Successful Spontaneous Breathing Trial Research Articles

Spontaneous breathing trials: how and for how long?

Guidelines recommend systematic performance of a spontaneous breathing trial (SBT) before extubation in ICUs, the objective being to reduce the risk of reintubation. In theory, a more challenging SBT performed with a T-piece may further reduce the risk of reintubation, whereas a less challenging SBT performed with pressure-support ventilation (PSV) may hasten extubation. Recent findings show that a more challenging SBT with a T-piece or for a prolonged duration do not help to reduce the risk of reintubation. In contrast, a less challenging SBT with PSV is easier to pass than a T-piece, and may hasten extubation without increased risk of reintubation. Although SBT with PSV and additional positive end-expiratory pressure is indeed a less challenging SBT, further studies are needed to generalize such an easy trial in daily practice. Earlier screening for a first SBT may also decrease time to extubation without increased risk of reintubation. Lastly, reconnection to the ventilator for a short period after successful SBT facilitates recovery from the SBT-induced alveolar derecruitment. Several recent clinical trials have improved assessment of the most adequate way to perform SBT before extubation.

Ability of parasternal intercostal muscle thickening fraction to predict reintubation in surgical patients with sepsis

ObjectivesWe aimed to evaluate the ability of the parasternal intercostal (PIC) thickening fraction during spontaneous breathing trial (SBT) to predict the need for reintubation within 48 h after extubation in surgical patients with sepsis.MethodsThis prospective observational study included adult patients with sepsis who were mechanically ventilated and indicated for SBT. Ultrasound measurements of the PIC thickening fraction and diaphragmatic excursion (DE) were recorded 15 min after the start of the SBT. After extubation, the patients were followed up for 48 h for the need for reintubation. The study outcomes were the ability of the PIC thickening fraction (primary outcome) and DE to predict reintubation within 48 h of extubation using area under receiver characteristic curve (AUC) analysis. The accuracy of the model including the findings of right PIC thickening fraction and right DE was also assessed using the current study cut-off values. Multivariate analysis was performed to identify independent risk factors for reintubation.ResultsWe analyzed data from 49 patients who underwent successful SBT, and 10/49 (20%) required reintubation. The AUCs (95% confidence interval [CI]) for the ability of right and left side PIC thickening fraction to predict reintubation were 0.97 (0.88–1.00) and 0.96 (0.86–1.00), respectively; at a cutoff value of 6.5–8.3%, the PIC thickening fraction had a negative predictive value of 100%. The AUCs for the PIC thickening fraction and DE were comparable; and both measures were independent risk factors for reintubation. The AUC (95% CI) of the model including the right PIC thickening fraction > 6.5% and right DE ≤ 18 mm to predict reintubation was 0.99 (0.92–1.00), with a positive predictive value of 100% when both sonographic findings are positive and negative predictive value of 100% when both sonographic findings are negative.ConclusionsAmong surgical patients with sepsis, PIC thickening fraction evaluated during the SBT is an independent risk factor for reintubation. The PIC thickening fraction has an excellent predictive value for reintubation. A PIC thickening fraction of ≤ 6.5–8.3% can exclude reintubation, with a negative predictive value of 100%. Furthermore, a combination of high PIC and low DE can also indicate a high risk of reintubation. However, larger studies that include different populations are required to replicate our findings and validate the cutoff values.

Prognostic value of the oxygenation index measured during mechanical ventilation and weaning. A retrospective cohort study.

The aim of this study was to investigate the predictive value of the ratio of oxygen saturation (ROX) index calculated during mechanical ventilation (MV) and the weaning period in evaluating readiness to weaning and the success of the spontaneous breathing trial (SBT), extubation, and mortality. We also compared the results of the ROX index calculated with partial arterial oxygen pressure (PaO2), arterial oxygen saturation (SaO2%), and probe oxygen saturation (SpO2%). In this retrospective cohort study, the ROX index was calculated by SpO2%, PaO2, and SaO2% separately using the ROX index formula (PaO2 or SaO2 or SpO2 /FiO2)/respiratory rate. ROX was calculated during the first three days of MV treatment and the weaning period daily (SBT). Positive end-expiratory pressure and peak inspiratory pressure values were also recorded during these measurements. These ROX values were used to analyze whether they predict weaning readiness, SBT, extubation failure (EF), and mortality. The study included 107 mechanically ventilated patients. Weaning could be tried in 64 (60%) of the 107 patients; 44 (69%) of the 64 patients succeeded, and extubation was performed. 19 (43%) of 44 patients had EF. ROX values calculated with PaO2 during MV and SBT predicted readiness to wean, EF, and mortality better than ROX values calculated with SaO2 and SpO2. ROX values calculated with PaO2 during the third day of MV had the highest sensitivity and specificity for EF (sensitivity: 81%, specificity: 70% for the ROX<11 value). The results of this study suggest that the calculation of ROX index, not only with SpO2% but also with arterial blood gas PaO2 and SaO2% values, may be helpful in predicting the weaning readiness evaluation, SBT, and extubation success and mortality. Further studies with more patients are necessary to verify and standardize these results.

