Influence of arterial blood gases on the renal arterial resistive index in intensive care unit.

BACKGROUND: Renal artery Doppler sonography with resistive index (RI) determination is a noninvasive, fast, and reliable diagnostic tool increasingly used in the intensive care unit (ICU) to predict and assess the reversibility of acute kidney injury (AKI). However, interpreting the RI can be challenging due to numerous influencing factors. While some studies have explored various confounding factors, arterial blood gases have received limited attention. Therefore, our study aims to evaluate the impact of arterial blood gases on the RI in the ICU setting. METHODS: This prospective observational study enrolled ICU patients who required blood gas analysis and had not experienced significant hemodynamic changes recently. The RI was measured using standardized Doppler ultrasound within an hour of the arterial blood gases sampling and analysis. RESULTS: A total of sixty-four patients were included in the analysis. Univariate analysis revealed a correlation between the RI and several variables, including PaCO2 (R = 0.270, p = 0.03), age (R = 0.574, p < 0.0001), diastolic arterial pressure (DAP) (R = - 0.368, p = 0.0028), and SaO2 (R = - 0.284, p = 0.0231). Multivariate analysis confirmed that age > 58 years and PaCO2 were significant factors influencing the RI, with respective odds ratios of 18.67 (p = 0.0003) and 1.132 (p = 0.0267). CONCLUSION: The interpretation of renal arterial RI should take into account thresholds for PaCO2, age, and diastolic arterial pressure. Further studies are needed to develop a comprehensive scoring system that incorporates all these cofactors for a reliable analysis of RI levels. Trial registration This observational study, registered under number 70-0914, received approval from local Ethical Committee of Toulouse University Hospital.

Efficacy of carbapenem vs non carbapenem ß-lactam therapy as empiric antimicrobial therapy in patients with extended-spectrum ß-lactamase-producing Enterobacterales urinary septic shock: a propensity-weighted multicenter cohort study.

BACKGROUND: The rise in antimicrobial resistance is a global threat responsible for about 33,000 deaths in 2015 with a particular concern for extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and has led to a major increase in the use of carbapenems, last-resort antibiotics. METHODS: In this retrospective propensity-weighted multicenter observational study conducted in 11 ICUs, the purpose was to assess the efficacy of non carbapenem regimen (piperacillin-tazobactam (PTZ) + aminoglycosides or 3rd-generation cephalosporin (3GC) + aminoglycosides) as empiric therapy in comparison with carbapenem in extended-spectrum ß-lactamase-producing Enterobacterales (ESBL-E) urinary septic shock. The primary outcome was Day-30 mortality. RESULTS: Among 156 patients included in this study, 69 received a carbapenem and 87 received non carbapenem antibiotics as empiric treatment. Baseline clinical characteristics were similar between the two groups. Patients who received carbapenem had similar Day-30 mortality (10/69 (15%) vs 6/87 (7%), OR = 1.99 [0.55; 5.34] p = 0.16), illness severity, resolution of septic shock, and ESBL-E infection recurrence rates than patients who received an empiric non carbapenem therapy. The rates of secondary infection with C. difficile were comparable. CONCLUSIONS: In ESBL-E urinary septic shock, empiric treatment with a non carbapenem regimen, including systematically aminoglycosides, was not associated with higher mortality, compared to a carbapenem regimen.

Co-Infection and Ventilator-Associated Pneumonia in Critically Ill COVID-19 Patients Requiring Mechanical Ventilation: A Retrospective Cohort Study.

Considering virus-related and drug-induced immunocompromised status of critically ill COVID-19 patients, we hypothesize that these patients would more frequently develop ventilator-associated pneumonia (VAP) than patients with ARDS from other viral causes. We conducted a retrospective observational study in two intensive care units (ICUs) from France, between 2017 and 2020. We compared bacterial co-infection at ICU admission and throughout the disease course of two retrospective longitudinally sampled groups of critically ill patients, who were admitted to ICU for either H1N1 or SARS-CoV-2 respiratory infection and depicted moderate-to-severe ARDS criteria upon admission. Sixty patients in the H1N1 group and 65 in the COVID-19 group were included in the study. Bacterial co-infection at the endotracheal intubation time was diagnosed in 33% of H1N1 and 16% COVID-19 patients (p = 0.08). The VAP incidence per 100 days of mechanical ventilation was 3.4 (2.2−5.2) in the H1N1 group and 7.2 (5.3−9.6) in the COVID-19 group (p < 0.004). The HR to develop VAP was of 2.33 (1.34−4.04) higher in the COVID-19 group (p = 0.002). Ten percent of H1N1 patients and 30% of the COVID-19 patients had a second episode of VAP (p = 0.013). COVID-19 patients have fewer bacterial co-infections upon admission, but the incidence of secondary infections increased faster in this group compared to H1N1 patients.

