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Study Objective: During laparoscopic surgery, the role of PEEP to improve outcome is controversial. Mechanistically, PEEP benefits depend on the extent of alveolar recruitment, which prevents ventilator-induced lung injury by reducing lung dynamic strain. The hypotheses of this study were that pneumoperitoneum-induced aeration loss and PEEP-induced recruitment are inter-individually variable, and that the recruitment-to-inflation ratio (R/I) can identify patients who benefit from PEEP in terms of strain reduction., Design: Sequential study., Setting: Operating room., Patients: Seventeen ASA I-III patients receiving robot-assisted prostatectomy during Trendelenburg pneumoperitoneum., Interventions and Measurements: Patients underwent end-expiratory lung volume (EELV) and respiratory/lung/chest wall mechanics (esophageal manometry and inspiratory/expiratory occlusions) assessment at PEEP = 0 cmH 2 O before and after pneumoperitoneum, at PEEP = 4 and 12 cmH 2 O during pneumoperitoneum. Pneumoperitoneum-induced derecruitment and PEEP-induced recruitment were assessed through a simplified method based on multiple pressure-volume curve. Dynamic and static strain changes were evaluated. R/I between 12 and 4 cmH 2 O was assessed from EELV. Inter-individual variability was rated with the ratio of standard deviation to mean (CoV)., Main Results: Pneumoperitoneum reduced EELV by (median [IqR]) 410 mL [80-770] (p < 0.001) and increased dynamic strain by 0.04 [0.01-0.07] (p < 0.001), with high inter-individual variability (CoV = 70% and 88%, respectively). Compared to PEEP = 4 cmH 2 O, PEEP = 12 cmH 2 O yielded variable amount of recruitment (139 mL [96-366] CoV = 101%), causing different extent of dynamic strain reduction (median decrease 0.02 [0.01-0.04], p = 0.002; CoV = 86%) and static strain increases (median increase 0.05 [0.04-0.07], p = 0.01, CoV = 33%). R/I (1.73 [0.58-3.35]) estimated the decrease in dynamic strain (p ≤0.001, r = -0.90) and the increase in static strain (p = 0.009, r = -0.73) induced by PEEP, while PEEP-induced changes in respiratory and lung mechanics did not., Conclusions: Trendelenburg pneumoperitoneum yields variable derecruitment: PEEP capability to revert these phenomena varies significantly among individuals. High R/I identifies patients in whom higher PEEP mostly reduces dynamic strain with limited static strain increases, potentially allowing individualized settings., Competing Interests: Declaration of competing interest DLG reports speaking fees or support for travel expenses by GE Healthcare, Intersurgical, Fisher and Paykel, Gilead and Pfizer. MA has received personal fees from Maquet, and a research grant by Toray. DLG and MA disclose a research grant by General Electric Healthcare., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Colistin, administered as intravenous colistimethate (CMS), is still used in the critical care setting and current guidelines recommend high dosage CMS in patients undergoing continuous renal replacement therapy (CRRT). Due to the paucity of real-life data, we aimed to describe colistin pharmacokinetic/pharmacodynamic (PK/PD) profile in a cohort of critically ill patients with infections due to carbapenem-resistant (CR) bacteria undergoing CRRT., Results: All consecutive patients admitted to three Intensive Care Units (ICUs) of a large metropolitan University Hospital, treated with colistin for at least 48 h at the dosage of 6.75 MUI q12, after 9 MIU loading dose, and undergoing CRRT were included. After the seventh dose, patients underwent blood serial sampling during a time frame of 24 h. We included 20 patients, who had CR-Acinetobacter baumannii ventilator-associated pneumonia and were characterized by a median SAPS II and SOFA score of 41 [34.5-59.3] and 9 [6.7-11], respectively. Fifteen patients died during ICU stay and six recovered renal function. Median peak and trough colistin concentrations were 16.6 mcg/mL [14.8-20.6] and 3.9 mcg/mL [3.3-4.4], respectively. Median area under the time-concentration curve (AUC 0 - 24 ) and average steady-state concentration (C ss, avg ) were 193.9 mcg h/mL [170.6-208.6] and 8.07 mcg/mL [7.1-8.7]. Probability of target attainment of colistin pharmacodynamics according to the fAUC 0 - 24 /MIC target ≥ 12 was 100% for MIC ≤ 2 mcg/mL and 85% for MIC = 4 mcg/ML, although exceeding the toxicity limit of C ss, avg 3-4 mcg/mL., Conclusions: In critically ill patients with CR infections undergoing CRRT, recommended CMS dosage resulted in colistin plasmatic levels above bacterial MIC 90 , but exceeding the safety C ss, avg . limit., Trial Registration: This trial was registered in ClinicalTrials.gov on 23/07/2021 with the ID NCT04995133 (https//clinicaltrials.gov/study/NCT04995133)., (© 2024. The Author(s).)