Peripheral perfusion index as a predictor of reintubation in critically ill surgical patients

PurposeWe aimed to evaluate the ability of the peripheral perfusion index (PPI) to predict reintubation of critically ill surgical patients.MethodsThis prospective observational study included mechanically ventilated adults who were extubated after a successful spontaneous breathing trial (SBT). The patients were followed up for the next 48 h for the need for reintubation. The heart rate, systolic blood pressure, respiratory rate, peripheral arterial oxygen saturation (SpO2), and PPI were measured before-, at the end of SBT, 1 and 2 h postextubation. The primary outcome was the ability of PPI 1 h postextubation to predict reintubation using area under the receiver operating characteristic curve (AUC) analysis. Univariate and multivariate analyses were performed to identify predictors for reintubation.ResultsData from 62 patients were analysed. Reintubation occurred in 12/62 (19%) of the patients. Reintubated patients had higher heart rate and respiratory rate; and lower SpO2 and PPI than successfully weaned patients. The AUC (95%confidence interval) for the ability of PPI at 1 h postextubation to predict reintubation was 0.82 (0.71–0.91) with a negative predictive value of 97%, at a cutoff value of ≤ 2.5. Low PPI and high respiratory rate were the independent predictors for reintubation.ConclusionPPI early after extubation is a useful tool for prediction of reintubation. Low PPI is an independent risk factor for reintubation. A PPI > 2.5, one hour after extubation can confirm successful extubation.

The diaphragmatic electrical activity during spontaneous breathing trial in patients with mechanical ventilation: physiological description and potential clinical utility

BackgroundsIncreased respiratory drive has been demonstrated to correlate with weaning failure, which could be quantified by electrical activity of the diaphragm (EAdi). We described the physiological process of EAdi-based parameters during the spontaneous breathing trial (SBT) and evaluated the change of EAdi-based parameters as potential predictors of weaning failure.MethodsWe conducted a prospective study in 35 mechanically ventilated patients who underwent a 2-hour SBT. EAdi and ventilatory parameters were continuously measured during the SBT. Diaphragm ultrasound was performed before the SBT and at the 30 min of the SBT. Three EAdi-based parameters were calculated: neuro-ventilatory efficiency, neuro-excursion efficiency and neuro-discharge per min.ResultsOf the thirty 35 patients studied, 25 patients were defined as SBT success, including 22 patients weaning successfully and 3 patients reintubated. Before the SBT, neuro-excursion efficiency differed significantly between two groups and had the highest predictive value for SBT failure (AUROC 0.875, p < 0.01). Early increases in EAdi were observed in SBT, which are more prominent in SBT failure group. One minute, changes in EAdi and neuro-discharge per min also predicted weaning outcome (AUROCs 0.944 and 0.918, respectively).ConclusionsEAdi-based parameters, especially neuro-excursion efficiency and changes in neuro-discharge per min, may detect impending weaning failure earlier than conventional indices. EAdi monitoring provides physiological insights and a more tailored approach to facilitate successful weaning. Further research should validate these findings and explore the utility of combined EAdi and diaphragm ultrasound assessment in weaning ICU patients from mechanical ventilation.Trial RegistrationRegistered at ClinicalTrials.gov on 20 September 2022 (Identifier: NCT05632822).

The Value of Ischemic Cardiac Biomarkers to Predict Spontaneous Breathing Trial or Extubation Failure: A Systematic Review.

