Mechanical influences on fluid leakage past the tracheal tube cuff in a benchtop model

Purpose: High-volume low-pressure (HVLP) cuffs on endotracheal tubes do not fully protect the lower airway from leakage of potentially contaminated secretions down the longitudinal folds within the cuff. Here, our purpose was to evaluate potential effects of positive end-expiratory pressure (PEEP), inspiratory effort intensity, and tube characteristics on fluid leakage past the cuff. Methods: This benchtop study at a research laboratory used a tracheal tube inserted into an artificial Plexiglas trachea connected to a ventilator and lung model. Methylene blue was deposited above the tube cuff to simulate subglottic secretions. Five PEEP levels (0, 5, 10, 15, and 20cmH2O) were tested with volume-controlled ventilation and three simulated inspiratory effort levels with pressure-support ventilation. Several cuff materials and tube sizes were tested. Results: The leakage occurrence rate ranged from 91% with zero PEEP to 8% with 15 and 20cmH2O PEEP and was indirectly proportional to the PEEP level with significant correlation (R 2=0.39, p<0.001), an effect not explained by higher peak inspiratory pressure. Low, moderate, and high inspiratory effort intensities were associated with 38%, 46%, and 75% leakage rates, respectively (p=0.024). Leakage flow was considerably less with polyurethane than with polyvinylchloride tubes (mean 0.5 versus 31.8ml/h). Leakage increased with larger tube diameters. Conclusion: This benchtop study shows that PEEP and a polyurethane cuff prevent leakage past the endotracheal tube cuff, whereas greater inspiratory effort and larger tube diameters for given tracheal size induce or worsen leakag

An updated study-level meta-analysis of randomised controlled trials on proning in ARDS and acute lung injury

International audienceINTRODUCTION: In patients with acute lung injury (ALI) and/or acute respiratory distress syndrome (ARDS), recent randomised controlled trials (RCTs) showed a consistent trend of mortality reduction with prone ventilation. We updated a meta-analysis on this topic. METHODS: RCTs that compared ventilation of adult patients with ALI/ARDS in prone versus supine position were included in this study-level meta-analysis. Analysis was made by a random-effects model. The effect size on intensive care unit (ICU) mortality was computed in the overall included studies and in two subgroups of studies: those that included all ALI or hypoxemic patients, and those that restricted inclusion to only ARDS patients. A relationship between studies' effect size and daily prone duration was sought with meta-regression. We also computed the effects of prone positioning on major adverse airway complications. RESULTS: Seven RCTs (including 1,675 adult patients, of whom 862 were ventilated in the prone position) were included. The four most recent trials included only ARDS patients, and also applied the longest proning durations and used lung-protective ventilation. The effects of prone positioning differed according to the type of study. Overall, prone ventilation did not reduce ICU mortality (odds ratio = 0.91, 95% confidence interval = 0.75 to 1.2; P = 0.39), but it significantly reduced the ICU mortality in the four recent studies that enrolled only patients with ARDS (odds ratio = 0.71; 95% confidence interval = 0.5 to 0.99; P = 0.048; number needed to treat = 11). Meta-regression on all studies disclosed only a trend to explain effect variation by prone duration (P = 0.06). Prone positioning was not associated with a statistical increase in major airway complications. CONCLUSIONS: Long duration of ventilation in prone position significantly reduces ICU mortality when only ARDS patients are considered

Severe Hypercapnia and Outcome of Mechanically Ventilated Patients with Moderate or Severe Acute Respiratory Distress Syndrome

PURPOSE: To analyze the relationship between hypercapnia developing within the first 48 h after the start of mechanical ventilation and outcome in patients with acute respiratory distress syndrome (ARDS). PATIENTS AND METHODS: We performed a secondary analysis of three prospective non-interventional cohort studies focusing on ARDS patients from 927 intensive care units (ICUs) in 40 countries. These patients received mechanical ventilation for more than 12 h during 1-month periods in 1998, 2004, and 2010. We used multivariable logistic regression and a propensity score analysis to examine the association between hypercapnia and ICU mortality. MAIN OUTCOMES: We included 1899 patients with ARDS in this study. The relationship between maximum PaCO2 in the first 48 h and mortality suggests higher mortality at or above PaCO2 of ≥50 mmHg. Patients with severe hypercapnia (PaCO2 ≥50 mmHg) had higher complication rates, more organ failures, and worse outcomes. After adjusting for age, SAPS II score, respiratory rate, positive end-expiratory pressure, PaO2/FiO2 ratio, driving pressure, pressure/volume limitation strategy (PLS), corrected minute ventilation, and presence of acidosis, severe hypercapnia was associated with increased risk of ICU mortality [odds ratio (OR) 1.93, 95% confidence interval (CI) 1.32 to 2.81; p = 0.001]. In patients with severe hypercapnia matched for all other variables, ventilation with PLS was associated with higher ICU mortality (OR 1.58, CI 95% 1.04-2.41; p = 0.032). CONCLUSIONS: Severe hypercapnia appears to be independently associated with higher ICU mortality in patients with ARDS.info:eu-repo/semantics/publishedVersio