Background: To determine whether a decrease in serum (1,3)-β-D-glucan (BDG) was associated with reduced mortality and to investigate the performance of BDG downslope in predicting clinical outcome in invasive candidiasis., Methods: Observational cohort study in ICU patients over a ten-year period (2012-2022) in Italy. Proven invasive candidiasis with at least 2 BDG determinations were considered., Results: In the study population of 103 patients (age 47 [35-62] years, SAPS II score 67 [52-77]) 68 bloodstream and 35 intrabdominal infections were recorded. Serial measurements showed that in 54 patients BDG decreased over time (BDG downslope group) while in 49 did not (N-BDG downslope group). Candida albicans was the pathogen most frequently isolated (61%) followed by C. parapsilosis (17%) and C. glabrata (12%), in absence of any inter-group difference. Invasive candidiasis related mortality was lower in BDG downslope than in N-BDG downslope group (17% vs 53%, p < 0.01). The multivariate Cox regression analysis showed the association of septic shock at infection occurrence and chronic liver disease with invasive candidiasis mortality (HR [95% CI] 3.24 [1.25-8.44] p = 0.02 and 7.27 [2.33-22.66] p < 0.01, respectively) while a BDG downslope was the only predictor of survival (HR [95% CI] 0.19 [0.09-0.43] p < 0.01). The area under the receiver operator characteristic curve for the performance of BDG downslope as predictor of good clinical outcome was 0.74 (p = 0.02) and our model showed that a BDG downslope > 70% predicted survival with both specificity and positive predictive value of 100%., Conclusions: A decrease in serum BDG was associated with reduced mortality and a steep downslope predicted survival with high specificity in invasive candidiasis., (© 2024. The Author(s).)

Background: The recruitment-to-inflation ratio (R/I) has been recently proposed to bedside assess response to PEEP. The impact of PEEP on ventilator-induced lung injury depends on the extent of dynamic strain reduction. We hypothesized that R/I may reflect the potential for lung recruitment (i.e. recruitability) and, consequently, estimate the impact of PEEP on dynamic lung strain, both assessed through computed tomography scan., Methods: Fourteen lung-damaged pigs (lipopolysaccharide infusion) underwent ventilation at low (5 cmH 2 O) and high PEEP (i.e., PEEP generating a plateau pressure of 28-30 cmH 2 O). R/I was measured through a one-breath derecruitment maneuver from high to low PEEP. PEEP-induced changes in dynamic lung strain, difference in nonaerated lung tissue weight (tissue recruitment) and amount of gas entering previously nonaerated lung units (gas recruitment) were assessed through computed tomography scan. Tissue and gas recruitment were normalized to the weight and gas volume of previously ventilated lung areas at low PEEP (normalized-tissue recruitment and normalized-gas recruitment, respectively)., Results: Between high (median [interquartile range] 20 cmH 2 O [18-21]) and low PEEP, median R/I was 1.08 [0.88-1.82], indicating high lung recruitability. Compared to low PEEP, tissue and gas recruitment at high PEEP were 246 g [182-288] and 385 ml [318-668], respectively. R/I was linearly related to normalized-gas recruitment (r = 0.90; [95% CI 0.71 to 0.97) and normalized-tissue recruitment (r = 0.69; [95% CI 0.25 to 0.89]). Dynamic lung strain was 0.37 [0.29-0.44] at high PEEP and 0.59 [0.46-0.80] at low PEEP (p < 0.001). R/I was significantly related to PEEP-induced reduction in dynamic (r = - 0.93; [95% CI - 0.78 to - 0.98]) and global lung strain (r = - 0.57; [95% CI - 0.05 to - 0.84]). No correlation was found between R/I and and PEEP-induced changes in static lung strain (r = 0.34; [95% CI - 0.23 to 0.74])., Conclusions: In a highly recruitable ARDS model, R/I reflects the potential for lung recruitment and well estimates the extent of PEEP-induced reduction in dynamic lung strain., (© 2024. The Author(s).)