Mass Training In Situ During COVID-19 Pandemic: Enhancing Efficiency and Minimizing Sick Leaves.

INTRODUCTION: Avoiding coronavirus disease 2019 (COVID-19) work-related infection in frontline healthcare workers is a major challenge. A massive training program was launched in our university hospital for anesthesia/intensive care unit and operating room staff, aiming at upskilling 2249 healthcare workers for COVID-19 patients' management. We hypothesized that such a massive training was feasible in a 2-week time frame and efficient in avoiding sick leaves. METHODS: We performed a retrospective observational study. Training focused on personal protective equipment donning/doffing and airway management in a COVID-19 simulated patient. The educational models used were in situ procedural and immersive simulation, peer-teaching, and rapid cycle deliberate practice. Self-learning organization principles were used for trainers' management. Ordinary disease quantity in full-time equivalent in March and April 2020 were compared with the same period in 2017, 2018, and 2019. RESULTS: A total of 1668 healthcare workers were trained (74.2% of the target population) in 99 training sessions over 11 days. The median number of learners per session was 16 (interquartile range = 9-25). In the first 5 days, the median number of people trained per weekday was 311 (interquartile range = 124-385). Sick leaves did not increase in March to April 2020 compared with the same period in the 3 preceding years. CONCLUSIONS: Massive training for COVID-19 patient management in frontline healthcare workers is feasible in a very short time and efficient in limiting the rate of sick leave. This experience could be used in the anticipation of new COVID-19 waves or for rapidly preparing hospital staff for an unexpected major health crisis.

Evolution of platelet activation parameters during septic shock in intensive care unit.

During severe sepsis, platelet activation may induce disseminate microvascular thrombosis, which play a key role in critical organ failure. Crucially, most of the studies in this field have explored platelet-leukocyte interactions in animal models, or explored platelets under the spectrum of thrombocytopenia or disseminated intravascular coagulation and have not taken into account the complex interplay that might exist between platelets and leukocytes during human septic shock nor the kinetics of platelet activation. Here, we assessed platelet activation parameters at the admission of patients with sepsis to the intensive care unit (ICU) and 48 hours later. Twenty-two patients were enrolled in the study, thirteen (59.1%) of whom were thrombocytopenic. The control group was composed of twelve infection-free patients admitted during the study period. The activation parameters studied included platelet-leukocyte interactions, assessed by flow cytometry in whole blood, as well as membrane surface and soluble platelet activation markers measured by flow cytometry and dedicated ELISA kits. We also investigated platelet aggregation and secretion responses of patients with sepsis following stimulation, compared to controls. At admission, the level of circulating monocyte-platelet and neutrophil-platelet heterotypic aggregates was significantly higher in sepsis patients compared to controls and returned to a level comparable to controls or even below 48 hours later. Basal levels of CD62P and CD63 platelet membrane exposure at admission and 48 hours later were low and similar to controls. In contrast, plasma level of soluble GPVI and soluble CD40 ligand was significantly increased in septic patients, at the two times of analysis, reflecting previous platelet activation. Platelet aggregation and secretion responses induced by specific agonists were significantly decreased in septic conditions, particularly 48 hours after admission. Hence, we have observed for the first time that critically ill septic patients compared to controls have both an early and durable platelet activation while their circulating platelets are less responsive to different agonists.

Assessment of Electrical Impedance Tomography to Set Optimal Positive End-Expiratory Pressure for Venoarterial Extracorporeal Membrane Oxygenation-Treated Patients.

