Noninvasive ventilation in COVID-19 patients aged ≥ 70 years-a prospective multicentre cohort study

BACKGROUND

Noninvasive ventilation (NIV) is a promising alternative to invasive mechanical ventilation (IMV) with a particular importance amidst the shortage of intensive care unit (ICU) beds during the COVID-19 pandemic. We aimed to evaluate the use of NIV in Europe and factors associated with outcomes of patients treated with NIV.

METHODS

This is a substudy of COVIP study-an international prospective observational study enrolling patients aged ≥ 70 years with confirmed COVID-19 treated in ICU. We enrolled patients in 156 ICUs across 15 European countries between March 2020 and April 2021.The primary endpoint was 30-day mortality.

RESULTS

Cohort included 3074 patients, most of whom were male (2197/3074, 71.4%) at the mean age of 75.7 years (SD 4.6). NIV frequency was 25.7% and varied from 1.1 to 62.0% between participating countries. Primary NIV failure, defined as need for endotracheal intubation or death within 30 days since ICU admission, occurred in 470/629 (74.7%) of patients. Factors associated with increased NIV failure risk were higher Sequential Organ Failure Assessment (SOFA) score (OR 3.73, 95% CI 2.36-5.90) and Clinical Frailty Scale (CFS) on admission (OR 1.46, 95% CI 1.06-2.00). Patients initially treated with NIV (n = 630) lived for 1.36 fewer days (95% CI - 2.27 to - 0.46 days) compared to primary IMV group (n = 1876).

CONCLUSIONS

Frequency of NIV use varies across European countries. Higher severity of illness and more severe frailty were associated with a risk of NIV failure among critically ill older adults with COVID-19. Primary IMV was associated with better outcomes than primary NIV. Clinical Trial Registration NCT04321265 , registered 19 March 2020, https://clinicaltrials.gov .

Detailed stratified GWAS analysis for severe COVID-19 in four European populations

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended genome-wide association meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung.

Restriction of Intravenous Fluid in ICU Patients with Septic Shock

BACKGROUND

Intravenous fluids are recommended for the treatment of patients who are in septic shock, but higher fluid volumes have been associated with harm in patients who are in the intensive care unit (ICU).

METHODS

In this international, randomized trial, we assigned patients with septic shock in the ICU who had received at least 1 liter of intravenous fluid to receive restricted intravenous fluid or standard intravenous fluid therapy; patients were included if the onset of shock had been within 12 hours before screening. The primary outcome was death from any cause within 90 days after randomization.

RESULTS

We enrolled 1554 patients; 770 were assigned to the restrictive-fluid group and 784 to the standard-fluid group. Primary outcome data were available for 1545 patients (99.4%). In the ICU, the restrictive-fluid group received a median of 1798 ml of intravenous fluid (interquartile range, 500 to 4366); the standard-fluid group received a median of 3811 ml (interquartile range, 1861 to 6762). At 90 days, death had occurred in 323 of 764 patients (42.3%) in the restrictive-fluid group, as compared with 329 of 781 patients (42.1%) in the standard-fluid group (adjusted absolute difference, 0.1 percentage points; 95% confidence interval [CI], -4.7 to 4.9; P = 0.96). In the ICU, serious adverse events occurred at least once in 221 of 751 patients (29.4%) in the restrictive-fluid group and in 238 of 772 patients (30.8%) in the standard-fluid group (adjusted absolute difference, -1.7 percentage points; 99% CI, -7.7 to 4.3). At 90 days after randomization, the numbers of days alive without life support and days alive and out of the hospital were similar in the two groups.

CONCLUSIONS

Among adult patients with septic shock in the ICU, intravenous fluid restriction did not result in fewer deaths at 90 days than standard intravenous fluid therapy. (Funded by the Novo Nordisk Foundation and others; CLASSIC ClinicalTrials.gov number, NCT03668236.).