Expert statements on the standard of care in critically ill adult patients with atypical haemolytic uraemic syndrome

Background Atypical haemolytic uraemic syndrome (aHUS) presents similarly to thrombotic thrombocytopenic purpura (TTP), and other causes or conditions with thrombotic microangiopathy (TMA) such as DIC or sepsis. Similarity in clinical presentation may hinder diagnosis and optimal treatment selection in the urgent setting in the ICU. However, there is currently no consensus on the diagnosis or treatment of aHUS for ICU specialists. This review aims to summarise available data on the diagnosis and treatment strategies of aHUS in the ICU in order to enhance the understanding of aHUS diagnosis and outcomes in patients managed in the ICU. Methods A review of the recent literature (January 2009 – March 2016) was performed to select the most relevant articles for ICU physicians. Results Based on the paucity of adult aHUS cases overall and within the ICU, no specific recommendations could be formally graded for the critical care setting. However, the expert panel recognises a core set of skills required by intensivists for diagnosing and managing patients with aHUS: recognising thrombotic microangiopathies, differentiating aHUS from related conditions, recognising involvement of other organ systems, understanding the pathophysiology of aHUS, knowing the diagnostic workup and relevant outcomes in critically ill aHUS patients, and knowing the standard of care for patients with aHUS based on available data and guidelines. Conclusions Managing critically ill patients with aHUS requires basic skills that, in the absence of sufficient data from patients treated within the ICU, can be gleaned from an increasingly relevant literature outside the ICU. More data on critically ill patients with aHUS are needed to validate these conclusions within the ICU setting

A worldwide assessment of the mechanical ventilation in patients with acute exacerbations of chronic obstructive pulmonary disease. Analysis of the VENTILAGROUP over time. A retrospective, multicenter study

Background: The trend over time and across different geographical areas of outcomes and management with noninvasive ventilation or invasive mechanical ventilation in patients admitted for acute exacerbations of chronic obstructive pulmonary disease and treated with ventilatory support is unknown. The purpose of this study was to describe outcomes and identify variables associated with survival for patients admitted to an intensive care unit (ICU) with acute exacerbation of chronic obstructive pulmonary disease [aeCOPD] who received noninvasive or invasive mechanical ventilation worldwide. Methods: Retrospective, multi-national, and multicenter studies, including four observational cohort studies, were carried out in 1998, 2004, 2010, and 2016 for the VENTILAGROUP following the same methodology. Results: A total of 1,848 patients from 1,253 ICUs in 38 countries admitted for aeCOPD and need of ventilatory support were identified in the four study cohorts and included in the study. The overall incidence of aeCOPD as a cause for ventilatory support at ICU admission significantly decreased over time and varied widely according to the gross national income. The mortality of patients admitted to ICU for aeCOPD and ventilatory support significantly decreased over time regardless of the geographical area and gross national income; however, there is a remarkable variability in ICU mortality according to geographical area and gross national income. The use of NPPV as the first attempt at ventilatory support has significantly increased over time, with a parallel reduction of invasive mechanical ventilation regardless of gross national income. Conclusion: In this worldwide observational study, including four sequential cohorts of patients over 18 years from 1998 to 2016, the mortality of patients admitted to ICU for aeCOPD and ventilatory support significantly decreased regardless of the geographical area and gross national income. Future research will need to investigate the reason for the remarkable variability in ICU mortality according to the geographical area, gross national income, and methods to select patients for the appropriate ventilatory support

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome: insights from the LUNG SAFE study

Contains fulltext : 218568.pdf (publisher's version ) (Open Access)BACKGROUND: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. METHODS: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 >/= 0.60 during hyperoxemia). RESULTS: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). CONCLUSIONS: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. TRIAL REGISTRATION: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake