Is there a benefit for anesthesiologists of adding difficult airway scenarios for learning fiberoptic intubation skills using virtual reality training? A randomized controlled study.

Fiberoptic intubation for a difficult airway requires significant experience. Traditionally only normal airways were available for high fidelity bronchoscopy simulators. It is not clear if training on difficult airways offers an advantage over training on normal airways. This study investigates the added value of difficult airway scenarios during virtual reality fiberoptic intubation training. A prospective multicentric randomized study was conducted 2019 to 2020, among 86 inexperienced anesthesia residents, fellows and staff. Two groups were compared: Group N (control, n = 43) first trained on a normal airway and Group D (n = 43) first trained on a normal, followed by three difficult airways. All were then tested by comparing their ORSIM® scores on 5 scenarios (1 normal and 4 difficult airways). The final evaluation ORSIM® score for the normal airway testing scenario was significantly higher for group N than group D: median score 76% (IQR 56.5-90) versus 58% (IQR 51.5-69, p = 0.0039), but there was no difference in ORSIM® scores for the difficult intubation testing scenarios. A single exposure to each of 3 different difficult airway scenarios did not lead to better fiberoptic intubation skills on previously unseen difficult airways, when compared to multiple exposures to a normal airway scenario. This finding may be due to the learning curve of approximately 5-10 exposures to a specific airway scenario required to reach proficiency.

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.

Anaesthesiologists' clinical judgment accuracy regarding preoperative full stomach: Diagnostic study in urgent surgical adult patients.

BACKGROUND: In urgent situations, preoperative full stomach assessment mostly relies on clinical judgment. Our primary objective was to assess the diagnostic performance of clinical judgment for the preoperative assessment of full stomach in urgent patients compared to gastric point-of-care ultrasound (PoCUS). Our secondary objective was to identify risk factors associated with PoCUS full stomach in urgent patients. METHODS: We led a prospective observational study at our Hospital, between January and July 2016. Adult patients admitted for urgent surgery were eligible. Patients with altered gastric sonoanatomy, interventions reducing stomach content, impossible lateral decubitus were excluded. Clinical judgment and risk factors of full stomach were collected before gastric PoCUS measurements. Ultrasonographic full stomach was defined by solid contents or liquid volume ≥ 1.5 ml kg-1. Diagnostic performance was assessed through sensitivity, specificity, accuracy, positive and negative predictive value. RESULTS: The prevalence of clinical and PoCUS full stomach in 196 included patients was 29% and 27%, respectively. Positive and negative predictive values were 42% (95% CI: 32.3-52.6%) and 79% (95% CI: 74.9-83.4%), respectively. Patients with PoCUS full stomach were clinically misdiagnosed in 55% of cases. PoCUS full stomach was associated with abdominal or gynaecological-obstetrical surgery (OR 3.6, 95% CI: 1.5-8.8, P < 0.01) but not with fasting durations. Positive solid intake after illness onset with respect to 6-h solid fasting rule was associated with PoCUS low-risk gastric content (OR 0.4, 95% CI: 0.2-0.9, P = 0.03). CONCLUSIONS: Clinical judgment showed poor-to-moderate performance in urgent surgical patients for the diagnosis of full stomach. Gastric PoCUS should be used to assess risk of full stomach in this population.

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.

Prevalence of malnutrition in coronavirus disease 19: the NUTRICOV study.

