Pharmacokinetic changes of antibiotic, antiviral, antituberculosis and antifungal agents during extracorporeal membrane oxygenation in critically ill adult patients

Renal Replacement Therapy as a New Indicator of Voriconazole Clearance in a Population Pharmacokinetic Analysis of Critically Ill Patients

AIMS

The pharmacokinetic (PK) profiles of voriconazole in intensive care unit (ICU) patients differ from that in other patients. We aimed to develop a population pharmacokinetic (PopPK) model to evaluate the effects of using extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT) and those of various biological covariates on the voriconazole PK profile.

METHODS

Modeling analyses of the PK parameters were conducted using the nonlinear mixed-effects modeling method (NONMEM) with a two-compartment model. Monte Carlo simulations (MCSs) were performed to observe the probability of target attainment (PTA) when receiving CRRT or not under different dosage regimens, different stratifications of quick C-reactive protein (qCRP), and different minimum inhibitory concentration (MIC) ranges.

RESULTS

A total of 408 critically ill patients with 746 voriconazole concentration-time data points were included in this study. A two-compartment population PK model with qCRP, CRRT, creatinine clearance rate (CLCR), platelets (PLT), and prothrombin time (PT) as fixed effects was developed using the NONMEM.

CONCLUSIONS

We found that qCRP, CRRT, CLCR, PLT, and PT affected the voriconazole clearance. The most commonly used clinical regimen of 200 mg q12h was sufficient for the most common sensitive pathogens (MIC ≤ 0.25 mg/L), regardless of whether CRRT was performed and the level of qCRP. When the MIC was 0.5 mg/L, 200 mg q12h was insufficient only when the qCRP was <40 mg/L and CRRT was performed. When the MIC was ≥2 mg/L, a dose of 300 mg q12h could not achieve ≥ 90% PTA, necessitating the evaluation of a higher dose.

Pharmacokinetic Modeling Using Real-World Data to Optimize Unfractionated Heparin Dosing in Pediatric Patients on Extracorporeal Membrane Oxygenation and Evaluate Target Achievement-Clinical Outcomes Relationship

Unfractionated heparin (UFH) is a commonly used anticoagulant for pediatric patients undergoing extracorporeal membrane oxygenation (ECMO), but evidence is lacking on the ideal dosing. We aimed to (1) develop a population pharmacokinetic (PK) model for UFH, measured through anti-factor Xa assay; (2) optimize UFH starting infusions and dose titrations through simulations; and (3) explore UFH exposure-clinical outcomes relationship. Data from 218 patients admitted to Utah's Primary Children's Hospital were retrospectively collected. A 1-compartment PK model with time-varying clearance (CL) adequately described UFH PK. Weight on CL and volume of distribution and ECMO circuit change on CL were significant covariates. The typical estimates for initial CL and first-order rate constant to reach steady-state CL were 0.57 L/(h·10 kg) and 0.02/h. Comparable to non-ECMO patients, the typical steady-state CL was 0.81 L/(h·10 kg). Simulations showed that a 75 IU/kg UFH bolus dose followed by starting infusions of 25 and 20 IU/h/kg for patients aged younger than 6 years and 6 years or older, respectively, achieved the therapeutic target in 56.6% of all patients, whereas only 3.1% exceeded the target. The proposed UFH titration schemes achieved the target in more than 90% of patients while less than 0.63% were above the target after 24 and 48 hours of treatment. The median intensive care unit survival time in patients within and below the target at 24 hours was 136 and 66 hours, respectively. In conclusion, PK model of UFH was developed for pediatric patients on ECMO. The proposed UFH dosing scheme attained the anti-factor Xa target rapidly and safely.

Isavuconazole Exposure in Critically Ill Patients Treated with Extracorporeal Membrane Oxygenation: Two Case Reports and a Narrative Literature Review

Effective dosing of isavuconazole in patients supported by extracorporeal membrane oxygenation (ECMO) is important due to the role of isavuconazole as a first-line treatment in patients with influenza- and COVID-19-associated pulmonary aspergillosis. To date, robust pharmacokinetic data in patients supported by ECMO are limited. Therefore, it is unknown whether ECMO independently impacts isavuconazole exposure. We measured isavuconazole plasma concentrations in two patients supported by ECMO and estimated individual pharmacokinetic parameters using non-compartmental analysis and two previously published population pharmacokinetic models. Furthermore, a narrative literature review on isavuconazole exposure in adult patients receiving ECMO was performed. The 24 h areas under the concentration-time curve and trough concentrations of isavuconazole were lower in both patients compared with exposure values published before. In the literature, highly variable isavuconazole concentrations have been documented in patients with ECMO support. The independent effect of ECMO versus critical illness itself on isavuconazole exposure cannot be deduced from our and previously published (case) reports. Pending additional data, therapeutic drug monitoring is recommended in critically ill patients, regardless of ECMO support.

Antimicrobial Pharmacokinetics and Pharmacodynamics in Critical Care: Adjusting the Dose in Extracorporeal Circulation and to Prevent the Genesis of Multiresistant Bacteria

Critically ill patients suffering from severe infections are prone to pathophysiological pharmacokinetic changes that are frequently associated with inadequate antibiotic serum concentrations. Minimum inhibitory concentrations (MICs) of the causative pathogens tend to be higher in intensive care units. Both pharmacokinetic changes and high antibiotic resistance likely jeopardize the efficacy of treatment. The use of extracorporeal circulation devices to support hemodynamic, respiratory, or renal failure enables pharmacokinetic changes and makes it even more difficult to achieve an adequate antibiotic dose. Besides a clinical response, antibiotic pharmacokinetic optimization is important to reduce the selection of strains resistant to common antibiotics. In this review, we summarize the present knowledge regarding pharmacokinetic changes in critically ill patients and we discuss the effects of extra-corporeal devices on antibiotic treatment together with potential solutions.

