Association of preoperative COVID-19 and postoperative respiratory morbidity during the Omicron epidemic wave: the DROMIS-22 multicentre prospective observational cohort study.

Background: Preoperative COVID-19 has been associated with excess postoperative morbi-mortality. Consequently, guidelines were developed that recommended the postponement of surgery for at least 7 weeks after the infection. We hypothesised that vaccination against the SARS-CoV-2 and the large predominance of the Omicron variant attenuated the effect of a preoperative COVID-19 on the occurrence of postoperative respiratory morbidity. Methods: We conducted a prospective cohort study in 41 French centres between 15 March and 30 May 2022 (ClinicalTrials NCT05336110), aimed at comparing the postoperative respiratory morbidity between patients with and without preoperative COVID-19 within 8 weeks prior to surgery. The primary outcome was a composite outcome combining the occurrence of pneumonia, acute respiratory failure, unexpected mechanical ventilation, and pulmonary embolism within the first 30 postoperative days. Secondary outcomes were 30-day mortality, hospital length-of-stay, readmissions, and non-respiratory infections. The sample size was determined to have 90% power to identify a doubling of the primary outcome rate. Adjusted analyses were performed using propensity score modelling and inverse probability weighting. Findings: Of the 4928 patients assessed for the primary outcome, of whom 92.4% were vaccinated against the SARS-CoV-2, 705 had preoperative COVID-19. The primary outcome was reported in 140 (2.8%) patients. An 8-week preoperative COVID-19 was not associated with increased postoperative respiratory morbidity (odds ratio 1.08 [95% CI 0.48-2.13]; p = 0.83). None of the secondary outcomes differed between the two groups. Sensitivity analyses concerning the timing between COVID-19 and surgery, and the clinical presentations of preoperative COVID-19 did not show any association with the primary outcome, except for COVID-19 patients with ongoing symptoms the day of surgery (OR 4.29 [1.02-15.8]; p = 0.04). Interpretation: In our Omicron-predominant, highly immunised population undergoing general surgery, a preoperative COVID-19 was not associated with increased postoperative respiratory morbidity. Funding: The study was fully funded by the French Society of Anaesthesiology and Intensive Care Medicine (SFAR).

Improving Wellness of Operating Room Personnel: A Light-Based Intervention on Perceived Nursing-Related Stress.

Background: Nursing is an emotionally demanding and physically draining occupation. Well-being of health care workers is essential to achieve success in care and have good cooperation relationships with other health professionals. Objective: The purpose of this study was to evaluate the effectiveness of a light-based intervention on perceived nursing-related stress in health care personnel working in an operating room environment. Methods: A total of 84 nurses participated in this randomized, cross-over controlled study. Intervention consisted of 4 weeks of bright blue-enriched light exposure using a LED head-mounted portable device (n = 42) or no light exposure (n = 42) separated by a 2-week washout period in a crossover fashion. Participants completes questionnaires for the Nursing Stress Scale (NSS). Results: Intervention and control groups were comparable in terms of demographics, with a median age of 34 (IQR: 27-49) and 69 (82%) female. The mean baseline NSS score was similar in both groups before intervention. The NSS score of the intervention group was significantly lower after intervention than the baseline score: the NSS score difference before and after intervention was 15.1 (SD 7.6) (p < 0.001) and 19.7 (SD 7.5) (p < 0.001) during the two successive periods of intervention, respectively. The cross-group comparison after intervention showed a significantly higher NSS score difference after intervention in the intervention group than the control group: 15.1 (SD 7.6) vs. 1.4 (SD 8.4) (p < 0.001) and 19.7 (SD 7.5) vs. 1.7 (SD 8.9) (p < 0.001) during the two successive periods of intervention, respectively. Conclusion: Alternative person-directed initiatives should be considered to improve the well-being of the health workforce in operating rooms, especially during the coronavirus pandemic.

Brief summary of French guidelines for the prevention, diagnosis and treatment of hospital-acquired pneumonia in ICU.