OBJECTIVES: Patients on venoarterial extracorporeal membrane oxygenation have many risk factors for pulmonary complications in addition to their heart failure. Optimal positive end-expiratory pressure is unknown in these patients. The aim was to evaluate the ability of electrical impedance tomography to help the physician to select the optimal positive end-expiratory pressure in venoarterial extracorporeal membrane oxygenation treated and mechanically ventilated patients during a positive end-expiratory pressure trial. DESIGN: Observational prospective monocentric. SETTING: University hospital. PATIENTS: Patients (n = 23) older than 18 years old, on mechanical ventilation and venoarterial extracorporeal membrane oxygenation. INTERVENTIONS: A decreasing positive end-expiratory pressure trial (20-5 cm H2O) in increments of 5 cm H2O was performed and monitored by a collection of clinical parameters, ventilatory and ultrasonographic (cardiac and pulmonary) to define an optimal positive end-expiratory pressure according to respiratory criteria (optimal positive end-expiratory pressure selected by physician with respiratory parameters), and then adjusted according to hemodynamic and cardiac tolerances (optimal positive end-expiratory pressure selected by physician with respiratory, hemodynamic, and echocardiographic parameters). At the same time, electrical impedance tomography data (regional distribution of ventilation, compliance, and overdistension collapse) were recorded and analyzed retrospectively to define the optimal positive end-expiratory pressure. MEASUREMENTS AND MAIN RESULTS: The median of this optimal positive end-expiratory pressure was 10 cm H2O in our population. Electrical impedance tomography showed that increasing positive end-expiratory pressure promoted overdistention of ventral lung, maximum at positive end-expiratory pressure 20 cm H20 (34% [interquartile range, 24.5-40]). Decreasing positive end-expiratory pressure resulted in collapse of dorsal lung (29% [interquartile range, 21-45.8]). The optimal positive end-expiratory pressure selected by physician with respiratory parameters was not different from the positive end-expiratory pressure chosen by the electrical impedance tomography. However, there is a negative impact of a high level of intrathoracic pressure on hemodynamic and cardiac tolerances. CONCLUSIONS: Our results support that electrical impedance tomography appears predictive to define optimal positive end-expiratory pressure on venoarterial extracorporeal membrane oxygenation, aided by echocardiography to optimize hemodynamic assessment and management.

A study of patients' quality of life more than 5 years after trauma: a prospective follow-up.

BACKGROUND: The long-term fate of severely injured patients in terms of their quality of life is not well known. Our aim was to assess the quality of life of patients who have suffered moderate to severe trauma and to identify primary factors of long-term quality of life impairment. METHODS: A prospective monocentric study conducted on a number of patients who were victims of moderate to severe injuries during the year 2012. Patients were selected based on an Injury Severity Score (ISS) more than or equal to 9. Quality of life was assessed by the MOS SF-36 and NHP scores as a primary evaluation criterion. The secondary evaluation criteria were the determination of the socio-economic impact on quality of life and the identification of factors associated with disability. RESULTS: Two hundred and eight patients were contacted by e-mail or telephone. Fifty-five patients participated in this study (with a participation level of 26.4%), including 78.2% men, with a median age of 46. Significant alterations in quality of life were observed with the NHP and MOS SF-36 scale, including physical and psychological components. This resulted in a major socio-economic impact as 26% of the patients could not resume their professional activities (n = 10), 20% required retraining in other lines of work, and 36.4% had a disability status. The study showed that scores ≤ 85 on the physical functioning variable of the MOS SF 36 scale was associated with disability. CONCLUSION: More than five years after a moderate to severe injury, patients' quality of life was significantly impacted, resulting in significant socio-economic consequences. Disability secondary to major trauma seems to be associated with a score ≤ 85 on the physical functioning dimension of the MOS SF-36 scale. This study raises the question of whether or not early rehabilitation programs should be implemented in order to limit the long-term impact of major trauma.

Assessment of electrical impedance tomography to set optimal positive end-expiratory pressure for veno-venous ECMO-treated severe ARDS patients.

