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Background: Levetiracetam is an antiepileptic drug used to prevent or treat seizure in patients with severe traumatic brain injury. This study aimed to develop and validate methodology suitable for measuring levetiracetam concentrations in human plasma and urine. Methods: Plasma or urine (10 μl) samples were spiked with [2H6]-levetiracetam and processed using an acetonitrile precipitation. ESI–LC–MS/MS was employed for analyte detection. Results: The levetiracetam calibration was linear from 0.1 to 50 mg/l in a combined matrix of plasma and urine. Intra- and inter-assay imprecision and accuracy in plasma were

Item does not contain fulltext BACKGROUND: Precision dosing programs are promising tools for optimising antimicrobial dosing. Selecting the ideal program for local application may be challenging due to the large variety of available programs with differing characteristics. OBJECTIVES: The objectives of this study were to systematically identify available precision dosing software programs to optimize antimicrobial dosing and describe the characteristics of each program. Details on the ability of programs to provide beta-lactam dosing support was also gathered. SOURCES: A systematic review search strategy was used to identify candidate software programs described in the literature in Embase and PubMed. A detailed survey was then developed to identify characteristics of programs, including details on the underlying methodology driving dosing software recommendations, interface characteristics, costs and regulatory affairs. Software developers from all identified programs were invited to participate in the survey. CONTENT: The systematic search results identified 18 programs. Fifteen developers responded to the survey (83%) and 11 programs provide dosing support for at least one beta-lactam. Fourteen programs can utilize measured drug concentrations to generate dosing recommendations, with 13 able to generate empiric dosing recommendations. Six programs integrate with local electronic health records and four are registered with at least one regulatory agency. Pharmacokinetic models in combination with Bayesian statistics is the most common methodology used to generate dosing recommendations, with 14 programs utilizing this method. IMPLICATIONS: There was significant variability in the available antimicrobial profiles and characteristics among dosing software programs. As healthcare providers will differ in their requirements within their local settings, clinicians should use these findings to identify potential candidate programs and, if feasible, trial these to ensure they meet their specific requirements.

Background: Patients with tuberculosis (TB) may develop multi-organ failure and require admission to intensive care. In these cases, the mortality rates are as high as 78% and may be caused by suboptimal serum concentrations of first-line TB drugs. This study aims to compare the pharmacokinetics of oral rifampin, isoniazid, pyrazinamide and ethambutol patients in intensive care units (ICU) to outpatients and to evaluate drug serum concentrations as a potential cause of mortality. Methods: A prospective pharmacokinetic (PK) study was performed in Amazonas State, Brazil. The primary PK parameters of outpatients who achieved clinical and microbiological cure were used as a comparative target in a non-compartmental analysis. Results: Thirteen ICU and twenty outpatients were recruited. The clearance and volume of distribution were lower for rifampin, isoniazid, pyrazinamide and ethambutol. ICU thirty-day mortality was 77% versus a cure rate of 89% in outpatients. Conclusions: ICU patients had a lower clearance and volume of distribution for rifampin, isoniazid, pyrazinamide and ethambutol compared to the outpatient group. These may reflect changes to organ function, impeded absorption and distribution to the site of infection in ICU patients and have the potential to impact clinical outcomes.

Medications prescribed for indications or at doses, frequencies or durations not approved by the Australian Therapeutic Goods Administration are considered "off-label". Critical illness makes seeking consent for off-label medication use impractical. We aimed to characterise the extent of off-label medication use in a tertiary medical-surgical intensive care unit (ICU) by auditing the electronic health records of all patients admitted over a one-month period. We found 25.4% of 2292 prescriptions made for 142 patients were off-label. Eighty-one (37.2%) of the total of 218 different prescribed medications were used at least once for an off-label indication. Medications commonly prescribed off-label included antacids (pantoprazole, esomeprazole), analgesics (fentanyl, morphine, ketamine, pregabalin), anticonvulsants (levetiracetam), antibiotics (cefazolin, erythromycin), antipsychotics (quetiapine, haloperidol), and cardiovascular agents (metoprolol, clonidine). Nearly all patients (88.0%) received at least one off-label medication during their ICU stay. Most off-label medications were used for conventional (albeit not licensed) reasons, but nine out of 81 (11.1%) were not; for example, acetazolamide for hypertension, aminophylline for oliguria, and dexmedetomidine for seizures. Recognising the challenges of formally registering an indication with the Therapeutic Goods Administration, but also the value of reducing the incidence of medications used for potentially incorrect purposes, we suggest guideline endorsement of what constitutes standard critical care practice as an alternative to regulatory control.

