ROX index performance to predict high-flow nasal oxygen outcome in Covid-19 related hypoxemic acute respiratory failure.

BACKGROUND: Given the pathophysiology of hypoxemia in patients with Covid-19 acute respiratory failure (ARF), it seemed necessary to evaluate whether ROX index (ratio SpO2/FiO2 to respiratory rate) could accurately predict intubation or death in these patients initially treated by high-flow nasal oxygenation (HFNO). We aimed, therefore, to assess the accuracy of ROX index to discriminate between HFNO failure (sensitivity) and HFNO success (specificity). METHODS: We designed a multicentre retrospective cohort study including consecutive patients with Covid-19 ARF. In addition to its accuracy, we assessed the usefulness of ROX index to predict HFNO failure (intubation or death) via logistic regression. RESULTS: Among 218 ARF patients screened, 99 were first treated with HFNO, including 49 HFNO failures (46 intubations, 3 deaths before intubation). At HFNO initiation (H0), ROX index sensitivity was 63% (95%CI 48-77%) and specificity 76% (95%CI 62-87%) using Youden's index. With 4.88 as ROX index cut-off at H12, sensitivity was 29% (95%CI 14-48%) and specificity 90% (95%CI 78-97%). Youden's index yielded 8.73 as ROX index cut-off at H12, with 87% sensitivity (95%CI 70-96%) and 45% specificity (95%CI 31-60%). ROX index at H0 was associated with HFNO failure (p = 0.0005) in univariate analysis. Multivariate analysis showed that SAPS II (p = 0.0003) and radiographic extension of pulmonary injuries (p = 0.0263), rather than ROX index, were predictive of HFNO failure. CONCLUSIONS: ROX index cut-off values seem population-specific and the ROX index appears to have a technically acceptable but clinically low capability to discriminate between HFNO failures and successes in Covid-19 ARF patients. In addition, SAPS II and pulmonary injuries at ICU admission appear more useful than ROX index to predict the risk of intubation.

Case report: CAR-T cell therapy-induced cardiac tamponade.

CD19-specific chimeric antigen receptor T (CAR-T) cell therapy has recently been shown to improve the prognosis of refractory diffuse large B-cell lymphoma (DLBCL). However, CAR-T cells may induce numerous adverse events, in particular cytokine release syndrome (CRS) which is frequently associated with cardiovascular manifestations. Among the latter, acute pericardial effusion represents less than 1% of cases and cardiac tamponade has only been reported once. The management and outcome of these severe complications are not well established. We report here, a case of cardiac tamponade associated with CRS in a context of CAR-T cell therapy, which required urgent pericardiocentesis. Case summary: A 65-year-old man with refractory DLBCL was treated with CAR-T cell therapy. He had a history of dilated cardiomyopathy with preserved ejection fraction and transient atrial fibrillation. A pericardial localization of the lymphoma was observed on the second relapse. One day after CAR-T cell infusion the patient was diagnosed with grade 1 CRS. Due to hypotension, he was treated with tocilizumab and dexamethasone, and then transferred to intensive care unit (ICU). Echocardiography performed at ICU admission showed acute pericardial effusion with signs of right ventricular heart failure due to cardiac tamponade. It was decided to perform pericardiocentesis despite grade IV thrombocytopenia in a context of aplasia. Analysis of pericardial fluid showed a large number of lymphoma cells and 73% of CAR-T cells amongst lymphocytes, a level that was similar in blood. Hemodynamic status improved after pericardiocentesis, and no recurrence of pericardial effusion was observed. The presence of a high count of activated CAR-T cells in the pericardial fluid as well as the short interval between CAR-T cells injection and the symptoms appear as potential arguments for a direct action of CAR-T cells in the mechanism of this adverse event. The patient was discharged from ICU after two days and initially exhibited a good response to DLBCL treatment. Unfortunately, he died fifty days after starting CAR-T cell therapy due to a new DLBCL relapse. Conclusion: Patients with a pericardial localization of DLBCL should be assessed for a risk of cardiac tamponade if receiving CAR-T cell therapy and presenting CRS. In this case, cardiac tamponade seems directly related to CAR-T cell expansion. Pericardiocentesis should be considered as a feasible and effective treatment if the risk of bleeding is well controlled, in association with anti-IL6 and corticosteroids.