In acute respiratory distress syndrome, the role of positive end-expiratory pressure (PEEP) to prevent ventilator-induced lung injury is controversial. Randomized trials comparing higher versus lower PEEP strategies failed to demonstrate a clinical benefit. This may depend on the inter-individually variable potential for lung recruitment (i.e. recruitability), which would warrant PEEP individualization to balance alveolar recruitment and the unavoidable baby lung overinflation produced by high pressure. Many techniques have been used to assess recruitability, including lung imaging, multiple pressure-volume curves and lung volume measurement. The Recruitment-to-Inflation ratio (R/I) has been recently proposed to bedside assess recruitability without additional equipment. R/I assessment is a simplified technique based on the multiple pressure-volume curve concept: it is measured by monitoring respiratory mechanics and exhaled tidal volume during a 10-cmH2O one-breath derecruitment maneuver after a short high-PEEP test. R/I scales recruited volume to respiratory system compliance, and normalizes recruitment to a proxy of actual lung size. With modest R/I (<0.3-0.4), setting low PEEP (5-8 cmH2O) may be advisable; with R/I>0.6-0.7, high PEEP (≥15 cmH2O) can be considered, provided that airway and/or transpulmonary plateau pressure do not exceed safety limits. In case of intermediate R/I (≈0.5), a more granular assessment of recruitability may be needed. This could be accomplished with advanced monitoring tools, like sequential lung volume measurement with granular R/I assessment or electrical impedance tomography monitoring during a decremental PEEP trial. In this review, we discuss R/I rationale, applications and limits, providing insights on its clinical use for PEEP selection in moderate-to-severe acute respiratory distress syndrome.

Background: Positive end-expiratory pressure (PEEP) can potentially modulate inspiratory effort (ΔPes), which is the major determinant of self-inflicted lung injury., Research Question: Does high PEEP reduce ΔPes in patients with moderate-to-severe ARDS on assisted ventilation?, Study Design and Methods: Sixteen patients with Pao 2 /Fio 2  ≤ 200 mm Hg and ΔPes ≥ 10 cm H 2 O underwent a randomized sequence of four ventilator settings: PEEP = 5 cm H 2 O or PEEP = 15 cm H 2 O + synchronous (pressure support ventilation [PSV]) or asynchronous (pressure-controlled intermittent mandatory ventilation [PC-IMV]) inspiratory assistance. ΔPes and respiratory system, lung, and chest wall mechanics were assessed with esophageal manometry and occlusions. PEEP-induced alveolar recruitment and overinflation, lung dynamic strain, and tidal volume distribution were assessed with electrical impedance tomography., Results: ΔPes was not systematically different at high vs low PEEP (pressure support ventilation: median, 20 cm H 2 O; interquartile range (IQR), 15-24 cm H 2 O vs median, 15 cm H 2 O; IQR, 13-23 cm H 2 O; P = .24; pressure-controlled intermittent mandatory ventilation: median, 20; IQR, 18-23 vs median, 19; IQR, 17-25; P = .67, respectively). Similarly, respiratory system and transpulmonary driving pressures, tidal volume, lung/chest wall mechanics, and pendelluft extent were not different between study phases. High PEEP resulted in lower or higher ΔPes, respiratory system driving pressure, and transpulmonary driving pressure according to whether this increased or decreased respiratory system compliance (r = -0.85, P < .001; r = -0.75, P < .001; r = -0.80, P < .001, respectively). PEEP-induced changes in respiratory system compliance were driven by its lung component and were dependent on the extent of PEEP-induced alveolar overinflation (r = -0.66, P = .006). High PEEP caused variable recruitment and systematic redistribution of tidal volume toward dorsal lung regions, thereby reducing dynamic strain in ventral areas (pressure support ventilation: median, 0.49; IQR, 0.37-0.83 vs median, 0.96; IQR, 0.62-1.56; P = .003; pressure-controlled intermittent mandatory ventilation: median, 0.65; IQR, 0.42-1.31 vs median, 1.14; IQR, 0.79-1.52; P = .002). All results were consistent during synchronous and asynchronous inspiratory assistance., Interpretation: The impact of high PEEP on ΔPes and lung stress is interindividually variable according to different effects on the respiratory system and lung compliance resulting from alveolar overinflation. High PEEP may help mitigate the risk of self-inflicted lung injury solely if it increases lung/respiratory system compliance., Trial Registration: ClinicalTrials.gov; No.: NCT04241874; URL: www., Clinicaltrials: gov., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: D. L. G. has received speaking fees from Gilead, Intersurgical, MSD, and GE; and reports having received travel accommodation by Fisher and Paykel, outside the submitted work. M. A. has received personal fees by Maquet and a research grant by Toray, outside the submitted work. D. L. G. and M. A. disclose a research grant by GE, outside the submitted work. None declared (G. B., V. G., A. B., L. D. C., T. R., L. S. M., L. M., T. M., G. S., G. D. P., M. A. P., R. R. D. S. S., L. B.)