PURPOSE: Ultra-protective ventilation with low tidal volume is used in severe acute respiratory distress syndrome (ARDS) patients under extracorporeal membrane oxygenation (ECMO). However, the optimal positive end-expiratory pressure (PEEP) is unknown. The aim of our study was to assess electrical impedance tomography's (EIT) ability to choose the best PEEP for these patients. MATERIALS AND METHODS: A recruitment maneuver and after a decremental PEEP trial from 20 to 5 cmH20 were monitored by EIT, with lung images divided into four ventral-to-dorsal horizontal regions of interest. For each patient, three EIT-based PEEP were defined: PEEP ODCLmin (lowest pressure with the least EIT-based collapse lung [CL] and overdistension [OD]), PEEP ODCL15 (lowest pressure able to limit EIT-based collapse to less than or equal to 15% with the least overdistension) and PEEP Comp (PEEP with the highest EIT-based compliance). RESULTS: High PEEP levels were significantly associated with more overdistension while decreasing PEEP led to more collapsed zones. PEEP ODCL15 and PEEP Comp were in complete agreement with the reference Pulmonary PEEP (chosen according to usual respiratory clinical and ultrasound criteria), PEEP ODCLmin was in average agreement with the Pulmonary PEEP. CONCLUSION: EIT may be a useful real-time monitoring technique to optimize the PEEP level in severe ARDS patients under ECMO. TAKE-HOME MESSAGE: Ultra-protective ventilation with low tidal volume is used in severe acute respiratory distress syndrome patients under extracorporeal membrane oxygenation (ECMO), but the optimal positive end-expiratory pressure is unknown. This trial shows that electrical impedance tomography may be an interesting non-invasive bedside tool to provide real-time monitoring of PEEP impact in severe ARDS patients under ECMO. The Pulmovista® electrical impedance tomography was provided by Dräger (Lübeck, Germany) during the study period. Dräger had no role in the study design, collection, analysis and interpretation of the data, writing the article, or the decision to submit the article for publication.

Diagnostic accuracy of a revised computed tomography angiography score for brain death confirmation, combining supra-tentorial arteries and infra-tentorial veins.

PURPOSE: The 4-point score is the corner stone of brain death (BD) confirmation using computed tomography angiography (CTA). We hypothesized that considering the superior petrosal veins (SPVs) may improve CTA diagnosis performance in BD setting. We aimed at comparing the diagnosis performance of three revised CTA scores including SPVs and the 4-point score in the confirmation of BD. METHODS: In this retrospective study, 69 consecutive adult-patients admitted in a French University Hospital meeting clinical brain death criteria and receiving at least one CTA were included. CTA images were reviewed by two blinded neuroradiologists. A first analysis compared the 4-point score, considered as the reference and three non-opacification scores: a "Toulouse score" including SPVs and middle cerebral arteries, a "venous score" including SPVs and internal cerebral veins and a "7-score" including all these vessels and the basilar artery. Psychometric tools, observer agreement and misclassification rates were assessed. A second analysis considered clinical examination as the reference. RESULTS: Brain death was confirmed by the 4-score in 59 cases (89.4 %). When compared to the 4-score, the Toulouse score displayed a 100 % positive predictive value, a substantial observer agreement (0.77 [0.53; 1]) and the least misclassification rate (3.03 %). Results were similar in the craniectomy subgroup. The Toulouse score was the only revised test that combined a sensitivity close to that of the 4-score (86.4 % [75.7; 93.6] and 89.4 % [79.4; 95.6], p-value < 0.001, respectively) and a substantial observer agreement. CONCLUSIONS: A score including SPVs and middle cerebral arteries is a valid method for BD confirmation using CTA even in patients receiving craniectomy.

Functional and Structural Integrity of Frontoparietal Connectivity in Traumatic and Anoxic Coma.