The accuracy of intensive care nurses' interpretation of chest radiographs to recognise misplacement of endotracheal and nasogastric tubes after a single training session and comparison with residents' interpretation.

BACKGROUND: Misplacements of endotracheal and nasogastric tubes are frequent encounters in critically ill patients. OBJECTIVES: The purpose of this study was to assess the effectiveness of a single standardised training session on the ability of intensive care registered nurses (RNs) to recognise the misplacement of endotracheal and nasogastric tubes on bedside chest radiographs of patients in intensive care units (ICUs). METHODS: In eight French ICUs, RNs received a 110-min standardised teaching on the position of endotracheal and nasogastric tubes on chest radiographs. Their knowledge was evaluated within the subsequent weeks. For 20 chest radiographs, each with an endotracheal and nasogastric tube, RNs had to indicate whether each tube was in the proper or incorrect position. Training success was defined as >90% for the lower bound of the 95% confidence interval (95% CI) of the mean correct response rate (CRR). Residents of the participating ICUs underwent the same evaluation (without prior specific training). RESULTS: In total, 181 RNs were trained and evaluated and 110 residents were evaluated. The global mean CRR for RNs was 84.6% (95% CI: 83.3-85.9), significantly higher than for residents (81.4% [95% CI: 79.7-83.2]) (P < 0.0001). The mean CRR for RNs and residents was 95.9% (93.9-98.0) and 97.0% (94.7-99.3) for misplaced nasogastric tubes (P = 0.54), 86.8% (85.2-88.5) and 82.6% (79.4-85.7) (P = 0.07) for nasogastric tubes in the correct position, 86.6% (83.8-89.3) and 62.7% (57.9-67.5) for misplaced endotracheal tubes (P < 0.0001), and 79.1% (76.6-81.6) and 84.7% (82.1-87.2) for endotracheal tubes in the correct position (P = 0.01), respectively. CONCLUSIONS: The ability of trained RNs to detect tube misplacement did not reach the predetermined arbitrary level, indicating training success. Their mean CRR was higher than that for residents and was considered satisfactory for detecting misplaced nasogastric tubes. This finding is encouraging but insufficient to ensure patient safety. Transferring responsibility for reading radiographs to detect the misplacement of endotracheal tubes to intensive care RNs will need a more advanced or more in-depth teaching method.

High-flow nasal cannula oxygen therapy: P-SILI or not P-SILI?

The risk of P-SILI with HFNC is controversial and may be less than with NIV. Some physiological mechanisms of the protective effect of HFNC are hypoxaemia correction, reduction of inspiratory efforts and homogeneity of lung volume distribution. https://bit.ly/3skOEKX.

High-flow nasal oxygen alone or alternating with non-invasive ventilation in critically ill immunocompromised patients with acute respiratory failure: a randomised controlled trial.

