Pathophysiology and Prevention of Ventriculostomy-Related Infections: A Review.

This qualitative review aims to summarize current knowledge on ventriculostomy-related infection (VRI) pathophysiology and its prevention. VRI generally occurs at day 10, mainly because of Gram-positive cocci, after a cerebrospinal fluid leak. Skin microbiota and biofilm seem to play a major role in VRI pathogenesis. Colonization of external ventricular drain by biofilm is universal and occurs quickly after catheter insertion. However, pathogens from the skin are more often associated with VRI than commensal bacteria. A review of proposed preventive measures shows that none has proven to be fully efficient. Periprocedural and prolonged systemic prophylactic antimicrobials have not shown to prevent VRIs and may promote the emergence of more resistant or pathogenic strains. Antimicrobial and silver-impregnated external ventricular drains, although promising, have not demonstrated preventive effects and may modify bacterial ecology. These results are consistent with the proposed pathophysiology. Finally, we will present a few propositions for future research that may help in improving our knowledge and thus better prevent VRIs. Until then, given the available data, limiting the duration of ventricular drainage may be the most attainable option to prevent VRIs.

Hydrocortisone plus fludrocortisone for community acquired pneumonia-related septic shock: a subgroup analysis of the APROCCHSS phase 3 randomised trial.

BACKGROUND: Glucocorticoids probably improve outcomes in patients hospitalised for community acquired pneumonia (CAP). In this a priori planned exploratory subgroup analysis of the phase 3 randomised controlled Activated Protein C and Corticosteroids for Human Septic Shock (APROCCHSS) trial, we aimed to investigate responses to hydrocortisone plus fludrocortisone between CAP and non-CAP related septic shock. METHODS: APROCCHSS was a randomised controlled trial that investigated the effects of hydrocortisone plus fludrocortisone, drotrecogin-alfa (activated), or both on mortality in septic shock in a two-by-two factorial design; after drotrecogin-alfa was withdrawn on October 2011, from the market, the trial continued on two parallel groups. It was conducted in 34 centres in France. In this subgroup study, patients with CAP were a preselected subgroup for an exploratory secondary analysis of the APROCCHSS trial of hydrocortisone plus fludrocortisone in septic shock. Adults with septic shock were randomised 1:1 to receive, in a double-blind manner, a 7-day treatment with daily administration of intravenous hydrocortisone 50 mg bolus every 6h and a tablet of 50 µg of fludrocortisone via the nasogastric tube, or their placebos. The primary outcome was 90-day all-cause mortality. Secondary outcomes included all-cause mortality at intensive care unit (ICU) and hospital discharge, 28-day and 180-day mortality, the number of days alive and free of vasopressors, mechanical ventilation, or organ failure, and ICU and hospital free-days to 90-days. Analysis was done in the intention-to-treat population. The trial was registered at ClinicalTrials.gov (NCT00625209). FINDINGS: Of 1241 patients included in the APROCCHSS trial, CAP could not be ruled in or out in 31 patients, 562 had a diagnosis of CAP (279 in the placebo group and 283 in the corticosteroid group), and 648 patients did not have CAP (329 in the placebo group and 319 in the corticosteroid group). In patients with CAP, there were 109 (39%) deaths of 283 patients at day 90 with hydrocortisone plus fludrocortisone and 143 (51%) of 279 patients receiving placebo (odds ratio [OR] 0·60, 95% CI 0·43-0·83). In patients without CAP, there were 148 (46%) deaths of 319 patients at day 90 in the hydrocortisone and fludrocortisone group and 157 (48%) of 329 patients in the placebo group (OR 0·95, 95% CI 0·70-1·29). There was significant heterogeneity in corticosteroid effects on 90-day mortality across subgroups with CAP and without CAP (p=0·046 for both multiplicative and additive interaction tests; moderate credibility). Of 1241 patients included in the APROCCHSS trial, 648 (52%) had ARDS (328 in the placebo group and 320 in the corticosteroid group). There were 155 (48%) deaths of 320 patients at day 90 in the corticosteroid group and 186 (57%) of 328 patients in the placebo group. The OR for death at day 90 was 0·72 (95% CI 0·53-0·98) in patients with ARDS and 0·85 (0·61-1·20) in patients without ARDS (p=0·45 for multiplicative interaction and p=0·42 for additive interaction). The OR for observing at least one serious adverse event (corticosteroid group vs placebo) within 180 days post randomisation was 0·64 (95% CI 0·46-0·89) in the CAP subgroup and 1·02 (0·75-1·39) in the non-CAP subgroup (p=0·044 for multiplicative interaction and p=0·042 for additive interaction). INTERPRETATION: In a pre-specified subgroup analysis of the APROCCHSS trial of patients with CAP and septic shock, hydrocortisone plus fludrocortisone reduced mortality as compared with placebo. Although a large proportion of patients with CAP also met criteria for ARDS, the subgroup analysis was underpowered to fully discriminate between ARDS and CAP modifying effects on mortality reduction with corticosteroids. There was no evidence of a significant treatment effect of corticosteroids in the non-CAP subgroup. FUNDING: Programme Hospitalier de Recherche Clinique of the French Ministry of Health, by Programme d'Investissements d'Avenir, France 2030, and IAHU-ANR-0004.