Outcome prediction during an ICU surge using a purely data-driven approach: A supervised machine learning case-study in critically ill patients from COVID-19 Lombardy outbreak

Purpose

COVID-19 disease frequently affects the lungs leading to bilateral viral pneumonia, progressing in some cases to severe respiratory failure requiring ICU admission and mechanical ventilation. Risk stratification at ICU admission is fundamental for resource allocation and decision making. We assessed performances of three machine learning approaches to predict mortality in COVID-19 patients admitted to ICU using early operative data from the Lombardy ICU Network.

Methods

This is a secondary analysis of prospectively collected data from Lombardy ICU network. A logistic regression, balanced logistic regression and random forest were built to predict survival on two datasets: dataset A included patient demographics, medications before admission and comorbidities, and dataset B included respiratory data the first day in ICU.

Results

Models were trained on 1484 patients on four outcomes (7/14/21/28 days) and reached the greatest predictive performance at 28 days (F1-score: 0.75 and AUC: 0.80). Age, number of comorbidities and male gender were strongly associated with mortality. On dataset B, mode of ventilatory assistance at ICU admission and fraction of inspired oxygen were associated with an increase in prediction performances.

Conclusions

Machine learning techniques might be useful in emergency phases to reach good predictive performances maintaining interpretability to gain knowledge on complex situations and enhance patient management and resources.

Efficacy of short-course colchicine treatment in hospitalized patients with moderate to severe COVID-19 pneumonia and hyperinflammation: a randomized clinical trial

Some patients with COVID-19 pneumonia develop an associated cytokine storm syndrome that aggravates the pulmonary disease. These patients may benefit of anti-inflammatory treatment. The role of colchicine in hospitalized patients with COVID-19 pneumonia and established hyperinflammation remains unexplored. In a prospective, randomized controlled, observer-blinded endpoint, investigator-initiated trial, 240 hospitalized patients with COVID-19 pneumonia and established hyperinflammation were randomly allocated to receive oral colchicine or not. The primary efficacy outcome measure was a composite of non-invasive mechanical ventilation (CPAP or BiPAP), admission to the intensive care unit, invasive mechanical ventilation requirement or death. The composite primary outcome occurred in 19.3% of the total study population. The composite primary outcome was similar in the two arms (17% in colchicine group vs. 20.8% in the control group; p = 0.533) and the same applied to each of its individual components. Most patients received steroids (98%) and heparin (99%), with similar doses in both groups. In this trial, including adult patients with COVID-19 pneumonia and associated hyperinflammation, no clinical benefit was observed with short-course colchicine treatment beyond standard care regarding the combined outcome measurement of CPAP/BiPAP use, ICU admission, invasive mechanical ventilation or death (Funded by the Community of Madrid, EudraCT Number: 2020-001841-38; 26/04/2020).

Spinal anesthesia and hypotensive events in hip fracture surgical repair in elderly patients: a meta-analysis

BACKGROUND

Spinal anesthesia (SA) is widely used for anesthetic management of patients undergoing hip surgery, and hypotension is the most common cardiovascular side effect of SA. This paper aims to assess the lowest effective dose of SA that reduces the occurrence of intraoperative hypotension in elderly patients scheduled for major lower limb orthopedic surgery.

METHODS

We conducted a systematic review of randomized controlled trials (RCTs) performed in elderly patients scheduled for surgical hip repair and a meta-analysis with meta-regression on the occurrence of hypotensive episodes at different effective doses of anesthetics. We searched PUBMED®, EMBASE®, and the Cochrane Controlled Clinical trials registered.

RESULTS

Our search retrieved 2085 titles, and after screening, 6 were finally included in both the qualitative and quantitative analysis, including 344 patients [15% (10-28) males], with a median (25th to 75th interquartile) age of 82 (80-85). The risk of bias assessment reported "low risk" for 5 (83.3%) and "some concerns" for 1 (16.7%) of the included RCTs. The low dose of SA of [mean 6.5 mg (1.9)] anesthetic was associated with a lower incidence of hypotension [OR = 0.09 (95%CI 0.04-0.21); p = 0.04; I² = 56.9%], as compared to the high-dose of anesthetic [mean 10.5 mg (2.4)].

CONCLUSIONS

In the included studies of this meta-analysis, a mean dose of 6.5 mg of SA was effective in producing intraoperative comfort and motor block and associated with a lower incidence of hypotension as compared to a mean dose of 10.5 mg.

