Annals of Intensive Care最新文献

Ventilatory management of acute respiratory distress syndrome (ARDS) requires a careful balance between achieving adequate gas exchange and minimizing ventilator-induced lung injury (VILI). Recent advances in bedside monitoring of respiratory mechanics have created new opportunities to individualize mechanical ventilation by aligning ventilator settings with the patient's dynamic pathophysiology. This review synthesizes current evidence on key respiratory mechanics parameters - such as driving pressure, respiratory system compliance, airway resistance, mechanical power - and examines how they can guide titration of tidal volume, positive end-expiratory pressure (PEEP), and respiratory rate. By integrating real-time assessments of respiratory mechanics, clinicians can reduce stress and strain, limit alveolar overdistension and collapse, and optimize oxygenation and ventilation. Moreover, practical strategies are discussed for implementing physiology-guided ventilation in the intensive care unit, with attention to patient-specific characteristics and the heterogeneity of ARDS subphenotypes. Respiratory mechanics-guided ventilation represents a pragmatic, individualized strategy that enhances lung protection, complements established protocols and may contribute to improve survival. Further experimental and clinical studies are required to validate these approaches and translate them into precision medicine for ARDS.

Background: Awake prone positioning (APP) reduces the risk of endotracheal intubation and mortality in COVID-19-related acute respiratory failure (ARF) receiving high-flow nasal oxygen (HFNO). However, a significant proportion of patients undergoing APP are ultimately intubated, and mortality in this subgroup remains high. We aimed to develop a predictive model to be applied within the first 24 h of APP to identify patients at higher risk of progressing to intubation within 72 h of APP initiation.

Methods: We conducted a secondary analysis of a prospective multicenter cohort including adult patients with COVID-19-related ARF admitted to six intensive care units in Argentina between June 2020 and January 2021. Eligible patients received HFNO and APP for at least 6 h per day. Physiological variables were collected at ICU admission (baseline) and 24 h after APP initiation. Two multivariable logistic regression models were developed using baseline and 24-hour variables, respectively. Predictors were selected based on clinical relevance and univariable associations. A final model was constructed by integrating variables retained from both time points.

Results: Of 400 patients included, 136 (34%) required intubation within the first 72 h. Patients who required intubation were older, had lower PaO₂ and PaO₂/FiO₂ ratios, and higher respiratory rates both at baseline and after 24 h. The final predictive model included five variables: age, respiratory rate, PaO₂, FiO₂, and SaO₂/FiO₂ ratio, all measured 24 h after APP initiation. A nomogram was developed based on this model to estimate the individual risk of early intubation.

Conclusion: In patients with COVID-19-related ARF treated with HFNO and APP, a model combining baseline characteristics and early physiological response can help predict the need for intubation within 72 h. This tool may support clinicians in identifying high-risk patients and making timely, individualized decisions about escalation of care.

A pressure distends blood vessels even when the heart is not beating and there is no blood flow. This is called mean circulatory filling pressure (MCFP). We will first discuss why it is physiologically necessary to have this base pressure. Although all pressures in the vasculature are the same when there is no flow, blood volume distributes based on the compliance of the walls in each compartment. The compliance of systemic venous compartment is by far the largest and contain most of the blood volume. When flow starts, volume redistributes among the vascular regions based on the compliance and resistance draining them. Because of it dominates the total compliance, pressure in the systemic venous compartment changes very little; it is called mean systemic filling pressure (MSFP). Under normal hemodynamic conditions, differences between MCFP and MSFP are trivial because venous compliance is so large compared to all other vascular regions. When cardiac function is maximal, MCFP determines the maximum possible cardiac output. MSFP is significant for two reasons. It is the upstream pressure driving blood back to the right heart. Importantly, it also is the downstream pressure for systemic capillary drainage. Thus, a high MSFP increases the risk of tissue edema. From our review of the studies, the pressure difference from MSFP to the right atrium (RAP) is generally in the 3 to 6 mmHg range so that MSFP can be approximated by adding values in this range to properly measured RAP. Ideally, MSFP should be less than 10 mmHg to limit capillary drainage.

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is increasingly used in patients with cardiogenic shock. It results in cardiopulmonary shunting with reduced native cardiac output. Volume expansion is usually administered to increase native cardiac output, in order to improve peripheric perfusion or to avoid thromboembolic complications in cardiac cavities. End-tidal carbon dioxide (EtCO₂) is known to be related to native cardiac output. Our hypothesis was that EtCO₂ changes induced by passive leg raising predict fluid responsiveness in patients under VA-ECMO.

Methods: In this prospective, interventional study, patients under VA-ECMO support were included, provided they required volume expansion. The protocol included three sequential steps: (1) Baseline in supine position (2) Passive leg raising (3) Volume expansion in basal position. Hemodynamic parameters were recorded at each step. Fluid responsiveness was defined as a velocity time integral at the left ventricle outflow tract increase of 15% or more after volume expansion. The ability of passive leg raising induced changes in EtCO₂ to predict fluid responsiveness was evaluated with area under the receiver operating characteristics curve (AUC).