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: Reverse triggering (RT) was described in 2013 as a form of patient-ventilator asynchrony, where patient's respiratory effort follows mechanical insufflation. Diagnosis requires esophageal pressure (P es ) or diaphragmatic electrical activity (EA di ), but RT can also be diagnosed using standard ventilator waveforms., Hypothesis: We wondered (1) how frequently RT would be present but undetected in the figures from literature, especially before 2013; (2) whether it would be more prevalent in the era of small tidal volumes after 2000., Methods: We searched PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials, from 1950 to 2017, with key words related to asynchrony to identify papers with figures including ventilator waveforms expected to display RT if present. Experts labelled waveforms. 'Definite' RT was identified when P es or EA di were in the tracing, and 'possible' RT when only flow and pressure waveforms were present. Expert assessment was compared to the author's descriptions of waveforms., Results: We found 65 appropriate papers published from 1977 to now, containing 181 ventilator waveforms. 21 cases of 'possible' RT and 25 cases of 'definite' RT were identified by the experts. 18.8% of waveforms prior to 2013 had evidence of RT. Most cases were published after 2000 (1 before vs. 45 after, p = 0.03). 54% of RT cases were attributed to different phenomena. A few cases of identified RT were already described prior to 2013 using different terminology (earliest in 1997). While RT cases attributed to different phenomena decreased after 2013, 60% of 'possible' RT remained missed., Conclusion: RT has been present in the literature as early as 1997, but most cases were found after the introduction of low tidal volume ventilation in 2000. Following 2013, the number of undetected cases decreased, but RT are still commonly missed. Reverse Triggering, A Missed Phenomenon in the Literature. Critical Care Canada Forum 2019 Abstracts. Can J Anesth/J Can Anesth 67 (Suppl 1), 1-162 (2020). https://doi-org.myaccess.library.utoronto.ca/ https://doi.org/10.1007/s12630-019-01552-z ., (© 2024. The Author(s).)

Introduction and Objectives: Quantifying breathing effort in non-intubated patients is important but difficult. We aimed to develop two models to estimate it in patients treated with high-flow oxygen therapy., Patients and Methods: We analyzed the data of 260 patients from previous studies who received high-flow oxygen therapy. Their breathing effort was measured as the maximal deflection of esophageal pressure (ΔPes). We developed a multivariable linear regression model to estimate ΔPes (in cmH 2 O) and a multivariable logistic regression model to predict the risk of ΔPes being >10 cmH 2 O. Candidate predictors included age, sex, diagnosis of the coronavirus disease 2019 (COVID-19), respiratory rate, heart rate, mean arterial pressure, the results of arterial blood gas analysis, including base excess concentration (BEa) and the ratio of arterial tension to the inspiratory fraction of oxygen (PaO 2 :FiO 2 ), and the product term between COVID-19 and PaO 2 :FiO 2 ., Results: We found that ΔPes can be estimated from the presence or absence of COVID-19, BEa, respiratory rate, PaO 2 :FiO 2, and the product term between COVID-19 and PaO 2 :FiO 2. The adjusted R 2 was 0.39. The risk of ΔPes being >10 cmH 2 O can be predicted from BEa, respiratory rate, and PaO 2 :FiO 2 . The area under the receiver operating characteristic curve was 0.79 (0.73-0.85). We called these two models BREF, where BREF stands for BReathing EFfort and the three common predictors: BEa (B), respiratory rate (RE), and PaO 2 :FiO 2 (F)., Conclusions: We developed two models to estimate the breathing effort of patients on high-flow oxygen therapy. Our initial findings are promising and suggest that these models merit further evaluation., Competing Interests: Conflicts of interest R.T. received travel support from SEDA Ltd, owns the patent n. 02021000007478 released by the Italian Ministry of Enterprises and Made in Italy, and is a co-founder of IREC Ltd (VAT number 02959080355); G.M.C. received payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing, or educational events from Getinge e MSD; E.C. owns the patent n. 02021000007478, released by the Italian Ministry of Enterprises and Made in Italy, and is a co-founder of IREC Ltd (VAT number 02959080355). All other authors declare no conflicts of interest related to this manuscript., (Copyright © 2024 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)

Our study investigates the post-mortem findings of the diaphragm's muscular structural changes in mechanically ventilated COVID-19 patients. Diaphragm samples of the right side from 42 COVID-19 critically ill patients were analyzed and correlated with the type and length of mechanical ventilation (MV), ventilatory parameters, prone positioning, and use of sedative drugs. The mean number of fibers was 550±626. The cross-sectional area was 4120±3280 μm2, while the muscular fraction was 0.607±0.126. The overall population was clustered into two distinct populations (clusters 1 and 2). Cluster 1 showed a lower percentage of slow myosin fiber and higher fast fiber content than cluster 2, 68% versus 82%, p<0.00001, and 29.8% versus 18.8%, p=0.00045 respectively. The median duration of MV was 180 (41-346) hours. In cluster 1, a relationship between assisted ventilation and fast myosin fiber percentage (R2=-0.355, p=0.014) was found. In cluster 2, fast fiber content increased with increasing the length of the controlled MV (R2=0.446, p=0.006). A high grade of fibrosis was reported. Cluster 1 was characterized by fibers' atrophy and cluster 2 by hypertrophy, supposing different effects of ventilation on the diaphragm but without excluding a possible direct viral effect on diaphragmatic fibers.