TRIAL REGISTRATION

CRD42020193627.

Lung response to prone positioning in mechanically-ventilated patients with COVID-19

BACKGROUND

Prone positioning improves survival in moderate-to-severe acute respiratory distress syndrome (ARDS) unrelated to the novel coronavirus disease (COVID-19). This benefit is probably mediated by a decrease in alveolar collapse and hyperinflation and a more homogeneous distribution of lung aeration, with fewer harms from mechanical ventilation. In this preliminary physiological study we aimed to verify whether prone positioning causes analogue changes in lung aeration in COVID-19. A positive result would support prone positioning even in this other population.

METHODS

Fifteen mechanically-ventilated patients with COVID-19 underwent a lung computed tomography in the supine and prone position with a constant positive end-expiratory pressure (PEEP) within three days of endotracheal intubation. Using quantitative analysis, we measured the volume of the non-aerated, poorly-aerated, well-aerated, and over-aerated compartments and the gas-to-tissue ratio of the ten vertical levels of the lung. In addition, we expressed the heterogeneity of lung aeration with the standardized median absolute deviation of the ten vertical gas-to-tissue ratios, with lower values indicating less heterogeneity.

RESULTS

By the time of the study, PEEP was 12 (10-14) cmH2O and the PaO2:FiO2 107 (84-173) mmHg in the supine position. With prone positioning, the volume of the non-aerated compartment decreased by 82 (26-147) ml, of the poorly-aerated compartment increased by 82 (53-174) ml, of the normally-aerated compartment did not significantly change, and of the over-aerated compartment decreased by 28 (11-186) ml. In eight (53%) patients, the volume of the over-aerated compartment decreased more than the volume of the non-aerated compartment. The gas-to-tissue ratio of the ten vertical levels of the lung decreased by 0.34 (0.25-0.49) ml/g per level in the supine position and by 0.03 (- 0.11 to 0.14) ml/g in the prone position (p < 0.001). The standardized median absolute deviation of the gas-to-tissue ratios of those ten levels decreased in all patients, from 0.55 (0.50-0.71) to 0.20 (0.14-0.27) (p < 0.001).

CONCLUSIONS

In fifteen patients with COVID-19, prone positioning decreased alveolar collapse, hyperinflation, and homogenized lung aeration. A similar response has been observed in other ARDS, where prone positioning improves outcome. Therefore, our data provide a pathophysiological rationale to support prone positioning even in COVID-19.

Early prediction of SARS-CoV-2 reproductive number from environmental, atmospheric and mobility data: A supervised machine learning approach

INTRODUCTION

SARS-CoV-2 was declared a pandemic by the WHO on March 11th, 2020. Public protective measures were enforced in every country to limit the diffusion of SARS-CoV-2. Its transmission, mainly by droplets, has been measured by the effective reproduction number (Rt) that counts the number of secondary cases caused in a population by an average infectious individual at time t. Current strategies to calculate Rt reflect the number of secondary cases after several days, due to a delay from symptoms onset to reporting. We propose a complementary Rt estimation using supervised machine learning techniques to predict short term variations with more timely results.

MATERIAL AND METHODS

Our primary goal was to predict Rt of the current day in the twelve provinces of Lombardy with the highest possible accuracy, and with no influence of the local testing strategies. We gathered data about mobility, weather, and pollution from different public sources as a proxy of human behavior and public health measures. We built four supervised machine learning algorithms with different strategies: the outcome variable was the daily median Rt values per province obtained from officially adopted algorithms.

RESULTS

Data from 243 days for every province were presented to our four models (from February 15th, 2020, to October 14th, 2020). Two models using differential calculation of Rt instead of the raw values showed the highest mean coefficient of determination (0.93 for both) and residuals reported the lowest mean error (-0.03 and 0.01) and standard deviation (0.13 for both) as well. The one with access to the value of Rt of the day before heavily relied on that feature for prediction, while the other one had more distributed weights.