IntroductionIn vitroandin vivopharmacokinetic/pharmacodynamic data describe improved activity of beta-lactam antibiotics when administered by prolonged infusion compared with standard intermittent infusion. There remains insufficient robust clinical trial data to support a widespread practice change. Patients with sepsis and septic shock are a population in whom prolonged infusion of beta-lactam antibiotics may improve survival. Two large multicentre randomised controlled trials (RCTs) comparing prolonged versus intermittent infusion of beta-lactam antibiotics in critically ill patients with sepsis or septic shock are due for completion in 2023. With existing RCT evidence, this systematic review and meta-analysis will include these new data to measure the clinical benefits of prolonged beta-lactam infusion in critically ill patients with sepsis.Methods and analysisThis protocol has been prepared according to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA) statement. This systematic review and meta-analysis will include RCTs that compare prolonged infusion with intermittent infusion of beta-lactam antibiotics in critically ill adult patients with sepsis. Medline (via PubMed), CINAHL, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), and other clinical trials registries will be searched to identify eligible RCTs for review. Two reviewers will perform the study selection and extraction processes with disagreements resolved by discussion or referral to a third reviewer if needed. The Cochrane Collaboration’s Risk-of-Bias Tool for Randomised Trials version 2 (RoB 2) will be used to evaluate the quality of included studies. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach will be used to evaluate the overall quality of evidence for each outcome measures Thea prioriprimary outcome is all-cause 90-day mortality. Secondary outcomes include intensive care unit (ICU) mortality, ICU length of stay, clinical cure, microbiological cure, and the development of adverse events. Bayesian random-effects meta-analyses will be conducted, with frequentist analyses planned for sensitivity analysis.Ethics and disseminationHuman research ethics approval is not required as the study involves the use of existing collections of data that are de-identified. It is expected that findings will be presented at national and international intensive care and infectious diseases meetings, and will be submitted to a peer-reviewed journal for publication.PROSPERO Registration Number: CRD42023399434

Critically ill patients are characterized by substantial pathophysiological changes that alter the pharmacokinetics (PK) of hydrophilic antibiotics, including carbapenems. Meropenem is a key antibiotic for multidrug-resistant Gram-negative bacilli, and such pathophysiological alterations can worsen treatment outcomes. This study aimed to determine the population PK of meropenem and to propose optimized dosing regimens for the treatment of multidrug-resistant Klebsiella pneumoniae in critically ill patients. Two plasma samples were collected from eligible patients over a dosing interval. Nonparametric population PK modeling was performed using Pmetrics. Monte Carlo simulations were applied to different dosing regimens to determine the probability of target attainment and the cumulative fraction of response, taking into account the local MIC distribution for K. pneumoniae. The targets of 40% and 100% for the fraction of time that free drug concentrations remained above the MIC (ƒT>MIC) were tested, as suggested for critically ill patients. A one-compartment PK model using data from 27 patients showed high interindividual variability. Significant PK covariates were the 8-h creatinine clearance for meropenem and the presence of an indwelling catheter for pleural, abdominal, or cerebrospinal fluid drainage for the meropenem volume of distribution. The target 100% ƒT>MIC for K. pneumoniae, with a MIC of ≤2 mg/liter, could be attained by the use of a continuous infusion of 2.0 g/day. Meropenem therapy in critically ill patients could be optimized for K. pneumoniae isolates with an MIC of ≤2 mg/liter by using a continuous infusion in settings with more than 50% isolates have a MIC of ≥32mg/L.

