Optimizing the Use of Antibiotic Agents in the Pediatric Intensive Care Unit: A Narrative Review

Update on Therapeutic Drug Monitoring of Beta-Lactam Antibiotics in Critically Ill Patients—A Narrative Review

Beta-lactam antibiotics remain one of the most preferred groups of antibiotics in critical care due to their excellent safety profiles and their activity against a wide spectrum of pathogens. The cornerstone of appropriate therapy with beta-lactams is to achieve an adequate plasmatic concentration of a given antibiotic, which is derived primarily from the minimum inhibitory concentration (MIC) of the specific pathogen. In a critically ill patient, the plasmatic levels of drugs could be affected by many significant changes in the patient’s physiology, such as hypoalbuminemia, endothelial dysfunction with the leakage of intravascular fluid into interstitial space and acute kidney injury. Predicting antibiotic concentration from models based on non-critically ill populations may be misleading. Therapeutic drug monitoring (TDM) has been shown to be effective in achieving adequate concentrations of many drugs, including beta-lactam antibiotics. Reliable methods, such as high-performance liquid chromatography, provide the accurate testing of a wide range of beta-lactam antibiotics. Long turnaround times remain the main drawback limiting their widespread use, although progress has been made recently in the implementation of different novel methods of antibiotic testing. However, whether the TDM approach can effectively improve clinically relevant patient outcomes must be proved in future clinical trials.

Perioperative Antibiotic Prophylaxis in Pediatric Cardiac Surgery-Simple Is Better

Pediatric cardiac surgery requires perioperative antibiotic prophylaxis (PAP) to reduce the risk of surgical site infections. However, the complexity of these procedures and the metabolic immaturity of children impede the establishment of PAP regimens that are both efficacious and in line with antimicrobial stewardship (AMS). In this study, we compared two PAP regimens: cefazolin with gentamicin (in a retrospective group) and cefazolin only (prospectively) in children undergoing elective cardiac surgery. In the prospective group, additional elements of AMS were introduced, i.e., restricted access to cefazolin and more diligent use of empirical antibiotics proceeded by consultation with an AMS team. The rate of surgical site infections (SSI), the scope of PAP deviations, and the postoperative use of antibiotics other than PAP within 30 days after surgery were analyzed. There were no significant differences in the rate of SSIs between the groups (3.9% vs. 1.2% in the prospective and retrospective groups, respectively (p = 0.35)). However, in the prospective group, the PAP violation was significantly reduced compared with the retrospective group (full compliance with the PAP regimen was 45.5% vs. 4.8%, p < 0.001, respectively). In addition, a reduction of postoperative antibiotic use was observed in the prospective group (0.991 vs. 1.932 defined daily doses, respectively).

Factors to be Considered in Advancing Pediatric Critical Care Across the World

This article reviews the many factors that have to be taken into account as we consider the advancement of pediatric critical care (PCC) in multiple settings across the world. The extent of PCC and the range of patients who are cared for in this environment are considered. Along with a review of the ongoing treatment and technology advances in the PCC setting, the structures and systems required to support these services are also considered. Finally the question of how PCC can be made sustainable in a volatile world with the impacts of global crises such as climate change is addressed.

Subinhibitory Concentrations of Antibiotics Exacerbate Staphylococcal Infection by Inducing Bacterial Virulence

