The Effect of Renal Replacement Therapy and Antibiotic Dose on Antibiotic Concentrations in Critically Ill Patients: Data From the Multinational Sampling Antibiotics in Renal Replacement Therapy Study.

BACKGROUND: The optimal dosing of antibiotics in critically ill patients receiving renal replacement therapy (RRT) remains unclear. In this study, we describe the variability in RRT techniques and antibiotic dosing in critically ill patients receiving RRT and relate observed trough antibiotic concentrations to optimal targets. METHODS: We performed a prospective, observational, multinational, pharmacokinetic study in 29 intensive care units from 14 countries. We collected demographic, clinical, and RRT data. We measured trough antibiotic concentrations of meropenem, piperacillin-tazobactam, and vancomycin and related them to high- and low-target trough concentrations. RESULTS: We studied 381 patients and obtained 508 trough antibiotic concentrations. There was wide variability (4-8-fold) in antibiotic dosing regimens, RRT prescription, and estimated endogenous renal function. The overall median estimated total renal clearance (eTRCL) was 50 mL/minute (interquartile range [IQR], 35-65) and higher eTRCL was associated with lower trough concentrations for all antibiotics (P < .05). The median (IQR) trough concentration for meropenem was 12.1 mg/L (7.9-18.8), piperacillin was 78.6 mg/L (49.5-127.3), tazobactam was 9.5 mg/L (6.3-14.2), and vancomycin was 14.3 mg/L (11.6-21.8). Trough concentrations failed to meet optimal higher limits in 26%, 36%, and 72% and optimal lower limits in 4%, 4%, and 55% of patients for meropenem, piperacillin, and vancomycin, respectively. CONCLUSIONS: In critically ill patients treated with RRT, antibiotic dosing regimens, RRT prescription, and eTRCL varied markedly and resulted in highly variable antibiotic concentrations that failed to meet therapeutic targets in many patients.

Secretory Phospholipase A2-IIA Protein and mRNA Pools in Extracellular Vesicles of Bronchoalveolar Lavage Fluid from Patients with Early Acute Respiratory Distress Syndrome: A New Perception in the Dissemination of Inflammation?

Secretory phospholipase-IIA A2 (sPLA2-IIA) is expressed in a variety of cell types under inflammatory conditions. Its presence in the bronchoalveolar lavage (BAL) fluid of patients with acute respiratory distress syndrome (ARDS) is associated with the severity of the injury. Exosomal type extracellular vesicles, (EVs), are recognized to perform intercellular communication. They may alter the immune status of recipient target cells through cargo shuttling. In this work, we characterized the exosomal type EVs isolated from BAL fluid of patients with early and late ARDS as compared to control/non-ARDS patients, through morphological (confocal and electron microscopy) and biochemical (dynamic light scattering, qRT-PCR, immunoblotting) approaches. We provide evidence for the presence of an sPLA2-IIA-carrying EV pool that coprecipitates with exosomes in the BAL fluid of patients with ARDS. PLA2G2A mRNA was present in all the samples, although more prominently expressed in early ARDS. However, the protein was found only in EVs from early phase ARDS. Under both forms, sPLA2-IIA might be involved in inflammatory responses of recipient lung cells during ARDS. The perception of the association of sPLA2-IIA to the early diagnosis of ARDS or even with a mechanism of development and propagation of lung inflammation can help in the adoption of appropriate and innovative therapeutic strategies.

Effects of inhaled carbon monoxide and glucocorticoids in porcine endotoxin sepsis.

BACKGROUND: Recent animal studies have demonstrated that pre-treatment with inhaled carbon monoxide (iCO) exert anti-inflammatory effects in various septic models. In all these models, there is no information whether iCO might act therapeutically after the onset of septic damage. The objective of this study was to investigate the potential anti-inflammatory effects of iCO to treat established injury in a model of porcine endotoxin sepsis. METHODS: Five groups of pigs (n=6 in each group), were studied under anesthesia and mechanical ventilation: healthy control group (HC); lipopolysaccharide (LPS) groups, animals received continuous IV infusion of LPS for 6 hours; 2.5 hours after of LPS infusion treated groups received either: 250 ppm of iCO for 3.5 h, (LPS+CO group); 3 mg/Kg hydrocorti-sone bolus [Steroid (ST)], (LPS+ST group); or both steroid and iCO, (LPS+CO+ST group). Measurements of haemodynamics, blood gases, respiratory mechanics and biochemistry of organ function, were made. At the end of the experiment lung tissue was taken for analysis of histology and inflammatory markers: tumor necrosis factor-alpha (TNF-α), nuclear factor kappa B (NF-κB), activator protein-1 (AP-1) and glucocorticoid receptor (GR). RESULTS: LPS administration induced a dramatic inflammatory injury in lungs, increased expression of TNF-α, NF-κB, AP-1, down regulation of GR, pulmonary hypertension and severe deterioration of respiratory mechanics, oxygenation and organ function. Treatment with steroids and to greater extent with iCO significantly improved the microscopic appearance of the lung but had no effect on inflammatory markers. iCO significantly decreased pulmonary hypertension induced by LPS, without an obvious protective effect on organ function. CONCLUSION: Using this porcine sepsis model we find that treatment with iCO after the septic damage decreases pulmonary hypertension and partially protects the lung tissue from the inflammatory destruction induced by LPS but has no beneficial effects on organ function.