gradient at a flow rate of 0.5 mL/min in a 4.5 min turn-around time. PDA detection wavelength was set individually for the analytes. The method was fully validated according to the European Medicines Agency (EMA) guideline. The lower limits of quantification for the analytes were between 0.05 and 0.8 μg/mL. The method is accurate (intra/inter-assay bias -8.4 to +12.4%) and precise (intra/inter-assay coefficient of variations 0.9-10.1%) over the clinically relevant plasma concentration ranges (upper limits of quantification 5-400 µg/mL). The applicability of the method has been successfully demonstrated by analyzing plasma samples collected from critically ill patients undergoing continuous renal replacement therapy.