Reducing the volume of blood sampled from neonatal or paediatric patients is important to facilitate research in a group that is under-represented in clinical studies. Not all patients have a cannula available for blood sampling, meaning there are real advantages in obtaining a blood microsample by skin prick. In this study, the results obtained from both capillary microsamples (CMS) and a microfluidic (MF)-CMS by skin prick are compared to conventional plasma sampled from an arterial catheter in a clinical bridging study. Six critically ill patients receiving meropenem were included with the incurred sample reanalysis test meeting the acceptance criteria for both CMS (n = 24 samples) and MF-CMS (n = 20 samples). Bland-Altman plots comparing MF-CMS to conventional arterial blood sampling revealed a difference of - 12.7 ± 22.1% (mean ± standard deviation (SD), and comparing CMS to conventional arterial blood sampling a difference of - 3.4 ± 17.0%. At - 12.7%, the bias between MF-CMS and conventional sampling is greater than the bias found with CMS, although within the limit of acceptability for analytical accuracy (that being ± 15%). Samples collected by skin prick and using CMS produced meropenem concentrations that were comparable to those obtained from conventional arterial catheter sampling. CMS samples were found to be stable when stored in the capillary tube for 24 h at 5 °C or for 4 h at room temperature.

The aim of this study was to report the pharmacokinetics (PK) of caspofungin in plasma and peritoneal fluid and to identify optimal dosing strategies in septic patients with intra-abdominal infections.Eleven patients with secondary peritonitis with septic shock received the standard dosing regimen of caspofungin. Total caspofungin plasma and peritoneal concentrations were subject to a population PK analysis using PmetricsFat-free mass (FFM) was retained in the final model of caspofungin, reporting a total clearance (standard deviation) of 0.78 (0.17) L/h and a central volume of distribution of 9.36 (2.61) L. The peritoneal fluid/plasma ratio of caspofungin was 33% on the first day of therapy (AUCThere is moderate penetration of caspofungin into the peritoneal cavity (33%). For empirical treatment, a dose escalation of 100 mg loading dose on the first day is suggested for higher FFM to ensure adequate concentrations into the abdominal cavity for the most susceptible candida species.

Background In the present study, the authors aimed to compare the pharmacokinetics (PK) of micafungin in critically ill patients receiving continuous veno-venous hemofiltration (CVVH, 30 mL/kg/h) with those of patients receiving equidoses of hemodiafiltration (CVVHDF, 15 mL/kg/h + 15 mL/kg/h) and determine the optimal dosing regimen using the developed model. Methods Patients with septic shock undergoing continuous renal replacement therapy (CRRT) and receiving a conventional dose of 100 mg micafungin once daily were eligible for inclusion. Total micafungin plasma concentrations from eight CVVH sessions and eight CVVHDF sessions were subjected to a population PK analysis using Pmetrics. Validation of the model performance was reinforced by external validation. Monte Carlo simulations were performed considering the total ratio of free drug area under the curve (AUC) over 24 h to the minimum inhibitory concentration (MIC) (AUC0-24/MIC) in plasma. Results The median total body weight (min-max) was 94.8 (66-138) kg. Micafungin concentrations were best described by a two-compartmental PK model. No covariates, including CRRT modality (CVVH or CVVHDF), were retained in the final model. The mean parameter estimates (standard deviation) were 0.96 (0.32) L/h for clearance and 14.8 (5.3) L for the central compartment volume. External validation confirmed the performance of the developed PK model. Dosing simulations did not support the use of standard 100 mg daily dosing, except for Candida albicans on the second day of therapy. A loading dose of 150 mg followed by 100 mg daily reached the probability of target attainment for all C. albicans and C. glabrata, but not for C. krusei and C. parapsilosis. Conclusions No difference was observed in micafungin PK between equidoses of CVVH and CVVHDF. A loading dose of 150 mg is required to achieve the PK/PD target for less susceptible Candida species from the first day of therapy.