BACKGROUND: The French Society of Anaesthesia and Intensive Care Medicine and the French Society of Intensive Care edited guidelines focused on hospital-acquired pneumonia (HAP) in intensive care unit. The goal of 16 French-speaking experts was to produce a framework enabling an easier decision-making process for intensivists. RESULTS: The guidelines were related to 3 specific areas related to HAP (prevention, diagnosis and treatment) in 4 identified patient populations (COPD, neutropenia, post-operative and paediatric). The literature analysis and the formulation of the guidelines were conducted according to the Grade of Recommendation Assessment, Development and Evaluation methodology. An extensive literature research over the last 10 years was conducted based on publications indexed in PubMed™ and Cochrane™ databases. CONCLUSIONS: HAP should be prevented by a standardised multimodal approach and the use of selective digestive decontamination in units where multidrug-resistant bacteria prevalence was below 20%. Diagnosis relies on clinical assessment and microbiological findings. Monotherapy, in the absence of risk factors for multidrug-resistant bacteria, non-fermenting Gram-negative bacilli and/or increased mortality (septic shock, organ failure), is strongly recommended. After microbiological documentation, it is recommended to reduce the spectrum and to prefer monotherapy for the antibiotic therapy of HAP, including for non-fermenting Gram-negative bacilli.

Ventilator-associated pneumonia in patients assisted by veno-arterial extracorporeal membrane oxygenation support: Epidemiology and risk factors of treatment failure.

INTRODUCTION: Ventilator-associated pneumonia (VAP) is frequent in Intensive Care Unit (ICU) patients. In the specific case of patients treated with Veno-Arterial Extracorporeal Membrane Oxygenation Support (VA-ECMO), VAP treatment failures (VAP-TF) have been incompletely investigated. METHODS: To investigate the risk factors of treatment failure (VAP-TF) in a large cohort of ICU patients treated with VA-ECMO, we conducted a retrospective study in a Surgical ICU about patients assisted with VA-ECMO between January 1, 2013, and December 31, 2014. Diagnosis of VAP was confirmed by a positive quantitative culture of a respiratory sample. VAP-TF was defined as composite of death attributable to pneumonia and relapse within 28 days of the first episode. RESULTS: In total, 152 patients underwent ECMO support for > 48h. During the VA-ECMO support, 85 (55.9%) patients developed a VAP, for a rate of 60.6 per 1000 ECMO days. The main pathogens identified were Pseudomonas aeruginosa and Enterobacteriaceae. VAP-TF occurred in 37.2% of patients and was associated with an increased 28-day mortality (Hazard Ratio 3.05 [1.66; 5.63], P<0.001), and VA-ECMO assistance duration (HR 1.47 [1.05-2.05], P = 0.025). Risk factors for VAP-TF were renal replacement therapy (HR 13.05 [1.73; 98.56], P = 0.013) and documentation of Pseudomonas aeruginosa (HR 2.36 [1.04; 5.35], P = 0.04). CONCLUSIONS: VAP in patients treated with VA-ECMO is associated with an increased morbidity and mortality. RRT and infection by Pseudomonas aeruginosa appear as strong risks factors of treatment failure. Further studies seem necessary to precise the best antibiotic management in these patients.

Pathophysiology of Escherichia coli pneumonia: Respective contribution of pathogenicity islands to virulence.

Ventilator-associated pneumonia (VAP) remains the most frequent life-threatening nosocomial infection. Enterobacteriaceae including Escherichia coli are increasingly involved. If a cumulative effect of pathogenicity islands (PAIs) has been shown for E. coli virulence in urinary tract or systemic infections, very little is known regarding pathophysiology of E. coli pneumonia. This study aimed to determine the role of each of the 7 PAIs present in pathogenic E. coli strain 536 in pneumonia pathophysiology. We used mutant strains to screen pathophysiological role of PAI in a rat pneumonia model. We also test individual gene mutants within PAI identified to be involved in pneumonia pathogenesis. Finally, we determined the prevalence of these genes of interest in E. coli isolates from feces and airways of ventilated patients. Only PAIs I and III were significantly associated with rat pneumonia pathogenicity. Only the antigen-43 (Ag43) gene in PAI III was significantly associated with bacterial pathogenicity. The prevalence of tested genes in fecal and airway isolates of ventilated patients did not differ between isolates. In contrast, genes encoding Ag43, the F17-fimbriae subunits, HmuR and SepA were more prevalent in VAP isolates with statistical significance for hmuR when compared to airway colonizing isolates. The E. coli PAIs involved in lung pathogenicity differed from those involved in urinary tract and bloodstream infections. Overall, extraintestinal E. coli virulence seems to rely on a combination of numerous virulence genes that have a cumulative effect depending on the infection site.

Hospital-acquired pneumonia in ICU.

The French Society of Anesthesia and Intensive Care Medicine and the French Society of Intensive Care edited guidelines focused on hospital-acquired pneumonia (HAP) in intensive care unit (ICU). The goal of 16 French-speaking experts was to produce a framework enabling an easier decision-making process for intensivists. The guidelines were related to 3 specific areas related to HAP (prevention, diagnosis and treatment) in 4 identified patient populations (COPD, neutropenia, postoperative and pediatric). The literature analysis and the formulation of the guidelines were conducted according to the Grade of Recommendation Assessment, Development and Evaluation methodology. An extensive literature research over the last 10 years was conducted based on publications indexed in PubMed™ and Cochrane™ databases. HAP should be prevented by a standardized multimodal approach and the use of selective digestive decontamination in units where multidrug-resistant bacteria prevalence was below 20%. Diagnosis relies on clinical assessment and microbiological findings. Monotherapy, in the absence of risk factors for multidrug-resistant bacteria, non-fermenting Gram negative bacilli and/or increased mortality (septic shock, organ failure), is strongly recommended. After microbiological documentation, it is recommended to reduce the spectrum and to prefer monotherapy for the antibiotic therapy of HAP, including for non-fermenting Gram-negative bacilli.

Extended-spectrum beta-lactamase--producing enterobacteriaceae in the intensive care unit: acquisition does not mean cross-transmission.

BACKGROUND: In intensive care unit (ICU), infection and colonization by resistant Gram-negative bacteria increase costs, length of stay and mortality. Extended-spectrum beta-lactamase--producing Enterobacteriaceae (ESBL-E) is a group of pathogens increasingly encountered in ICU setting. Conditions that promote ESBL-E acquisition are not completely understood. The increasing incidence of infections related to ESBL-E and the unsolved issues related to ESBL-E cross-transmission, prompted us to assess the rates of referred and acquired cases of ESBL-E in ICU and to assess patient-to-patient cross-transmission of ESBL-E using a multimodal microbiological analysis. METHODS: During a 5-month period, all patients admitted to a medical ICU were tested for ESBL-E carriage. A rectal swab was performed at admission and then twice a week until discharge or death. ESBL-E strains were analyzed according to antibiotic susceptibility pattern, rep-PCR (repetitive-element Polymerase chain reaction) chromosomal analysis, and plasmid PCR (Polymerase chain reaction) analysis of ESBL genes. Patient-to-patient transmission was deemed likely when 2 identical strains were found in 2 patients hospitalized simultaneously in the ICU. RESULTS: Among the 309 patients assessed for ESBL-E carriage on admission, 25 were found to carry ESBL-E (importation rate: 8%). During follow-up, acquisition was observed among 19 of them (acquisition rate: 6.5%). Using the multimodal microbiological approach, we found only one case of likely patient-to-patient ESBL-E transmission. CONCLUSIONS: In unselected ICU patients, we found rather low rates of ESBL-E referred and acquired cases. Only 5% of acquisitions appeared to be related to patient-to-patient transmission. These data highlight the importance of jointly analyzing phenotypic profile and molecular data to discriminate strains of ESBL-E.

Effects of Proanthocyanidins on Adhesion, Growth, and Virulence of Highly Virulent Extraintestinal Pathogenic Escherichia coli Argue for Its Use to Treat Oropharyngeal Colonization and Prevent Ventilator-Associated Pneumonia.

OBJECTIVE: In the context of increasing microbial resistance and limited new antimicrobials, we aimed to study the antimicrobial effects of cranberry proanthocyanidin extracts on Escherichia coli growth, adhesion to epithelial cells, and lung infection. DESIGN: Experimental in vitro and in vivo investigation. SETTING: University research laboratory. SUBJECTS: Seventy-eight 6- to 8-week-old male Balb/C mice. INTERVENTIONS: In vitro, the effect of increasing concentrations of cranberry proanthocyanidin on bacterial growth of different clinical E. coli isolates was evaluated. Ex vivo, adhesion of E. coli to fresh human buccal epithelial cells was measured in the presence or absence of cranberry proanthocyanidin using microscopy. In vivo, lung bacterial count, pulmonary immune response (neutrophil murine chemokine keratinocyte-derived cytokine measurement and polymorphonuclear recruitment in bronchoalveolar lavage fluid), and lethality were evaluated in a pneumonia mouse model with E. coli precultured with or without cranberry proanthocyanidin. E. coli isolates originated from ventilated ICU patients with respiratory tract colonization or ventilator- associated pneumonia. They differed in number of virulence genes. MEASUREMENTS AND MAIN RESULTS: A significant inhibition of bacterial growth was observed with increasing concentration of cranberry proanthocyanidin, affecting both time to maximal growth and maximal growth rate (p<0.0001 for both). The minimal concentration at which this effect occurred was 250 µg/mL. Cranberry proanthocyanidin significantly reduced E. coli adhesion to fresh buccal epithelial cells by up to 80% (p<0.001). Bacterial counts in homogenized lungs and bronchoalveolar lavage fluid were decreased after cranberry proanthocyanidin exposition (p<0.05 and p<0.01, respectively). Cranberry proanthocyanidin also decreased KC concentrations and polymorphonuclear cell recruitment in bronchoalveolar lavage fluid (p<0.05 for both). At identical inoculum, mortality was reduced by more than half in mice inoculated with E. coli exposed to cranberry proanthocyanidin (p<0.01). CONCLUSION: Cranberry proanthocyanidins exhibit potent effects on growth, adhesion, and virulence of oropharyngeal and lung isolates of E. coli, suggesting that cranberry proanthocyanidin could be of clinical interest to reduce oropharyngeal colonization and prevent lung infection.

