Factors associated with decreased compliance after on-site extracorporeal membrane oxygenation cannulation for acute respiratory distress syndrome: A retrospective, observational cohort study

Background

Extracorporeal membrane oxygenation (ECMO) for acute respiratory distress syndrome (ARDS) is systematically associated with decreased respiratory system compliance (CRS). It remains unclear whether transportation to the referral ECMO center, changes in ventilatory mode or settings to achieve ultra-protective ventilation, or the natural evolution of ARDS drives this change in respiratory mechanics. Herein, we assessed the precise moment when CRS decreases after ECMO cannulation and identified factors associated with decreased CRS.

Methods

To rule out the effect of transportation and the different modes of ventilation on CRS, we conducted a retrospective, single-center, observational cohort study from January 2013 to May 2020, on 22 patients with severe ARDS requiring on-site ECMO and ventilated in pressure-controlled mode to achieve ultra-protective ventilation. CRS was assessed at different time points ranging from 12 h before ECMO cannulation to 72 h after ECMO cannulation. The primary outcome was the relative change in CRS between 3 h before and 3 h after ECMO cannulation. The secondary outcomes included variables associated with the relative changes in CRS within the first 3 h after ECMO cannulation and the relative changes in CRS at each time point.

Results

CRS decreased within the first 3 h after ECMO cannulation (-28.3%, 95% confidence interval [CI]: -38.8 to -17.9, P<0.001), while the decrease was mild before and after these first 3 h after ECMO cannulation. To achieve ultra-protective ventilation, respiratory rate decreased in the mean by -13 breaths/min (95% CI: -15 to -11) and driving pressure by -8.3 cmH2O (95% CI: -11.2 to -5.3), resulting in decreased tidal volume by -3.3 mL/kg of predicted body weight (95% CI: -3.9 to -2.6) as compared to before ECMO cannulation (P <0.001 for all). Plateau pressure reduction, driving pressure reduction, and tidal volume reduction were significantly associated with decreased CRS after ECMO cannulation, whereas neither respiratory rate, positive end-expiratory pressure, inspired fraction of oxygen, fluid balance, nor mean airway pressure was associated with decreased CRS.

Conclusions

Decreased driving pressure resulting in lower tidal volume to achieve ultra-protective ventilation after ECMO cannulation was associated with a marked decrease in CRS in ARDS patients with on-site ECMO cannulation.

Critically ill patients with infective endocarditis, neurological complications and indication for cardiac surgery: a multicenter propensity-adjusted study

BACKGROUND

The benefit-risk balance and optimal timing of surgery for severe infective endocarditis (IE) with ischemic or hemorrhagic strokes is unknown. The study aim was to compare the neurological outcome between patients receiving surgery or not.

METHODS

In a prospective register-based multicenter ICU study, patients were included if they met the following criteria: (i) left-sided IE with an indication for heart surgery; (ii) with cerebral complications documented by cerebral imaging before cardiac surgery; (iii) with Sequential Organ Failure Assessment score ≥ 3. Exclusion criteria were isolated right-sided IE, in-hospital acquired IE and patients with cerebral complications only after cardiac surgery. In the primary analysis, the prognostic value of surgery in term of disability at 6 month was assessed by using a propensity score-adjusted logistic regression.

RESULTS

192 patients were included including ischemic stroke (74.5%) and hemorrhagic lesion (15.6%): 67 (35%) had medical treatment and 125 (65%) cardiac surgery. In the propensity score-adjusted logistic regression, a favorable 6-month neurological outcome was associated with surgery (odds ratio 13.8 (95% CI 6.2-33.7). The 1-year mortality was strongly reduced with surgery in the fixed-effect propensity-adjusted Cox model (hazard ratio 0.18; 95% CI 0.11-0.27; p < 0.001). These effects remained whether the patients received delayed surgery (n = 62/125) or not and whether they were deeply comatose (Glasgow Coma Scale ≤ 10) or not.

CONCLUSIONS

In critically ill IE patients with an indication for surgery and previous cerebral events, a better propensity-adjusted neurological outcome was associated with surgery compared with medical treatment.

Physiologic Effects of Reconnection to the Ventilator for 1 Hour Following a Successful Spontaneous Breathing Trial

BACKGROUND

Reconnection to the ventilator for 1 h following a successful spontaneous breathing trial (SBT) may reduce reintubation rates compared with direct extubation. However, the physiologic mechanisms leading to this effect are unclear.

RESEARCH QUESTION

Does reconnection to the ventilator for 1 h reverse alveolar derecruitment induced by SBT, and is alveolar derecruitment more pronounced with a T-piece than with pressure-support ventilation (PSV)?

STUDY DESIGN AND METHODS

This is an ancillary study of a randomized clinical trial comparing SBT performed with a T-piece or with PSV. Alveolar recruitment was assessed by using measurement of end-expiratory lung volume (EELV).

RESULTS

Of the 25 patients analyzed following successful SBT, 11 underwent SBT with a T-piece and 14 with PSV. At the end of the SBT, EELV decreased by -30% (95% CI, -37 to -23) compared with baseline prior to the SBT. This reduction was greater with a T-piece than with PSV: -43% (95% CI, -51 to -35) vs -20% (95% CI, -26 to -13); P < .001. Following reconnection to the ventilator for 1 h, EELV accounted for 96% (95% CI, 92 to 101) of baseline EELV and did not significantly differ from prior to the SBT (P = .104). Following 10 min of reconnection to the ventilator, EELV wasted at the end of the SBT was completely recovered using PSV (P = .574), whereas it remained lower than prior to the SBT using a T-piece (P = .010).

INTERPRETATION

Significant alveolar derecruitment was observed at the end of an SBT and was markedly more pronounced with a T-piece than with PSV. Reconnection to the ventilator for 1 h allowed complete recovery of alveolar derecruitment.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT04227639; URL: www.

CLINICALTRIALS

gov.

Continuous positive airway pressure or high-flow nasal cannula oxygen therapy for acute hypoxemic respiratory failure unrelated to COVID-19: Another brick in the wall?

See related article

Sex difference in the risk of extubation failure in ICUs

BACKGROUND

Little attention has been paid to potential differences in prognosis between mechanically ventilated males and females in intensive care units (ICUs). We hypothesized that a sex gap in the risk of extubation failure in ICUs may exist.

METHODS

Post hoc analysis of a large-scale clinical trial including patients at high risk of extubation failure in ICUs, with the aim of assessing the risk of extubation failure according to sex. The primary outcome was reintubation within the 7 days following extubation.

RESULTS

Out of 641 patients, 425 (66%) were males and 216 (34%) were females. Males were more likely to be admitted for cardiac arrest and to have underlying ischemic heart disease whereas females were more likely to be admitted for coma and to have obesity. Whereas the rate of reintubation at 48 h was significantly higher in males than in females (11.0% vs. 6.0%; difference, + 5.0 [95% CI, 0.2 to 9.2]; P = 0.038), the rate of reintubation at day 7 did not significantly differ between males and females (16.7% vs. 11.1%; difference, + 5.6% [95%CI, - 0.3 to 10.8], P = 0.059). Using multivariable logistic regression analysis, male sex was independently associated with reintubation within the 7 days following extubation (adjusted OR 1.70 [95% CI, 1.01 to 2.89]; P = 0.048), even after adjustment on reason for admission, body-mass index, severity score, respiratory rate before extubation, and noninvasive ventilation after extubation.

CONCLUSION

In this post hoc analysis of a clinical trial including a homogeneous subset of patients at high risk of extubation failure, sex was independently associated with reintubation. The role of sex on outcomes should be systematically examined in future studies of critically ill patients.

High-flow nasal cannula oxygen versus conventional oxygen therapy for acute respiratory failure due to COVID-19: a systematic review and meta-analysis

BACKGROUND

The effectiveness of high-flow nasal cannula oxygen therapy (HFNC) in patients with acute respiratory failure due to COVID-19 remains uncertain. We aimed at assessing whether HFNC is associated with reduced risk of intubation or mortality in patients with acute respiratory failure due to COVID-19 compared with conventional oxygen therapy (COT).