Recent European Society of Parenteral and Enteral Nutrition guidelines highlighted the interest of prevention, diagnosis and treatment of malnutrition in the management of coronavirus disease 19 (COVID-19) patients. The aim of our study was to evaluate the prevalence of malnutrition in patients hospitalised for COVID-19. In a prospective observational cohort study malnutrition was diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM) two-step approach. Patients were divided into two groups according to the diagnosis of malnutrition. Covariate selection for the multivariate analysis was based on P <0·2 in univariate analysis, with a logistic regression model and a backward elimination procedure. A partitioning of the population was realised. Eighty patients were prospectively enrolled. Thirty patients (37·5 %) had criteria for malnutrition. The need for intensive care unit admission (n 46, 57·5 %) was similar in the two groups. Three patients who died (3·75 %) were malnourished. Multivariate analysis exhibited that low BMI (OR 0·83, 95 % CI 0·73, 0·96, P = 0·0083), dyslipidaemia (OR 29·45, 95 % CI 3·12, 277·73, P = 0·0031), oral intake reduction <50 % (OR 3·169, 95 % CI 1·04, 9·64, P = 0·0422) and glomerular filtration rate (Chronic Kidney Disease Epidemiology Collaboration; CKD-EPI) at admission (OR 0·979, 95 % CI 0·96, 0·998, P = 0·0297) were associated with the occurrence of malnutrition. We demonstrate the existence of a high prevalence of malnutrition in a general cohort of COVID-19 inpatients according to GLIM criteria. Nutritional support in COVID-19 care seems an essential element.

Outcome of community- versus hospital-acquired intra-abdominal infections in intensive care unit: a retrospective study.

BACKGROUND: To compare patients hospitalised in the intensive care unit (ICU) after surgery for community-acquired intra-abdominal infection (CA-IAI) and hospital-acquired intra-abdominal infection (HA-IAI) in terms of mortality, severity and complications. METHODS: Retrospective study including all patients admitted to 2 ICUs within 48 h of undergoing surgery for peritonitis. RESULTS: Two hundred twenty-six patients were enrolled during the study period. Patients with CA-IAI had an increased 28-day mortality rate compared to those with HA-IAI (30% vs 15%, respectively (p = 0.009)). At 90 days, the mortality rates were 36.7 and 37.5% in the CA-IAI group and HA-IAI group, respectively, with a similar APACHE II score on admission (median: 21 [15-25] vs. 21 [15-24] respectively, p = 0.63). The patients with HA-IAI had prolonged ICU and hospital stays (median: 17 [7-36] vs. 6[3-12] days, p < 0.001 and 41 [24-66] vs. 17 [7-32] days, p = 0.001), and experienced more complications (reoperation and reintubation) than those with CA-IAI. CONCLUSION: CA-IAI group had higher 28-day mortality rate than HA-IAI group. Mortality was similar at 90 days but those with HA-IAI had a prolonged ICU and hospital stay. In addition, they developed more complications.

Improving Provision of Preanesthetic Information Through Use of the Digital Conversational Agent "MyAnesth": Prospective Observational Trial.

BACKGROUND: Due to time limitations, the preanesthetic consultation (PAC) is not the best time for patients to integrate information specific to their perioperative care pathway. OBJECTIVE: The main objectives of this study were to evaluate the effectiveness of a digital companion on patients' knowledge of anesthesia and their satisfaction after real-life implementation. METHODS: We conducted a prospective, monocentric, comparative study using a before-and-after design. In phase 1, a 9-item self-reported anesthesia knowledge test (Delphi method) was administered to patients before and after their PAC (control group: PAC group). In phase 2, the study was repeated immediately after the implementation of a digital conversational agent, MyAnesth (@+PAC group). Patients' satisfaction and their representations for anesthesia were also assessed using a Likert scale and the Abric method of hierarchized evocation. RESULTS: A total of 600 tests were distributed; 205 patients and 98 patients were included in the PAC group and @+PAC group, respectively. Demographic characteristics and mean scores on the 9-point preinformation test (PAC group: 4.2 points, 95% CI 3.9-4.4; @+PAC: 4.3 points, 95% CI 4-4.7; P=.37) were similar in the two groups. The mean score after receiving information was better in the @+PAC group than in the PAC group (6.1 points, 95% CI 5.8-6.4 points versus 5.2 points, 95% CI 5.0-5.4 points, respectively; P<.001), with an added value of 0.7 points (95% CI 0.3-1.1; P<.001). Among the respondents in the @+PAC group, 82% found the information to be clear and appropriate, and 74% found it easily accessible. Before receiving information, the central core of patients' representations for anesthesia was focused on the fear of being put to sleep and thereafter on caregiver skills and comfort. CONCLUSIONS: The implementation of our digital conversational agent in addition to the PAC improved patients' knowledge about their perioperative care pathway. This innovative audiovisual support seemed clear, adapted, easily accessible, and reassuring. Future studies should focus on adapting both the content and delivery of a digital conversational agent for the PAC in order to maximize its benefit to patients.