BACKGROUND: Although non-invasive ventilation (NIV) is recommended for immunocompromised patients with acute respiratory failure in the intensive care unit (ICU), it might have deleterious effects in the most severe patients. High-flow nasal oxygen (HFNO) alone might be an alternative method to reduce mortality. We aimed to determine whether HFNO alone could reduce the rate of mortality at day 28 compared with HFNO alternated with NIV. METHODS: FLORALI-IM is a multicentre, open-label, randomised clinical trial conducted in 29 ICUs (28 in France and one in Italy). Adult immunocompromised patients with acute respiratory failure, defined as respiratory rate of 25 breaths per min or more and a partial pressure of arterial oxygen to inspired fraction of oxygen ratio of 300 mm Hg or lower, were randomly assigned (1:1) to HFNO alone (HFNO alone group) or NIV alternating with HFNO (NIV group). Key exclusion criteria were severe hypercapnia above 50 mm Hg, patients who could strongly benefit from NIV (ie, those with underlying chronic lung disease, with cardiogenic pulmonary oedema, or who were postoperative), severe shock, impaired consciousness defined as Glasgow coma score ≤12, urgent need for intubation, do not intubate order, and contraindication to NIV. Patients were assigned using computer-generated permuted blocks and were stratified according to centre and to the type of immunosuppression using a centralised web-based management system. In the HFNO alone group, patients were continuously treated by HFNO with a gas flow rate of 60 L/min or the highest tolerated. In the NIV group, patients were treated with NIV with a first session of at least 4 h, and then by sessions for a minimal duration of 12 h a day, with a dedicated ventilator, targeting a tidal volume below 8 mL/kg of predicted bodyweight, and with a positive end-expiratory level of at least 8 cm H2O. NIV sessions were interspaced with HFNO delivered as in the HFNO alone group. The primary outcome was mortality at day 28 and was assessed in the intention-to-treat population. Secondary outcomes were mortality in the ICU, in hospital, at day 90 and at day 180, intubation at day 28, length of stay in the ICU and in hospital, number of ventilator-free days at day 28, number of oxygenation technique-free days at day 28, and efficacy and tolerance of oxygenation techniques. The trial is registered with ClinicalTrials.gov, NCT02978300, and is complete. FINDINGS: Between Jan 21, 2017 to March 4, 2019, of 497 eligible patients, 300 were randomly assigned but one patient withdrew consent, leaving 299 patients included in the intention-to-treat analysis (154 assigned to the HFNO alone group and 145 assigned to NIV group). Mortality rate at day 28 was 36% (95% CI 29·2 to 44·2; 56 of 154 patients) in the HFNO alone group and 35% (27·9 to 43·2; 51 of 145 patients) in the NIV group (absolute difference 1·2% [95% CI -9·6 to 11·9]; p=0·83). None of the other prespecified secondary outcomes were different between groups except for greater decreased discomfort after initiation of HFNO than with NIV (-4 mm on visual analogic scale [IQR -18 to 4] vs 0 mm [-16 to 17]; p=0·040). INTERPRETATION: In critically ill immunocompromised patients with acute respiratory failure, the mortality rate did not differ between HFNO alone and NIV alternating with HFNO. However, study power was limited, so results should be interpreted with caution. FUNDING: French Ministry of Health.

Beneficial Effects of Noninvasive Ventilation after Extubation in Obese or Overweight Patients: A Post Hoc Analysis of a Randomized Clinical Trial.

Rationale: Although noninvasive ventilation (NIV) may prevent reintubation in patients at high risk of extubation failure in 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. Methods:Post hoc analysis of a multicenter randomized controlled trial (not prespecified) comparing NIV alternating with high-flow nasal oxygen versus high-flow nasal oxygen 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 kg/m2 ⩽ BMI < 30 kg/m2), and 213 (34%) were normal or underweight (BMI < 25 kg/m2). 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 high-flow nasal oxygen than with high-flow nasal oxygen alone in obese or overweight patients: 7% (15/204) versus 20% (41/206) (difference, -13% [95% confidence interval, -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 high-flow nasal oxygen alone in obese or overweight patients (2% vs. 9%; difference, -6% [95% confidence interval, -11 to -2]; P = 0.006). Conclusions: Prophylactic NIV alternating with high-flow nasal oxygen immediately after extubation significantly decreased the risk of reintubation and death compared with high-flow nasal oxygen alone in obese or overweight patients at high risk of extubation failure. By contrast, NIV was not effective in normal or underweight patients. Clinical trial registered with www.clinicaltrials.gov (NCT03121482).

High-flow oxygen therapy versus noninvasive ventilation: a randomised physiological crossover study of alveolar recruitment in acute respiratory failure.

High-flow nasal cannula (HFNC) oxygen therapy has recently shown clinical benefits in hypoxaemic acute respiratory failure (ARF) patients, while the value of noninvasive ventilation (NIV) remains debated. The primary end-point was to compare alveolar recruitment using global end-expiratory electrical lung impedance (EELI) between HFNC and NIV. Secondary end-points compared regional EELI, lung volumes (global and regional tidal volume variation (V T)), respiratory parameters, haemodynamic tolerance, dyspnoea and patient comfort between HFNC and NIV, relative to face mask (FM). A prospective randomised crossover physiological study was conducted in patients with hypoxaemic ARF due to pneumonia. They received alternately HFNC, NIV and FM. 16 patients were included. Global EELI was 4083 with NIV and 2921 with HFNC (p=0.4). Compared to FM, NIV and HFNC significantly increased global EELI by 1810.5 (95% CI 857-2646) and 826 (95% CI 399.5-2361), respectively. Global and regional V T increased significantly with NIV compared to HFNC or FM, but not between HFNC and FM. NIV yielded a significantly higher pulse oxygen saturation/inspired oxygen fraction ratio compared to HFNC (p=0.03). No significant difference was observed between HFNC, NIV and FM for dyspnoea. Patient comfort score with FM was not significantly different than with HFNC (p=0.1), but was lower with NIV (p=0.001). This study suggests a potential benefit of HFNC and NIV on alveolar recruitment in patients with hypoxaemic ARF. In contrast with HFNC, NIV increased lung volumes, which may contribute to overdistension and its potentially deleterious effect in these patients.