Pharmacokinetic Alterations Associated with Critical Illness

Haemodynamic, metabolic, and biochemical derangements in critically ill patients affect drug pharmacokinetics and pharmacodynamics making dose optimisation particularly challenging. Appropriate therapeutic dosing depends on the knowledge of the physiologic changes caused by the patient's comorbidities, underlying disease, resuscitation strategies, and polypharmacy. Critical illness will result in altered drug protein binding, ionisation, and volume of distribution; it will also decrease oral drug absorption, intestinal and hepatic metabolism, and renal clearance. In contrast, the resuscitation strategies and the use of vasoactive drugs may oppose these effects by leading to a hyperdynamic state that will increase blood flow towards the major organs including the brain, heart, kidneys, and liver, with the subsequent increase of drug hepatic metabolism and renal excretion. Metabolism is the main mechanism for drug clearance and is one of the main pharmacokinetic processes affected; it is influenced by patient-specific factors, such as comorbidities and genetics; therapeutic-specific factors, including drug characteristics and interactions; and disease-specific factors, like organ dysfunction. Moreover, organ support such as mechanical ventilation, renal replacement therapy, and extracorporeal membrane oxygenation may contribute to both inter- and intra-patient variability of drug pharmacokinetics. The combination of these competing factors makes it difficult to predict drug response in critically ill patients. Pharmacotherapy targeted to therapeutic goals and therapeutic drug monitoring is currently the best option for the safe care of the critically ill. The aim of this paper is to review the alterations in drug pharmacokinetics associated with critical illness and to summarise the available evidence.

Impact of Extracorporeal Membrane Oxygenation in an Infant Treated with Vancomycin: A Case Report

Vancomycin is a glycopeptide antibiotic used for prophylaxis and treatment of infections caused by methicillin-resistant Staphylococcus aureus. Although major organ sizes and functions mature during infancy, pharmacokinetic studies, especially those focused on infants, are limited. Changes in extracorporeal membrane oxygenation-related drug disposition largely contribute to changes in pharmacokinetics. Here, pharmacokinetic profiles of vancomycin in an infant receiving extracorporeal membrane oxygenation therapy are presented. A two-month-old Japanese infant with moderately decreased renal function was started on 12.0 mg/kg vancomycin every 8 h from day X for prophylaxis of pneumonia during extracorporeal membrane oxygenation therapy. As the trough concentration of vancomycin observed on day X+3 was 27.1 μg/mL, vancomycin was then discontinued. The trough concentration decreased to 18.6 μg/mL 24 h after discontinuation, and 9.0 mg/kg vancomycin every 12 h was restarted from day X+5. On day X+6, the trough concentration increased to 36.1 μg/mL, and vancomycin therapy was again discontinued. On day X+7, the trough concentration decreased to 22.4 μg/mL. The pharmacokinetic profiles of vancomycin based on first-order conditional estimation in this infant were as follows: plasma clearance = 0.053 L/kg/hour, distribution volume = 2.19 L/kg, and half-life = 29.5 h. This research reported the prolonged half-life of vancomycin during extracorporeal membrane oxygenation in infants with moderately decreased renal function.

Dose Optimization of Meropenem in Patients on Veno-Arterial Extracorporeal Membrane Oxygenation in Critically Ill Cardiac Patients: Pharmacokinetic/Pharmacodynamic Modeling

Background: Our objective was to determine an optimal dosage regimen of meropenem in patients receiving veno-arterial extracorporeal membrane oxygenation (V-A ECMO) by developing a pharmacokinetic/pharmacodynamic (PK/PD) model. Methods: This was a prospective cohort study. Blood samples were collected during ECMO (ECMO-ON) and after ECMO (ECMO-OFF). The population pharmacokinetic model was developed using nonlinear mixed-effects modeling. A Monte Carlo simulation was used (n = 10,000) to assess the probability of target attainment. Results: Thirteen adult patients on ECMO receiving meropenem were included. Meropenem pharmacokinetics was best fitted by a two-compartment model. The final pharmacokinetic model was: CL (L/h) = 3.79 × 0.44CRRT, central volume of distribution (L) = 2.4, peripheral volume of distribution (L) = 8.56, and intercompartmental clearance (L/h) = 21.3. According to the simulation results, if more aggressive treatment is needed (100% fT > MIC target), dose increment or extended infusion is recommended. Conclusions: We established a population pharmacokinetic model for meropenem in patients receiving V-A ECMO and revealed that it is not necessary to adjust the dosage depending on V-A ECMO. Instead, more aggressive treatment is needed than that of standard treatment, and higher dosage is required without continuous renal replacement therapy (CRRT). Also, extended infusion could lead to better target attainment, and we could provide updated nomograms of the meropenem dosage regimen.

An LC-MS/MS method for the simultaneous determination of 18 antibacterial drugs in human plasma and its application in therapeutic drug monitoring

Antimicrobial resistance (AMR) is a major threat to global health due to the wide use of antibacterial drugs. Multiple studies show that the pharmacokinetic/pharmacodynamic (PK/PD) studies of antibiotics are an approach to prevent/delay AMR. The pharmacokinetic parameters of antibiotics are the basis of PK/PD studies, and therapeutic drug monitoring (TDM) is the key method to obtain pharmacokinetic information. We developed an ultra-performance liquid chromatography–tandem mass spectrometry to determine 18 antibacterial drugs (piperacillin, cefazolin, cefuroxime, cefoperazone, ceftriaxone, cefepime, aztreonam, meropenem, imipenem, levofloxacin, moxifloxacin, azithromycin, clindamycin, tigecycline, linezolid, vancomycin, voriconazole and caspofungin) in human plasma for practical clinical usage. Samples were prepared using protein precipitation with methanol. Chromatographic separation was accomplished in 6 min on a BEH C₁₈ column (2.1 × 100 mm, 1.7 µm) using a gradient elution of acetonitrile and 0.1% formic acid in water at a flow rate of 0.3 ml/min. The electrospray ionization source interface was operated in the positive and negative ionization modes. Inter- and intra-day precision, accuracy, recovery, matrix effect, and stability were validated according to the Food and Drug Administration guidance. The correlation coefficients of calibration curves were all greater than 0.99. The accuracies of the 18 antibacterial drugs ranged from 89.1% to 112.4%. The intra-day precision of the analytes ranged from 1.4% to 9.3% and the inter-day precision from 2.1% to 7.2%. The matrix effects ranged from 93.1% to 105.8% and the extraction recoveries ranged between 90.1% and 109.2%. The stabilities of the 18 antibacterial drugs in plasma were evaluated by analyzing three different concentrations following storage at three storage conditions. All samples displayed variations less than 15.0%. The validated method was successfully applied to routine clinical TDM for 231 samples.

Sepsis Associated with Extracorporeal Membrane Oxygenation

Sepsis in patients on extracorporeal membrane oxygenation (ECMO) remains a serious complication. Its presence is a poor prognostic marker and increases overall mortality. Adult patients with prolonged duration on ECMO are at high risk of developing sepsis. Ventilator-associated pneumonia and bloodstream infections are the main sources of infection these patients. A strong early suspicion, drawing adequate volume for blood cultures, and early and timely administration of empirical antibiotics can help control the infection and decrease the morbidity and mortality. The diagnostic and the treatment are both challenging. Cardiac patients have increased risk of nosocomial infection while on ECMO, which may be in part due to longer cannulation times, as well as increased likelihood of undergoing major procedures or having an open chest.

β-Lactam Therapeutic Drug Monitoring in Critically Ill Patients: Weighing the Challenges and Opportunities to Assess Clinical Value

OBJECTIVE:

DATA SOURCES:

STUDY SELECTION:

DATA EXTRACTION:

DATA SYNTHESIS:

CONCLUSIONS:

Rifampicin for COVID-19

Vaccinations for coronavirus disease-2019 (COVID-19) have begun more than a year before, yet without specific treatments available. Rifampicin, critically important for human medicine (World Health Organization’s list of essential medicines), may prove pharmacologically effective for treatment and chemoprophylaxis of healthcare personnel and those at higher risk. It has been known since 1969 that rifampicin has a direct selective antiviral effect on viruses which have their own RNA polymerase (severe acute respiratory syndrome coronavirus 2), like the main mechanism of action of remdesivir. This involves inhibition of late viral protein synthesis, the virion assembly, and the viral polymerase itself. This antiviral effect is dependent on the administration route, with local application resulting in higher drug concentrations at the site of viral replication. This would suggest also trying lung administration of rifampicin by nebulization to increase the drug’s concentration at infection sites while minimizing systemic side effects. Recent in silico studies with a computer-aided approach, found rifampicin among the most promising existing drugs that could be repurposed for the treatment of COVID-19.

Antibiotics and ECMO in the Adult Population—Persistent Challenges and Practical Guides

Extracorporeal membrane oxygenation (ECMO) is an emerging treatment modality associated with a high frequency of antibiotic use. However, several covariables emerge during ECMO implementation, potentially jeopardizing the success of antimicrobial therapy. These variables include but are not limited to: the increased volume of distribution, altered clearance, and adsorption into circuit components, in addition to complex interactions of antibiotics in critical care illness. Furthermore, ECMO complicates the assessment of antibiotic effectiveness as fever, or other signs may not be easily detected, the immunogenicity of the circuit affects procalcitonin levels and other inflammatory markers while disrupting the immune system. We provided a review of pharmacokinetics and pharmacodynamics during ECMO, emphasizing practical application and review of patient-, illness-, and ECMO hardware-related factors.

Antifungal Drugs TDM: Trends and Update

PURPOSE

The increasing burden of invasive fungal infections results in growing challenges to antifungal (AF) therapeutic drug monitoring (TDM). This review aims to provide an overview of recent advances in AF TDM.

METHODS

We conducted a PubMed search for articles during 2016-2020 using "TDM" or "pharmacokinetics" or "drug-drug-interaction" with "antifungal," consolidated for each AF. Selection was limited to English language articles with human data on drug exposure.

RESULTS

More than 1000 articles matched the search terms. We selected 566 publications. The latest findings tend to confirm previous observations in real-life clinical settings. The pharmacokinetic variability related to special populations is not specific but must be considered. AF benefit-to-risk ratio, drug-drug interaction (DDI) profiles, and minimal inhibitory concentrations for pathogens must be known to manage at-risk situations and patients. Itraconazole has replaced ketoconazole in healthy volunteers DDI studies. Physiologically based pharmacokinetic modeling is widely used to assess metabolic azole DDI. AF prophylactic use was studied more for Aspergillus spp. and Mucorales in oncohematology and solid organ transplantation than for Candida (already studied). Emergence of central nervous system infection and severe infections in immunocompetent individuals both merit special attention. TDM is more challenging for azoles than amphotericin B and echinocandins. Fewer TDM requirements exist for fluconazole and isavuconazole (ISZ); however, ISZ is frequently used in clinical situations in which TDM is recommended. Voriconazole remains the most challenging of the AF, with toxicity limiting high-dose treatments. Moreover, alternative treatments (posaconazole tablets, ISZ) are now available.

CONCLUSIONS

TDM seems to be crucial for curative and/or long-term maintenance treatment in highly variable patients. TDM poses fewer cost issues than the drugs themselves or subsequent treatment issues. The integration of clinical pharmacology into multidisciplinary management is now increasingly seen as a part of patient care.

Machines that help machines to help patients: optimising antimicrobial dosing in patients receiving extracorporeal membrane oxygenation and renal replacement therapy using dosing software

Intensive care unit (ICU) patients with end-organ failure will require specialised machines or extracorporeal therapies to support the failing organs that would otherwise lead to death. ICU patients with severe acute kidney injury may require renal replacement therapy (RRT) to remove fluid and wastes from the body, and patients with severe cardiorespiratory failure will require extracorporeal membrane oxygenation (ECMO) to maintain adequate oxygen delivery whilst the underlying pathology is evaluated and managed. The presence of ECMO and RRT machines can further augment the existing pharmacokinetic (PK) alterations during critical illness. Significant changes in the apparent volume of distribution (V_d) and drug clearance (CL) for many important drugs have been reported during ECMO and RRT. Conventional antimicrobial dosing regimens rarely consider the impact of these changes and consequently, are unlikely to achieve effective antimicrobial exposures in critically ill patients receiving ECMO and/or RRT. Therefore, an in-depth understanding on potential PK changes during ECMO and/or RRT is required to inform antimicrobial dosing strategies in patients receiving ECMO and/or RRT. In this narrative review, we aim to discuss the potential impact of ECMO and RRT on the PK of antimicrobials and antimicrobial dosing requirements whilst receiving these extracorporeal therapies. The potential benefits of therapeutic drug monitoring (TDM) and dosing software to facilitate antimicrobial therapy for critically ill patients receiving ECMO and/or RRT are also reviewed and highlighted.

Voriconazole pharmacokinetics in a critically ill patient during extracorporeal membrane oxygenation

The pharmacokinetics (PK) of several drugs including antimicrobials might be highly altered during extracorporeal membrane oxygenation (ECMO) therapy. We present the change of voriconazole (VRC) PK during ECMO in a critically ill patient who received intravenous VRC at a maintenance dose of 200 mg every 12 h for empirical antifungal therapy. Two PK profiles were drawn before and after the initiation of ECMO therapy. Though the trough levels (both C₀ and C₁₂) with ECMO were slightly lower than that without ECMO (12.58 and 12.84 vs. 14.02 μg/mL), the peak levels and the area under the concentration-time curve from 0 h to 6 h (AUC_0-6) were comparable (16.36 vs. 16.06 μg/mL and 90.78 vs. 91.45 μg·h/mL, respectively), indicating that VRC plasma exposure during ECMO therapy did not greatly decrease in our patient. The circuit factors including the type of membrane should be taken into account to further identify the effects of ECMO on the PK of VRC.

Excessive unbound cefazolin concentrations in critically ill patients receiving veno-arterial extracorporeal membrane oxygenation (vaECMO): an observational study

The scope of extracorporeal membrane oxygenation (ECMO) is expanding, nevertheless, pharmacokinetics in patients receiving cardiorespiratory support are fairly unknown leading to unpredictable drug concentrations. Currently, there are no clear guidelines for antibiotic dosing during ECMO. This study aims to evaluate the pharmacokinetics (PK) of cefazolin in patients undergoing ECMO treatment. Total and unbound plasma cefazolin concentration of critically ill patients on veno-arterial ECMO were determined. Observed PK was compared to dose recommendations calculated by an online available, free dosing software. Concentration of cefazolin varied broadly despite same dosage in all patients. The mean total and unbound plasma concentration were high showing significantly (p = 5.8913 E−09) greater unbound fraction compared to a standard patient. Cefazolin clearance was significantly (p = 0.009) higher in patients with preserved renal function compared with CRRT. Based upon the calculated clearance, the use of dosing software would have led to lower but still sufficient concentrations of cefazolin in general. Our study shows that a “one size fits all” dosing regimen leads to excessive unbound cefazolin concentration in these patients. They exhibit high PK variability and decreased cefazolin clearance on ECMO appears to compensate for ECMO- and critical illness-related increases in volume of distribution.

A Large Retrospective Assessment of Voriconazole Exposure in Patients Treated with Extracorporeal Membrane Oxygenation

BACKGROUND

Voriconazole is one of the first-line therapies for invasive pulmonary aspergillosis. Drug concentrations might be significantly influenced by the use of extracorporeal membrane oxygenation (ECMO). We aimed to assess the effect of ECMO on voriconazole exposure in a large patient population.

METHODS

Critically ill patients from eight centers in four countries treated with voriconazole during ECMO support were included in this retrospective study. Voriconazole concentrations were collected in a period on ECMO and before/after ECMO treatment. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure and to assess the impact of possible saturation of the circuit's binding sites over time.

RESULTS

Sixty-nine patients and 337 samples (190 during and 147 before/after ECMO) were analyzed. Subtherapeutic concentrations (<2 mg/L) were observed in 56% of the samples during ECMO and 39% without ECMO (p = 0.80). The median trough concentration, for a similar daily dose, was 2.4 (1.2-4.7) mg/L under ECMO and 2.5 (1.4-3.9) mg/L without ECMO (p = 0.58). Extensive inter-and intrasubject variability were observed. Neither ECMO nor squared day of ECMO (saturation) were retained as significant covariates on voriconazole exposure.

CONCLUSIONS

No significant ECMO-effect was observed on voriconazole exposure. A large proportion of patients had voriconazole subtherapeutic concentrations.

Evaluation, Treatment, and Impact of Neurologic Injury in Adult Patients on Extracorporeal Membrane Oxygenation: a Review

Purpose

Extracorporeal membrane oxygen (ECMO) is increasingly used as an advanced form of life support for cardiac and respiratory failure. Unfortunately, in infrequent instances, circulatory and/or respiratory recovery is overshadowed by neurologic injury that can occur in patients who require ECMO. As such, knowledge of ECMO and its implications on diagnosis and treatment of neurologic injuries is indispensable for intensivists and neurospecialists.

Recent findings

The most common neurologic injuries include intracerebral hemorrhage, ischemic stroke, seizure, cerebral edema, intracranial hypertension, global cerebral hypoxia/anoxia, and brain death. These result from events prior to initiation of ECMO, failure of ECMO to provide adequate oxygen delivery, and/or complications that occur during ECMO. ECMO survivors also experience neurological and psychological sequelae similar to other survivors of critical illness.

Summary

Since many of the risk factors for neurologic injury cannot be easily mitigated, early diagnosis and intervention are crucial to limit morbidity and mortality from neurologic injury during ECMO.

Influenza management with new therapies

PURPOSE OF REVIEW

Influenza represents a significant treatment burden to critical care services. A variety of treatment strategies exist, with more and more therapeutic avenues opening up as research progresses. We examined both pharmacological and supportive treatment strategies currently available to see how they might be applied in an ICU setting.

RECENT FINDINGS

Supportive care in Influenza centres around optimizing respiratory failure, particularly through well established and recognized ventilatory strategies. Noninvasive ventilation and high-flow nasal oxygen may have a limited role in selected patients under carefully monitored circumstances. Drug therapy exerts only a modest clinical effect and has been poorly studied in the critically ill, though there is some evidence to support the use of neuraminidase inhibitors (NAI) - particularly oseltamivir - as early as possible in this cohort. Newer agents have failed to demonstrate superiority over NAIs but may be useful options if the patient fails to respond or should resistant influenza strains emerge. Steroid therapy, in the absence of another indication, must be recommended against given the repeated trend towards increased mortality in this group.

SUMMARY

Influenza management is an evolving field of significant interest to any critical care provider. Currently, good respiratory supportive care and early enteral oseltamivir are the best supported treatment strategies. Further study in the intensive care setting will be needed before the use of novel agents can be recommended.

Pharmacokinetics of meropenem in children with sepsis undergoing extracorporeal life support: A prospective observational study

What is known and Objective

Meropenem, a broad‐spectrum carbapenem, is frequently used to treat severe bacterial infections in critically ill children. Recommendations for meropenem doses in adult infections are available; however, few studies have been published regarding the use of meropenem in children with sepsis, especially in those receiving continuous renal replacement therapy (CRRT) and extracorporeal membrane oxygenation (ECMO). We aimed to investigate the pharmacokinetic (PK) parameters of meropenem in children with sepsis receiving extracorporeal life support (ECLS).