Results: 41 patients were studied; 58 passive leg raising - volume expansion tests were recorded. Fluid responsiveness was observed in 38 of the 58 measurements (65%). Passive leg raising test has correctly mimicked volume expansion (intraclass correlation coefficient 0.83 [0.73-0.9]). Considering all measurements, AUC of passive leg raising-changes in velocity time integral to predict fluid responsiveness was 0.89 [0.79-0.99] and remained good whatever the basal native cardiac output. Sensitivity and specificity were 92% [85-100] and 80% [69-90] respectively for a threshold of 15%. AUC of passive leg raising-induced changes in EtCO₂ for predicting fluid responsiveness was good (0.98 [0.95-1]) only when basal native cardiac output was ≤ 1 L/min.

Conclusion: Passive leg raising test can predict fluid responsiveness under VA-ECMO. EtCO₂ changes induced by passive leg raising test can be used to detect fluid responsiveness in patients with native cardiac output ≤ 1 L/min under VA-ECMO. This test is easy to perform, reliable and may help to avoid unnecessary and potentially harmful fluid loading.

Background: Assessing sources of job stress in intensive care units is a critical issue for preventing many occupational health and care-related issues, such as burnout, voluntary turnover and decrease in quality and safety of care. Accordingly, this French nation-wide multicentre study aims to provide supplementary evidence regarding the validity of a recent tool: the Perceived Stressors in Intensive Care Units (PS-ICU) scale. More precisely, this study has three main objectives: to 1) confirm the metrological properties of the PS-ICU scale on a large sample of professionals; 2) test its measurement invariance between nurses, physicians and residents (initial population targeted by the scale); 3) examine whether the scale would also be suited for use with nursing auxiliaries. In addition, depending on the results (which may suggest the removal of several items), this study offers the possibility to shorten the scale to facilitate its use.

Method and results: 2241 ICU professionals (1135 nurses, 308 physicians, 179 residents, and 619 nursing auxiliaries; overall participation rate of 58.10%) from 42 ICUs in France, voluntarily completed an online questionnaire collecting socio-demographic data and perceived job stressors (PS-ICU). Exploratory structural equation modelling (ESEM), unidimensional reliability (McDonald's Omega) and item response theory (IRT) analyses overall confirmed the metrological properties of the scale, while several items were removed and the sixth factor ("lack of support and resources from the organisation") measured by the scale was revised. Results regarding measurement invariance show that the PS-ICU scale can be used to compare occupational groups, including nursing auxiliaries. Finally, all analyses resulted in a reduction of the scale to a 26-item version.

Conclusions: The PS-ICU scale, which measures generic and ICU-specific job stress factors, is a valid and reliable scale that can be used to collect data from nurses, physicians and residents, as well as from nursing auxiliaries. With 26 items, it can be used by researchers and managers in ICUs to assess the extent and type of stress factors perceived by healthcare professionals.

Acute kidney injury and other organ dysfunction in the setting of heart failure are primarily determined by a low cardiac output status and venous congestion, which is a sequence of increases in heart filling pressures. Early point-of-care ultrasound assessment of the inferior vena cava, lung ultrasound for pulmonary congestion, and focused echocardiography have become increasingly used in the bedside evaluation of congestive heart failure and assessment of the left ventricle. The congestion disrupts venous outflow in abdominal organs, most notably the kidneys and liver, and can be noninvasively evaluated with Doppler ultrasound, known as the venous excess. Such flow abnormalities have been repeatedly linked to congestive organ dysfunction and poorer clinical outcomes. In this review, we outline a thorough, bedside approach to assessing venous congestion using Doppler imaging. Venous Excess Ultrasound (VExUS) is an emerging protocol that offers a point-of-care ultrasonic method for grading systemic congestion and tailoring diuretic management. The purpose of this review is to evaluate VExUS's potential applications and critically appraise current evidence on its effectiveness in directing decongestive therapy for patients with acute decompensated heart failure. In conclusion, multiple Doppler venous congestion assessment emerges as a promising, noninvasive tool for the instantaneous assessment of organ congestion in cardiorenal syndrome, helping in the management of fluid and diuretic administration. Its accuracy, however, depends on the sonographer's proficiency. Larger-scale studies are needed to confirm their applicability in clinical practice.

Intravenous lipid emulsions (ILE) were first proposed in 1998 as a treatment for bupivacaine-induced cardiac arrest. Since then, their use has expanded to include poisonings by various lipophilic drugs such as tricyclic antidepressants, calcium channel blockers, and antipsychotics. This 2025 narrative review explores the evolving pathophysiological mechanisms of ILE therapy, including the lipid sink and lipid shuttle theories, as well as non-scavenging cardiotonic effects such as membrane stabilization, mitochondrial support, and modulation of vascular tone. It summarizes recent findings from randomized controlled trials, cohort studies, animal models, and case registries. While clinical trials demonstrate potential benefits-particularly in tramadol, clozapine, and organophosphate poisonings-mortality reduction remains unproven, and evidence is limited by study heterogeneity and low methodological quality. Adverse effects, although rare, include acute pancreatitis, interference with laboratory testing, and fat overload syndrome, especially at high infusion volumes. Current guidelines recommend ILEs as a first-line treatment for local anesthetic systemic toxicity and as a second-line option in life-threatening poisonings involving other lipophilic agents. However, significant uncertainty remains regarding optimal indications, dosing strategies, and long-term safety. High-quality, multicenter studies and updated registries are needed to refine these recommendations and clarify the role of ILEs in clinical toxicology.