OBJECTIVES To describe micafungin pharmacokinetic (PK) alterations of sepsis induced in piglets and to determine whether the porcine septic model is able to predict the PK of micafungin in septic patients at the plasma and peritoneal sites. METHODS From healthy (n = 8) and septic piglet group (n = 16), total micafungin concentrations were subject to a population PK analysis using Monolix®. Data from 16 septic humans patients from others studies was used to compare micafungin PK between septic piglets and septic patients. RESULTS Sepsis induced in piglets slightly alters the total clearance and the volume of distribution, while inter-compartment clearance is increased (from 3.88 to 5.74 L/h) as well as the penetration into peritoneal cavity (from 61 to 90%). In septic human patients, PK parameters are similar except for the Vd, which is corrected by an allometric factor based on the body weight of each species. Micafungin penetration into peritoneal cavity of humans is lower than in septic piglets (40 versus 90%). CONCLUSIONS The sepsis induced in the porcine model alters the PK of micafungin comparable to that in humans. In addition, micafungin PK is similar between these two species at the plasma level taking into account the allometric relationship of the body weight of these species on the central volume of distribution. The porcine septic plasma model would be able to predict the micafungin PK in the septic patients. However, further studies on peritoneal penetration are necessary to characterize this inter-species difference.

To compare clinical outcomes for open, laparoscopic, and robotic hernia repairs for direct, unilateral inguinal hernia repairs, with particular focus on 30-day morbidity surgical site infection (SSI); surgical site occurrence (SSO); SSI/SSO requiring procedural interventions (SSOPI), reoperation, and recurrence.The Abdominal Core Health Quality Collaborative database was queried for patients undergoing elective, primary, 3 cm medial, unilateral inguinal hernia repairs with an open (Lichtenstein), laparoscopic, or robotic operative approach. Preoperative demographics and patient characteristics, operative techniques, and outcomes were studied. A 1-to-1 propensity score matching algorithm was used for each operative approach pair to reduce selection bias.There were 848 operations included: 297 were open, 285 laparoscopic, and 266 robotic hernia repairs. There was no evidence of a difference in primary endpoints at 30 days including SSI, SSO, SSI/SSO requiring procedural interventions (SSOPI), reoperation, readmission, or recurrence for any of the operative approach pairs (open vs. robotic, open vs. laparoscopic, robotic vs. laparoscopic). For the open vs. laparoscopic groups, QoL score at 30 day was lower (better) for laparoscopic surgery compared to open surgery (OR 0.53 [0.31, 0.92], p = 0.03), but this difference did not hold at the 1-year survey (OR 1.37 [0.48, 3.92], p = 0.55). Similarly, patients who underwent robotic repair were more likely to have a higher (worse) 30-day QoL score (OR 2.01 [1.18, 3.42], p = 0.01), but no evidence of a difference at 1 year (OR 0.83 [0.3, 2.26] p = 0.71).Our study did not reveal significant post-operative outcomes between open, laparoscopic, and robotic approaches for large medial inguinal hernias. Surgeons should continue to tailor operative approach based on patient needs and their own surgical expertise.

Morbidity and mortality related to ventriculitis in neurocritical care patients remain high. Antibiotic dose optimization may improve therapeutic outcomes. In this study, a population pharmacokinetic model of meropenem in infected critically ill patients was developed. We applied the final model to determine optimal meropenem dosing regimens required to achieve targeted cerebrospinal fluid exposures. Neurocritical care patients receiving meropenem and with a diagnosis of ventriculitis or extracranial infection were recruited from two centers to this study. Serial plasma and cerebrospinal fluid samples were collected and assayed. Population pharmacokinetic modeling and Monte Carlo dosing simulations were performed using Pmetrics. We sought to determine optimized dosing regimens that achieved meropenem cerebrospinal fluid concentrations above pathogen MICs for 40% of the dosing interval, or a higher target ratio of meropenem cerebrospinal fluid trough concentrations to pathogen MIC of ≥1. In total, 53 plasma and 34 cerebrospinal fluid samples were obtained from eight patients. Meropenem pharmacokinetics were appropriately described using a three-compartment model with linear plasma clearance scaled for creatinine clearance and cerebrospinal fluid penetration scaled for patient age. Considerable interindividual pharmacokinetic variability was apparent, particularly in the cerebrospinal fluid. Percent coefficients of variation for meropenem clearance from plasma and cerebrospinal fluid were 41.7% and 89.6%, respectively; for meropenem, the volume of distribution in plasma and cerebrospinal fluid values were 63.4% and 58.3%, respectively. High doses (up to 8 to 10 g/day) improved attainment of meropenem cerebrospinal fluid target exposures, particularly for less susceptible organisms (MICs, ≥0.25 mg/L). Standard meropenem doses of 2 g every 8 h may not achieve effective concentrations in cerebrospinal fluid in all critically ill patients. Higher doses, or alternative dosing methods (e.g., loading dose followed by continuous infusion) may be required to optimize cerebrospinal fluid exposures. Doses of up to 8 to 10 g/day either as intermittent boluses or continuous infusion would be suitable for patients with augmented renal clearance; lower doses may be considered for patients with impaired renal function as empirical suggestions. Ongoing dosing should be tailored to the individual patient circumstances. Notably, the study population was small and dosing recommendations may not be generalizable to all critically ill patients.