Methods

This was a prospective observational clinical study of children with sepsis receiving ECMO or CRRT in the paediatric intensive care unit (PICU) of a children's hospital. The enrolled children received 20 mg/kg meropenem infusion over 1 hour, every 8 hours, and were grouped into children receiving ECMO, children receiving CRRT and children receiving neither ECMO nor CRRT. Plasma meropenem concentrations were determined using a validated high‐performance liquid chromatography‐tandem mass spectrometry (HPLC‐MS/MS). The key PK parameters were determined using the non‐compartmental approach.

Results and discussion

Twenty‐seven patients were finally enrolled. The eCLCR of the CRRT group was lower than that of the ECMO group. The values of elimination half‐life (t_1/2), area under the plasma concentration‐time curve (AUC_tau), area under the plasma concentration‐time curve from time zero to infinity (AUC_0‐∞), and total clearance (CL) in the ECMO group were not different from those of the other groups (all p > 0.05). However, the AUC_tau (p = 0.0137) and AUC_0‐∞ (p = 0.0234) significantly decreased after filtration through a hemofiltration membrane in patients receiving CRRT.

What is new and Conclusion

No significant alterations in the PK parameters of meropenem occurred in children with sepsis administered ECMO and/or CRRT. Further investigations including PK modelling could provide evidence for appropriate meropenem dosing regimens during ECLS administration.

Prospective Cohort Study of Population Pharmacokinetics and Pharmacodynamic Target Attainment of Vancomycin in Adults on Extracorporeal Membrane Oxygenation

The aim of this study was to develop a population pharmacokinetics (PK) model for vancomycin and to evaluate its pharmacodynamic target attainment in adults on extracorporeal membrane oxygenation (ECMO). After a single 1,000-mg dose of vancomycin, samples were collected 9 times per patient prospectively. A population PK model was developed using a nonlinear mixed-effect model. The probability of target attainment (PTA) of vancomycin was evaluated for various dosing strategies using Monte Carlo simulation. The ratio of the area under the vancomycin concentration-time curve at steady state over 24 h to the MIC (AUC/MIC ratio) was investigated by applying the vancomycin breakpoint distribution of MICs for methicillin-resistant Staphylococcus aureus A total of 22 adult patients with 194 concentration measurements were included. The population PK was best described by a three-compartment model with a proportional residual error model. Vancomycin clearance and steady-state volume of distribution were 4.01 liters/h (0.0542 liters/h/kg) and 29.6 liters (0.400 liters/kg), respectively. If the treatment target AUC/MIC value was only ≥400, a total daily dose of 3 to 4 g would be optimal (PTA of ≥90%) for patients with normal renal function (estimated glomerular filtration rate [eGFR] = 60 to 120 ml/min/1.73 m²) when the MIC was presumed to be 1 mg/liter. However, AUC/MIC values of 400 to 600 were difficult to attain with any dosing strategy regardless of MIC and eGFR. Thus, it is hard to achieve efficacy and safety targets in patients on ECMO using the population dosing approach with Monte Carlo simulations, and therapeutic drug monitoring should be implemented in these patients.

Pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

Anidulafungin, caspofungin and micafungin are three widely used echinocandin drugs licensed for the treatment of invasive fungal infections, and their clinical use is widespread. To evaluate pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients by comparing the differences in pharmacokinetic parameters between critically ill patients and healthy volunteers or general patients.

METHODS

MEDLINE, EMBASE, The Cochrane Library and Pubmed were searched from inception until 6 September 2018. Studies investigating the pharmacokinetic parameters of echinocandins in critically ill patients, healthy volunteers or general patients were included. Our primary outcomes included AUC0-24 h , Cmax and Cmin (24 hours). Two reviewers independently reviewed all titles, abstracts and text, and extracted data. We applied R software (R 2017) to conduct meta-analysis.

RESULTS AND DISCUSSION

Of 3235 articles screened, 17 studies were included in the data synthesis. Descriptive data from single-arm studies show that critically ill patients who received caspofungin had more stable AUC0-24 h than those who received anidulafungin and micafungin. The Cmax of critically ill patients who received caspofungin and micafungin was similar to healthy volunteers. However, the Cmax in critically ill patients who received anidulafungin was lower than in healthy volunteers. The Cmin and T1/2 of critically ill patients who received caspofungin were larger than in healthy volunteers. The Vd and CL of critically ill patients receiving anidulafungin and micafungin were larger than in healthy volunteers.

WHAT IS NEW AND CONCLUSION

This systematic review provides an analysis of the pharmacokinetic/pharmacodynamics variability of echinocandins in critically ill patients. Based on the limited data available, caspofungin has less pharmacokinetic/pharmacodynamics variability than anidulafungin and micafungin.

Pharmacokinetics and Monte Carlo Dosing Simulations of Imipenem in Critically Ill Patients with Life-Threatening Severe Infections During Support with Extracorporeal Membrane Oxygenation

Background

Extracorporeal membrane oxygenation (ECMO), a cardiopulmonary bypass device, has been found to increase the profound pathophysiological changes associated with life-threatening severe infections in patients with multiple comorbidities, which results in alterations of pharmacokinetic patterns for antibiotics.

Objectives

The aims of this study were (1) to determine the pharmacokinetics of imipenem and (2) to assess the probability of target attainment (PTA) for imipenem in critically ill patients with life-threatening severe infections during support with ECMO.

Methods

The pharmacokinetic studies were carried out following administration of 0.5 g of imipenem every 6 h on the 4th dose of drug administration in 10 patients and a Monte Carlo simulation was performed to determine the PTA of achieving 40% exposure time during which the plasma drug concentrations remained above minimum inhibitory concentration (T > _MIC) and 80% T > _MIC.

Results

The median values of volume of distribution and total clearance (CL) of imipenem in these patients were 13.98 L and 9.78 L/h, respectively. A high PTA (≥ 90%) for a target of 80% with a MIC of 4 μg/mL in patients with CL_CR 60–120 mL/min and flow rate of ECMO circuit 3–5.5 L/min was observed when imipenem was administered by a 4-h infusion of 1 g every 6 h.

Conclusions

A high dosage regimen such as 1 g every 6 h of imipenem may be required to achieve pharmacodynamic targets against less susceptible pathogens in this patient population.