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 ).

Role of Non-Invasive Respiratory Supports in COVID-19 Acute Respiratory Failure Patients with Do Not Intubate Orders.

The current gold-standard treatment for COVID-19-related hypoxemic respiratory failure is invasive mechanical ventilation. However, do not intubate orders (DNI), prevent the use of this treatment in some cases. The aim of this study was to evaluate if non-invasive ventilatory supports can provide a good therapeutic alternative to invasive ventilation in patients with severe COVID-19 infection and a DNI. Data were collected from four centres in three European countries. Patients with severe COVID-19 infection were included. We emulated a hypothetical target trial in which outcomes were compared in patients with a DNI order treated exclusively by non-invasive respiratory support with patients who could be intubated if necessary. We set up a propensity score and an inverse probability of treatment weighting to remove confounding by indication. Four-hundred patients were included: 270 were eligible for intubation and 130 had a DNI order. The adjusted risk ratio for death among patients eligible for intubation was 0.81 (95% CI 0.46 to 1.42). The median length of stay in acute care for survivors was similar between groups (18 (10-31) vs. (19 (13-23.5); p = 0.76). The use of non-invasive respiratory support is a good compromise for patients with severe COVID-19 and a do not intubate order.

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.

Non-invasive ventilation alternating with high-flow nasal oxygen versus high-flow nasal oxygen alone after extubation in COPD patients: a post hoc analysis of a randomized controlled trial.

BACKGROUND: Several randomized clinical trials have shown that non-invasive ventilation (NIV) applied immediately after extubation may prevent reintubation in patients at high-risk of extubation failure. However, most of studies included patients with chronic respiratory disorders as well as patients without underlying respiratory disease. To date, no study has shown decreased risk of reintubation with prophylactic NIV after extubation among patients with chronic obstructive pulmonary disease (COPD). We hypothesized that prophylactic NIV after extubation may decrease the risk of reintubation in COPD patients as compared with high-flow nasal oxygen. We performed a post hoc subgroup analysis of COPD patients included in a multicenter, randomized, controlled trial comparing prophylactic use of NIV alternating with high-flow nasal oxygen versus high-flow nasal oxygen alone immediately after extubation. RESULTS: Among the 651 patients included in the original study, 150 (23%) had underlying COPD including 86 patients treated with NIV alternating with high-flow nasal oxygen and 64 patients treated with high-flow nasal oxygen alone. The reintubation rate was 13% (11 out of 86 patients) with NIV and 27% (17 out of 64 patients) with high-flow nasal oxygen alone [difference, - 14% (95% CI - 27% to - 1%); p = 0.03]. Whereas reintubation rates were significantly lower with NIV than with high-flow nasal oxygen alone at 72 h and until ICU discharge, mortality in ICU did not differ between groups: 6% (5/86) with NIV vs. 9% (6/64) with high-flow nasal oxygen alone [difference - 4% (95% CI - 14% to 5%); p = 0.40]. CONCLUSIONS: In COPD patients, prophylactic NIV alternating with high-flow nasal oxygen significantly decreased the risk of reintubation compared with high-flow nasal oxygen alone. Trial registration The study was registered at http://www.clinicaltrials.gov with the trial registration number NCT03121482 (20 April 2017).

Is COPD associated with increased risk for microaspiration in intubated critically ill patients?