Guidelines for surgical prophylactic dosing of cefazolin in bariatric surgery vary in terms of recommended dose. This study aimed to describe the plasma and interstitial fluid (ISF) cefazolin pharmacokinetics in patients undergoing bariatric surgery and to determine an optimum dosing regimen. Abdominal subcutaneous ISF concentrations (measured using microdialysis) and plasma samples were collected at regular time points after administration of cefazolin 2 g intravenously. Total and unbound cefazolin concentrations were assayed and then modeled using Pmetrics. Monte Carlo dosing simulations (n = 5,000) were used to define cefazolin dosing regimens able to achieve a fractional target attainment (FTA) of >95% in the ISF suitable for the MIC for Staphylococcus aureus in isolates of ≤2 mg · L(−1) and for a surgical duration of 4 h. Fourteen patients were included, with a mean (standard deviation [SD]) bodyweight of 148 (35) kg and body mass index (BMI) of 48 kg · m(−2). Cefazolin protein binding ranged from 14 to 36% with variable penetration into ISF of 58% ± 56%. Cefazolin was best described as a four-compartment model including nonlinear protein binding. The mean central volume of distribution in the final model was 18.2 (SD 3.31) L, and the mean clearance was 32.4 (SD 20.2) L · h(−1). A standard 2-g dose achieved an FTA of >95% for all patients with BMIs ranging from 36 to 69 kg · m(−2). A 2-g prophylactic cefazolin dose achieves appropriate unbound plasma and ISF concentrations in obese and morbidly obese bariatric surgery patients.

The objective of this study was to describe the total and unbound population pharmacokinetics of ceftriaxone in critically ill adult patients and to define optimized dosing regimens. Total and unbound ceftriaxone concentrations were obtained from two pharmacokinetic studies and from a therapeutic drug monitoring (TDM) program at a tertiary hospital intensive care unit. Population pharmacokinetic analysis and Monte Carlo simulations were used to assess the probability of achieving a free trough concentration/MIC ratio of ≥1 using Pmetrics for R. A total of 474 samples (267 total and 207 unbound) were available from 36 patients. A two-compartment model describing ceftriaxone-albumin binding with both nonrenal and renal elimination incorporating creatinine clearance to explain the between-patient variability best described the data. An albumin concentration of ≤20 g/L decreased the probability of target attainment (PTA) by up to 20% across different dosing regimens and simulated creatinine clearances. A ceftriaxone dose of 1 g twice daily is likely therapeutic in patients with creatinine clearance of 130 mL/min) who are infected by pathogens with a MIC of ≥0.5 mg/L. The ceftriaxone dose should be based on the patient’s renal function and albumin concentration, as well as the isolate MIC. Hypoalbuminemia decreases the PTA in patients receiving intermittent dosing by up to 20%.