ClinicalTrial.gov Identifier

NCT03776305, date of registration: 11 December 2018.

Electronic supplementary material

The online version of this article (10.1007/s13318-020-00643-3) contains supplementary material, which is available to authorized users.

Use of cidofovir with extracorporeal membrane oxygenation to treat adenovirus-associated acute respiratory distress syndrome in paediatric patients- a case series

WHAT IS KNOWN AND OBJECTIVE

Reports of cidofovir dosing with extracorporeal membrane oxygenation (ECMO) support are limited. This case series describes our clinical experience and provides a literature review regarding cidofovir dosing in paediatric patients requiring ECMO support.

CASE SUMMARY

Three patients with adenovirus-associated acute respiratory distress syndrome (ARDS) were treated with cidofovir while requiring ECMO support. A 27-month-old patient was treated with cidofovir 1 mg/kg/dose three times weekly, and a 19-month-old patient and an 18-year-old patient were treated with cidofovir 5 mg/kg/dose weekly.

WHAT IS NEW AND CONCLUSION

This case series describes the dosing and positive clinical response of cidofovir in paediatric patients with adenovirus-associated ARDS requiring ECMO support.

Population Pharmacokinetics of Caspofungin among Extracorporeal Membrane Oxygenation Patients during the Postoperative Period of Lung Transplantation

Little is known about the influence of extracorporeal membrane oxygenation (ECMO) on the pharmacokinetics (PK) of caspofungin. The aim of this study was to describe population PK of caspofungin in patients with and without ECMO during the postoperative period of lung transplantation (LTx) and to investigate covariates influencing caspofungin PK. We compared ECMO patients with non-ECMO patients, and patients before and after ECMO weaning as self-controls, to analyzed changes in caspofungin PK. Eight serial blood samples were collected from each patient for PK analysis. The population PK of caspofungin was described using nonlinear mixed-effects modeling. Twelve ECMO and 7 non-ECMO lung transplant recipients were enrolled in this study. None of the patients received renal replacement therapy during any part of the study period. The PK of caspofungin was best described by a two-compartment model. There were no significant differences in the PK parameters and concentrations of caspofungin among the ECMO, non-ECMO, and self-control group. In the final covariate model, we found that there was a significant association between the male gender and increased distribution volume, that a higher sequential organ failure assessment score was related to an increase in intercompartmental clearance, and that a longer operative time was related to an increase in clearance and the volume of distribution. ECMO did not have a significant impact on the PK of caspofungin in patients after LTx. Some factors were identified as statistically significant covariates related to the PK of caspofungin; however, their impact on clinical practice of caspofungin needs to be investigated further in more studies. (This study has been registered at ClinicalTrials.gov under identifier NCT03766282.).

Pharmacokinetics/Pharmacodynamics of Antiviral Agents Used to Treat SARS-CoV-2 and Their Potential Interaction with Drugs and Other Supportive Measures: A Comprehensive Review by the PK/PD of Anti-Infectives Study Group of the European Society of Antimicrobial Agents

There is an urgent need to identify optimal antiviral therapies for COVID-19 caused by SARS-CoV-2. We have conducted a rapid and comprehensive review of relevant pharmacological evidence, focusing on (1) the pharmacokinetics (PK) of potential antiviral therapies; (2) coronavirus-specific pharmacodynamics (PD); (3) PK and PD interactions between proposed combination therapies; (4) pharmacology of major supportive therapies; and (5) anticipated drug-drug interactions (DDIs). We found promising in vitro evidence for remdesivir, (hydroxy)chloroquine and favipiravir against SARS-CoV-2; potential clinical benefit in SARS-CoV-2 with remdesivir, the combination of lopinavir/ritonavir (LPV/r) plus ribavirin; and strong evidence for LPV/r plus ribavirin against Middle East Respiratory Syndrome (MERS) for post-exposure prophylaxis in healthcare workers. Despite these emerging data, robust controlled clinical trials assessing patient-centred outcomes remain imperative and clinical data have already reduced expectations with regard to some drugs. Any therapy should be used with caution in the light of potential drug interactions and the uncertainty of optimal doses for treating mild versus serious infections.

Imipenem Population Pharmacokinetics: Therapeutic Drug Monitoring Data Collected in Critically Ill Patients with or without Extracorporeal Membrane Oxygenation

Carbapenem pharmacokinetic (PK) profiles are significantly different in critically ill patients because of the drastic variability of the patients' physiological parameters. Published population PK studies have mainly focused on specific diseases, and the majority of these studies had small sample sizes. The aim of this study was to develop a population PK model of imipenem in critically ill patients that estimated the influence of various clinical and biological covariates and the use of extracorporeal membrane oxygenation (ECMO) and continuous renal replacement therapy (CRRT). A two-compartment population PK model with creatinine clearance (CL_CR), body weight (WT), and ECMO as fixed effects was developed using the nonlinear mixed-effects model (NONMEM). A Monte Carlo simulation was performed to evaluate various dosing schemes and different levels of covariates based on the pharmacokinetic/pharmacodynamic index (ƒ%T>MIC) for the range of clinically relevant MICs. The results showed that there may be insufficient drug use in the clinical routine drug dose regimen, and 750 mg every 6 h (q6h) could achieve a higher treatment success rate. The blood concentrations of imipenem in ECMO patients were lower than those in non-ECMO patients; therefore, dosages may need to be increased. The dosage may need adjustment for patients with a CL_CR of ≤70 ml/min, but the dose should be lowered carefully to avoid the insufficient drug exposure. Dose adjustment is not necessary for patients with WT ranging from 50 to 80 kg. Due to the large variation in PK profile of imipenem in critically ill patients, therapeutic drug monitoring (TDM) should be carried out to optimize drug regimens.

The effect of veno-arterial extracorporeal oxygenation and nasogastric tube administration on the pharmacokinetic profile of abacavir, lamivudine and dolutegravir: a case report

BACKGROUND

Pharmacokinetic (PK) changes can affect antiretroviral (ARV) systemic exposure for critically ill patients living with HIV (CI-PLWH). Studies to guide ARV adjustments in this population are limited.