Antibiotics are widely used for the treatment of bacterial infections. However, injudicious use of antibiotics based on an empirical method may lead to the emergence of resistant strains. Despite appropriate administration of antibiotics, their concentrations may remain subinhibitory in the body, due to individual variations in tissue distribution and metabolism rates. This may promote bacterial virulence and complicate the treatment strategies. To investigate whether the administration of certain classes of antibiotics will induce bacterial virulence and worsen the infection under in vivo conditions. Different classes of antibiotics were tested in vitro for their ability to induce virulence in a methicillin-resistant S. aureus strain Mu3 and clinical isolates. Antibiotic-induced pathogenicity was assessed in vivo using mouse peritonitis and bacteremia models. In vitro, β-lactam antibiotics and tetracyclines induced the expression of multiple surface-associated virulence factors as well as the secretion of toxins. In peritonitis and bacteremia models, mice infected with MRSA and treated with ampicillin, ceftazidime, or tetracycline showed enhanced bacterial pathogenicity. The release of induced virulence factors in vivo was confirmed in a histological examination. Subinhibitory concentrations of antibiotics belonging to β-lactam and tetracycline aggravated infection by inducing staphylococcal virulence in vivo. Thus, when antibiotics are required, it is preferable to employ combination therapy and to initiate the appropriate treatment plan, following diagnosis. Our findings emphasize the risks associated with antibiotic-based therapy and underline the need for alternative therapeutic options. IMPORTANCE Antibiotics are widely applied to treat infectious diseases. Empirically treatment with incorrect antibiotics, or even correct antibiotics always falls into subinhibitory concentrations, due to dosing, distribution, or secretion. In this study, we have systematically evaluated in vitro virulence induction effect of antibiotics and in vivo exacerbated infection. The major highlight of this work is to prove the β-lactam and tetracyclines antibiotics exacerbated disease is due to their induction effect on staphylococcal virulence. This phenomenon is common and suggests that if β-lactam antibiotics remain the first line of defense during empirical therapy, we either need to increase patient reliability or the treatment approach may improve in the future when paired with anti-virulence drugs.

Case Report: Therapeutic Drug Monitoring of Polymyxin B During Continuous Renal Replacement Therapy in Two Pediatric Patients: Do Not Underestimate Extracorporeal Clearance

Background: Polymyxin B has become the last choice for patient with carbapenem-resistant bacterial infection. However, the optimal dosing of polymyxin B in critically ill children receiving continuous renal replacement therapy (CRRT) remains unclear.

Case Presentation: Two cases of critically ill pediatric patients (7 years old) with acute kidney injury requiring continuous renal replacement (CRRT) received polymyxin B treatment due to carbapenem-resistant organism bloodstream infections. Therapeutic drug monitoring (TDM) of polymyxin B was carried out by liquid chromatography tandem mass spectrometry (LC-MS/MS). The average steady-state plasma concentration (C_ss,avg) of 2–4 mg/L was set as the target level. Initial polymyxin B dose was 1 mg/kg every 12 h, and the C_ss,avg at 4–5th dosing were 1.76 and 1.06 mg/L for patient 1 and patient 2, respectively. TDM-guided polymyxin B dose was escalated to 2 mg/kg every 12 h for both patients, resulting in the C_ss,avg of 2.60 and 1.73 mg/L, and the infection was controlled subsequently. C_ss,avg of polymyxin B with the same dosing regimens and infusion length were different during CRRT and after termination of CRRT for both patients (2.60 mg/L vs. 4.94 mg/L with 2 mg/kg every 12 h in 2 h infusion for patient 1; and 1.73 mg/L vs. 3.53 mg/L with 2 mg/kg every 12 h in 2 h infusion for patient 2). The estimation of drug exposure (estimated by AUC_ss,12h at the same dose) during CRRT and cessation of CRRT showed that 45% and 51% of polymyxin B was cleared during CRRT.

Conclusion: Our study showed high clearance of polymyxin B through CRRT, and supplanted dosing of polymyxin B is necessary in pediatric patients undergoing CRRT.

Antimicrobial Therapy in Pediatric Sepsis: What Is the Best Strategy?

Pediatric sepsis is a relevant cause of morbidity and mortality in this age group. Children are affected differently in high and low-income countries. Antibiotics are crucial for the treatment of sepsis, but indiscriminate use can increase resistance worldwide. The choice of a correct empiric therapy takes into consideration the site of infection, local epidemiology, host comorbidities and recent antibiotic exposure. Antibiotics should be administered in the first hour for patients with septic shock, and always intravenously or via intraosseous access. Culture results and clinical improvement will guide de-escalation and length of treatment. New diagnostic methods can help improve the prescription of adequate treatment. Prevention of sepsis includes vaccination and prevention of healthcare-associated infections. More research and education for awareness of sepsis is needed to improve care.