Antimicrobial de-escalation (ADE) is defined as the discontinuation of one or more antimicrobials in empirical therapy, or the replacement of a broad-spectrum antimicrobial with a narrower-spectrum antimicrobial. The aim of this review is to provide an overview of the available literature on the effectiveness and safety of ADE in critically ill patients, with a focus on special conditions such as anti-fungal therapy and high-risk categories. Although it is widely considered a safe strategy for antimicrobial stewardship (AMS), to date, there has been no assessment of the effect of de-escalation on the development of resistance. Conversely, some authors suggest that prolonged antibiotic treatment may be a side effect of de-escalation, especially in high-risk categories such as neutropenic critically ill patients and intra-abdominal infections (IAIs). Moreover, microbiological documentation is crucial for increasing ADE rates in critically ill patients with infections, and efforts should be focused on exploring new diagnostic tools to accelerate pathogen identification. For these reasons, ADE can be safely used in patients with infections, as confirmed by high-quality and reliable microbiological samplings, although further studies are warranted to clarify its applicability in selected populations.

Few data are available on the lung microbiota composition of patients with coronavirus disease 2019-related acute respiratory distress syndrome (C-ARDS) receiving invasive mechanical ventilation (IMV). Moreover, it has never been investigated whether there is a potential correlation between lung microbiota communities and respiratory mechanics. We performed a prospective observational study in two intensive care units of a university hospital in Italy. Lung microbiota was investigated by bacterial 16S rRNA gene sequencing, performed on bronchoalveolar lavage fluid samples withdrawn after intubation. The lung bacterial communities were analyzed after stratification by respiratory system compliance/predicted body weight (Crs) and ventilatory ratio (VR). Weaning from IMV and hospital survival were assessed as secondary outcomes. In 70 C-ARDS patients requiring IMV from 1 April through 31 December 2020, the lung microbiota composition (phylum taxonomic level, permutational multivariate analysis of variance test) significantly differed between who had low Crs vs those with high Crs ( P = 0.010), as well as in patients with low VR vs high VR ( P = 0.012). As difference-driving taxa, Proteobacteria ( P = 0.017) were more dominant and Firmicutes ( P = 0.040) were less dominant in low- vs high-Crs patients. Similarly, Proteobacteria were more dominant in low- vs high-VR patients ( P = 0.013). After multivariable regression analysis, we further observed lung microbiota diversity as a negative predictor of weaning from IMV and hospital survival (hazard ratio = 3.31; 95% confidence interval, 1.52-7.20, P = 0.048). C-ARDS patients with low Crs/low VR had a Proteobacteria-dominated lung microbiota. Whether patients with a more diverse lung bacterial community may have more chances to be weaned from IMV and discharged alive from the hospital warrants further large-scale investigations., Importance: Lung microbiota characteristics were demonstrated to predict ventilator-free days and weaning from mechanical ventilation in patients with acute respiratory distress syndrome (ARDS). In this study, we observed that in severe coronavirus disease 2019 patients with ARDS who require invasive mechanical ventilation, lung microbiota characteristics were associated with respiratory mechanics. Specifically, the lung microbiota of patients with low respiratory system compliance and low ventilatory ratio was characterized by Proteobacteria dominance. Moreover, after multivariable regression analysis, we also found an association between patients' microbiota diversity and a higher possibility of being weaned from mechanical ventilation and discharged alive from the hospital. For these reasons, lung microbiota characterization may help to stratify patient characteristics and orient the delivery of target interventions. (This study has been registered at ClinicalTrials.gov on 17 February 2020 under identifier NCT04271345.)., Registered at ClinicalTrials.gov, 17 February 2020 (NCT0427135)., Competing Interests: The authors declare no conflict of interest.