METHODS

A PK analysis was conducted in a 44-year-old CI-PLWH who presented for a heart and lung transplant on veno-arterial extracorporeal membrane oxygenation (VA ECMO). Home ARV therapy (ART) of co-formulated abacavir/lamivudine/dolutegravir (ABC/3TC/DTG) was continued. ARV serum concentrations were obtained during and after VA ECMO. Two blood levels were drawn at 1 h, for maximum serum concentration (C_max) and a serum trough (C_t). ARVs were given as a single tablet crushed via nasogastric tube.

RESULTS

Area under the concentration-time curve (AUC_0-t) was calculated using non-compartmental analysis. C_max and AUC_0-t were higher during VA ECMO compared with post-decannulation. The C_max of ABC was >2.5-fold higher than the mean in the reference. C_max and C_t post VA ECMO were within range of referenced literature for all ARVs. C_max and AUC_0-t of DTG post VA ECMO was approximately four- to fivefold lower than referenced literature. HIV virological suppression was maintained throughout the hospitalization.

CONCLUSIONS

ART adjustments would not be required for this patient. Additional studies are needed to assess effects of VA ECMO and crushed tube administration of ARVs in CI-PLWH.

Sequestration of Voriconazole and Vancomycin Into Contemporary Extracorporeal Membrane Oxygenation Circuits: An in vitro Study

Background: Bacterial and fungal infections are common and often contribute to death in patients undergoing extracorporeal membrane oxygenation (ECMO). Drug disposition is altered during ECMO, and adsorption in the circuit is an established causative factor. Vancomycin and voriconazole are widely used, despite the lack of evidence-based prescription guidelines. Objective: The objective of this study was to determine the extraction of voriconazole and vancomycin by the Xenios/Novalung ECMO circuits. Methods: We have set up nine closed-loop ECMO circuits, consisting of four different iLAActivve ^® kits for neonatal, pediatric, and adult support: three iLA-ActivveMiniLung ^® petite kits, two iLA-ActivveMiniLung ^® kits, two iLA-ActivveiLA ^® kits, and two iLA-Activve X-lung ^® kits. The circuits were primed with whole blood and maintained at physiologic conditions for 24 h. Voriconazole and vancomycin were injected as a single-bolus age-related dose into the circuits. Pre-membrane (P2) blood samples were obtained at baseline and after drug injection at 2, 10, 30, 180, 360 min, and 24 h. A control sample at 2 min was collected for spontaneous drug degradation testing at 24 h. Results: Seventy-two samples were analyzed in triplicate. The mean percentage of drug recovery at 24 h was 20% for voriconazole and 62% for vancomycin. Conclusions: The extraction of voriconazole and vancomycin by contemporary ECMO circuits is clinically relevant across all age-related circuit sizes and may result in reduced drug exposure in vivo.

Pharmacokinetics of Imipenem in Critically Ill Patients with Life-threatening Severe Infections During Support with Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become increasingly used for lifesaving respiratory and/or cardiac failure support in critically ill patients, including those with life-threatening severe infections. This cardiopulmonary bypass device has been shown to enhance the profound pathophysiological changes in this patient population, resulting in an alteration of the pharmacokinetics of antimicrobial agents.

OBJECTIVE

The aim of this study was to determine the effect of ECMO on the pharmacokinetics of imipenem in critically ill patients supported by this cardiopulmonary bypass device.

METHODS

The study was conducted in critically ill patients with respiratory and/or cardiac failure and severe infections who were supported by ECMO. All patients received a 1-h infusion of 0.5 g of imipenem every 6 h and imipenem pharmacokinetics studies were carried out on the fourth dose of drug administration.

RESULTS

Ten patients were enrolled in this study. The pharmacokinetics parameters of imipenem were found to be highly variable. The volume of distribution, total clearance, elimination half-life and the area under the concentration-time curve between 0 and 6 h were 33.38 ± 13.89 L, 9.99 ± 10.47 L/h, 12.01 ± 29.63 h and 88.93 ± 54.07 mg∙h/L, respectively.

CONCLUSIONS

Pathophysiological changes in critically ill patients with severe infections during support with ECMO had a greater impact on altered pharmacokinetic patterns of imipenem than those that occur in critically ill patients without ECMO support. Therefore, the largest licensed dose, 1 g every 6 h, of imipenem, may be required to maintain adequate drug concentrations to achieve the pharmacokinetic/pharmacodynamic targets for effective antimicrobial therapy in this patient population.

Patterns of Medication Exposure in Children on Extracorporeal Membrane Oxygenation: A Step in Prioritizing Future Pharmacologic Studies

To identify medications administered to pediatric patients on extracorporeal membrane oxygenation and to review the available pharmacokinetics and pharmacodynamics literature for the most commonly administered medications.

Design

Retrospective single-center study.

Setting

ICUs at Children's Hospital of Philadelphia.

Patients

Pediatric patients supported by extracorporeal membrane oxygenation between October 1, 2014, and September 30, 2018.

Interventions

None.

Measurements and Main Results

Drug exposure was described according to age group (< 1 mo, 1 mo to < 2 yr, 2 to < 12 yr, and > 12 yr) and ICU (cardiac, neonatal, pediatric). The association of drug exposure with patient's characteristics was examined using one-way analysis of variance for categorical variables and linear regression for continuous variables. All pharmacokinetics and pharmacodynamics literature for the 50 most commonly administered medications on extracorporeal membrane oxygenation was reviewed, with inclusion of studies that reported dosing regimens in conjunction with pharmacokinetics or pharmacodynamics data. A total of 179 different medications were administered to 254 children. Cumulative drug exposure increased with the duration of extracorporeal membrane oxygenation from a median (interquartile) of 10 drugs (6-14) at 1 week to 31 drugs (21-45) at 5 weeks following cannulation. There were significant differences in total drug exposure between age groups and ICUs. With exclusion of in vitro studies, published literature was available to support the use of 40% (20/50) of the most commonly administered medications. Dosing guidance was available for 20% (10/50) of medications and was primarily based on simulations and retrospective studies focusing on neonates and infants.

Conclusions

This study highlights specific needs for future pharmacokinetics and pharmacodynamics studies. Dosing guidelines are essential to optimize the care of critically ill children supported by extracorporeal membrane oxygenation.