BACKGROUND: Although COPD patients are at higher risk for aspiration when breathing spontaneously, no information is available on the risk for microaspiration in invasively ventilated COPD patients. The aim of our study was to determine the relationship between COPD and abundant microaspiration in intubated critically ill patients. METHODS: This was a retrospective analysis of prospectively collected data, provided by 3 randomized controlled trials on microaspiration in critically ill patients receiving invasive mechanical ventilation for more than 48 h. Abundant microaspiration was defined as the presence of pepsin and or alpha-amylase at significant levels in tracheal aspirates. In all study patients, pepsin and alpha-amylase were quantitatively measured in all tracheal aspirates collected during a 48-h period. COPD was defined using spirometry criteria. RESULTS: Among the 515 included patients, 70 (14%) had proven COPD. Pepsin and alpha-amylase were quantitatively measured in 3873 and 3764 tracheal aspirates, respectively. No significant difference was found in abundant microaspiration rate between COPD and non-COPD patients (62 of 70 patients (89%) vs 366 of 445 (82%) patients, p = 0.25). Similarly, no significant difference was found in abundant microaspiration of gastric contents (53% vs 45%, p = 0.28), oropharyngeal secretions (71% vs 71%, p = 0.99), or VAP (19% vs 22%, p = 0.65) rates between the two groups. No significant difference was found between COPD and non-COPD patients in duration of mechanical ventilation, ICU length of stay, or ICU mortality. CONCLUSIONS: Our results suggest that COPD is not associated with increased risk for abundant microaspiration in intubated critically ill patients.

Performance of the ROX index to predict intubation in immunocompromised patients receiving high-flow nasal cannula for acute respiratory failure.

BACKGROUND: Delayed intubation is associated with high mortality. There is a lack of objective criteria to decide the time of intubation. We assessed a recently described combined oxygenation index (ROX index) to predict intubation in immunocompromised patients. The study is a secondary analysis of randomized trials in immunocompromised patients, including all patients who received high-flow nasal cannula (HFNC). The first objective was to evaluate the accuracy of the ROX index to predict intubation for patients with acute respiratory failure. RESULTS: In the study, 302 patients received HFNC. Acute respiratory failure was mostly related to pneumonia (n = 150, 49.7%). Within 2 (1-3) days, 115 (38.1%) patients were intubated. The ICU mortality rate was 27.4% (n = 83). At 6 h, the ROX index was lower for patients who needed intubation compared with those who did not [4.79 (3.69-7.01) vs. 6.10 (4.48-8.68), p < 0.001]. The accuracy of the ROX index to predict intubation was poor [AUC = 0.623 (0.557-0.689)], with low performance using the threshold previously found (4.88). In multivariate analysis, a higher ROX index was still independently associated with a lower intubation rate (OR = 0.89 [0.82-0.96], p = 0.04). CONCLUSION: A ROX index greater than 4.88 appears to have a poor ability to predict intubation in immunocompromised patients with acute respiratory failure, although it remains highly associated with the risk of intubation and may be useful to stratify such risk in future studies.

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.

[Theophylline adenosine dipyridamole (CTAD) and citrate evaluation to survey unfractionated heparin treatment: a delayed centrifugation validation for anti-Xa measurement?]. / Évaluation du citrate théophylline adénosine dipyridamole (CTAD) et du citrate comme anticoagulant dans la surveillance du traitement par héparine non fractionnée : validation d'une centrifugation différée pour le dosage de l'anti-Xa.

Unfractionated heparin (UFH) is the main anticoagulante used in intensive care unit. The anticoagulant effect is monitored by activated partial thrombin time (aPTT) and anti-Xa activity (anti-Xa) measurement. However, delayed centrifugation induces platelet factor 4 (PF4) release and anti-Xa decrease. Several studies have concluded that aPTT and anti-Xa measurement should be performed within 2 hours in citrated anticoagulant but may be delayed longer in citrate theophylline adenosine and dypiridamol (CTAD) anticoagulant. The objective of this study was to compare the stability of both aPTT and anti-Xa in citrate and CTAD samples, and to determine the effect of delayed centrifugation on both aPTT, anti-Xa results, and PF4 release in citrate samples only. METHODS: aPTT and anti-Xa were measured in citrate and CTAD anticoagulant samples from 93 patients. Delayed centrifugation was performed in citrate samples from 31 additional patients, with hourly aPTT and anti-Xa measurement from 1 to 6 hours. In 14 of these last patients, PF4 release was also evaluated with Human CXCL4/PF4 Quantikine ELISA Kit. RESULTS: We observed a significant correlation between citrate and CTAD anticoagulant for aPTT (r2=0.94) and anti-Xa (r2=0.95). With Bland-Altman correlation, a minor bias was observed for anti-Xa (-0.025±0.041). Delayed centrifugation in citrated anticoagulant showed an excellent concordance from 1 to 4 hours for aPTT (-4.0±5.3 s) and anti-Xa (1.10-9±0.058 UI/mL) measurements. Moreover, PF4 release was not different between 1 hour (31.5±14.7 ng/mL) and 4 hours (33.8±11.8 ng/mL). CONCLUSION: We have demonstrated that anti-Xa measurement for unfractionated heparin should be done 4 hours in citrated plasma and that CTAD was not better than citrate. However, these initial findings require confirmation using other aPTT and calibrated anti-Xa assays.