Background: Myocardial injury is prevalent among patients hospitalized for COVID-19. However, the role of COVID-19 vaccines in modifying the risk of myocardial injury is unknown., Objectives: To assess the role of vaccines in modifying the risk of myocardial injury in COVID-19., Methods: We enrolled COVID-19 patients admitted from March 2021 to February 2022 with known vaccination status and ≥1 assessment of hs-cTnI within 30 days from the admission. The primary endpoint was the occurrence of myocardial injury (hs-cTnI levels >99th percentile upper reference limit)., Results: 1019 patients were included (mean age 67.7±14.8 years, 60.8% male, 34.5% vaccinated against COVID-19). Myocardial injury occurred in 145 (14.2%) patients. At multivariate logistic regression analysis, advanced age, chronic kidney disease and hypertension, but not vaccination status, were independent predictors of myocardial injury. In the analysis according to age tertiles distribution, myocardial injury occurred more frequently in the III tertile (≥76 years) compared to other tertiles (I tertile:≤60 years;II tertile:61-75 years) (p<0.001). Moreover, in the III tertile, vaccination was protective against myocardial injury (OR 0.57, CI 95% 0.34-0.94; p=0.03), while a previous history of coronary artery disease was an independent positive predictor. In contrast, in the I tertile, chronic kidney disease (OR 6.94, 95% CI 1.31-36.79, p=0.02) and vaccination (OR 4.44, 95% CI 1.28-15.34, p=0.02) were independent positive predictors of myocardial injury., Conclusions: In patients ≥76 years, COVID-19 vaccines were protective for the occurrence of myocardial injury, while in patients ≤60 years, myocardial injury was associated with previous COVID-19 vaccination. Further studies are warranted to clarify the underlying mechanisms., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Objectives: In patients with COVID-19 respiratory failure, controlled mechanical ventilation (CMV) is often necessary during the acute phases of the disease. Weaning from CMV to pressure support ventilation (PSV) is a key objective when the patient's respiratory functions improve. Limited evidence exists regarding the factors predicting a successful transition to PSV and its impact on patient outcomes., Design: Retrospective observational cohort study., Setting: Twenty-four Italian ICUs from February 2020 to May 2020., Patients: Mechanically ventilated ICU patients with COVID-19-induced respiratory failure., Intervention: The transition period from CMV to PSV was evaluated. We defined it as "failure of assisted breathing" if the patient returned to CMV within the first 72 hours., Measurements and Main Results: Of 1260 ICU patients screened, 514 were included. Three hundred fifty-seven patients successfully made the transition to PSV, while 157 failed. Pao 2 /Fio 2 ratio before the transition emerged as an independent predictor of a successful shift (odds ratio 1.00; 95% CI, 0.99-1.00; p = 0.003). Patients in the success group displayed a better trend in Pao 2 /Fio 2 , Paco 2 , plateau and peak pressure, and pH level. Subjects in the failure group exhibited higher ICU mortality (hazard ratio 2.08; 95% CI, 1.42-3.06; p < 0.001), an extended ICU length of stay (successful vs. failure 21 ± 14 vs. 27 ± 17 d; p < 0.001) and a longer duration of mechanical ventilation (19 ± 18 vs. 24 ± 17 d, p = 0.04)., Conclusions: Our study emphasizes that the Pao 2 /Fio 2 ratio was the sole independent factor associated with a failed transition from CMV to PSV. The unsuccessful transition was associated with worse outcomes., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Society of Critical Care Medicine.)

Severe infections frequently require admission to the intensive care unit and cause life-threatening complications in critically ill patients. In this setting, severe infections are acknowledged as prerequisites for the development of sepsis, whose pathophysiology implies a dysregulated host response to pathogens, leading to disability and mortality worldwide.Vitamin D is a secosteroid hormone that plays a pivotal role to maintain immune system homeostasis, which is of paramount importance to resolve infection and modulate the burden of sepsis. Specifically, vitamin D deficiency has been widely reported in critically ill patients and represents a risk factor for the development of severe infections, sepsis and worse clinical outcomes. Several studies have demonstrated the feasibility, safety and effectiveness of vitamin D supplementation strategies to improve vitamin D body content, but conflictual results support its benefit in general populations of critically ill patients. In contrast, small randomised clinical trials reported that vitamin D supplementation may improve host-defence to pathogen invasion via the production of cathelicidin and specific cytokines. Nonetheless, no large scale investigations have been designed to specifically assess the impact of vitamin D supplementation on the outcome of critically ill septic patients admitted to the intensive care unit., (© 2024. The Author(s).)