Background: It is unclear whether other cardiac biomarkers than NT-proBNP can be useful in the risk stratification of patients weaning from mechanical ventilation. The aim of this study is to summarize the role of ischemic cardiac biomarkers in predicting spontaneous breathing trial (SBT) or extubation failure. Methods: We systematically searched Embase, MEDLINE, Web of Science, and Cochrane Central for studies published before January 2024 that reported the association between ischemic cardiac biomarkers and SBT or extubation failure. Data were extracted using a standardized form and methodological assessment was performed using the QUIPS tool. Results: Seven observational studies investigating four ischemic cardiac biomarkers (Troponin-T, Troponin-I, CK-MB, Myoglobin) were included. One study reported a higher peak Troponin-I in patients with extubation failure compared to extubation success (50 ng/L [IQR, 20-215] versus 30 ng/L [IQR, 10-86], p = 0.01). A second study found that Troponin-I measured before the SBT was higher in patients with SBT failure in comparison to patients with SBT success (100 ± 80 ng/L versus 70 ± 130 ng/L, p = 0.03). A third study reported a higher CK-MB measured at the end of the SBT in patients with weaning failure (SBT or extubation failure) in comparison to weaning success (8.77 ± 20.5 ng/mL versus 1.52 ± 1.42 ng/mL, p = 0.047). Troponin-T and Myoglobin as well as Troponin-I and CK-MB measured at other time points were not found to be related to SBT or extubation failure. However, most studies were underpowered and with high risk of bias. Conclusions: The association with SBT or extubation failure is limited for Troponin-I and CK-MB and appears absent for Troponin-T and Myoglobin, but available studies are hampered by significant methodological drawbacks. To more definitively determine the role of ischemic cardiac biomarkers, future studies should prioritize larger sample sizes, including patients at risk of cardiac disease, using stringent SBTs and structured timing of laboratory measurements before and after SBT.

Effect of Reintubation Within 48 Hours on Mortality in Critically Ill Patients After Planned Extubation.

Re-intubation is necessary in 2% to 30% of cases of patients receiving a planned extubation. This procedure is associated with prolonged mechanical ventilation, a greater need for tracheostomy, a higher incidence of ventilator-associated pneumonia, and higher mortality. The aim of this study was to evaluate the effect of re-intubation within 48 h on mortality after planned extubation by using a randomized controlled trial database. Secondary analysis of a multi-center randomized trial, which evaluated the effect of reconnection to mechanical ventilation for 1 h after a successful spontaneous breathing trial, followed by extubation. The study included adult subjects who received invasive mechanical ventilation for > 12 h. The subjects were divided into an extubation failure group and an extubation success group. The outcome was in-hospital mortality. Two multivariate logistic regression models were constructed to identify independent factors associated with mortality. Among the 336 subjects studied, extubation failed in 52 (15.4%) and they were re-intubated within 48 h. Most re-intubations occurred between 12 and 24 h after planned extubation (median [interquartile range] 16 [6-36] h). Mortality of the extubation failure group was higher both in the ICU (32.6% vs 6.6%; odds ratio [OR] 6.77, 95% CI 3.22-14.24; P < .001) and in-hospital (42.3% vs 14.0%; OR 4.47, 95% CI 2.34-8.51; P < .001) versus the extubation success group. Multivariate logistic regression analyses showed that re-intubation within 48 h was independently associated with both ICU mortality (OR 6.10, 95% CI 2.84-13.07; P < .001) and in-hospital mortality (OR 3.36, 95% CI 1.67-6.73; P = .001). In-hospital mortality was also associated with rescue noninvasive ventilation after extubation (OR 2.44, 95% CI 1.25-4.75; P = .009). Re-intubation within 48 h after planned extubation was associated with mortality in subjects who were critically ill.

Assessing the reproducibility and predictive value of objective cough measurement for successful withdrawal of invasive ventilatory support in adult patients

BackgroundUtilizing clinical tests, such as objective cough measurement, can assist in predicting the success of the weaning process in critically ill patients.MethodsA multicenter observational analytical study was conducted within a prospective cohort of patients recruited to participate in COBRE-US. We assessed the capability of objective cough measurement to predict the success of the spontaneous breathing trial (SBT) and extubation. Intra- and inter-observer reproducibility of the cough test and was evaluated using the intraclass correlation coefficient (ICC) and Cohen’s weighted kappa. We used receiver operating characteristic curves (ROC-curve) to evaluate the predictive ability of objective cough measurement.ResultsWe recruited 367 subjects who were receiving invasive mechanical ventilation. A total of 451 objective cough measurements and 456 SBTs were conducted. A significant association was found between objective cough measurement and successful SBT (OR: 1.68; 95% CI 1.48–1.90; p = 0.001). The predictive capability of the objective cough test for SBT success had a ROC-curve of 0.58 (95% CI: 0.56–0.61). Objective cough measurement to predict successful extubation had a ROC-curve of 0.61 (95% CI: 0.56–0.66). The intraobserver reproducibility exhibited an ICC of 0.94 (95% CI: 0.89–0.96; p < 0.001), while the interobserver reproducibility demonstrated an ICC of 0.72 (95% CI: 0.51–0.85; p < 0.001). The intraobserver agreement, assessed using Cohen’s weighted kappa was 0.94 (95% CI: 0.93–0.99; p < 0.001), whereas the interobserver agreement was 0.84 (95% CI: 0.67 − 0.10; p < 0.001).ConclusionsThe objective measurement of cough using the method employed in our study demonstrates nearly perfect intra-observer reproducibility and agreement. However, its ability to predict success or failure in the weaning process is limited.