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.

High-flow nasal cannula therapy: clinical practice in intensive care units.

BACKGROUND: Despite the extensive use of high-flow nasal cannula (HFNC) therapy in intensive care units (ICU) for acute respiratory failure (ARF), its daily clinical practice has not been assessed. We designed a regional survey in ICUs in North-west France to evaluate ICU physicians' clinical practice with HFNC. MATERIALS AND METHODS: We sent an observational survey to ICU physicians from 34 French ICUs over a 6-month period in 2016-2017. The survey included questions regarding the indications and expected efficiency of HFNC, practical aspects of use (initiation, weaning) and satisfaction. Comparisons between junior and senior ICU physicians were performed using a Fischer exact test. RESULTS: Among the 235 ICU physicians contacted, 137 responded (58.3%) all of whom regularly used HFNC. Hypoxemic ARF was considered a good indication for HFNC by all 137, but only 30% expected HFNC success (i.e., avoiding intubation in at least 60% of cases). Among hypoxemic indications, 30% of juniors considered acute pulmonary edema a good indication versus 74% of seniors (p < 0.0001). Hypercapnic ARF was considered a good indication by 33% with only 2% expecting HFNC success. A need for conventional oxygen therapy ≥ 6 L/min justified HFNC therapy for 40% and ≥ 9 L/min for 39% of responders. 58% of ICU physicians started HFNC therapy with a FiO2 ≥ 50% and 28% with a gas flow ≥ 50 L/min. Practices for HFNC weaning were heterogeneous: 48% considered a FiO2 ≤ 30%; whereas, 30% considered a FiO2 ≤ 30% with a high flow ≤ 20 L/min. Criteria for HFNC failure (i.e., need for intubation) were ventilatory pauses or arrest (97%), persistent hypoxemia (95%), respiratory acidosis (81%), worsening of breathing (95%, 100% of seniors and 86% of juniors, p = 0.003), bronchial congestion (75%) and circulatory failure (61%, 72% of seniors and 44% of juniors, p = 0.007). CONCLUSION: HFNC is used by ICU physicians in many situations of ARF, despite their relatively low expectations of success, especially in cases of hypercapnia. Clinical practices appear somewhat heterogeneous. Despite the physiological benefit of HFNC, further prospective observational studies are still required on HFNC outcomes and daily practices.

Center effect in intubation risk in critically ill immunocompromised patients with acute hypoxemic respiratory failure.

BACKGROUND: Acute respiratory failure is the leading reason for intensive care unit (ICU) admission in immunocompromised patients, and the need for invasive mechanical ventilation has become a major clinical endpoint in randomized controlled trials (RCTs). However, data are lacking on whether intubation is an objective criteria that is used unbiasedly across centers. This study explores how this outcome varies across ICUs. METHODS: Hierarchical models and permutation procedures for testing multiple random effects were applied on both data from an observational cohort (the TRIAL-OH study: 703 patients, 17 ICUs) and a randomized controlled trial (the HIGH trial: 776 patients, 31 ICUs) to characterize ICU variation in intubation risk across centers. RESULTS: The crude intubation rate varied across ICUs from 29 to 80% in the observational cohort and from 0 to 86% in the RCT. This center effect on the mean ICU intubation rate was statistically significant, even after adjustment on individual patient characteristics (observational cohort: p value = 0.013, median OR 1.48 [1.30-1.72]; RCT: p value 0.004, median OR 1.51 [1.36-1.68]). Two ICU-level characteristics were associated with intubation risk (the annual rate of intubation procedure per center and the time from respiratory symptoms to ICU admission) and could partly explain this center effect. In the RCT that controlled for the use of high-flow oxygen therapy, we did not find significant variation in the effect of oxygenation strategy on intubation risk across centers, despite a significant variation in the need for invasive mechanical ventilation. CONCLUSION: Intubation rates varied considerably among ICUs, even after adjustment on individual characteristics.