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, Web of Science, and CENTRAL databases for randomized controlled trials (RCTs) and observational studies comparing HFNC vs. COT in patients with acute respiratory failure due to COVID-19, published in English from inception to December 2022. Pediatric studies, studies that compared HFNC with a noninvasive respiratory support other than COT and those in which intubation or mortality were not reported were excluded. Two authors independently screened and selected articles for inclusion, extracted data, and assessed the risk of bias. Fixed-effects or random-effects meta-analysis were performed according to statistical heterogeneity. Primary outcomes were risk of intubation and mortality across RCTs. Effect estimates were calculated as risk ratios and 95% confidence interval (RR; 95% CI). Observational studies were used for sensitivity analyses.

RESULTS

Twenty studies were analyzed, accounting for 8383 patients, including 6 RCTs (2509 patients) and 14 observational studies (5874 patients). By pooling the 6 RCTs, HFNC compared with COT significantly reduced the risk of intubation (RR 0.89, 95% CI 0.80 to 0.98; p = 0.02) and reduced length of stay in hospital. HFNC did not significantly reduce the risk of mortality (RR 0.93, 95% CI 0.77 to 1.11; p = 0.40).

CONCLUSIONS

In patients with acute respiratory failure due to COVID-19, HFNC reduced the need for intubation and shortened length of stay in hospital without significant decreased risk of mortality. Trial registration The study was registered on the International prospective register of systematic reviews (PROSPERO) at https://www.crd.york.ac.uk/prospero/ with the trial registration number CRD42022340035 (06/20/2022).

Sleep Assessment in Critically Ill Patients With Acute Hypoxemic Respiratory Failure

BACKGROUND

Sleep deprivation alters respiratory muscle performance and may precipitate respiratory failure. This study aimed to assess sleep in subjects admitted to ICU for acute hypoxemic respiratory failure and its role in the risk of intubation.

METHODS

This was a prospective observational single-center cohort study including subjects admitted to ICU for de novo acute hypoxemic respiratory failure defined as breathing frequency ≥ 25 breaths/min or clinical signs of respiratory distress and PaO2 /FIO2 < 300 mm Hg while receiving high-flow nasal oxygen. Subjects with altered consciousness, central nervous or psychiatric disorders, continuous sedation or neuroleptic medication, or were uncooperative were excluded. Sleep was assessed by complete polysomnography (PSG) the night following ICU admission. The main outcome was to assess sleep among subjects with acute hypoxemic respiratory failure and to compare sleep between subjects who eventually required intubation to those who did not.

RESULTS

Over a 24-month inclusion period, 34 subjects had complete PSG, among whom 5 (15%) required intubation in the ICU. Total sleep time was 4.2 h in median (interquartile range 2.9-6.8); deep-sleep duration was 70 min (34-127), and rapid eye movement (REM) sleep duration was 9 min (0-28). Among them, 13 subjects (38%) had no REM sleep. Total sleep time and duration of deep and REM sleep stages did not differ between subjects who required intubation and those successfully treated with high-flow nasal oxygen.

CONCLUSIONS

Whereas total sleep time remained relatively preserved in critically ill subjects with acute hypoxemic respiratory failure, REM sleep time was uncommon or completely absent in a large number of subjects. Sleep did not differ between subjects who required intubation and those who did not. However, given a trend toward an increased risk of intubation in subjects with a complete absence of REM sleep, further studies are needed to better explore the impact of REM sleep on the risk of intubation.

Skin biopsy in adult patients with meningococcal purpura fulminans: a multicenter retrospective cohort study

BACKGROUND

Neisseria meningitidis is the leading responsible bacterium of Purpura Fulminans (PF) accounting for two thirds of PF. Skin biopsy is a simple and minimally invasive exam allowing to perform skin culture and polymerase chain reaction (PCR) to detect Neisseria meningitidis. We aimed to assess the sensitivity of skin biopsy in adult patients with meningococcal PF.

METHODS

A 17-year multicenter retrospective cohort study including adult patients admitted to the ICU for a meningococcal PF in whom a skin biopsy with conventional and/or meningococcal PCR was performed.

RESULTS

Among 306 patients admitted for PF, 195 had a meningococcal PF (64%) with a skin biopsy being performed in 68 (35%) of them. Skin biopsy was performed in median 1 day after the initiation of antibiotic therapy. Standard culture of skin biopsy was performed in 61/68 (90%) patients and grew Neisseria meningitidis in 28 (46%) of them. Neisseria meningitidis PCR on skin biopsy was performed in 51/68 (75%) patients and was positive in 50 (98%) of them. Among these 50 positive meningococcal PCR, five were performed 3 days or more after initiation of antibiotic therapy. Finally, skin biopsy was considered as contributive in 60/68 (88%) patients. Identification of the meningococcal serogroup was obtained with skin biopsy in 48/68 (71%) patients.

CONCLUSIONS

Skin biopsy with conventional culture and meningococcal PCR has a global sensitivity of 88% and should be systematically considered in case of suspected meningococcal PF even after the initiation of antimicrobial treatment.

High-flow nasal cannula oxygen therapy in acute hypoxemic respiratory failure and COVID-19-related respiratory failure

Although standard oxygen face masks are first-line therapy for patients with acute hypoxemic respiratory failure, high-flow nasal cannula oxygen therapy has gained major popularity in intensive care units. The physiological effects of high-flow oxygen counterbalance the physiological consequences of acute hypoxemic respiratory failure by lessening the deleterious effects of intense and prolonged inspiratory efforts generated by patients. Its simplicity of application for physicians and nurses and its comfort for patients are other arguments for its use in this setting. Although clinical studies have reported a decreased risk of intubation with high-flow oxygen compared with standard oxygen, its survival benefit is uncertain. A more precise definition of acute hypoxemic respiratory failure, including a classification of severity based on oxygenation levels, is needed to better compare the efficiencies of different non-invasive oxygenation support methods (standard oxygen, high-flow oxygen, and non-invasive ventilation). Additionally, the respective role of each non-invasive oxygenation support method needs to be established through further clinical trials in acute hypoxemic respiratory failure, especially in severe forms.

Spontaneous-Breathing Trials with Pressure-Support Ventilation or a T-Piece

BACKGROUND

Spontaneous-breathing trials can be performed with the use of either pressure-support ventilation (PSV) or a T-piece. Whether PSV trials may result in a shorter time to tracheal extubation than T-piece trials, without resulting in a higher risk of reintubation, among patients who have a high risk of extubation failure is unknown.

METHODS

In this multicenter, open-label trial, we randomly assigned patients who had a high risk of extubation failure (i.e., were &gt;65 years of age or had an underlying chronic cardiac or respiratory disease) to undergo spontaneous-breathing trials performed with the use of either PSV (with a pressure-support level of 8 cm of water and no positive end-expiratory pressure) or a T-piece. The primary outcome was the total time without exposure to invasive ventilation (reported as the number of ventilator-free days) at day 28 after the initial spontaneous-breathing trial. Secondary outcomes included extubation within 24 hours and extubation within 7 days after the initial spontaneous-breathing trial, as well as reintubation within 7 days after extubation.

RESULTS

A total of 969 patients (484 in the PSV group and 485 in the T-piece group) were included in the analysis. At day 28, the median number of ventilator-free days was 27 (interquartile range, 24 to 27) in the PSV group and 27 (interquartile range, 23 to 27) in the T-piece group (difference, 0 days; 95% confidence interval [CI], -0.5 to 1; P = 0.31). Extubation was performed within 24 hours in 376 patients (77.7%) in the PSV group and in 350 patients (72.2%) in the T-piece group (difference, 5.5 percentage points; 95% CI, 0.01 to 10.9), and extubation was performed within 7 days in 473 patients (97.7%) and 458 patients (94.4%), respectively (difference, 3.3 percentage points; 95% CI, 0.8 to 5.9). Reintubation was performed in 72 of 481 patients (14.9%) in the PSV group and in 65 of 477 patients (13.6%) in the T-piece group (difference, 1.3 percentage points; 95% CI, -3.1 to 5.8). Cardiac or respiratory arrest was a reason for reintubation in 9 patients (3 in the PSV group and 6 in the T-piece group).

CONCLUSIONS

Among patients who had a high risk of extubation failure, spontaneous-breathing trials performed with PSV did not result in significantly more ventilator-free days at day 28 than spontaneous-breathing trials performed with a T-piece. (Supported by the French Ministry of Health; TIP-EX ClinicalTrials.gov number, NCT04227639.).

Effect of High-Flow Nasal Cannula Oxygen vs Standard Oxygen Therapy on Mortality in Patients With Respiratory Failure Due to COVID-19: The SOHO-COVID Randomized Clinical Trial

IMPORTANCE

The benefit of high-flow nasal cannula oxygen (high-flow oxygen) in terms of intubation and mortality in patients with respiratory failure due to COVID-19 is controversial.