OBJECTIVES: Recovery from coma might critically depend on the structural and functional integrity of frontoparietal networks. We aimed to measure this integrity in traumatic brain injury and anoxo-ischemic (cardiac arrest) coma patients by using an original multimodal MRI protocol. DESIGN: Prospective cohort study. SETTING: Three Intensive Critical Care Units affiliated to the University in Toulouse (France). PATIENTS: We longitudinally recruited 43 coma patients (Glasgow Coma Scale at the admission < 8; 29 cardiac arrest and 14 traumatic brain injury) and 34 age-matched healthy volunteers. Exclusion criteria were disorders of consciousness lasting more than 30 days and focal brain damage within the explored brain regions. Patient assessments were conducted at least 2 days (5 ± 2 d) after complete withdrawal of sedation. All patients were followed up (Coma Recovery Scale-Revised) 3 months after acute brain injury. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Functional and structural MRI data were recorded, and the analysis was targeted on the posteromedial cortex, the medial prefrontal cortex, and the cingulum. Univariate analyses and machine learning techniques were used to assess diagnostic and predictive values. Coma patients displayed significantly lower medial prefrontal cortex-posteromedial cortex functional connectivity (area under the curve, 0.94; 95% CI, 0.93-0.95). Cardiac arrest patients showed specific structural disturbances within posteromedial cortex. Significant cingulum architectural disturbances were observed in traumatic brain injury patients. The machine learning medial prefrontal cortex-posteromedial cortex multimodal classifier had a significant predictive value (area under the curve, 0.96; 95% CI, 0.95-0.97), best combination of subregions that discriminates a binary outcome based on Coma Recovery Scale-Revised). CONCLUSIONS: This exploratory study suggests that frontoparietal functional disconnections are specifically observed in coma and their structural counterpart provides information about brain injury mechanisms. Multimodal MRI biomarkers of frontoparietal disconnection predict 3-month outcome in our sample. These findings suggest that fronto-parietal disconnection might be particularly relevant for coma outcome prediction and could inspire innovative precision medicine approaches.

Outcome of Critically Ill Patients With Influenza Infection: A Retrospective Study.

BACKGROUND: Influenza causes significant morbidity and mortality in adults, and numerous patients require intensive care unit (ICU) admission. Acute respiratory distress syndrome (ARDS) is clearly described in this context, but other clinical presentations exist that need to be assessed for incidence and outcome. The primary goal of this study was to describe the characteristics of patients admitted in ICU for influenza, their clinical presentation, and the 3-month mortality rate. The second objective was to search for 3-month mortality risk factors. METHODS: This is a retrospective study including all patients admitted to 3 ICUs due to influenza-related disease between October 2013 and June 2016, which assesses the 3-month mortality rate. We compared clinical presentation, biological data, and outcome at 3 months between survivors and non-survivors. We created a predicting 3-month mortality model with Classification and Regression Tree analysis. RESULTS: Sixty-nine patients were included, 50 patients (72.5%) for ARDS, 5 (7.2%) for myocarditis, and 14 (20.3%) for acute respiratory failure without ARDS criteria. Non-typed influenza A was found in 30 cases (43.5%), influenza A H1N1 in 18 (26.1%), H3N2 in 3 (4.3%), and influenza B in 18 cases (27.5%). The 3-month mortality rate was 29% (n = 20). Extracorporeal membrane oxygenation (ECMO) was implanted in 23 patients, without any significant increase in mortality (39% vs 24% without ECMO, P = .19). A creatinine serum superior to 96 µmol/L, an aspartate aminotransferase level superior to 68 UI/L, and a Pao2/Fio2 ration below 110 were associated with 3-month mortality in our predictive mortality model. CONCLUSION: Influenza in ICUs may have several clinical presentations. The mortality rate is high, but ECMO may be an effective rescue therapy.

Risk factor analysis for linezolid-associated thrombocytopenia in critically ill patients.

Linezolid is an antibiotic used against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus. Its primary adverse effect is haematotoxicity. The objective of this study was to analyse the risk factors for onset of thrombocytopenia in critically ill patients treated with linezolid. This was a retrospective, single-centre study of 72 patients. Platelets were measured from D0 to D20 after the start of treatment. The risk factors for thrombocytopenia were identified using a multivariate logistic regression analysis following a Monte Carlo simulation. Following ROC curve analysis, a baseline platelet count lower than 108 × 109/L and a Cmin higher than 4 mg/L, with respective odds ratios of 117 (95% CI [97-206]) and 3 (95% CI [1.5-6.2]) in the simulated population, were identified as risk factors. Among the source population patients combining these 2 factors, a significantly higher number developed thrombocytopenia (66.7% vs. 33.3%, p = 0.0042). A baseline platelet count lower than 108 × 109/L and a Cmin higher than 4 mg/L are risk factors for the onset of thrombocytopenia in critically ill patients treated with linezolid.

Anticoagulation Monitoring Under ECMO Support: A Comparative Study Between the Activated Coagulation Time and the Anti-Xa Activity Assay.