Alteration of skin perfusion in mottling area during septic shock.

BACKGROUND: Mottling score has been reported to be a strong predictive factor during septic shock. However, the pathophysiology of mottling remains unclear. METHODS: In patients admitted in ICU for septic shock, we measured on the same area the mean skin perfusion by laser Doppler, the mottling score, and variations of both indices between T1 (6 hours after vasopressors were started) and T2 (24 hours later). RESULTS: Fourteen patients were included, SAPS II was 56 [37-71] and SOFA score at T1 was 10 [7-12]. The mean skin surface area analyzed was 4108 ± 740 mm2; 1184 ± 141 measurements were performed over each defined skin surface area. Skin perfusion was significantly different according to mottling score and decreased from 37 [31-42] perfusion units (PUs) for a mottling score of [0-1] to 22 [20-32] PUs for a mottling score of [2-3] and 23 [16-28] for a score of [4-5] (Kruskal-Wallis test, P = 0.05). We analyzed skin perfusion changes during resuscitation in each patient and together with mottling score variations between T1 and T2 using a Wilcoxon signed-rank test. Among the 14 patients included, mottling score increased (worsened) in 5 patients, decreased (improved) in 5 patients, and remained stable in 4 patients. Baseline skin perfusion at T1 was arbitrarily scored 100%. Mean skin perfusion significantly decreased in all the patients whose mottling score worsened from 100% baseline to 63.2 ± 10.7% (P = 0.001), mean skin perfusion significantly increased in all patients whose mottling score improved from 100% baseline to 172.6 ± 46.8% (P = 0.001), and remained stable in patients whose mottling score did not change (100.5 ± 6.8%, P = 0.95). CONCLUSIONS: We have shown that mottling score variations and skin perfusion changes during septic shock resuscitation were correlated, providing additional evidence that mottling reflects skin hypoperfusion.

Pathophysiology of Escherichia coli ventilator-associated pneumonia: implication of highly virulent extraintestinal pathogenic strains.

PURPOSE: To characterize Escherichia coli ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients by determining antibioresistance and genotypic characteristics of E. coli isolates responsible for VAP or lung colonization, by comparing them with their oropharyngeal and rectal counterparts and by assessing representative isolates' virulence in a pneumonia mouse model. METHODS: Patients under mechanical ventilation for more than 72 h were screened for simultaneous presence of E. coli in rectal, oropharyngeal, and respiratory samples (colonization or VAP). If present, E. coli isolates were characterized by antimicrobial susceptibility, phylogenetic grouping, and virulence factor (VF) gene content determination. BALB/c mice were challenged intranasally with 3.6 × 10(8) colony-forming units (CFU) of patients' E. coli isolates. RESULTS: Multisite E. coli colonization was observed in 19 % of patients (25 patients, 12 with E. coli VAP). One hundred fifteen distinct E. coli isolates were analyzed. B2 phylogenetic group was predominant, with high VF gene content and low antimicrobial resistance. Antimicrobial resistance diversity was observed in four patients with VAP. E. coli isolates from VAP patients were more frequently B2 isolates, with significantly greater VF gene content than lung colonization isolates. Among screened VF genes, iroN and sfa appeared important for lung infection. A very strong correlation (R (2) = 0.99) was found between VF gene content and mortality in the mouse model. CONCLUSIONS: This is the first study establishing antibioresistance and genotypic characteristics of E. coli isolates responsible for VAP in adult ICU patients. These isolates are highly virulent specific extraintestinal pathogenic E. coli strains expressing virulence factors, representing potential targets for new therapies.

Comparison of superior vena cava and femoroiliac vein pressure according to intra-abdominal pressure.

BACKGROUND: Previous studies have shown a good agreement between central venous pressure (CVP) measurements from catheters placed in superior vena cava and catheters placed in the abdominal cava/common iliac vein. However, the influence of intra-abdominal pressure on such measurements remains unknown. METHODS: We conducted a prospective, observational study in a tertiary teaching hospital. We enrolled patients who had indwelling catheters in both superior vena cava (double lumen catheter) and femoroiliac veins (dialysis catheter) and into the bladder. Pressures were measured from all the sites, CVP, femoroiliac venous pressure (FIVP), and intra-abdominal pressure. RESULTS: A total of 30 patients were enrolled (age 62 ± 14 years; SAPS II 62 (52-76)). Fifty complete sets of measurements were performed. All of the studied patients were mechanically ventilated (PEP 3 cmH20 (2-5)). We observed that the concordance between CVP and FIVP decreased when intra-abdominal pressure increased. We identified 14 mmHg as the best intra-abdominal pressure cutoff, and we found that CVP and FIVP were significantly more in agreement below this threshold than above (94% versus 50%, P = 0.002). CONCLUSIONS: We reported that intra-abdominal pressure affected agreement between CVP measurements from catheter placed in superior vena cava and catheters placed in the femoroiliac vein. Agreement was excellent when intra-abdominal pressure was below 14 mmHg.

Femoral venous catheter: a misleading cause of gas in the liver.

OBJECTIVES: The presence of a femoral venous catheter could be associated with gas presence in the hepatic veins. This entity should be recognized to avoid a misdiagnosis of gas presence in the portal veins or in the biliary tract. Objectives are to assess: 1) the incidence of gas presence in the hepatic veins in intensive care unit patients explored by abdominal computed tomography scan; 2) the rate of gas presence in the liver in intensive care unit patients with a catheter inserted in the femoral vein; and 3) the specific imaging features. DESIGN: A retrospective study in a medical intensive care unit in a teaching hospital in France. MEASUREMENTS: All consecutive abdominal computed tomography scans performed in intensive care unit patients between 2008 and 2010 were retrospectively reviewed independently by an intensivist and a radiologist. Presence of gas in the liver was noticed and its location was specified using multiplanar reconstruction. MAIN RESULTS: We analyzed 235 computed tomography scans (performed in 207 patients). Gas was identified in the liver on 10.2% of computed tomography scans. Gas was located in the hepatic veins in 12 cases (50%), in the biliary tract in ten cases (41.7%), and in the portal veins in two cases (8.3%). All patients with gas in the hepatic veins had a femoral venous catheter. Characteristics of gas location within the hepatic veins on computed tomography scan axial views were not different from those of gas located in the biliary tract or in the portal venous system. Gas was present in the hepatic veins in 12 of 83 (14.5%) of the computed tomography scans with a femoral venous catheter and was associated with gas presence in other vessels of the inferior vena cava system in five of 12 (41.7%) cases. CONCLUSIONS: Gas located in the hepatic veins related to femoral venous catheter is a frequent cause of gas in the liver in intensive care unit patients. This imaging feature could be misleading. Multiplanar reconstruction should be performed to differentiate this aspect from those of gas in the biliary tract or in the portal venous system.

Beneficial effects of loxapine on agitation and breathing patterns during weaning from mechanical ventilation.

INTRODUCTION: Interruption of sedation during weaning from mechanical ventilation often leads to patient agitation because of withdrawal syndrome. We tested the short-term efficacy and tolerance of loxapine in this situation. METHODS: Nineteen mechanically ventilated patients with marked agitation after sedation withdrawal were included. Three agitation scales, the Richmond Agitation Sedation Scale (RASS), the Motor Activity Assessment Scale (MAAS), and the Ramsay and physiological variables (respiratory rate, airway occlusion pressure during the first 0.1 second of inspiration (P0.1), heart rate and systolic arterial blood pressure) were recorded before and after loxapine administration. RESULTS: Loxapine dramatically improved all agitation scores (RASS and MASS decreased from 2 +/- 0 to -1.1 +/- 2.3, and 5.4 +/- 0.5 to 2.7 +/- 1.6, respectively; Ramsay increased from 1.0 +/- 0 to 3.5 +/- 1.5, 60 minutes after loxapine administration, P < 0.05 for all scores) as well as P0.1 (6 +/- 4.2 to 1.8 +/- 1.8 cm H2O; P < 0.05) and respiratory rate (from 31.2 +/- 7.2 to 23.4 +/- 7.8; P < 0.05) without hemodynamic adverse events. No side effects occurred. Sixteen (84%) patients were successfully managed with loxapine, sedation was resumed in two others, and one patient self-extubated without having to be reintubated. CONCLUSIONS: Loxapine was safe and effective in treating agitation in a small group of mechanically ventilated patients and improved respiratory physiologic parameters, enabling the weaning process to be pursued. A multicenter trial is under way to confirm these promising results.