OBJECTIVE

To determine whether the use of high-flow oxygen, compared with standard oxygen, could reduce the rate of mortality at day 28 in patients with respiratory failure due to COVID-19 admitted in intensive care units (ICUs).

DESIGN, SETTING, AND PARTICIPANTS

The SOHO-COVID randomized clinical trial was conducted in 34 ICUs in France and included 711 patients with respiratory failure due to COVID-19 and a ratio of partial pressure of arterial oxygen to fraction of inspired oxygen equal to or below 200 mm Hg. It was an ancillary trial of the ongoing original SOHO randomized clinical trial, which was designed to include patients with acute hypoxemic respiratory failure from all causes. Patients were enrolled from January to December 2021; final follow-up occurred on March 5, 2022.

INTERVENTIONS

Patients were randomly assigned to receive high-flow oxygen (n = 357) or standard oxygen delivered through a nonrebreathing mask initially set at a 10-L/min minimum (n = 354).

MAIN OUTCOMES AND MEASURES

The primary outcome was mortality at day 28. There were 13 secondary outcomes, including the proportion of patients requiring intubation, number of ventilator-free days at day 28, mortality at day 90, mortality and length of stay in the ICU, and adverse events.

RESULTS

Among the 782 randomized patients, 711 patients with respiratory failure due to COVID-19 were included in the analysis (mean [SD] age, 61 [12] years; 214 women [30%]). The mortality rate at day 28 was 10% (36/357) with high-flow oxygen and 11% (40/354) with standard oxygen (absolute difference, -1.2% [95% CI, -5.8% to 3.4%]; P = .60). Of 13 prespecified secondary outcomes, 12 showed no significant difference including in length of stay and mortality in the ICU and in mortality up until day 90. The intubation rate was significantly lower with high-flow oxygen than with standard oxygen (45% [160/357] vs 53% [186/354]; absolute difference, -7.7% [95% CI, -14.9% to -0.4%]; P = .04). The number of ventilator-free days at day 28 was not significantly different between groups (median, 28 [IQR, 11-28] vs 23 [IQR, 10-28] days; absolute difference, 0.5 days [95% CI, -7.7 to 9.1]; P = .07). The most common adverse events were ventilator-associated pneumonia, occurring in 58% (93/160) in the high-flow oxygen group and 53% (99/186) in the standard oxygen group.

CONCLUSIONS AND RELEVANCE

Among patients with respiratory failure due to COVID-19, high-flow nasal cannula oxygen, compared with standard oxygen therapy, did not significantly reduce 28-day mortality.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04468126.

Evolution of respiratory system compliance and potential for lung recruitment in COVID-19-induced acute respiratory distress syndrome

Background

Coronavirus disease 2019 (COVID-19) has been frequently complicated by severe acute respiratory distress syndrome (ARDS) with prolonged invasive ventilation. While respiratory system compliance and lung recruitability have been described within the first days after ICU admission, data about their longitudinal changes are still limited. Therefore, we conducted this study to assess the evolution of respiratory system compliance and lung recruitability in patients with COVID-19-related ARDS.

Method

We conducted a prospective single-center study in patients admitted for COVID-19-related ARDS during the first wave of the pandemic, from March 16, 2020 to April 10, 2020. Respiratory system compliance was calculated daily at clinical positive end-expiratory pressure (PEEP) during passive breathing. The potential for lung recruitment was assessed by measuring the volume derecruited between PEEP 15 cmH₂O and 5 cmH₂O, and using the calculation of the recruitment-to-inflation ratio (R/I ratio). Recruitable lung was considered when the R/I ratio was at least 0.5. The primary outcome was the evolution of respiratory mechanics over time. The secondary outcome was the evolution of lung recruitability over time.

Results

Thirty-two patients were included in this study. The respiratory mechanics were assessed 222 times (7 ± 5 times per patient). Respiratory system compliance at clinical PEEP was 29.1 mL/cmH₂O (interquartile range [IQR]: 24.1-33.9 mL/cmH₂O) and decreased significantly over time (P <0.0001). Lung recruitability was assessed in 22 out of the 32 patients (60 assessments). The median volume derecruited between PEEP 15 cmH₂O and 5 cmH₂O was 246.8 mL (IQR: 180.8-352.2 mL) and the median R/I ratio was 0.56 (IQR: 0.39-0.73). Neither changed significantly over time. The proportion of patients with recruitable lung was 50.0% (6/12) within the first 3 days after intubation, 69.2% (9/13) between day 4 and day 7, and 66.7% (8/12) after day 7 (P=0.7934).

Conclusions

In our cohort, respiratory system compliance was low and decreased over time. The potential for lung recruitment was high and persisted despite prolonged mechanical ventilation, suggesting that maintaining high PEEP levels in the later course of COVID-19 could be adequate.

Noninvasive Oxygenation in Patients with Acute Respiratory Failure: Current Perspectives

Purpose of Review

High-flow nasal oxygen and noninvasive ventilation are two alternative strategies to standard oxygen in the management of acute respiratory failure.

Discussion

Although high-flow nasal oxygen has gained major popularity in ICUs due to its simplicity of application, good comfort for patients, efficiency in improving oxygenation and promising results in patients with acute hypoxemic respiratory failure, further large clinical trials are needed to confirm its superiority over standard oxygen. Non-invasive ventilation may have deleterious effects, especially in patients exerting strong inspiratory efforts, and no current recommendations support its use in this setting. Protective non-invasive ventilation using higher levels of positive-end expiratory pressure, more prolonged sessions and other interfaces such as the helmet may have beneficial physiological effects leading to it being proposed as alternative to high-flow nasal oxygen in acute hypoxemic respiratory failure. By contrast, non-invasive ventilation is the first-line strategy of oxygenation in patients with acute exacerbation of chronic lung disease, while high-flow nasal oxygen could be an alternative to non-invasive ventilation after partial reversal of respiratory acidosis. Questions remain about the target populations and non-invasive oxygen strategy representing the best alternative to standard oxygen in acute hypoxemic respiratory failure. As concerns acute on-chronic-respiratory failure, the place of high-flow nasal oxygen remains to be evaluated.

: A Post-Hoc Analysis of a Randomized Clinical Trial

RATIONALE

Whereas non-invasive ventilation (NIV) may prevent reintubation in patients at high-risk of extubation failure in intensive care units (ICUs), this oxygenation strategy has not been specifically assessed in obese patients.

OBJECTIVES

We hypothesized that NIV may decrease the risk of reintubation in obese patients compared with high-flow nasal oxygen (HFNO).

METHODS

Post-hoc analysis of a multicenter, randomized, controlled trial (not pre-specified) comparing NIV alternating with HFNO versus HFNO alone after extubation, with the aim of assessing NIV effects according to patient body-mass index (BMI).

MEASUREMENTS AND MAIN RESULTS

Among 623 patients at high-risk of extubation failure, 206 (33%) were obese (BMI≥30 kg/m2), 204 (33%) were overweight (25≤BMI<30), and 213 (34%) were normal or underweight (BMI<25). Significant heterogeneity of NIV effects on the rate of reintubation was found according to BMI (Pinteraction=0.007). Reintubation rates at day 7 were significantly lower with NIV alternating with HFNO than with HFNO alone in obese or overweight patients: 7% (15/204) vs. 20% (41/206); difference, -13%; [95% CI, -19 to -6]; P=0.0002; whereas it did not significantly differ in normal or underweight patients. In-ICU mortality was significantly lower with NIV than with HFNO alone in obese or overweight patients (2% vs. 9%; difference, -6%; [95% CI, -11 to -2]; P=0.006).

CONCLUSIONS

Prophylactic NIV alternating with HFNO immediately after extubation significantly decreased the risk of reintubation and death as compared with HFNO alone in obese or overweight patients at high-risk of extubation failure. By contrast, NIV was not effective in normal or underweight patients.

β Agonist Delivery by High-Flow Nasal Cannula During COPD Exacerbation: A Prospective Physiological Study

BACKGROUND

Whereas high-flow nasal cannula (HFNC) oxygen therapy is increasingly used in patients with exacerbation of COPD, the effectiveness of β ₂ agonist nebulization through HFNC has been poorly assessed. We hypothesized that salbutamol vibrating-mesh nebulization through HFNC improves pulmonary function tests in subjects with COPD.