Mortality Trend of Severe COVID-19 in Under-Vaccinated Population Admitted to ICU in French Amazonia.

(1) Background: Until December 2021, French Guiana (FG), located in South America, faced four consecutive COVID-19 epidemic waves. This study sought to analyze the mortality trend of severe COVID-19 patients admitted to the referral ICU of FG. (2) Methods: We conducted a prospective, observational, and non-interventional study in ICU at Cayenne Hospital. We included 383 patients older than 18 admitted with SARS-CoV-2-related pneumonia hospitalized from May 2020 to December 2021. The study covers three periods. Period 1 (Waves 1 and 2, original variant), period 2 (Wave 3, Gamma variant), and period 3 (Wave 4, Delta variant). (3) Results: The median age was 63 years (52-70). Frailty was diagnosed in 36 patients over 70 (32.4%). Only 4.8% of patients were vaccinated. The median ICU LOS was 10 days (6-19). Hospital mortality was 37.3%. It was 30.9% in period 1, 36.6% in period 2 (p = 0.329 vs. period 1), and 47.1% in period 3 (0.015 vs. period 1). In multivariate analysis, independent factors associated with hospital mortality included age greater than 40 years (]40-60 years] OR = 5.2, 95%CI: 1.4-19.5; (]60-70 years] OR = 8.5, 95%CI: 2.2-32; (]70+ years] OR = 17.9, 95%CI: 4.5-70.9), frailty (OR = 5.6, 95%CI: 2.2-17.2), immunosuppression (OR = 2.6, 95%CI: 1.05-6.7), and MV use (OR = 11, 95%CI: 6.1-19.9). This model had an overall sensitivity of 72%, a specificity of 80.4%, a positive predictive value of 68.7%, and a negative predictive value of 82.8%. (4) Conclusions: The mortality of severe COVID-19 patients in French Amazonia was higher during the Delta variant wave. This over-death could be explained by the virulence of the responsible SARS-CoV-2 variant and the under-vaccination coverage of the studied population.

Multiple trauma in pregnant women: injury assessment, fetal radiation exposure and mortality. A multicentre observational study.

BACKGROUND: Fetal radiation exposure in pregnant women with trauma is a concern. The purpose of this study was to evaluate fetal radiation exposure with regard to the type of injury assessment performed. METHODS: It is a multicentre observational study. The cohort study included all pregnant women suspected of severe traumatic injury in the participating centres of a national trauma research network. The primary outcome was the cumulative radiation dose (mGy) received by the fetus with respect to the type of injury assessment initiated by the physician in charge of the pregnant patient. Secondary outcomes were maternal and fetal morbi-mortality, the incidence of haemorrhagic shock and the physicians' imaging assessment with consideration of their medical specialty. RESULTS: Fifty-four pregnant women were admitted for potential major trauma between September 2011 and December 2019 in the 21 participating centres. The median gestational age was 22 weeks [12-30]. 78% of women (n = 42) underwent WBCT. The remaining patients underwent radiographs, ultrasound or selective CT scans based on clinical examination. The median fetal radiation doses were 38 mGy [23-63] and 0 mGy [0-1]. Maternal mortality (6%) was lower than fetal mortality (17%). Two women (out of 3 maternal deaths) and 7 fetuses (out of 9 fetal deaths) died within the first 24 h following trauma. CONCLUSIONS: Immediate WBCT for initial injury assessment in pregnant women with trauma was associated with a fetal radiation dose below the 100 mGy threshold. Among the selected population with either a stable status with a moderate and nonthreatening injury pattern or isolated penetrating trauma, a selective strategy seemed safe in experienced centres.