Cerebral Venous Thrombosis and Subdural Collection in a Comatose Patient: Do Not Forget Intracranial Hypotension. A Case Report.

BACKGROUND: The typical sign of intracranial hypotension (IH) is postural headache. However, IH can be associated with a large diversity of clinical or radiological signs leading to difficult diagnosis especially in case of coma. The association of cerebral venous thrombosis (CVT) and subdural hemorrhage is rare but should suggest the diagnosis of IH. METHODS: Case report. CASE DESCRIPTION: We report here a case of comatose patient due to spontaneous IH complicated by CVT and subdural hemorrhage. The correct diagnosis was delayed due to many confounding factors. IH was suspected after subdural hemorrhage recurrence and confirmed by magnetic resonance imaging (MRI). After 2 epidural patches with colloid, favorable outcome was observed. DISCUSSION: The most common presentation of IH is postural orthostatic headaches. In the present case report, the major clinical signs were worsening of consciousness and coma, which are a rare presentation. Diagnosis of IH is based on the association of clinical history, evocative symptomatology, and cerebral imaging. CVT occurs in 1-2% of IH cases and the association between IH, CVT, and subdural hemorrhage is rare. MRI is probably the key imaging examination. In the present case, epidural patch was performed after confounding factors for coma had been treated. Benefit of anticoagulation had to be balanced in this case with potential hemorrhagic complications, especially within the brain. CONCLUSION: Association of CVT and subdural hemorrhage should lead to suspect IH. Brain imaging can help and find specific signs of IH.

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.

Crosstalk between brain, lung and heart in critical care.

Extracerebral complications, especially pulmonary and cardiovascular, are frequent in brain-injured patients and are major outcome determinants. Two major pathways have been described: brain-lung and brain-heart interactions. Lung injuries after acute brain damages include ventilator-associated pneumonia (VAP), acute respiratory distress syndrome (ARDS) and neurogenic pulmonary œdema (NPE), whereas heart injuries can range from cardiac enzymes release, ECG abnormalities to left ventricle dysfunction or cardiogenic shock. The pathophysiologies of these brain-lung and brain-heart crosstalk are complex and sometimes interconnected. This review aims to describe the epidemiology and pathophysiology of lung and heart injuries in brain-injured patients with the different pathways implicated and the clinical implications for critical care physicians.

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.

Incidence and predicting factors of perioperative complications during monitored anesthesia care for awake craniotomy.

STUDY OBJECTIVE: To assess incidence and predicting factors of awake craniotomy complications. DESIGN: Retrospective cohort study. SETTING: Operating room and Post Anesthesia Care unit. PATIENTS: 162 patients who underwent 188 awake craniotomy procedures for brain tumor, ASA I to III, with monitored anesthesia care. MEASUREMENTS: We classified procedures in 3 groups: major event group, minor event group, and no event group. Major events were defined as respiratory failure requiring face mask or invasive ventilation; hemodynamic instability treated by vasoactive drugs, or bradycardia treated by atropine, bleeding >500 ml, transfusion, gaseous embolism, cardiac arrest; seizure, cerebral edema, or any events leading to stopping of the cerebral mapping. Minor event was defined as any complication not classified as major. Multivariate logistic regression was used to determine predicting factors of major complication, adjusted for age and ASA score. MAIN RESULTS: 45 procedures (24%) were classified in major event group, 126 (67%) in minor event group, and 17 (9%) in no event group. Seizure was the main complication (n = 13). Asthma (odds ratio: 10.85 [1.34; 235.6]), Remifentanil infusion (odds ratio: 2.97 [1.08; 9.85]) and length of the operation after the brain mapping (odds ratio per supplementary minute: 1.01 [1.01; 1.03]) were associated with major events. CONCLUSIONS: Previous medical history of asthma, remifentanil infusion and a long duration of neurosurgery after cortical mapping appear to be risk factors for major complications during AC.

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.

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.