METHODS

We conducted a physiological crossover study including subjects admitted to the ICU for severe exacerbation of COPD. After subject improvement allowing a 3-h washout period without bronchodilator, pulmonary function tests were performed while breathing through HFNC alone and after salbutamol vibrating-mesh nebulization through HFNC. The primary end point consisted in the changes in FEV₁ before and after salbutamol nebulization. Secondary end points included the changes in FVC, peak expiratory flow (PEF), airway resistance, and clinical parameters.

RESULTS

Among the 15 subjects included, mean (SD) FEV₁ significantly increased after salbutamol nebulization from 931 mL (383) to 1,019 (432), mean difference +87 mL (95% CI 30-145) (P = .006). Similarly, FVC and PEF significantly increased, +174 mL (95% CI 66-282) (P = .004) and +0.3 L/min (95% CI 0-0.6) (P = .037), respectively. Airway resistances and breathing frequency did not significantly differ, whereas heart rate significantly increased after nebulization.

CONCLUSIONS

In subjects with severe exacerbation of COPD, salbutamol vibrating-mesh nebulization through HFNC induced a significant bronchodilator effect with volume and flow improvement.

Noninvasive ventilation vs. high-flow nasal cannula oxygen for preoxygenation before intubation in patients with obesity: a post hoc analysis of a randomized controlled trial

BACKGROUND

Critically ill patients with obesity may have an increased risk of difficult intubation and subsequent severe hypoxemia. We hypothesized that pre-oxygenation with noninvasive ventilation before intubation as compared with high-flow nasal cannula oxygen may decrease the risk of severe hypoxemia in patients with obesity.

METHODS

Post hoc subgroup analysis of critically ill patients with obesity (body mass index ≥ 30 kg·m^-2) from a multicenter randomized controlled trial comparing preoxygenation with noninvasive ventilation and high-flow nasal oxygen before intubation of patients with acute hypoxemic respiratory failure (PaO₂/FiO₂ < 300 mm Hg). The primary outcome was the occurrence of severe hypoxemia (pulse oximetry < 80%) during the intubation procedure.

RESULTS

Among the 313 patients included in the original trial, 91 (29%) had obesity with a mean body mass index of 35 ± 5 kg·m^-2. Patients with obesity were more likely to experience an episode of severe hypoxemia during intubation procedure than patients without obesity: 34% (31/91) vs. 22% (49/222); difference, 12%; 95% CI 1 to 23%; P = 0.03. Among patients with obesity, 40 received preoxygenation with noninvasive ventilation and 51 with high-flow nasal oxygen. Severe hypoxemia occurred in 15 patients (37%) with noninvasive ventilation and 16 patients (31%) with high-flow nasal oxygen (difference, 6%; 95% CI - 13 to 25%; P = 0.54). The lowest pulse oximetry values during intubation procedure were 87% [interquartile range, 77-93] with noninvasive ventilation and 86% [78-92] with high-flow nasal oxygen (P = 0.98). After multivariable analysis, factors independently associated with severe hypoxemia in patients with obesity were intubation difficulty scale > 5 points and respiratory primary failure as reason for admission.

CONCLUSIONS

Patients with obesity and acute hypoxemic respiratory failure had an increased risk of severe hypoxemia during intubation procedure as compared to patients without obesity. However, preoxygenation with noninvasive ventilation may not reduce this risk compared with high-flow nasal oxygen. Trial registration Clinical trial number: NCT02668458 ( http://www.clinicaltrials.gov ).

Non-invasive ventilation versus high-flow nasal oxygen for postextubation respiratory failure in ICU: a post-hoc analysis of a randomized clinical trial

Background

In intensive care units (ICUs), patients experiencing post-extubation respiratory failure have poor outcomes. The use of noninvasive ventilation (NIV) to treat post-extubation respiratory failure may increase the risk of death. This study aims at comparing mortality between patients treated with NIV alternating with high-flow nasal oxygen or high-flow nasal oxygen alone.

Methods

Post-hoc analysis of a multicenter, randomized, controlled trial focusing on patients who experienced post-extubation respiratory failure within the 7 days following extubation. Patients were classified in the NIV group or the high-flow nasal oxygen group according to oxygenation strategy used after the onset of post-extubation respiratory failure. Patients reintubated within the first hour after extubation and those promptly reintubated without prior treatment were excluded. The primary outcome was mortality at day 28 after the onset of post-extubation respiratory failure.

Results

Among 651 extubated patients, 158 (25%) experienced respiratory failure and 146 were included in the analysis. Mortality at day 28 was 18% (15/84) using NIV alternating with high-flow nasal oxygen and 29% (18/62) with high flow nasal oxygen alone (difference, − 11% [95% CI, − 25 to 2]; p = 0.12). Among the 46 patients with hypercapnia at the onset of respiratory failure, mortality at day 28 was 3% (1/33) with NIV and 31% (4/13) with high-flow nasal oxygen alone (difference, − 28% [95% CI, − 54 to − 6]; p = 0.006). The proportion of patients reintubated 48 h after the onset of post-extubation respiratory failure was 44% (37/84) with NIV and 52% (32/62) with high-flow nasal oxygen alone (p = 0.21).

Conclusions

In patients with post-extubation respiratory failure, NIV alternating with high-flow nasal oxygen might not increase the risk of death.

Trial registration number

The trial was registered at http://www.clinicaltrials.gov with the registration number NCT03121482 the 20th April 2017.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03621-6.

Menstrual toxic shock syndrome: a French nationwide multicenter retrospective study

BACKGROUND

Studies describing the clinical features and short-term prognosis of patients admitted to the intensive care unit (ICU) for menstrual toxic shock syndrome (m-TSS) are lacking.

METHODS

This was a multicenter retrospective cohort study of patients with a clinical diagnosis of m-TSS admitted between January 1, 2005 and December 31, 2020 in 43 French pediatric (n=7) or adult (n=36) ICUs. The aim of the study was to describe the clinical features and short-term prognosis, as well as assess the 2011 Centers for Disease and Control (CDC) diagnostic criteria, of critically ill patients with m-TSS.

RESULTS

In total, 102 patients with m-TSS (median age: 18 [16-24] years) were admitted to one of the participating ICUs. All blood cultures (n=102) were sterile. Methicillin-sensitive Staphylococcus aureus grew from 92 of 96 vaginal samples. Screening for super-antigenic toxin gene sequences was performed for 76 of the 92 (83%) vaginal samples positive for Staphylococcus aureus and TSST-1 isolated from 66 (87%) strains. At ICU admission, no patient met the 2011 CDC criteria for confirmed m-TSS and only 53 (52%) fulfilled the criteria for probable m-TSS. Eighty-one patients (79%) were treated with anti-toxin antibiotic therapy and eight (8%) received intravenous immunoglobulins. Eighty-six (84%) patients required vasopressors and 21 (21%) tracheal intubation. No patient required limb amputation or died in the ICU.

CONCLUSIONS

In this large multicenter series of patients included in ICUs for m-TSS, none died or required limb amputation. The CDC criteria should not be used for the clinical diagnosis of m-TSS at ICU admission.

High risk of pulmonary embolism in acute respiratory distress syndrome related to COVID-19: an observational controlled-cohort study

Background

COVID-19 may induce endovascular injury of pulmonary vessels and could be associated with increased risk of pulmonary embolism. The main objective was to compare the incidence of pulmonary embolism in patients with acute respiratory distress syndrome (ARDS) related to COVID-19 versus patients with pulmonary ARDS unrelated to COVID-19.

Methods

This is an observational controlled-cohort study performed at a single center of a university teaching hospital in France. The incidence of pulmonary embolism was prospectively assessed using computed tomography pulmonary angiography (CTPA) in patients with ARDS related to COVID-19 and compared to patients from a 3-year historical cohort of patients with pulmonary ARDS unrelated to COVID-19. In patients with ARDS related to COVID-19, CTPA was performed approximately 7 days after intubation or earlier in case of respiratory or hemodynamic worsening.

Results

CTPA was performed in 29 out of the 42 patients (69%) with ARDS related to COVID-19 and in 51 out of the 156 patients (33%) from the historical cohort of patients with pulmonary ARDS unrelated to COVID-19. Incidence of pulmonary embolism was 40% (17/42) in patients with ARDS related to COVID-19 and 3% (5/156) in the historical cohort (P=0.001). The proportion of patients with pulmonary embolism among all patients who had CTPA was 59% (17/29) in patients with ARDS related to COVID-19 and 10% (5/51) in the historical cohort (P=0.0001). After adjustment on the interval between ICU admission and computed tomography, COVID-19 remained independently associated with pulmonary embolism.