Association of Organizational Pathways With the Delay of Emergency Surgery.

Importance: Delayed admission of patients with surgical emergencies to the operating room occurs frequently and is associated with poor outcomes. In France, where 3 distinct organizational pathways in hospitals exist (a dedicated emergency operating room and team [DET], a dedicated operating room in a central operating theater [DOR], and no dedicated structure or team [NOR]), neither the incidence nor the influence of delayed urgent surgery is known, and no guidelines are available to date. Objective: To examine the overall frequency of delayed admission of patients with surgical emergencies to the operating room across the 3 organizational pathways in hospitals in France. Design, Setting, and Participants: This prospective multicenter cohort study was conducted in 10 French tertiary hospitals. All consecutive adult patients admitted for emergency surgery from October 5 to 16, 2020, were included and prospectively monitored. Patients requiring pediatric surgery, obstetrics, interventional radiology, or endoscopic procedures were excluded. Exposures: Emergency surgery. Main Outcomes and Measures: The main outcome was the global incidence of delayed emergency surgery across 3 predefined organizational pathways: DET, DOR, and NOR. The ratio between the actual time to surgery (observed duration between surgical indication and incision) and the ideal time to surgery (predefined optimal duration between surgical indication and incision according to the Non-Elective Surgery Triage classification) was calculated for each patient. Surgery was considered delayed when this ratio was greater than 1. Results: A total of 1149 patients were included (mean [SD] age, 55 [21] years; 685 [59.9%] males): 649 in the DET group, 320 in the DOR group, and 171 in the NOR group (missing data: n = 5). The global frequency of surgical delay was 32.5% (95% CI, 29.8%-35.3%) and varied across the 3 organizational pathways: DET, 28.4% (95% CI, 24.8%-31.9%); DOR, 32.2% (95% CI, 27.0%-37.4%); and NOR, 49.1% (95% CI, 41.6%-56.7%) (P < .001). The adjusted odds ratio for delay was 1.80 (95% CI, 1.17-2.78) when comparing NOR with DET. Conclusions and Relevance: In this cohort study, the frequency of delayed emergency surgery in France was 32.5%. Reduced delays were found in organizational pathways that included dedicated theaters and teams. These preliminary results may pave the way for comprehensive large-scale studies, from which results may potentially inform new guidelines for quicker and safer access to emergency surgery.

Antimicrobial Susceptibility of Community-Acquired Urine Bacterial Isolates in French Amazonia.

Bacterial resistance in community-acquired urinary tract infections (UTIs) is increasing worldwide. Our study aimed to assess the microbiological epidemiology and antimicrobial susceptibility patterns of community-acquired urine bacterial isolates in French Amazonia. Our study is retrospective. It was conducted from January 2015 to December 2019 in the microbiology laboratory of the Cayenne General Hospital (French Guiana). It includes all positive urine samples from adult (> 18 years) outpatients (N = 2,533). Isolated microorganisms were Gram-negative rods in 83.9%, mainly Enterobacterales (98.4%). The main isolated bacteria were Escherichia coli (58.7%) and Klebsiella pneumoniae (13.3%). Among the isolated E. coli, 37.2% were susceptible to amoxicillin, 77.9% to amoxicillin/clavulanic acid, 94.9% to cefotaxime, 78.9% to ofloxacin, and 98.9% to nitrofurantoin. In 106 cases (5.1%), isolated Enterobacterales were extended-spectrum ß-lactamase producers (5% of E. coli and 8.9% of K. pneumoniae). Overall, high levels of cross- and co-resistance were registered. The main isolated Gram-positive bacteria was Staphylococcus saprophyticus (28.9%). It was resistant to oxacillin in 52.5% of cases and susceptible to nitrofurantoin in 99.1% of cases. Patients with S. saprophyticus were young women in almost all cases. In conclusion, the most isolated microorganisms from outpatient urinalyses were E. coli and K. pneumoniae. They showed a high resistance rate to amoxicillin, but they were susceptible to the most remaining antibiotics. S. saprophyticus was isolated mainly in young women and was resistant to oxacillin in half of the cases. Interestingly, nitrofurantoin was active against most isolated organisms and can be considered as empirical treatment in uncomplicated UTIs.

Emerging Maripa Hantavirus as a Potential Cause of a Severe Health Threat in French Guiana.

We describe the clinical parameters and management of nine confirmed cases of hantavirus pulmonary syndrome reported in French Guiana since 2008. All patients were admitted to Cayenne Hospital. Seven patients were men and the mean age was 48 years (range, 19-71 years). Two phases characterized the disease. The prodromal phase was characterized by fever (77.8%), myalgia (66.7%), and gastrointestinal symptoms (vomiting and diarrhea; 55.6%) starting, on average, 5 days before the illness phase, which was characterized by respiratory failure in all patients. Five patients died (55.6%) and the length of stay in the intensive care unit was 19 days (range, 11-28 days) for survivors. Detection of two back-to-back recent cases highlights the reason to screen for hantavirus infection during the nonspecific phase of the disease, in particular when concomitant pulmonary infection and digestive disorders are observed. Specific longitudinal serological surveys must also be used to identify other potential clinical forms of the disease in French Guiana.

Clinical outcome of wild-type AmpC-producing Enterobacterales infection in critically ill patients treated with ß-lactams: a prospective multicenter study.

BACKGROUND: ß-lactams are the main antibiotics used against wild-type AmpC-producing Enterobacterales (wtAE). However, they may fail or select AmpC-overproducing mutants. Our aim was to assess factors associated with clinical failure of ß-lactams in the treatment of wtAE infection. METHODS: From September 2017 to December 2020, we prospectively included all consecutive patients treated by definitive ß-lactams therapy for wtAE infection in four university ICUs. Clinical failure was defined as inadequate response to antimicrobial therapy leading to death or to the switch for a broader-spectrum antibiotic. RESULTS: 177 patients were included and 29.4% progressed to clinical failure. E. cloacae was the most prevalent species (42.4%) and ventilator-associated pneumonia (VAP) was the most frequent wtAE infection (69.5%). Cefepime and cefotaxime were used as definitive antibiotic treatment in 42.9% and 27.7% of patients, respectively. Occurrence of AmpC-overproduction was documented in 5.6% of patients and was associated with clinical failure (p = 0.004). In multivariate analysis, VAP (p < 0.001, OR 11.58 [95% CI 3.11-43.02] and K. aerogenes (p = 0.030, OR 3.76 [95% CI 1.13-12.46]) were independently associated with clinical failure. Conversely, cefotaxime as definitive treatment was found inversely associated with the risk of clinical failure (p = 0.022, OR 0.25 [95% CI 0.08-0.82]). After inverse probability weighting, cefotaxime showed a 20% risk reduction of clinical failure (95% CI 5-35%, p = 0.007) whatever the location of infection, the SOFA score on the day of wtAE infection, or the bacterial species. CONCLUSIONS: Clinical failure in the treatment of wtAE infections is associated with the infection site and the causal microorganism. Additionally, cefotaxime use is probably protective against clinical failure in wtAE infection.

In-Flight Medical Emergencies Management by Anesthetist-Intensivists and Emergency Physicians.

BACKGROUND: In-flight medical emergencies (IME) are challenging situations: aircraft cabins are noisy and narrow, medical supplies are scarce, and high-altitude related physiological changes may worsen chronic respiratory or cardiac conditions. The aim of this study was to assess the extent to which anesthetist-intensivists and emergency physicians are aware of IME specificities.METHODS: A questionnaire containing 21 items was distributed to French anesthetist-intensivists and emergency physicians between January and May 2020 using the mailing list of the French Society of Anesthesia and Intensive Care Medicine and the French Society of Emergency Medicine. The following topics were evaluated: high-altitude related physiological changes, medical and human resources available inside commercial aircraft, common medical incidents likely to happen on board, and previous personal experiences.RESULTS: The questionnaire was completed by 1064 physicians. The items corresponding to alterations in the arterial oxygen saturation, respiratory rate, and heart rate at cruising altitude were answered correctly by less than half of the participants (respectively, 3%, 42%, and 44% of the participants). Most responders (83%) were interested in a complementary training on IME management.DISCUSSION: The present study illustrates the poor knowledge in the medical community of the physiological changes induced by altitude and their consequences. In addition to offering specific theoretical courses to the medical community, placing sheets in commercial aircraft summarizing the optimal management of the main emergencies likely to happen on board might be an interesting tool.Diop S, Birnbaum R, Cook F, Mounier R. In-flight medical emergencies management by anesthetist-intensivists and emergency physicians. Aerosp Med Hum Perform. 2022; 93(8):633-636.

Machine learning-based prediction of emergency neurosurgery within 24 h after moderate to severe traumatic brain injury.

BACKGROUND: Rapid referral of traumatic brain injury (TBI) patients requiring emergency neurosurgery to a specialized trauma center can significantly reduce morbidity and mortality. Currently, no model has been reported to predict the need for acute neurosurgery in severe to moderate TBI patients. This study aims to evaluate the performance of Machine Learning-based models to establish to predict the need for neurosurgery procedure within 24 h after moderate to severe TBI. METHODS: Retrospective multicenter cohort study using data from a national trauma registry (Traumabase®) from November 2011 to December 2020. Inclusion criteria correspond to patients over 18 years old with moderate or severe TBI (Glasgow coma score ≤ 12) during prehospital assessment. Patients who died within the first 24 h after hospital admission and secondary transfers were excluded. The population was divided into a train set (80% of patients) and a test set (20% of patients). Several approaches were used to define the best prognostic model (linear nearest neighbor or ensemble model). The Shapley Value was used to identify the most relevant pre-hospital variables for prediction. RESULTS: 2159 patients were included in the study. 914 patients (42%) required neurosurgical intervention within 24 h. The population was predominantly male (77%), young (median age 35 years [IQR 24-52]) with severe head injury (median GCS 6 [3-9]). Based on the evaluation of the predictive model on the test set, the logistic regression model had an AUC of 0.76. The best predictive model was obtained with the CatBoost technique (AUC 0.81). According to the Shapley values method, the most predictive variables in the CatBoost were a low initial Glasgow coma score, the regression of pupillary abnormality after osmotherapy, a high blood pressure and a low heart rate. CONCLUSION: Machine learning-based models could predict the need for emergency neurosurgery within 24 h after moderate and severe head injury. Potential clinical benefits of such models as a decision-making tool deserve further assessment. The performance in real-life setting and the impact on clinical decision-making of the model requires workflow integration and prospective assessment.

Characteristics of Snakebite-Related Infection in French Guiana.

Wound infection is frequently reported following snakebite (SB). This study is retrospective. It was conducted in the emergency department and the Intensive Care Unit (ICU) of Cayenne General Hospital between 1 January 2016 and 31 July 2021. We included 172 consecutive patients hospitalized for SB envenoming. All patients were monitored for wound infection. Sixty-three patients received antibiotics at admission (36.6%). The main antibiotic used was amoxicillin-clavulanate (92.1%). Wound infection was recorded in 55 cases (32%). It was 19% in grade 1, 35% in grade 2, and 53% in grade 3. It included abscess (69.1%), necrotizing fasciitis (16.4%), and cellulitis (21.8%). The time from SB to wound infection was 6 days (IQR: 3-8). The main isolated microorganisms were A. hydrophila and M. morganii (37.5% and 18.8% of isolated organisms). Surgery was required in 48 patients (28.1%), and a necrosectomy was performed on 16 of them (33.3%). The independent factors associated with snakebite-associated infection were necrosis (p < 0.001, OR 13.15, 95% CI: 4.04-42.84), thrombocytopenia (p = 0.002, OR: 3.37, 95% CI: 1.59-7.16), and rhabdomyolysis (p = 0.046, OR: 2.29, 95% CI: 1.02-5.19). In conclusion, wound infection following SB is frequent, mainly in grade 2 and 3 envenomed patients, especially those with necrosis, thrombocytopenia, and rhabdomyolysis. The main involved bacteria are A. hydrophila and M. morganii.

Impact of Antibiotic Consumption on the Acquisition of Extended-Spectrum ß-Lactamase Producing Enterobacterales Carriage during the COVID-19 Crisis in French Guiana.

(1) Background: During the COVID-19 outbreak, several studies showed an increased prevalence of extended-spectrum ß-lactamase producing Enterobacterales (ESBL-PE) carriage in intensive care units (ICUs). Our objective was to assess the impact of antibiotic prescriptions on the acquisition of ESBL-PE in ICUs during the COVID-19 crisis. (2) Methods: We conducted an observational study between 1 April 2020, and 31 December 2021, in the medical-surgical ICU of the Cayenne General Hospital. We defined two periods: Period 1 with routine, empirical antibiotic use, and Period 2 with no systematic empiric antibiotic prescription. (3) Results: ICU-acquired ESBL-PE carriage was 22.8% during Period 1 and 9.4% during Period 2 (p = 0.005). The main isolated ESBL-PE was Klebsiella pneumoniae (84.6% in Period 1 and 58.3% in Period 2). When using a generalized linear model with a Poisson family, exposure to cefotaxime was the only factor independently associated with ESBL-PE acquisition in ICU (p = 0.002, IRR 2.59 (95% IC 1.42-4.75)). The propensity scores matching estimated the increased risk for cefotaxime use to acquire ESBL-PE carriage at 0.096 (95% CI = 0.02-0.17), p = 0.01. (4) Conclusions: Exposure to cefotaxime in patients with severe COVID-19 is strongly associated with the emergence of ESBL-PE in the context of maximal infection control measures.

Learning from terrorist mass casualty incidents: a global survey.

BACKGROUND: Reports published directly after terrorist mass casualty incidents frequently fail to capture difficulties that may have been encountered. An anonymised consensus-based platform may enable discussion and collaboration on the challenges faced. Our aim was to identify where to focus improvement for future responses. METHODS: We conducted a mixed methods study by email of clinicians' experiences of leading during terrorist mass casualty incidents. An initial survey identified features that worked well, or failed to, during terrorist mass casualty incidents plus ongoing challenges and changes that were implemented as a result. A follow-up, quantitative survey measured agreement between responses within each of the themes using a Likert scale. RESULTS: Thirty-three participants responded from 22 hospitals that had received casualties from a terrorist incident, representing 17 cities in low-middle, middle and high income countries. The first survey identified themes of sufficient (sometimes abundant) human resource, although coordination of staff was a challenge. Difficulties highlighted were communication, security, and management of blast injuries. The most frequently implemented changes were education on specific injuries, revising future plans and preparatory exercises. Persisting challenges were lack of time allocated to training and psychological well-being. The follow-up survey recorded highest agreement amongst correspondents on the need for re-triage at hospital (90% agreement), coordination roles (85% agreement), flexibility (100% agreement), and large-scale exercises (95% agreement). CONCLUSION: This survey collates international experience gained from clinicians managing terrorist mass casualty incidents. The organisation of human response, rather than consumption of physical supplies, emerged as the main finding. NHSH Clinical Effectiveness Unit project registration number: 2020/21-036.

Gunshot and stab wounds in France: descriptive study from a national trauma registry.

PURPOSE: Severe trauma is a major problem worldwide. In France, blunt trauma (BT) is predominant and few studies are available on penetrating trauma (PT). The purpose of this study was to perform a descriptive analysis of severe gunshot (GSW) and stab wounds (SW) in patients who were treated in French trauma centers. METHODS: Retrospective study on prospectively collected data in a national trauma registry. All adult (> 15 years) trauma patients primarily admitted in 1 of the 17 trauma centers members of the Traumabase between January 2015 to December 2018 were included. Data from patients who had a PT were compared with those who had suffered a BT over the same period. Due to the known differences between GSW and SW, sub-group analyses on data from GSW, SW and BT were also performed. RESULTS: 8128 patients were included. Twelve percent of the study group had a PT. The main mechanism of PT was SW (68.1%). Five hundred and eighty patients with PT (59.4%) required surgery within the first 24 h. Severe hemorrhage was more frequent in penetrating traumas (11.2% vs. 7.8% p < 0.001). Hospital mortality following PT was 8.9% vs 11% for blunt trauma (p = 0.047). Among PT the mortality after GSW was ten times higher than after SW (23.8% vs 2%). CONCLUSION: This work is the largest study to date that has specifically focused on GSW and SW in France, and will help improving knowledge in managing such patients in our country.

In vitro study of factors influencing the duration of antimicrobial protection of antimicrobial-impregnated external ventricular drains.