PURPOSE: Extra Corporeal Membrane Oxygenation (ECMO) is used in cases of severe respiratory and/or circulatory failure over periods of several days to several weeks. Its circuitry requires a closely monitored anticoagulation therapy that is empirically supported by activated clotting time (ACT)-a method often associated with large inter- and intraindividual variability. We aimed to compare the measurement of heparin activity with ACT and the direct measurement of the heparin activity (anti-Xa) in a large ECMO population. METHODS: All patients treated by venoarterial or venovenous ECMO in our intensive care unit between January 2014 and December 2015 were prospectively included. A concomitant measurement of the anti-Xa activity and ACT was performed on the same sample collected twice a day (morning-evening) for unfractionated heparin adaptation with an ACT target range of 180 to 220 seconds. RESULTS: One hundred and nine patients (men 69.7%, median age 54 years) treated with ECMO (70.6% venoarterial) were included. Spearman analysis found no correlation between anti-Xa and ACT (ρ < 0.4) from day 1 and worsened over time. Kappa analysis showed no agreement between the respective target ranges of ACT and anti-Xa. CONCLUSIONS: We demonstrate that concomitant measurement of ACT and anti-Xa activity is irrelevant in ECMO patients. Since ACT is poorly correlated with heparin dosage, anti-Xa activity appears to be a more suitable assay for anticoagulation monitoring.

Kinetics of mean platelet volume predicts mortality in patients with septic shock.

INTRODUCTION: Thrombocytopenia is well recognized as a poor prognosis sign associated with increased mortality and prolonged Intensive Care Unit (ICU) stay, particularly in septic patients. Mean platelet volume (MPV) could represent a relevant predictive marker of mortality. Here we investigated whether MPV kinetics during the first 15 days after hospital admission has a potential prognostic value for clinical outcome in septic shock. METHODS: We performed a retrospectively analysis of a cohort of 301 septic patients admitted in ICU. Three-month mortality was the primary endpoint. The prognostic value of the covariates of interest was ascertained by multidimensional analysis. We proposed a classification and regression trees analysis to predict survival probability. RESULTS: MPV kinetics was significantly different between 90-day survivors and non-survivors when followed during 15 days (except on day 3). 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality (Hazard Ratio (HR) 3.796, 95% Confidence Interval (CI) [1.96-7.35], p = 0.0001) in multivariate analysis. Base excess on day 4 <1.9mmol/L was also a predictive factor of mortality (HR 2.972, 95%CI [1.38-6.40], p = 0.0054. CONCLUSION: MPV increase during the first 15 days after ICU admission in non-survivors was observed during septic shock and 10-day MPV >11.6fL was an independent predictive factor of 90-day mortality. This could be explained by the emergent response to acute platelet loss during septic shock, leading to megakaryocyte rupture to produce new but potentially immature platelets in the circulation. Therefore, continuous monitoring of MPV may be a useful parameter to stratify mortality risk in septic shock.

Risk factors for acquisition of carbapenem-resistance during treatment with carbapenem in the intensive care unit: a prospective study.

The emergence of carbapenemases in gram-negative aerobes is worrying. The aim of this prospective study was to estimate the incidence of acquisition of carbapenem-resistance during treatment in ICU and to identify the risk factors. This was a prospective, observational, cohort study. This study was conducted at intensive care unit, academic medical center, Toulouse Rangueil University Hospital. Patients were included if they received antibiotic treatment with carbapenem for more than 48 h. Biological samples were taken in accordance with current practice in the unit. The main endpoint was the occurrence of bacterial resistance to carbapenems occurring between the onset of treatment and the patient's exit from the ICU. Uni- and multi-variate analyses were carried out. Of the 364 patients admitted to the unit between May and November 2014, 78 were included in our study and 16 (20.51%) developed resistance. The two main risk factors were a length of stay in ICU of more than 29 days (HR = 3.61, p = 0.01) and the presence of Pseudomonas aeruginosa in the samples taken before the start of treatment (HR = 5.31, p = 0.002). No resistance due to carbapenemase production was observed in this study. The prescription of carbapenems in the ICU setting must adhere to the expert guidelines. In light of our results, special attention must be paid to patients whose stay in intensive care is prolonged, and those in whom Pseudomonas aeruginosa is isolated from bacteriological samples taken before the beginning of antibiotic therapy.

Risk factors and the resistance mechanisms involved in Pseudomonas aeruginosa mutation in critically ill patients.