Conclusions

Pulmonary embolism was particularly frequent in patients with ARDS related to COVID-19, thereby suggesting that CTPA should be systematically performed in these patients.

Survival in Immunocompromised Patients Ultimately Requiring Invasive Mechanical Ventilation: A Pooled Individual Patient Data Analysis

Rationale: Acute respiratory failure (ARF) is associated with high mortality in immunocompromised patients, particularly when invasive mechanical ventilation is needed. Therefore, noninvasive oxygenation/ventilation strategies have been developed to avoid intubation, with uncertain impact on mortality, especially when intubation is delayed. Objectives: We sought to report trends of survival over time in immunocompromised patients receiving invasive mechanical ventilation. The impact of delayed intubation after failure of noninvasive strategies was also assessed. Methods: Systematic review and meta-analysis using individual patient data of studies that focused on immunocompromised adult patients with ARF requiring invasive mechanical ventilation. Studies published in English were identified through PubMed, Web of Science, and Cochrane Central (2008-2018). Individual patient data were requested from corresponding authors for all identified studies. We used mixed-effect models to estimate the effect of delayed intubation on hospital mortality and described mortality rates over time. Measurements and Main Results: A total of 11,087 patients were included (24 studies, three controlled trials, and 21 cohorts), of whom 7,736 (74%) were intubated within 24 hours of ICU admission (early intubation). The crude mortality rate was 53.2%. Adjusted survivals improved over time (from 1995 to 2017, odds ratio [OR] for hospital mortality per year, 0.96 [0.95-0.97]). For each elapsed day between ICU admission and intubation, mortality was higher (OR, 1.38 [1.26-1.52]; P < 0.001). Early intubation was significantly associated with lower mortality (OR, 0.83 [0.72-0.96]), regardless of initial oxygenation strategy. These results persisted after propensity score analysis (matched OR associated with delayed intubation, 1.56 [1.44-1.70]). Conclusions: In immunocompromised intubated patients, survival has improved over time. Time between ICU admission and intubation is a strong predictor of mortality, suggesting a detrimental effect of late initial oxygenation failure.

Automated detection and quantification of reverse triggering effort under mechanical ventilation

BACKGROUND

Reverse triggering (RT) is a dyssynchrony defined by a respiratory muscle contraction following a passive mechanical insufflation. It is potentially harmful for the lung and the diaphragm, but its detection is challenging. Magnitude of effort generated by RT is currently unknown. Our objective was to validate supervised methods for automatic detection of RT using only airway pressure (Paw) and flow. A secondary objective was to describe the magnitude of the efforts generated during RT.

METHODS

We developed algorithms for detection of RT using Paw and flow waveforms. Experts having Paw, flow and esophageal pressure (Pes) assessed automatic detection accuracy by comparison against visual assessment. Muscular pressure (Pmus) was measured from Pes during RT, triggered breaths and ineffective efforts.

RESULTS

Tracings from 20 hypoxemic patients were used (mean age 65 ± 12 years, 65% male, ICU survival 75%). RT was present in 24% of the breaths ranging from 0 (patients paralyzed or in pressure support ventilation) to 93.3%. Automatic detection accuracy was 95.5%: sensitivity 83.1%, specificity 99.4%, positive predictive value 97.6%, negative predictive value 95.0% and kappa index of 0.87. Pmus of RT ranged from 1.3 to 36.8 cmH₂0, with a median of 8.7 cmH₂0. RT with breath stacking had the highest levels of Pmus, and RTs with no breath stacking were of similar magnitude than pressure support breaths.

CONCLUSION

An automated detection tool using airway pressure and flow can diagnose reverse triggering with excellent accuracy. RT generates a median Pmus of 9 cmH₂O with important variability between and within patients.

TRIAL REGISTRATION

BEARDS, NCT03447288.

T-piece versus pressure-support ventilation for spontaneous breathing trials before extubation in patients at high risk of reintubation: protocol for a multicentre, randomised controlled trial (TIP-EX)

INTRODUCTION

In intensive care unit (ICU), the decision of extubation is a critical time because mortality is particularly high in case of reintubation. To reduce that risk, guidelines recommend to systematically perform a spontaneous breathing trial (SBT) before extubation in order to mimic the postextubation physiological conditions. SBT is usually performed with a T-piece disconnecting the patient from the ventilator or with low levels of pressure-support ventilation (PSV). However, work of breathing is lower during PSV than during T-piece. Consequently, while PSV trial may hasten extubation, it may also increase the risk of reintubation. We hypothesise that, compared with T-piece, SBT performed using PSV may hasten extubation without increasing the risk of reintubation.

METHODS AND ANALYSIS

This study is an investigator-initiated, multicentre randomised controlled trial comparing T-piece vs PSV for SBTs in patients at high risk of reintubation in ICUs. Nine hundred patients will be randomised with a 1:1 ratio in two groups according to the type of SBT. The primary outcome is the number of ventilator-free days at day 28, defined as the number of days alive and without invasive mechanical ventilation between the initial SBT (day 1) and day 28. Secondary outcomes include the number of days between the initial SBT and the first extubation attempt, weaning difficulty, the number of patients extubated after the initial SBT and not reintubated within the following 72 hours, the number of patients extubated within the 7 days following the initial SBT, the number of patients reintubated within the 7 days following extubation, in-ICU length of stay and mortality in ICU, at day 28 and at day 90.

ETHICS AND DISSEMINATION

The study has been approved by the central ethics committee 'Ile de France V' (2019-A02151-56) and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT04227639.

Long-term Quality of Life in Adult Patients Surviving Purpura Fulminans: An Exposed-Unexposed Multicenter Cohort Study

BACKGROUND

Long-term health-related quality of life (HR-QOL) of patients surviving the acute phase of purpura fulminans (PF) has not been evaluated.

METHODS

This was a French multicenter exposed-unexposed cohort study enrolling patients admitted in 55 intensive care units (ICUs) for PF from 2010 to 2016. Adult patients surviving the acute phase of PF (exposed group) were matched 1:1 for age, sex, and Simplified Acute Physiology Score II with septic shock survivors (unexposed group). HR-QOL was assessed during a phone interview using the 36-Item Short-Form Health Survey (SF-36) questionnaire, the Hospital Anxiety and Depression (HAD) scale, the Impact of Event Scale-Revised (IES-R), and the activity of daily living (ADL) and instrumental ADL (IADL) scales. The primary outcome measure was the physical component summary (PCS) of the SF-36 questionnaire.

RESULTS

Thirty-seven survivors of PF and 37 of septic shock were phone-interviewed at 55 (interquartile range [IQR], 35-83) months and 44 (IQR, 35-72) months, respectively, of ICU discharge (P = .23). The PCS of the SF-36 was not significantly different between exposed and unexposed patients (median, 47 [IQR, 36-53] vs 54 [IQR, 36-57]; P = .18). There was also no significant difference between groups regarding the mental component summary of the SF-36, and the HAD, IES-R, ADL and IADL scales. Among the 37 exposed patients, those who required limb amputation (n = 12/37 [32%]) exhibited lower PCS (34 [IQR, 24-38] vs 52 [IQR, 42-56]; P = .001) and IADL scores (7 [IQR, 4-8] vs 8 [IQR, 7-8]; P = .021) compared with nonamputated patients.

CONCLUSIONS

Long-term HR-QOL does not differ between patients surviving PF and those surviving septic shock unrelated to PF. Amputated patients have an impaired physical HR-QOL but a preserved mental health.

CLINICAL TRIALS REGISTRATION

NCT03216577.

Reliability of methods to estimate the fraction of inspired oxygen in patients with acute respiratory failure breathing through non-rebreather reservoir bag oxygen mask

Severity of hypoxaemia can be assessed using the partial pressure of arterial oxygen to fraction of inspired oxygen ratio (FiO2). However, in patients breathing through non-rebreather reservoir bag oxygen mask, accuracy of bedside FiO2 estimation methods remains to be tested. In a post-hoc analysis of a multicentre clinical trial, three FiO2 estimation methods were compared with FiO2 measured with a portable oxygen analyser introduced in the oxygen mask. Among 262 patients analysed, mean (SD) measured FiO2 was 65% (13). The 3%-formula (21% + oxygen flow rate in L/min × 3) was the most accurate method to estimate FiO2. Other methods overestimated FiO2 and hypoxaemia severity, so they should be avoided.