Background: Noninvasive respiratory support (NRS), including high-flow nasal oxygen therapy (HFNOT), noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP), are routinely used in the perioperative period. Objectives : This narrative review provides an overview on the perioperative use of NRS. Preoperative, intraoperative, and postoperative respiratory support is discussed, along with potential future areas of research. Results : During induction of anesthesia, in selected patients at high risk of difficult intubation, NIV is associated with improved gas exchange and reduced risk of postoperative respiratory complications. HFNOT demonstrated an improvement in oxygenation. Evidence on the intraoperative use of NRS is limited. Compared with conventional oxygenation, HFNOT is associated with a reduced risk of hypoxemia during procedural sedation, and recent data indicate a possible role for HFNOT for intraoperative apneic oxygenation in specific surgical contexts. After extubation, "preemptive" NIV and HFNOT in unselected cohorts do not affect clinical outcome. Postoperative "curative" NIV in high-risk patients and among those exhibiting signs of respiratory failure can reduce reintubation rate, especially after abdominal surgery. Data on postoperative "curative" HFNOT are limited. Conclusions : There is increasing evidence on the perioperative use of NRS. Use of NRS should be tailored based on the patient's specific characteristics and type of surgery, aimed at a personalized cost-effective approach.

Background: Positive end-expiratory pressure (PEEP) benefits in acute respiratory distress syndrome are driven by lung dynamic strain reduction. This depends on the variable extent of alveolar recruitment. The recruitment-to-inflation ratio estimates recruitability across a 10-cm H2O PEEP range through a simplified maneuver. Whether recruitability is uniform or not across this range is unknown. The hypotheses of this study are that the recruitment-to-inflation ratio represents an accurate estimate of PEEP-induced changes in dynamic strain, but may show nonuniform behavior across the conventionally tested PEEP range (15 to 5 cm H2O)., Methods: Twenty patients with moderate-to-severe COVID-19 acute respiratory distress syndrome underwent a decremental PEEP trial (PEEP 15 to 13 to 10 to 8 to 5 cm H2O). Respiratory mechanics and end-expiratory lung volume by nitrogen dilution were measured the end of each step. Gas exchange, recruited volume, recruitment-to-inflation ratio, and changes in dynamic, static, and total strain were computed between 15 and 5 cm H2O (global recruitment-to-inflation ratio) and within narrower PEEP ranges (granular recruitment-to-inflation ratio)., Results: Between 15 and 5 cm H2O, median [interquartile range] global recruitment-to-inflation ratio was 1.27 [0.40 to 1.69] and displayed a linear correlation with PEEP-induced dynamic strain reduction (r = -0.94; P < 0.001). Intraindividual recruitment-to-inflation ratio variability within the narrower ranges was high (85% [70 to 109]). The relationship between granular recruitment-to-inflation ratio and PEEP was mathematically described by a nonlinear, quadratic equation (R2 = 0.96). Granular recruitment-to-inflation ratio across the narrower PEEP ranges itself had a linear correlation with PEEP-induced reduction in dynamic strain (r = -0.89; P < 0.001)., Conclusions: Both global and granular recruitment-to-inflation ratio accurately estimate PEEP-induced changes in lung dynamic strain. However, the effect of 10 cm H2O of PEEP on lung strain may be nonuniform. Granular recruitment-to-inflation ratio assessment within narrower PEEP ranges guided by end-expiratory lung volume measurement may aid more precise PEEP selection, especially when the recruitment-to-inflation ratio obtained with the simplified maneuver between PEEP 15 and 5 cm H2O yields intermediate values that are difficult to interpret for a proper choice between a high and low PEEP strategy., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Society of Anesthesiologists.)