BACKGROUND: The objective of this study was to determine the main risk factors of Pseudomonas aeruginosa mutation as well as the mechanisms of acquired resistance. METHODS: We conducted a 2-year prospective study in patients who were carriers of a Pseudomonas aeruginosa strain and who had been admitted to a medical/surgical ICU. RESULTS: Of the 153 patients who were included, 34 had a mutation in their strain. In a multivariate analysis, a duration of ventilation > 24 days was a risk factor for mutation (risk ratio 4.29; CI 95% 1.94-9.49) while initial resistance was a protective factor (RR 0.36; CI 95% 0.18-0.71). In a univariate analysis, exposure of P. aeruginosa to ceftazidime was associated with an over-production of AmpC cephalosporinase and exposure to meropenem was associated with impermeability. A segmentation method based on the duration of ventilation (> 24 days), initial resistance, and exposure of strains to ceftazidime made it possible to predict at 83% the occurrence of mutation. CONCLUSION: The duration of ventilation and the presence of resistance as soon as P. aeruginosa is identified are predictive factors of mutation in ICU patients.

Hemodynamic efficiency of hemodialysis treatment with high cut-off membrane during the early period of post-resuscitation shock: The HYPERDIA trial.

BACKGROUND: After resuscitation of cardiac arrest (CA), an acute circulatory failure occurs in about 50% of cases, which shares many characteristics with septic shock. Most frequently, supportive treatments are poorly efficient to prevent multiple organ failure and death. We evaluated whether an early plasma removal of inflammatory mediators using high cut-off continuous veno-venous hemodialysis (HCO-CVVHD) could improve hemodynamic status and outcome of these patients. PATIENTS AND METHODS: We performed a randomized open-label trial. Patients with post-cardiac arrest shock (defined as requirement of norepinephrine or epinephrine infusion > 1 mg/h) were included. The experimental group received 2 distinct sessions of HCO-CVVHD during the first 48 h following ICU admission. The control group received continuous veno-venous hemofiltration (CVVH) with standard membranes if needed. The primary endpoint was the delay to shock resolution asssessed by the length of catecholamine infusion. Number of vasopressors-free days at day 28, arterial blood pressure measures every 6-hours, daily fluid balance and mortality (ICU and day-28) were evaluated as secondary endpoints. RESULTS: 35 patients were included: 17 (median age 68.4, 59% male) in the HCO-CVVHD group and 18 (median age 66.3, 83% male) in the control group. Baseline characteristics did not differ between the two groups. Day-28 mortality rate was 64.7% and 72.2% in the HCO-CVVHD and control group, respectively (p = 0.72). Probability of vasopressors discontinuation over time was similar in the two groups (p for logrank test = 0.67). Number of day-28 catecholamine-free days was 25.1 [0, 26.5] and 24.5 [0, 26.2] in the HCO-CVVHD and control group, respectively (p = 0.65). No difference was observed regarding the daily-dose of vasopressors, arterial pressure profile and fluid balance. CONCLUSION: In cardiac arrest patients, HCO-CVVHD did not decrease the lenght of post-resuscitation shock and had no significant effect on hemodynamic profile. REGISTRATION: NCT00780299.

Topological disintegration of resting state functional connectomes in coma.

Graph theory has been playing an increasingly important role in understanding the organizational properties of brain networks, subsequently providing new tools for the search of neural correlates of consciousness, particularly in the context of patients recovering from severe brain injury. However, this approach is not without challenges, as it usually relies on arbitrarily fixing a threshold in order to retain the strongest connections proportionally equal across subjects. This method increases the comparability between individuals or groups but it risks the inclusion of false positive and therefore spurious connections, especially in the context of brain disorders. Resting state data acquired in 25 coma patients and 22 healthy subjects was compared. We obtained a representative fixed density of significant connections by first applying a p-value-based threshold on healthy subjects' networks and then choosing a threshold at which all individuals exhibited meaningful connections. The obtained threshold (i.e. 10%) was used to construct graphs in the patient group. The findings showed that coma patients have lower number of significant connections with approximately 50% of them not fulfilling the criteria of the fixed density threshold. The remaining patients with relatively preserved global functional connectivity had sufficient significant connections between regions, but showed signs of major whole-brain network reorganization. These results warrant careful consideration in the construction of functional connectomes in patients with disorders of consciousness and set the scene for future studies investigating potential clinical implications of such an approach.