Pressure-Support Ventilation vs T-Piece During Spontaneous Breathing Trials Before Extubation Among Patients at High Risk of Extubation Failure: A Post-Hoc Analysis of a Clinical Trial

BACKGROUND

Spontaneous breathing trial (SBT) using a T-piece remains the most frequently performed trial before extubation in ICUs.

RESEARCH QUESTION

We aimed at determining whether initial SBT using pressure-support ventilation (PSV) could increase successful extubation rates among patients at high risk of extubation failure.

STUDY DESIGN AND METHODS

Post hoc analysis of a multicenter trial focusing on reintubation in patients at high-risk of extubation failure. The initial SBT was performed using PSV or T-piece according to the physician/center decision. The primary outcome was the proportion of patients successfully extubated 72 hours after initial SBT, that is, extubated after initial SBT and not reintubated within the following 72 hours.

RESULTS

Among the 641 patients included in the original study, initial SBT was performed using PSV (7.0 cm H₂O in median without positive end-expiratory pressure) in 243 patients (38%) and using a T-piece in 398 patients (62%). The proportion of patients successfully extubated 72 hours after initial SBT was 67% (162/243) using PSV and 56% (223/398) using T-piece (absolute difference 10.6%; 95% CI, 2.8 to 28.1; P = .0076). The proportion of patients extubated after initial SBT was 77% (186/283) using PSV and 63% (249/398) using T-piece (P = .0002), whereas reintubation rates within the following 72 hours did not significantly differ (13% vs 10%, respectively; P = .4259). Performing an initial SBT using PSV was independently associated with successful extubation (adjusted OR, 1.60; 95% CI, 1.30 to 2.18; P = .0061).

INTERPRETATION

In patients at high risk of extubation failure in the ICU, performing an initial SBT using PSV may hasten extubation without an increased risk of reintubation.

Role of ICU-acquired weakness on extubation outcome among patients at high risk of reintubation

Background

Whereas ICU-acquired weakness may delay extubation in mechanically ventilated patients, its influence on extubation failure is poorly known. This study aimed at assessing the role of ICU-acquired weakness on extubation failure and the relation between limb weakness and cough strength.

Methods

A secondary analysis of two previous prospective studies including patients at high risk of reintubation after a planned extubation, i.e., age greater than 65 years, with underlying cardiac or respiratory disease, or intubated for more than 7 days prior to extubation. Patients intubated less than 24 h and those with a do-not-reintubate order were not included. Limb and cough strength were assessed by a physiotherapist just before extubation. ICU-acquired weakness was clinically diagnosed as limb weakness defined as Medical Research Council (MRC) score < 48 points and severe weakness as MRC sum-score < 36. Cough strength was assessed using a semi-quantitative 5-Likert scale. Extubation failure was defined as reintubation or death within the first 7 days following extubation.

Results

Among 344 patients at high risk of reintubation, 16% experienced extubation failure (56/344). They had greater severity and lower MRC sum-score (41 ± 16 vs. 49 ± 13, p < 0.001) and were more likely to have ineffective cough than the others. The prevalence of ICU-acquired weakness at the time of extubation was 38% (130/244). The extubation failure rate was 12% (25/214) in patients with no limb weakness vs. 18% (12/65) and 29% (19/65) in those with moderate and severe limb weakness, respectively (p < 0.01). MRC sum-score and cough strength were weakly but significantly correlated (rho = 0.28, p < .001). After multivariate logistic regression analyses, the lower the MRC sum-score the greater the risk of reintubation; severe limb weakness was independently associated with extubation failure, even after adjustment on cough strength and severity at admission.

Conclusion

ICU-acquired weakness was diagnosed in 38% in this population of patients at high risk at the time of extubation and was independently associated with extubation failure in the ICU.

Pneumococcal purpura fulminans in asplenic or hyposplenic patients: a French multicenter exposed-unexposed retrospective cohort study

Background

Pneumococcal infections remain the main cause of overwhelming post-splenectomy infections, and purpura fulminans may develop in almost 20% of patients with overwhelming post-splenectomy infection. We aimed at describing the impact of asplenia/hyposplenia on the clinical features and the outcomes of adult patients admitted to the intensive care unit (ICU) for pneumococcal purpura fulminans.

Methods

A 17-year national multicenter retrospective cohort study included adult patients admitted to 55 French ICUs for an infectious purpura fulminans from 2000 to 2016. Patients with pneumococcal purpura fulminans were analyzed according to the absence or presence of asplenia/hyposplenia.

Results

Among the 306 patients admitted to the ICU for purpura fulminans, 67 (22%) had a pneumococcal purpura fulminans, of whom 34 (51%) had asplenia (n = 29/34, 85%) or hyposplenia (n = 5/34, 15%) and 33 (49%) had eusplenia. The prevalence of pneumococcal purpura fulminans was seven times higher in asplenic/hyposplenic patients compared to eusplenic patients with purpura fulminans (n = 34/39, 87% vs. n = 33/267, 12%; p < 0.001). The median time interval between the occurrence of asplenia/hyposplenia and ICU admission was 20 [9–32] years. Pneumococcal vaccine coverage was 35% in asplenic/hyposplenic patients. Purpura was more frequently reported before ICU admission in asplenic/hyposplenic patients (n = 25/34, 73% vs. n = 13/33, 39%; p = 0.01). The rate of bacteremia did not differ between asplenic/hyposplenic and eusplenic patients (n = 31/34, 91% vs n = 27/33, 82%; p = 0.261). SAPS II (60 ± 14 vs. 60 ± 18; p = 0.244) and SOFA (13 [1–5] vs. 14 [1–4, 6]; p = 0.48) scores did not differ between asplenic/hyposplenic and eusplenic patients. There were no significant differences between asplenic/hyposplenic and eusplenic patients regarding the rate of limb amputation (n = 9/34, 26% vs. 15/33, 45%; p = 0.11) and hospital mortality (n = 20/34, 59% vs. n = 15/33, 45%; p = 0.27).

Conclusions

Half of pneumococcal purpura fulminans episodes occurred in asplenic or hyposplenic patients. Pneumococcal vaccine coverage was reported in one third of asplenic/hyposplenic patients. Half of pneumococcal purpura fulminans episodes occurred more than 20 years after splenectomy. Outcomes of pneumococcal purpura fulminans did not show significant differences between patients with or without asplenia or hyposplenia, although the small number of patients included limited our power to detect potential differences between groups.

Benefit-to-risk balance of bronchoalveolar lavage in the critically ill. A prospective, multicenter cohort study

Purpose

To assess the benefit-to-risk balance of bronchoalveolar lavage (BAL) in intensive care unit (ICU) patients.

Methods

In 16 ICUs, we prospectively collected adverse events during or within 24 h after BAL and assessed the BAL input for decision making in consecutive adult patients. The occurrence of a clinical adverse event at least of grade 3, i.e., sufficiently severe to need therapeutic action(s), including modification(s) in respiratory support, defined poor BAL tolerance. The BAL input for decision making was declared satisfactory if it allowed to interrupt or initiate one or several treatments.

Results

We included 483 BAL in 483 patients [age 63 years (interquartile range (IQR) 53–72); female gender: 162 (33.5%); simplified acute physiology score II: 48 (IQR 37-61); immunosuppression 244 (50.5%)]. BAL was begun in non-intubated patients in 105 (21.7%) cases. Sixty-seven (13.9%) patients reached the grade 3 of adverse event or higher. Logistic regression showed that a BAL performed by a non-experienced physician (non-pulmonologist, or intensivist with less than 10 years in the specialty or less than 50 BAL performed) was the main predictor of poor BAL tolerance in non-intubated patients [OR: 3.57 (95% confidence interval 1.04–12.35); P = 0.04]. A satisfactory BAL input for decision making was observed in 227 (47.0%) cases and was not predictable using logistic regression.

Conclusions

Adverse events related to BAL in ICU patients are not infrequent nor necessarily benign. Our findings call for an extreme caution, when envisaging a BAL in ICU patients and for a mandatory accompaniment of the less experienced physicians.

Electronic supplementary material

The online version of this article (10.1007/s00134-019-05896-4) contains supplementary material, which is available to authorized users.