DISCUSSION

The model that had not access to the Rt value of the previous day and used Rt differential value as outcome (FDRt) was considered the most robust according to the metrics. Its forecasts were able to predict the trend that Rt values would have developed over different weeks, but it was not particularly accurate in predicting the precise value of Rt. A correlation among mobility, atmospheric, features, pollution and Rt values is plausible, but further testing should be performed.

Association between tracheostomy timing and outcomes for older critically ill COVID-19 patients: prospective observational study in European intensive care units

BACKGROUND

Tracheostomy is performed in patients expected to require prolonged mechanical ventilation, but to date optimal timing of tracheostomy has not been established. The evidence concerning tracheostomy in COVID-19 patients is particularly scarce. We aimed to describe the relationship between early tracheostomy (≤10 days since intubation) and outcomes for patients with COVID-19.

METHODS

This was a prospective cohort study performed in 152 centres across 16 European countries from February to December 2020. We included patients aged ≥70 yr with confirmed COVID-19 infection admitted to an intensive care unit, requiring invasive mechanical ventilation. Multivariable analyses were performed to evaluate the association between early tracheostomy and clinical outcomes including 3-month mortality, intensive care length of stay, and duration of mechanical ventilation.

RESULTS

The final analysis included 1740 patients with a mean age of 74 yr. Tracheostomy was performed in 461 (26.5%) patients. The tracheostomy rate varied across countries, from 8.3% to 52.9%. Early tracheostomy was performed in 135 (29.3%) patients. There was no difference in 3-month mortality between early and late tracheostomy in either our primary analysis (hazard ratio [HR]=0.96; 95% confidence interval [CI], 0.70-1.33) or a secondary landmark analysis (HR=0.78; 95% CI, 0.57-1.06).

CONCLUSIONS

There is a wide variation across Europe in the timing of tracheostomy for critically ill patients with COVID-19. However, we found no evidence that early tracheostomy is associated with any effect on survival amongst older critically ill patients with COVID-19.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT04321265.

Increased 30-day mortality in very old ICU patients with COVID-19 compared to patients with respiratory failure without COVID-19

Purpose

The number of patients ≥ 80 years admitted into critical care is increasing. Coronavirus disease 2019 (COVID-19) added another challenge for clinical decisions for both admission and limitation of life-sustaining treatments (LLST). We aimed to compare the characteristics and mortality of very old critically ill patients with or without COVID-19 with a focus on LLST.

Methods

Patients 80 years or older with acute respiratory failure were recruited from the VIP2 and COVIP studies. Baseline patient characteristics, interventions in intensive care unit (ICU) and outcomes (30-day survival) were recorded. COVID patients were matched to non-COVID patients based on the following factors: age (± 2 years), Sequential Organ Failure Assessment (SOFA) score (± 2 points), clinical frailty scale (± 1 point), gender and region on a 1:2 ratio. Specific ICU procedures and LLST were compared between the cohorts by means of cumulative incidence curves taking into account the competing risk of discharge and death.

Results

693 COVID patients were compared to 1393 non-COVID patients. COVID patients were younger, less frail, less severely ill with lower SOFA score, but were treated more often with invasive mechanical ventilation (MV) and had a lower 30-day survival. 404 COVID patients could be matched to 666 non-COVID patients. For COVID patients, withholding and withdrawing of LST were more frequent than for non-COVID and the 30-day survival was almost half compared to non-COVID patients.

Conclusion

Very old COVID patients have a different trajectory than non-COVID patients. Whether this finding is due to a decision policy with more active treatment limitation or to an inherent higher risk of death due to COVID-19 is unclear.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-022-06642-z.

Clinical and organizational factors associated with mortality during the peak of first COVID-19 wave: the global UNITE-COVID study

PURPOSE

To accommodate the unprecedented number of critically ill patients with pneumonia caused by coronavirus disease 2019 (COVID-19) expansion of the capacity of intensive care unit (ICU) to clinical areas not previously used for critical care was necessary. We describe the global burden of COVID-19 admissions and the clinical and organizational characteristics associated with outcomes in critically ill COVID-19 patients.

METHODS

Multicenter, international, point prevalence study, including adult patients with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) and a diagnosis of COVID-19 admitted to ICU between February 15th and May 15th, 2020.