BACKGROUND AND OBJECTIVE: Critical illness-related corticosteroid insufficiency (CIRCI) describes hypothalamic-pituitary-axis impairment during critical illness associated with three major pathophysiological events; dysregulation of the hypothalamic-pituitary-axis, altered cortisol metabolism, and tissue corticosteroid resistance. Similar changes are evident with regard to mineralocorticoid dysfunction in critical illness. Hyperreninemic hypoaldosteronism describes a sub-population of critically ill patients with an impaired adrenal aldosterone response to increased levels of renin. In the light of the recent demonstration of significant mortality improvements associated with adjunctive glucocorticoid treatment in combination with fludrocortisone in septic shock, and the suggestion that angiotensin II is effective in treating vasodilatory shock, the clinical relevance of mineralocorticoid dysfunction in critical illness requires further exploration. This interpretative review considers hyperreninemic hypoaldosteronism, a concept worth re-examining in the light of the potential mortality benefit of mineralocorticoid supplementation in critical illness. We compare the pathophysiological and clinical characteristics of CIRCI and hyperreninemic hypoaldosteronism, two syndromes that represent corticosteroid and mineralocorticoid dysfunction in critical illness. We highlight gaps in the literature and give novel insights into the limitations of assessment, diagnosis and treatment. METHODS: English language abstracts and articles published before June 2021 were identified through PubMed and Google Scholar. Randomized trials, observational studies, basic sciences studies, systematic and narrative reviews were considered. Reference lists of articles were searched for further relevant material. KEY CONTENT AND FINDINGS: Difficulties are encountered in interpreting measures of gluco- and mineralo-corticoid activity in critical illness. Aldosterone levels, like cortisol, have been shown to be increased in sepsis and hemorrhagic shock. The finding of hyperreninemia and hyperaldosteronism with an aldosterone/plasma renin activity ratio below 2 should prompt consideration of hyperreninemic hypoaldosteronism, a finding, which likely signifies the loss of negative feedback control of the renin-angiotensin-aldosterone system. CONCLUSIONS: As there is evidence to suggest that in acute critical illness, hyperreninemic hypoaldosteronism, is associated with poor outcomes, co-administration of hydrocortisone with fludrocortisone in patients with septic shock should be considered. In keeping with the concept of CIRCI, we suggest the term critical illness-related mineralocorticoid insufficiency as a more appropriate description of the impaired aldosterone response to increased levels of renin seen in this group of patients.

Objectives To compare the bacterial killing and emergence of resistance of intermittent versus prolonged (extended and continuous infusions) infusion dosing regimens of piperacillin/tazobactam against two Escherichia coli clinical isolates in a dynamic hollow-fibre infection model (HFIM). Methods Three piperacillin/tazobactam dosing regimens (4/0.5 g 8 hourly as 0.5 and 4 h infusions and 12/1.5 g/24 h continuous infusion) against a ceftriaxone-susceptible, non-ESBL-producing E. coli 44 (Ec44, MIC 2 mg/L) and six piperacillin/tazobactam dosing regimens (4/0.5 g 8 hourly as 0.5 and 4 h infusions and 12/1.5 g/24 h continuous infusion; 4/0.5 g 6 hourly as 0.5 and 3 h infusions and 16/2 g/24 h continuous infusion) were simulated against a ceftriaxone-resistant, AmpC- and ESBL-producing E. coli 50 (Ec50, MIC 8 mg/L) in a HFIM over 7 days (initial inoculum ∼107 cfu/mL). Total and less-susceptible subpopulations and MICs were determined. Results All simulated dosing regimens against Ec44 exhibited 4 log10 of bacterial killing over 8 h without regrowth and resistance emergence throughout the experiment. For Ec50, there was the initial bacterial killing of 4 log10 followed by regrowth to 1011 cfu/mL within 24 h against all simulated dosing regimens, and the MICs for resistant subpopulations exceeded 256 mg/L at 72 h. Conclusions Our study suggests that, for critically ill patients, conventional intermittent infusion, or prolonged infusions of piperacillin/tazobactam may suppress resistant subpopulations of non-ESBL-producing E. coli clinical isolates. However, intermittent, or prolonged infusions may not suppress the resistant subpopulations of AmpC- and ESBL-producing E. coli clinical isolates. More studies are required to confirm these findings.