Influence of Noninvasive Ventilation Protocol on Intubation Rates in Subjects With De Novo Respiratory Failure

BACKGROUND

The use of noninvasive ventilation (NIV) is debated in de novo respiratory failure. Prolonged sessions, using a dedicated NIV ventilator, with high PEEP levels could be associated with better outcomes than shorter sessions using an ICU ventilator, with low PEEP levels. We performed a systematic review of randomized controlled trials to test whether the incidence of intubation was influenced by the NIV protocol in subjects admitted to the ICU for de novo respiratory failure.

METHODS

We selected randomized trials on NIV indexed in medical literature databases from their inception to April 2018. Pediatric studies, those performed outside of the ICU, trials with subjects on NIV for a reason other than de novo respiratory failure, and studies in which NIV protocol was not specified were excluded. Two authors independently extracted intubation rates and the NIV protocol (prolonged or short sessions, type of ventilator, and PEEP levels).

RESULTS

Fourteen studies, which included 750 subjects treated with NIV for de novo respiratory failure in ICU, were analyzed. Overall intubation rate was 38%, 95% CI 31-45% and was not influenced by prolonged NIV sessions or the type of ventilator. The 154 subjects treated with PEEP greater than the median overall PEEP (6 cm H₂O) had a PEEP level of 8 ± 2 cm H₂O and a pressure support level of 7 ± 2 cm H₂O. Their intubation rate was lower than the 293 subjects treated with lower PEEP levels (25%, 95% CI 15-37% vs 43%, 95% CI 33-54%, respectively, P = .03). Inclusion criteria were heterogeneous, and critical information on NIV application were frequently lacking.

CONCLUSIONS

Except for high PEEP levels that might be associated with lower intubation rates, the protocol for carrying out NIV does not seem to influence intubation rate in patients with de novo respiratory failure.

Effect of Postextubation High-Flow Nasal Oxygen With Noninvasive Ventilation vs High-Flow Nasal Oxygen Alone on Reintubation Among Patients at High Risk of Extubation Failure: A Randomized Clinical Trial

IMPORTANCE

High-flow nasal oxygen may prevent postextubation respiratory failure in the intensive care unit (ICU). The combination of high-flow nasal oxygen with noninvasive ventilation (NIV) may be an optimal strategy of ventilation to avoid reintubation.

OBJECTIVE

To determine whether high-flow nasal oxygen with prophylactic NIV applied immediately after extubation could reduce the rate of reintubation, compared with high-flow nasal oxygen alone, in patients at high risk of extubation failure in the ICU.

DESIGN, SETTING, AND PARTICIPANTS

Multicenter randomized clinical trial conducted from April 2017 to January 2018 among 641 patients at high risk of extubation failure (ie, older than 65 years or with an underlying cardiac or respiratory disease) at 30 ICUs in France; follow-up was until April 2018.

INTERVENTIONS

Patients were randomly assigned to high-flow nasal oxygen alone (n = 306) or high-flow nasal oxygen alternating with NIV (n = 342) immediately after extubation.

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of patients reintubated at day 7; secondary outcomes included postextubation respiratory failure at day 7, reintubation rates up until ICU discharge, and ICU mortality.

RESULTS

Among 648 patients who were randomized (mean [SD] age, 70 [10] years; 219 women [34%]), 641 patients completed the trial. The reintubation rate at day 7 was 11.8% (95% CI, 8.4%-15.2%) (40/339) with high-flow nasal oxygen and NIV and 18.2% (95% CI, 13.9%-22.6%) (55/302) with high-flow nasal oxygen alone (difference, -6.4% [95% CI, -12.0% to -0.9%]; P = .02). Among the 11 prespecified secondary outcomes, 6 showed no significant difference. The proportion of patients with postextubation respiratory failure at day 7 (21% vs 29%; difference, -8.7% [95% CI, -15.2% to -1.8%]; P = .01) and reintubation rates up until ICU discharge (12% vs 20%, difference -7.4% [95% CI, -13.2% to -1.8%]; P = .009) were significantly lower with high-flow nasal oxygen and NIV than with high-flow nasal oxygen alone. ICU mortality rates were not significantly different: 6% with high-flow nasal oxygen and NIV and 9% with high-flow nasal oxygen alone (difference, -2.4% [95% CI, -6.7% to 1.7%]; P = .25).

CONCLUSIONS AND RELEVANCE

In mechanically ventilated patients at high risk of extubation failure, the use of high-flow nasal oxygen with NIV immediately after extubation significantly decreased the risk of reintubation compared with high-flow nasal oxygen alone.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03121482.

Is immunosuppression status a risk factor for noninvasive ventilation failure in patients with acute hypoxemic respiratory failure? A post hoc matched analysis

Background

Recent European/American guidelines recommend noninvasive ventilation (NIV) as a first-line therapy to manage acute hypoxemic respiratory failure in immunocompromised patients. By contrast, NIV may have deleterious effects in nonimmunocompromised patients and experts have been unable to offer a recommendation. Immunocompromised patients have particularly high mortality rates when they require intubation. However, it is not clear whether immunosuppression status is a risk factor for NIV failure. We assessed the impact of immunosuppression status on NIV failure in a post hoc analysis pooling two studies including patients with de novo acute hypoxemic respiratory failure treated with NIV. Patients with hypercapnia, acute exacerbation of chronic lung disease, cardiogenic pulmonary edema, or with do-not-intubate order were excluded.

Results

Among the 208 patients included in the analysis, 71 (34%) were immunocompromised. They had higher severity scores upon ICU admission, higher pressure-support levels, and minute ventilation under NIV, and were more likely to have bilateral lung infiltrates than nonimmunocompromised patients. Intubation and in-ICU mortality rates were higher in immunocompromised than in nonimmunocompromised patients: 61% vs. 43% (p = 0.02) and 38% vs. 15% (p < 0.001), respectively. After adjustment or using a propensity score-matched analysis, immunosuppression was not associated with intubation, whereas it remained independently associated with ICU mortality with an adjusted odds ratio of 2.64 (95% CI 1.24–5.67, p = 0.01).

Conclusions

Immunosuppression status may directly influence mortality but does not seem to be associated with an increased risk of intubation in patients with de novo acute hypoxemic respiratory failure treated with NIV. Studies in this specific population are needed.

Electronic supplementary material

The online version of this article (10.1186/s13613-019-0566-z) contains supplementary material, which is available to authorized users.

High-flow nasal oxygen therapy alone or with non-invasive ventilation in immunocompromised patients admitted to ICU for acute hypoxemic respiratory failure: the randomised multicentre controlled FLORALI-IM protocol

INTRODUCTION

Non-invasive ventilation (NIV) is recommended as first-line therapy in respiratory failure of critically ill immunocompromised patients as it can decrease intubation and mortality rates as compared with standard oxygen. However, its recommendation is only conditional. Indeed, the use of NIV in this setting has been challenged recently based on results of trials finding similar outcomes with or without NIV or even deleterious effects of NIV. To date, NIV has been compared with standard oxygen but not to high-flow nasal oxygen therapy (HFOT) in immunocompromised patients. Several studies have found lower mortality rates using HFOT alone than when using HFOT with NIV sessions in patients with de novo respiratory failure, and even in immunocompromised patients. We are hypothesising that HFOT alone is more effective than HFOT with NIV sessions and reduces mortality of immunocompromised patients with acute hypoxemic respiratory failure.

METHODS AND ANALYSIS

This study is an investigator-initiated, multicentre randomised controlled trial comparing HFOT alone or with NIV in immunocompromised patients admitted to intensive care unit (ICU) for severe acute hypoxemic respiratory failure. Around 280 patients will be randomised with a 1:1 ratio in two groups. The primary outcome is the mortality rate at day 28 after inclusion. Secondary outcomes include the rate of intubation in each group, length of ICU and hospital stay and mortality up to day 180.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT02978300.

Non-invasive ventilation or high-flow oxygen therapy: When to choose one over the other?

It has been found that high-flow oxygen therapy (HFOT) can reduce mortality of patients admitted to intensive care unit (ICU) for de novo acute respiratory failure (ARF) as compared to non-invasive ventilation (NIV). HFOT might therefore be considered as a first-line strategy of oxygenation in these patients. The beneficial effects of HFOT may be explained by its good tolerance and by physiological characteristics including delivery of high FiO₂ , positive end expiratory pressure (PEEP) effect and continuous dead space washout contributing to decreased work of breathing. In contrast, NIV should be used cautiously in patients with de novo ARF due to high tidal volumes promoted by pressure support and that may potentially worsen pre-existing lung injury. Although recent studies have reported no benefit and even deleterious effects of NIV in immunocompromised patients with ARF, the experts have recommended its use as a first-line strategy. In patients with acute-on-chronic respiratory failure and respiratory acidosis, it has been clearly shown that NIV is the best strategy of oxygenation. However, HFOT seems able to reverse respiratory acidosis and further studies are needed to evaluate whether HFOT could represent an alternative to standard oxygen. Although NIV is recommended to treat ARF in post-operative patients or to prevent post-extubation respiratory failure in ICU, recent large-scale randomized studies suggest that HFOT could be equivalent to NIV. While recent recommendations have been established from studies comparing NIV with standard oxygen, new studies are needed to compare NIV versus HFOT in order to better define the appropriate indications for both treatments.

Clinical features and outcome of patients with acute respiratory failure revealing anti-synthetase or anti-MDA-5 dermato-pulmonary syndrome: a French multicenter retrospective study

Background

Anti-synthetase (AS) and dermato-pulmonary associated with anti-MDA-5 antibodies (aMDA-5) syndromes are near one of the other autoimmune inflammatory myopathies potentially responsible for severe acute interstitial lung disease. We undertook a 13-year retrospective multicenter study in 35 French ICUs in order to describe the clinical presentation and the outcome of patients admitted to the ICU for acute respiratory failure (ARF) revealing AS or aMDA-5 syndromes.

Results

From 2005 to 2017, 47 patients (23 males; median age 60 [1st–3rd quartiles 52–69] years, no comorbidity 85%) were admitted to the ICU for ARF revealing AS (n = 28, 60%) or aMDA-5 (n = 19, 40%) syndromes. Muscular, articular and cutaneous manifestations occurred in 11 patients (23%), 14 (30%) and 20 (43%) patients, respectively. Seventeen of them (36%) had no extra-pulmonary manifestations. C-reactive protein was increased (139 [40–208] mg/L), whereas procalcitonine was not (0.30 [0.12–0.56] ng/mL). Proportion of patients with creatine kinase ≥ 2N was 20% (n = 9/47). Forty-two patients (89%) had ARDS, which was severe in 86%, with a rate of 17% (n = 8/47) of extra-corporeal membrane oxygenation requirement. Proportion of patients who received corticosteroids, cyclophosphamide, rituximab, intravenous immunoglobulins and plasma exchange were 100%, 72%, 15%, 21% and 17%, respectively. ICU and hospital mortality rates were 45% (n = 21/47) and 51% (n = 24/47), respectively. Patients with aMDA-5 dermato-pulmonary syndrome had a higher hospital mortality than those with AS syndrome (n = 16/19, 84% vs. n = 8/28, 29%; p = 0.001).

Conclusions

Intensivists should consider inflammatory myopathies as a cause of ARF of unknown origin. Extra-pulmonary manifestations are commonly lacking. Mortality is high, especially in aMDA-5 dermato-pulmonary syndrome.

High-flow nasal cannula oxygen therapy alone or with non-invasive ventilation during the weaning period after extubation in ICU: the prospective randomised controlled HIGH-WEAN protocol

INTRODUCTION

Recent practice guidelines suggest applying non-invasive ventilation (NIV) to prevent postextubation respiratory failure in patients at high risk of extubation failure in intensive care unit (ICU). However, such prophylactic NIV has been only a conditional recommendation given the low certainty of evidence. Likewise, high-flow nasal cannula (HFNC) oxygen therapy has been shown to reduce reintubation rates as compared with standard oxygen and to be as efficient as NIV in patients at high risk. Whereas HFNC may be considered as an optimal therapy during the postextubation period, HFNC associated with NIV could be an additional means of preventing postextubation respiratory failure. We are hypothesising that treatment associating NIV with HFNC between NIV sessions may be more effective than HFNC alone and may reduce the reintubation rate in patients at high risk.

METHODS AND ANALYSIS

This study is an investigator-initiated, multicentre randomised controlled trial comparing HFNC alone or with NIV sessions during the postextubation period in patients at high risk of extubation failure in the ICU. Six hundred patients will be randomised with a 1:1 ratio in two groups according to the strategy of oxygenation after extubation. The primary outcome is the reintubation rate within the 7 days following planned extubation. Secondary outcomes include the number of patients who meet the criteria for moderate/severe respiratory failure, ICU length of stay and mortality up to day 90.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee and patients will be included after informed consent. The results will be submitted for publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03121482.

Clinical spectrum and short-term outcome of adult patients with purpura fulminans: a French multicenter retrospective cohort study

PURPOSE

Data on purpura fulminans (PF) in adult patients are scarce and mainly limited to meningococcal infections. Our aim has been to report the clinical features and outcomes of adult patients admitted in the intensive care unit (ICU) for an infectious PF, as well as the predictive factors for limb amputation and mortality.

METHODS

A 17-year national multicenter retrospective cohort study in 55 ICUs in France from 2000 to 2016, including adult patients admitted for an infectious PF defined by a sudden and extensive purpura, together with the need for vasopressor support. Primary outcome variables included hospital mortality and amputation during the follow-up period (time between ICU admission and amputation, death or end of follow-up).

RESULTS

Among the 306 included patients, 126 (41.2%; 95% CI 35.6-46.9) died and 180 (58.8%; 95% CI 53.3-64.3) survived during the follow-up period [13 (3-24) days], including 51/180 patients (28.3%, 95% CI 21.9-35.5) who eventually required limb amputations, with a median number of 3 (1-4) limbs amputated. The two predominantly identified microorganisms were Neisseria meningitidis (63.7%) and Streptococcus pneumoniae (21.9%). By multivariable Cox model, SAPS II [hazard-ratio (HR) = 1.03 (1.02-1.04); p < 0.001], lower leucocytes [HR 0.83 (0.69-0.99); p = 0.034] and platelet counts [HR 0.77 (0.60-0.91); p = 0.007], and arterial blood lactate levels [HR 2.71 (1.68-4.38); p < 0.001] were independently associated with hospital death, while a neck stiffness [HR 0.51 (0.28-0.92); p = 0.026] was a protective factor. Infection with Streptococcus pneumoniae [sub-hazard ratio 1.89 (1.06-3.38); p = 0.032], together with arterial lactate levels and ICU admission temperature, was independently associated with amputation by a competing risks analysis.

CONCLUSION

Purpura fulminans carries a high mortality and morbidity. Pneumococcal PF leads to a higher risk of amputation.

TRIALS REGISTRATION

NCT03216577.

Multicentric Standardized Flow Cytometry Routine Assessment of Patients With Sepsis to Predict Clinical Worsening

BACKGROUND

In this study, we primarily sought to assess the ability of flow cytometry to predict early clinical deterioration and overall survival in patients with sepsis admitted in the ED and ICU.

METHODS

Patients admitted for community-acquired acute sepsis from 11 hospital centers were eligible. Early (day 7) and late (day 28) deaths were notified. Levels of CD64^pos granulocytes, CD16^pos monocytes, CD16^dim immature granulocytes (IGs), and T and B lymphocytes were assessed by flow cytometry using an identical, cross-validated, robust, and simple consensus standardized protocol in each center.

RESULTS

Among 1,062 patients screened, 781 patients with confirmed sepsis were studied (age, 67 ± 48 years; Simplified Acute Physiology Score II, 36 ± 17; Sequential Organ Failure Assessment, 5 ± 4). Patients were divided into three groups (sepsis, severe sepsis, and septic shock) on day 0 and on day 2. On day 0, patients with sepsis exhibited increased levels of CD64^pos granulocytes, CD16^pos monocytes, and IGs with T-cell lymphopenia. Clinical severity was associated with higher percentages of IGs and deeper T-cell lymphopenia. IG percentages tended to be higher in patients whose clinical status worsened on day 2 (35.1 ± 35.6 vs 43.5 ± 35.2, P = .07). Increased IG percentages were also related to occurrence of new organ failures on day 2. Increased IG percentages, especially when associated with T-cell lymphopenia, were independently associated with early (P < .01) and late (P < .01) death.

CONCLUSIONS

Increased circulating IGs at the acute phase of sepsis are linked to clinical worsening, especially when associated with T-cell lymphopenia. Early flow cytometry could help clinicians to target patients at high risk of clinical deterioration.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT01995448; URL: www.clinicaltrials.gov.