Effects of an Ex Vivo Pediatric Extracorporeal Membrane Oxygenation Circuit on the Sequestration of Mycophenolate Mofetil, Tacrolimus, Hydromorphone, and Fentanyl

OBJECTIVES

With the expanding use of extracorporeal membrane oxygenation (ECMO), understanding drug pharmacokinetics has become increasingly important, particularly in pediatric patients. This ex vivo study examines the effect of a pediatric Quadrox-iD ECMO circuit on the sequestration and binding of mycophenolate mofetil (MMF), tacrolimus, and hydromorphone hydrochloride, which have not been extensively studied to date in pediatric ECMO circuits. Fentanyl, which has been well studied, was used as a comparator.

METHODS

ECMO circuits were set up using Quadrox-iD pediatric oxygenators and centrifugal pumps. The circuit was primed with whole blood and a reservoir was attached to represent a 5-kg patient. Fourteen French venous and 12 French arterial ECMO cannulas were inserted into the sealed reservoir. Temperature, pH, PO₂, and PCO₂ were monitored and corrected. MMF, tacrolimus, hydromorphone, and fentanyl were injected into the ECMO circuit. Serial blood samples were taken from a postoxygenator site at intervals over 12 hours, and levels were measured.

RESULTS

Hydromorphone hydrochloride was not as significantly sequestered by the ex vivo pediatric ECMO circuit when compared with fentanyl. Both mycophenolic acid and tacrolimus serum concentrations were stable in the circuit over 12 hours.

CONCLUSIONS

Hydromorphone may represent a useful medication for pain control for pediatric patients on ECMO due to its minimal sequestration. Mycophenolic acid and tacrolimus also did not show significant sequestration in the circuit, which was unexpected given their lipophilicity and protein-binding characteristics, but may provide insight into unexplored pharmacokinetics of particular medications in ECMO circuits.

Treatment of pulmonary blastomycosis with high-dose liposomal amphotericin B in a patient receiving extracorporeal membrane oxygenation

Blastomycosis-associated acute respiratory distress syndrome (ARDS) has a rare incidence. We report the case of a 29-year-old man with blastomycosis-associated ARDS receiving extracorporeal membrane oxygenation and managed with high-dose liposomal amphotericin B. This case illustrates the importance of timely diagnosis of pulmonary blastomycosis and appropriate dosing of antifungal therapy.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Influenza virus-related critical illness: prevention, diagnosis, treatment

Annual seasonal influenza epidemics of variable severity result in significant morbidity and mortality in the United States (U.S.) and worldwide. In temperate climate countries, including the U.S., influenza activity peaks during the winter months. Annual influenza vaccination is recommended for all persons in the U.S. aged 6 months and older, and among those at increased risk for influenza-related complications in other parts of the world (e.g. young children, elderly). Observational studies have reported effectiveness of influenza vaccination to reduce the risks of severe disease requiring hospitalization, intensive care unit admission, and death. A diagnosis of influenza should be considered in critically ill patients admitted with complications such as exacerbation of underlying chronic comorbidities, community-acquired pneumonia, and respiratory failure during influenza season. Molecular tests are recommended for influenza testing of respiratory specimens in hospitalized patients. Antigen detection assays are not recommended in critically ill patients because of lower sensitivity; negative results of these tests should not be used to make clinical decisions, and respiratory specimens should be tested for influenza by molecular assays. Because critically ill patients with lower respiratory tract disease may have cleared influenza virus in the upper respiratory tract, but have prolonged influenza viral replication in the lower respiratory tract, an endotracheal aspirate (preferentially) or bronchoalveolar lavage fluid specimen (if collected for other diagnostic purposes) should be tested by molecular assay for detection of influenza viruses.Observational studies have reported that antiviral treatment of critically ill adult influenza patients with a neuraminidase inhibitor is associated with survival benefit. Since earlier initiation of antiviral treatment is associated with the greatest clinical benefit, standard-dose oseltamivir (75 mg twice daily in adults) for enteric administration is recommended as soon as possible as it is well absorbed in critically ill patients. Based upon observational data that suggest harms, adjunctive corticosteroid treatment is currently not recommended for children or adults hospitalized with influenza, including critically ill patients, unless clinically indicated for another reason, such as treatment of asthma or COPD exacerbation, or septic shock. A number of pharmaceutical agents are in development for treatment of severe influenza.

Monitoring of adult patient on venoarterial extracorporeal membrane oxygenation in intensive care medicine

Nowadays high-tech medical assist device therapy is a crucial part of intensive care medicine. Especially, management of circulatory assist device systems poses an increasing challenge for intensive care medicine. So far, autonomous recommendations for monitoring of extracorporeal life support systems in the form of guidelines or position papers are lacking. The purpose of this paper was to present an orientation guide on this important topic.

Clinical complications during veno-arterial extracorporeal membrane oxigenation in post-cardiotomy and non post-cardiotomy shock: still the achille's heel

Extracorporeal membrane oxygenation (ECMO) is life-saving for potentially reversible heart failure and respiratory injuries not responsive to conventional therapies. Technological innovations have produced over the years significant improvements in ECMO devices (pump, cannula design and oxygenator) and have allowed a better risk/benefit profile. Alongside with recognized advantages in the treatment of very sick patients, ECMO remains an invasive procedure for mechanical circulatory support (MCS) and it is associated with complications that strongly influence the prognosis. Current review was designed to provide a comprehensive outline on ECMO complications, analyzing risk factors and strategies of management, focusing on adult population undergoing veno-arterial ECMO (VA-ECMO) therapy.

Pharmacokinetics and Pharmacodynamics of Antimicrobials in Critically Ill Patients

Critically ill patients with severe infections often have altered pharmacokinetic and pharmacodynamic variables that lead to challenging treatment decisions. These altered variables can often lead to inadequate dosing and poor treatment outcomes. The pharmacokinetic parameters include absorption, distribution, metabolism, and excretion. Pharmacodynamics is the relationship between drug serum concentrations and pharmacologic and toxicologic properties of the medication. In addition to these altered parameters, these critically ill patients frequently are receiving organ support in the forms of continuous renal replacement therapy or extra-corporeal membrane oxygenation. Altered pharmacodynamics can lead to decreased end-organ perfusion, which can ultimately lead to treatment failure or exposure-related toxicity. The most common antimicrobials utilized in the intensive care unit are classified by the pharmacodynamic principles of time-dependent, concentration-dependent, and concentration dependent with time-dependence. Thus, the aim of this review is to outline pharmacokinetic and pharmacodynamic changes of critically ill patients with severe infections and provide strategies for optimal antibiotic agent dosing in these patients.