While the use of intraperitoneal (i.p.) gentamicin is common in the treatment of peritoneal dialysis (PD)-related infections, the ability of these regimens to attain pharmacodynamic target indices of interest in blood and dialysate has not been widely reported. Pharmacokinetic (PK) data were obtained and analyzed from a multiple-dose PK study of i.p. gentamicin with 24 patients who received the drug at 0.6 mg/kg dose of body weight. The probability of target attainment (PTA) for indices of treatment success (i.p. peak/MIC ratio > 10) and toxicity (plasma area under the concentration-time curve [AUC]

BackgroundThe risk of SARS-CoV-2 transmission to healthcare workers increases during aerosol-generating procedures such as endotracheal intubation.ObjectivesWe tested the effectiveness of a novel barrier mouthpiece in reducing clinician exposure to aerosols and droplets during endotracheal intubation.DesignA prospective case control study was carried out, with a single operator performing eight simulated intubations with and without the device on two different high-fidelity manikin models which produced aerosols and droplets.SettingThe study was performed during June 2020, at the Clinical Skills Development Service, Brisbane, Australia.InterventionsSimulated scenarios included 1) intubation during cardiopulmonary resuscitation 2) intubation while pre-oxygenating via high flow nasal cannula. Photographic images were obtained during each intubation and digitally analyzed using ImageJ v2.1.0/1.53c.PatientsNot applicable.Main outcome measuresAerosol and droplets were quantified using pixel counts. Overall results were expressed as means (± SD), with comparisons between groups made using a two-tailed Student’s T-test under the assumption of unequal variances. A P value of ≤ 0.05 was considered as statistically significant.ResultsFirst pass intubation was achieved in all scenarios, with and without the barrier device. Pixel counts demonstrated significant overall reduction in aerosol and droplet exposure when the barrier device was used during intubation [Mean (SD) count:509 (860) vs 10169 (11600); P=0.014]. The highest exposure risk to airborne particles was observed during simulated induction, prior to laryngoscopy and intubation.ConclusionsThe novel barrier device was effective in reducing environmental exposure to aerosols and droplets during intubation without negatively affecting first pass intubation. The highest risk of exposure to airborne particles was during induction, before intubation takes place. Clinical trials are indicated to further test the feasibility and efficacy of this device.Trial registrationNot applicable.KEY POINTSThis prospective, preclinical study represents a pilot trial of a novel barrier mouthpiece for reducing clinician exposure to aerosols and droplets during endotracheal intubation.In eight simulated intubations with and without the barrier mouthpiece, the device proved effective in reducing environmental exposure to aerosols and droplets (measured in pixels) during intubation, without negatively affecting first pass intubation.The novel barrier mouthpiece represents a possible solution for reducing the risk of respiratory pathogen transmission during endotracheal intubation without hampering the procedure itself, although larger preclinical and clinical trials are necessary.

Escherichia coli ST131 is a recently emerged antibiotic resistant clone responsible for high rates of urinary tract and bloodstream infections. Despite its global dominance, the precise mechanisms that have driven the rapid dissemination of ST131 remain unknown. Here, we show that the plasmid-associated resistance gene encoding the AAC(6’)-Ib-cr enzyme that inactivates the fluoroquinolone (FQ) antibiotic ciprofloxacin is present in >70% of strains from the most rapidly expanding subgroup of multidrug resistant ST131. Using a series of genome-edited and plasmid-cured isogenic strains, we demonstrate that the aac(6’)-Ib-cr gene confers a selective advantage on ST131 in the presence of ciprofloxacin, even in strains containing chromosomal GyrA and ParC FQ-resistance mutations. Further, we identify a pattern of emerging carbapenem resistance in other common E. coli clones carrying both aac(6’)-Ib-cr and chromosomal FQ-resistance mutations, suggesting this dual resistance combination may also impart a selective advantage on these non-ST131 antibiotic resistant lineages.