RESULTS

4994 patients from 280 ICUs in 46 countries were included. Included ICUs increased their total capacity from 4931 to 7630 beds, deploying personnel from other areas. Overall, 1986 (39.8%) patients were admitted to surge capacity beds. Invasive ventilation at admission was present in 2325 (46.5%) patients and was required during ICU stay in 85.8% of patients. 60-day mortality was 33.9% (IQR across units: 20%-50%) and ICU mortality 32.7%. Older age, invasive mechanical ventilation, and acute kidney injury (AKI) were associated with increased mortality. These associations were also confirmed specifically in mechanically ventilated patients. Admission to surge capacity beds was not associated with mortality, even after controlling for other factors.

CONCLUSIONS

ICUs responded to the increase in COVID-19 patients by increasing bed availability and staff, admitting up to 40% of patients in surge capacity beds. Although mortality in this population was high, admission to a surge capacity bed was not associated with increased mortality. Older age, invasive mechanical ventilation, and AKI were identified as the strongest predictors of mortality.

A 'Multiomic' Approach of Saliva Metabolomics, Microbiota, and Serum Biomarkers to Assess the Need of Hospitalization in Coronavirus Disease 2019

BACKGROUND AND AIMS

The SARS-CoV-2 pandemic has overwhelmed the treatment capacity of the health care systems during the highest viral diffusion rate. Patients reaching the emergency department had to be either hospitalized (inpatients) or discharged (outpatients). Still, the decision was taken based on the individual assessment of the actual clinical condition, without specific biomarkers to predict future improvement or deterioration, and discharged patients often returned to the hospital for aggravation of their condition. Here, we have developed a new combined approach of omics to identify factors that could distinguish coronavirus disease 19 (COVID-19) inpatients from outpatients.

METHODS

Saliva and blood samples were collected over the course of two observational cohort studies. By using machine learning approaches, we compared salivary metabolome of 50 COVID-19 patients with that of 270 healthy individuals having previously been exposed or not to SARS-CoV-2. We then correlated the salivary metabolites that allowed separating COVID-19 inpatients from outpatients with serum biomarkers and salivary microbiota taxa differentially represented in the two groups of patients.

RESULTS

We identified nine salivary metabolites that allowed assessing the need of hospitalization. When combined with serum biomarkers, just two salivary metabolites (myo-inositol and 2-pyrrolidineacetic acid) and one serum protein, chitinase 3-like-1 (CHI3L1), were sufficient to separate inpatients from outpatients completely and correlated with modulated microbiota taxa. In particular, we found Corynebacterium 1 to be overrepresented in inpatients, whereas Actinomycetaceae F0332, Candidatus Saccharimonas, and Haemophilus were all underrepresented in the hospitalized population.

CONCLUSION

This is a proof of concept that a combined omic analysis can be used to stratify patients independently from COVID-19.

An international survey of adherence to Surviving Sepsis Campaign Guidelines 2016 regarding fluid resuscitation and vasopressors in the initial management of septic shock

BACKGROUND

Our survey aimed to evaluate adherence to Surviving Sepsis Campaign (SSC) Guidelines 2016 among intensive care practitioners and to identify issues that remain controversial or lack clarity.

METHODS

Members of the European Society of Intensive Care Medicine (ESICM) were surveyed using an anonymous web-based survey written by an international group of experts. The primary outcome measure was the rate of adherence to specific recommendations. Secondary outcomes were to describe areas of controversy and lack of data and to associate specific practices with clinician characteristics.

RESULTS

Overall 820 questionnaires were completed. The SCC recommendations 2016 most adhered to were the choice of norepinephrine as first-line vasoactive drug (96.5%), vasopressor prescription based on therapeutic goal rather than dose (83.4%), targeting a specific mean arterial blood pressure during vasopressor use (77.9%), monitoring of blood pressure invasively (62.8%) and adding vasopressin or epinephrine as a second vasoactive agent (83.4%). We identified an internal conflict with regards to parallel versus sequential administration of fluids and vasoactive drugs and regional differences in practice that may be related to drug availabilities.