Background: To explore the association between endotoxin activity (EA) and septic cardiomyopathy (SCM), the relationship between endotoxin removal by Polymyxin-B hemoperfusion (PMX-HP) and recovery from SCM (R-SCM), and the correlation between R-SCM and the 28-day mortality in septic patients admitted to the intensive care unit (ICU)., Methods: Observational study that included patients admitted to two ICUs of a tertiary university hospital between April 2011 and December 2019, who received PMX-HP for sepsis/septic shock. The SCM and R-SCM were assessed by transthoracic echocardiography., Results: Among 148 patients, SCM was diagnosed in 60 (46%) of them and had no relationship with median EA (SCM group: 0.73; no-SCM group: 0.66, p = 0.48). Recovery from SCM was observed in 24 patients (49%) and was independently associated with the PMX-HP (OR 4.19, 95%CI [1.22, 14.3]; p = 0.02) and the SAPS2 II score (OR 0.94, 95%CI [0.9, 0.98]; p = 0.006). In the SCM group, the 28-day mortality was 60% and was independently predicted by R-SCM (OR 0.02, 95%CI [0.001, 0.3] p = 0.005) and SAPS II score (OR 1.11, 95%CI [1.01, 1.23] p = 0.037)., Conclusions: In septic patients, EA was not associated with SCM. However, endotoxin removal by Polymyxin-B hemoperfusion was associated with recovery from cardiomyopathy, which was a predictor of lower 28-day mortality., (© 2023 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Background: COVID-19 vaccination has been proved to be effective in preventing hospitalization and illness progression, even though data on mortality of vaccinated patients in the intensive care unit (ICU) are conflicting. The aim of this study was to investigate the characteristics of vaccinated patients admitted to ICU according to their immunization cycle and to outline the risk factors for 28-day mortality. This observational study included adult patients admitted to ICU for acute respiratory failure (ARF) due to SARS-CoV-2 and who had received at least one dose of vaccine., Results: Fully vaccination was defined as a complete primary cycle from < 120 days or a booster dose from > 14 days. All the other patients were named partially vaccinated. One-hundred sixty patients (91 fully and 69 partially vaccinated) resulted eligible, showing a 28-day mortality rate of 51.9%. Compared to partially vaccinated, fully vaccinated were younger (69 [60-77.5] vs. 74 [66-79] years, p 0.029), more frequently immunocompromised (39.56% vs. 14.39%, p 0.003), and affected by at least one comorbidity (90.11% vs 78.26%, p 0.045), mainly chronic kidney disease (CKD) (36.26% vs 20.29%, p 0.035). At multivariable analysis, independent predictors of 28-day mortality were as follows: older age [OR 1.05 (CI 95% 1.01-1.08), p 0.005], history of chronic obstructive pulmonary disease (COPD) [OR 3.05 (CI 95% 1.28-7.30), p 0.012], immunosuppression [OR 3.70 (CI 95% 1.63-8.40), p 0.002], and admission respiratory and hemodynamic status [PaO 2 /FiO 2 and septic shock: OR 0.99 (CI 95% 0.98-0.99), p 0.009 and 2.74 (CI 95% 1.16-6.48), p 0.022, respectively]., Conclusions: Despite a full vaccination cycle, severe COVID-19 may occur in patients with relevant comorbidities, especially immunosuppression and CKD. Regardless the immunization status, predisposing conditions (i.e., older age, COPD, and immunosuppression) and a severe clinical presentation were predictors of 28-day mortality., (© 2023. The Author(s).)

Background: The risk of barotrauma associated with different types of ventilatory support is unclear in COVID-19 patients. The primary aim of this study was to evaluate the effect of the different respiratory support strategies on barotrauma occurrence; we also sought to determine the frequency of barotrauma and the clinical characteristics of the patients who experienced this complication., Methods: This multicentre retrospective case-control study from 1 March 2020 to 28 February 2021 included COVID-19 patients who experienced barotrauma during hospital stay. They were matched with controls in a 1:1 ratio for the same admission period in the same ward of treatment. Univariable and multivariable logistic regression (OR) were performed to explore which factors were associated with barotrauma and in-hospital death., Results: We included 200 cases and 200 controls. Invasive mechanical ventilation was used in 39.3% of patients in the barotrauma group, and in 20.1% of controls (p<0.001). Receiving non-invasive ventilation (C-PAP/PSV) instead of conventional oxygen therapy (COT) increased the risk of barotrauma (OR 5.04, 95% CI 2.30 - 11.08, p<0.001), similarly for invasive mechanical ventilation (OR 6.24, 95% CI 2.86-13.60, p<0.001). High Flow Nasal Oxygen (HFNO), compared with COT, did not significantly increase the risk of barotrauma. Barotrauma frequency occurred in 1.00% [95% CI 0.88-1.16] of patients; these were older (p=0.022) and more frequently immunosuppressed (p=0.013). Barotrauma was shown to be an independent risk for death (OR 5.32, 95% CI 2.82-10.03, p<0.001)., Conclusions: C-PAP/PSV compared with COT or HFNO increased the risk of barotrauma; otherwise HFNO did not. Barotrauma was recorded in 1.00% of patients, affecting mainly patients with more severe COVID-19 disease. Barotrauma was independently associated with mortality., Trial Registration: this case-control study was prospectively registered in clinicaltrial.gov as NCT04897152 (on 21 May 2021)., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Sociedade Portuguesa de Pneumologia. Published by Elsevier España, S.L.U. All rights reserved.)