To describe epidemiology and age-related mortality in critically ill older adults with intra-abdominal infection.A secondary analysis was undertaken of a prospective, multi-national, observational study (Abdominal Sepsis Study, ClinicalTrials.gov #NCT03270345) including patients with intra-abdominal infection from 309 intensive care units (ICUs) in 42 countries between January and December 2016. Mortality was considered as ICU mortality, with a minimum of 28 days of observation when patients were discharged earlier. Relationships with mortality were assessed by logistic regression analysis.The cohort included 2337 patients. Four age groups were defined: middle-aged patients [reference category; 40-59 years; n=659 (28.2%)], young-old patients [60-69 years; n=622 (26.6%)], middle-old patients [70-79 years; n=667 (28.5%)] and very old patients [≥80 years; n=389 (16.6%)]. Secondary peritonitis was the predominant infection (68.7%) and was equally prevalent across age groups. Mortality increased with age: 20.9% in middle-aged patients, 30.5% in young-old patients, 31.2% in middle-old patients, and 44.7% in very old patients (P0.001). Compared with middle-aged patients, young-old age [odds ratio (OR) 1.62, 95% confidence interval (CI) 1.21-2.17], middle-old age (OR 1.80, 95% CI 1.35-2.41) and very old age (OR 3.69, 95% CI 2.66-5.12) were independently associated with mortality. Other independent risk factors for mortality included late-onset hospital-acquired intra-abdominal infection, diffuse peritonitis, sepsis/septic shock, source control failure, liver disease, congestive heart failure, diabetes and malnutrition.For ICU patients with intra-abdominal infection, age60 years was associated with mortality; patients aged ≥80 years had the worst prognosis. Comorbidities and overall disease severity further compromised survival. As all of these factors are non-modifiable, it remains unclear how to improve outcomes.

Objectives To describe the population pharmacokinetics of cefotaxime and desacetylcefotaxime in critically ill paediatric patients and provide dosing recommendations. We also sought to evaluate the use of capillary microsampling to facilitate data-rich blood sampling. Methods Patients were recruited into a pharmacokinetic study, with cefotaxime and desacetylcefotaxime concentrations from plasma samples collected at 0, 0.5, 2, 4 and 6 h used to develop a population pharmacokinetic model using Pmetrics. Monte Carlo dosing simulations were tested using a range of estimated glomerular filtration rates (60, 100, 170 and 200 mL/min/1.73 m2) and body weights (4, 10, 15, 20 and 40 kg) to achieve pharmacokinetic/pharmacodynamic (PK/PD) targets, including 100% ƒT>MIC with an MIC breakpoint of 1 mg/L. Results Thirty-six patients (0.2–12 years) provided 160 conventional samples for inclusion in the model. The pharmacokinetics of cefotaxime and desacetylcefotaxime were best described using one-compartmental model with first-order elimination. The clearance and volume of distribution for cefotaxime were 12.8 L/h and 39.4 L, respectively. The clearance for desacetylcefotaxime was 10.5 L/h. Standard dosing of 50 mg/kg q6h was only able to achieve the PK/PD target of 100% ƒT>MIC in patients >10 kg and with impaired renal function or patients of 40 kg with normal renal function. Conclusions Dosing recommendations support the use of extended or continuous infusion to achieve cefotaxime exposure suitable for bacterial killing in critically ill paediatric patients, including those with severe or deep-seated infection. An external validation of capillary microsampling demonstrated skin-prick sampling can facilitate data-rich pharmacokinetic studies.

Extracorporeal membrane oxygenation (ECMO) can affect antimicrobial pharmacokinetics. This case report describes a 33-year-old male with newly diagnosed acquired immunodeficiency syndrome presenting in acute severe type 1 respiratory failure. On investigation, the patient had positive cultures for Candida albicans from respiratory specimens and high blood cytomegalovirus titres, and required venovenous ECMO therapy for refractory respiratory failure. Intravenous fluconazole (6 mg/kg, 24-h) and ganciclovir (5 mg/kg, 12-h) was commenced. Pre-oxygenator, post-oxygenator and arterial blood samples were collected after antibiotic administration, and were analysed for total fluconazole and ganciclovir concentrations. Although there was a 40% increase in the volume of distribution for fluconazole relative to healthy volunteers, the pharmacodynamic targets for prophylaxis were still met. The area under the curve exposure of ganciclovir (50.78 mg•h/L) achieved target thresholds. The ECMO circuit had no appreciable effect on achievement of therapeutic exposures of fluconazole and ganciclovir.