CONCLUSION

The use of vasopressors and fluid use in septic shock is largely compliant with current guidelines but several controversies should be addressed in future guideline iterations.

Accuracy of cumulative volumes of fluid challenge to assess fluid responsiveness in critically ill patients with acute circulatory failure: a pharmacodynamic approach

BACKGROUND

The relationship between the dose (volume of fluid) and the effect (increase of stroke volume [SV]) has been poorly described. We hypothesised that the analysis of the dynamic response of SV during fluid challenge (FC) helps to determine the optimal volume of FC, along with its diagnostic accuracy parameters for fluid responsiveness.

METHODS

A prospective observational study was conducted in critically ill patients with circulatory failure. Patients monitored with oesophageal Doppler and assigned to an FC of 500 ml of crystalloid were included. The areas under the curve (AUC) and 95% confidence intervals (CI₉₅) of the receiver operating characteristic curves for cumulative volumes from 50 to 450 ml were determined for fluid responsiveness (SV increase ≥15% from baseline) along with other parameters of diagnostic accuracy. In the pharmacodynamic analysis, dose-effect and dose-response models were constructed, with determination of median and 90% effective dose (ED₅₀ and ED₉₀).

RESULTS

Forty-five patients were included. The AUC increased with cumulative volumes of FC up to 250 ml (AUC₂₅₀ 0.93 [CI₉₅: 0.85-1.00]), followed by a plateau above 0.95 of AUC. The optimal volume was 250 ml, associated with a specificity of 0.89 [CI₉₅: 0.78-1.00], a sensitivity of 0.92 [CI₉₅: 0.69-1.00], and a threshold of 9.6% increase in SV. The ED₅₀ was 156 [CI₉₅: 136-177] ml and the ED₉₀ was 312 [CI₉₅: 269-352] ml.

CONCLUSIONS

A volume of FC of 250 ml with a threshold of 9.6% increase in SV showed the highest accuracy in detecting fluid responsiveness in critically ill patients with shock.

CLINICAL TRIAL REGISTRATION

.

Disease-course adapting machine learning prognostication models in critically ill elderly COVID-19 patients: a multi-centre cohort study with external validation

Background

The COVID-19 pandemic caused by SARS-CoV-2 is challenging health care systems globally. The disease disproportionately affects the elderly population, both in terms of disease severity and mortality risk.

Objective

The aim of this study was to evaluate machine learning–based prognostication models for critically ill elderly COVID-19 patients, which dynamically incorporated multifaceted clinical information on evolution of the disease.

Methods

This multicenter cohort study (COVIP study) obtained patient data from 151 intensive care units (ICUs) from 26 countries. Different models based on the Sequential Organ Failure Assessment (SOFA) score, logistic regression (LR), random forest (RF), and extreme gradient boosting (XGB) were derived as baseline models that included admission variables only. We subsequently included clinical events and time-to-event as additional variables to derive the final models using the same algorithms and compared their performance with that of the baseline group. Furthermore, we derived baseline and final models on a European patient cohort, which were externally validated on a non-European cohort that included Asian, African, and US patients.

Results

In total, 1432 elderly (≥70 years old) COVID-19–positive patients admitted to an ICU were included for analysis. Of these, 809 (56.49%) patients survived up to 30 days after admission. The average length of stay was 21.6 (SD 18.2) days. Final models that incorporated clinical events and time-to-event information provided superior performance (area under the receiver operating characteristic curve of 0.81; 95% CI 0.804-0.811), with respect to both the baseline models that used admission variables only and conventional ICU prediction models (SOFA score, P<.001). The average precision increased from 0.65 (95% CI 0.650-0.655) to 0.77 (95% CI 0.759-0.770).

Conclusions

Integrating important clinical events and time-to-event information led to a superior accuracy of 30-day mortality prediction compared with models based on the admission information and conventional ICU prediction models. This study shows that machine-learning models provide additional information and may support complex decision-making in critically ill elderly COVID-19 patients.

Trial Registration

ClinicalTrials.gov NCT04321265; https://clinicaltrials.gov/ct2/show/NCT04321265

Hemodynamic resuscitation with fluids bolus and norepinephrine increases severity of lung damage in an experimental model of septic shock

OBJECTIVE

Hemodynamic resuscitation is considered a cornerstone of the initial treatment of septic shock. However, there is growing concern about its side effects. Our objective was to assess the relationship between fluid administration and norepinephrine infusion and the development of lung injury.

DESIGN

Randomized in vivo study in rabbits.

SETTING

University animal research laboratory.

PATIENTS

Eighteen New Zealand rabbits. Control group (SHAM, n=6), Sepsis group with or without hemodynamic resuscitation (ETX-R, n=6; ETX-NR, n=6).

INTERVENTIONS

Sepsis was induced by intravenous lipopolysaccharide administration and animals were followed-up for 4h. Hemodynamic resuscitation with Ringer lactate (20mL·kg^-1) was administered and later norepinephrine was initiated 3h after sepsis induction. At the end, the left lung was excised.

MAIN VARIABLES OF INTEREST

An indwelling arterial catheter and an esophageal Doppler were placed. Lung mechanics were monitored with side stream spirometry. Lung damage was analyzed by histopathological examination.

RESULTS

The SHAM group did not show hemodynamic or respiratory changes. Lipopolysaccharide administration aimed an increase in cardiac output and arterial hypotension. In the ETX-NR group, animals remained hypotensive until the end of the experiment. Resuscitation with fluids and norepinephrine reversed arterial hypotension. Compared to the ETX-NR group, the remaining lung of the ETX-R group showed greater accumulation of neutrophils and reactive type-II pneumocytes, thicker alveolar wall, alveolar hemorrhage and non-aerated pulmonary areas. Lung injury score was larger in the ETX-R group.

CONCLUSIONS

In our experimental study, following a strategy with bolus fluids and late norepinephrine used in the early phase of endotoxic septic shock has a negative influence on the development of lung injury.

Ten answers to key questions for fluid management in intensive care

This review focuses on fluid management of critically ill patients. The topic is addressed based on 10 single questions with simplified answers that provide clinicians with the basic information needed at the point of care in treating patients in the Intensive Care Unit. The review has didactic purposes and may serve both as an update on fluid management and as an introduction to the subject for novices in critical care. There is an urgent need to increase awareness regarding the potential risks associated with fluid overload. Clinicians should be mindful not only of the indications for administering fluid loads and of the type of fluids administered, but also of the importance to set safety limits. Lastly, it is important to implement proactive strategies seeking to establish negative fluid balance as soon as the clinical conditions are considered to be stable and the risk of deterioration is low.

Does the definition of fluid responsiveness affect passive leg raising reliability? A methodological ancillary analysis from a multicentric study

BACKGROUND

Fluid challenge (FC) is often adopted as gold standard used to assess the reliability of passive leg raising (PLR) in predicting fluid responsiveness in the intensive care unit (ICU). This study aimed to address the impact of the different definitions and timings used to assess FC response on PLR reliability.

METHODS

Ancillary study from a data set of a multicentric study in 85 ICU patient with acute circulatory failure who received a FC (500 mL of crystalloids in 10 minutes) within the first 48h of ICU admission, preceded by PLR in 30 patients. FC response was assessed considering the changes in cardiac index (CI) and stroke volume index (SVI) using different thresholds and at different timepoints.

RESULTS

The definitions of fluid responsiveness by using CI or SVI with a 15% increase after 10 minutes were associated to the best performances of the PLR [AUC (95% CI) 0.94 (0.83-1.01); vs. AUC (95% CI) 0.95 (0.87-1.02)]. The sensitivity of the PLR by adopting the CI or the SVI as reference variable ranged from 54.1% to 67.6% and from 81.5% to 100.0%; the specificity from 65.9% to 78.0% and from 79.5% to 100.0%, respectively. Considering all the subgroups, the number of responders 10 minutes after FC administration was higher as compared to 15 and 30 minutes (140 vs. 120 and 125, respectively, p < 0.05).

CONCLUSIONS

The reliability of the PLR test to predict fluid responsiveness depends on the definition of FC adopted. The timing of FC outcome assessment affected the overall fluid responsiveness.