BACKGROUND: In vitro and clinical studies assessing the duration of the protective activity of antimicrobial-impregnated external ventricular drains (AI-EVDs) gave conflicting results. OBJECTIVES: To identify factors associated with decreased antimicrobial activity of AI-EVDs that were not taken into account in previous in vitro models. METHODS: We performed in vitro experiments with Bactiseal™ AI-EVDs, under different conditions. Tested parameters were chosen to mimic conditions in which AI-EVDs are used: perfusion by saline (at different flow rates) or not perfused, dwelling medium (air, saline, saline+protein, lipid) and temperature. Antimicrobial activity was assessed by measurement of inhibitory diameters of a 0.5 cm portion of an AI-EVD (cut every 2 days) placed onto agar plates covered by a standardized Staphylococcus spp. inoculum (three different isolates). MS was used to measure concentrations of rifampicin and clindamycin after 48 h of dwelling. RESULTS: In univariate analysis, most of the tested factors were associated with reduced antimicrobial activity: liquid media (as compared with ambient air), perfusion whatever the rate flow (as compared with no perfusion) and presence of protein in the media. In multivariate analysis, dwelling in media (lipid or saline) was the most constantly associated with a reduction of inhibition diameters (P < 0.01), as compared with ambient air. After 48 h of dwelling, the clindamycin concentration was higher than 100 and 450 mg/L in saline and saline+BSA, respectively. CONCLUSIONS: The medium in which an AI-EVD is dwelling plays a significant role in the duration of AI-EVD activity. These results may explain conflicting results between clinical and in vitro studies.

Assessment of Bacterial Colonization of Intracranial Pressure Transducers: A Prospective Study.

OBJECTIVES: Cerebral infections related to the presence of an intraparenchymal intracranial pressure transducer (ICPT) are rare. We assessed the incidence of ICPT-related infections and colonization using culture, molecular biology, and electron microscopy. METHODS: All consecutive patients in a neurosurgical intensive care unit who had an ICPT inserted between March 2017 and February 2018 were prospectively included. Presence of colonization on the ICPTs was assessed after removal using culture, scanning electron microscopy (SEM), and next-generation sequencing (NGS). RESULTS: Fifty-three ICPTs (53 patients), indwelling for a median of 4 (range 3-7) days, were studied. Median patient follow-up was 3 months. SEM, microbial culture, and NGS were performed for 91%, 79%, and 72% of ICPTs, respectively; 28 ICPTs (53%) were assessed using all three techniques. No patient developed ICPT-related infection. Microbial cultures were positive for two of the ICPTs (5%); colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was observed on 35/48 (73%) of ICPTs. A median of 10 (8-12) operational taxonomic units were identified for each ICPT, most being of environmental origin. There was no association between biofilm maturity and antimicrobial treatment or duration of ICPT insertion. Antimicrobial treatment was associated with decreased alpha and beta-diversity (p = 0.01). CONCLUSIONS: We observed no ICPT-related cerebral infections although colonization was identified on all ICPTs using NGS and SEM. Mature biofilm was the main bacterial lifestyle on the ICPTs.

Clinical relevance and impact of Corynebacterium isolation in lower respiratory tract of critically ill patients requiring mechanical ventilation.

PURPOSE: Corynebacterium spp. (C. spp.) is commonly considered as a contaminant in respiratory specimens. No study has ever focused on its clinical relevance in the lower respiratory tract of patients admitted to the intensive care unit (ICU) and requiring mechanical ventilation. The aims were to describe the characteristics of ICU patients with a C. spp. positive deep respiratory specimen, to investigate the impact of C. spp. on the occurrence of pneumonia, and to evaluate the outcomes of these pneumonia. METHODS: We retrospectively included all adult patients admitted to ICU in a 1000-bed University Hospital (2007-2017) who had a C. spp. positive lower respiratory tract specimen at a significant quantitative level. We used clinical, radiological, and microbiological criteria to classify the likelihood of such pneumonia. RESULTS: Among the 31 patients included, acute respiratory failure and postoperative care after major surgery were the main reasons of admission. SAPS II was 47 [34-60]. C. spp. pneumonia was considered as probable, possible and unlikely in 10, 14, and 7 patients, respectively. Fifty-two and 94% of C. spp. strains were sensitive to amoxicillin, and vancomycin/linezolid, respectively. Seventeen patients had a complete course of antibiotic against C. spp. The overall ICU mortality was 58%. CONCLUSION: Corynebacterium spp seems to be responsible for authentic pneumonia in mechanically ventilated patients. It should be considered as clinically relevant when predominantly present in respiratory specimen from patients suspected with pneumonia in ICU, and empirically treated.