Spontaneous breathing trial with pressure support on positive end-expiratory pressure and extensive use of non-invasive ventilation versus T-piece in difficult-to-wean patients from mechanical ventilation: a randomized controlled trial

BackgroundThe aim of this study is to assess whether a strategy combining spontaneous breathing trial (SBT) with both pressure support (PS) and positive end-expiratory pressure (PEEP) and extended use of post-extubation non-invasive ventilation (NIV) (extensively-assisted weaning) would shorten the time until successful extubation as compared with SBT with T-piece (TP) and post-extubation NIV performed in selected patients as advocated by guidelines (standard weaning), in difficult-to-wean patients from mechanical ventilation.MethodsThe study is a single-center prospective open label, randomized controlled superiority trial with two parallel groups and balanced randomization with a 1:1 ratio. Eligible patients were intubated patients mechanically ventilated for more than 24 h who failed their first SBT using TP. In the extensively-assisted weaning group, SBT was performed with PS (7 cmH2O) and PEEP (5 cmH2O). In case of SBT success, an additional SBT with TP was performed. Failure of this SBT-TP was an additional criterion for post-extubation NIV in this group in addition to other recommended criteria. In the standard weaning group, SBT was performed with TP, and NIV was performed according to international guidelines. The primary outcome criterion was the time between inclusion and successful extubation evaluated with a Cox model with adjustment on randomization strata.ResultsFrom May 2019 to March 2023, 98 patients were included and randomized in the study (49 in each group). Four patients were excluded from the intention-to-treat population (2 in both groups); therefore, 47 patients were analyzed in each group. The extensively-assisted weaning group had a higher median age (68 [58–73] vs. 62 [55–71] yrs.) and similar sex ratio (62% male vs. 57%). Time until successful extubation was not significantly different between extensively-assisted and standard weaning groups (median, 172 [50–436] vs. 95 [47–232] hours, Cox hazard ratio for successful extubation, 0.88 [95% confidence interval: 0.55–1.42] using the standard weaning group as a reference; p = 0.60). All secondary outcomes were not significantly different between groups.ConclusionAn extensively-assisted weaning strategy did not lead to a shorter time to successful extubation than a standard weaning strategy.Trial registration The trial was registered on ClinicalTrials.gov (NCT03861117), on March 1, 2019, before the inclusion of the first patient. https://clinicaltrials.gov/study/NCT03861117.

Spontaneous Breathing Trial Techniques for Extubating Adults and Children Who Are Critically Ill

Considerable controversy exists regarding the best spontaneous breathing trial (SBT) technique to use. To summarize trials comparing alternative SBTs. Several databases (MEDLINE [from inception to February 2023], the Cochrane Central Register of Controlled Trials [in February 2023], and Embase [from inception to February 2023] and 5 conference proceedings (from January 1990 to April 2023) were searched in this systematic review and meta-analysis. Randomized trials directly comparing SBT techniques in critically ill adults or children and reporting at least 1 clinical outcome were selected. Paired reviewers independently screened citations, abstracted data, and assessed quality for the systematic review and meta-analysis using Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA guidelines). Data were pooled using random-effects models. Primary outcomes included SBT success, extubation success, and reintubation. The systematic review and meta-analysis identified 40 trials that included 6716 patients. Low-quality evidence (14 trials [n = 4459]) suggested that patients were not more likely to pass a pressure support (PS) compared with a T-piece SBT (risk ratio [RR], 1.04; 95% CI, 0.97-1.11; P = .31; I2 = 73%), unless 1 outlier trial accounting for all heterogeneity was excluded (RR, 1.09; 95% CI, 1.06-1.12; P < .001; I2 = 0% [13 trials; n = 3939]; moderate-quality evidence), but were significantly more likely to be successfully extubated (RR, 1.07; 95% CI, 1.04-1.10; P < .001; I2 = 0%; 16 trials [n = 4462]; moderate-quality evidence). Limited data (5 trials [n = 502]) revealed that patients who underwent automatic tube compensation/continuous positive airway pressure compared with PS SBTs had a significantly higher successful extubation rate (RR, 1.10; 95% CI, 1.00-1.21; P = .04; I2 = 0% [low-quality evidence]). Compared with T-piece SBTs, high-flow oxygen SBTs (3 trials [n = 386]) had significantly higher successful extubation (RR, 1.06; 95% CI, 1.00-1.11; P = .04; I2 = 0%) and lower reintubation (RR, 0.37; 95% CI, 0.21-0.65; P = <.001; I2 = 0% [both low-quality evidence]) rates. Credible subgroup effects were not found. In this systematic review and meta-analysis, the findings suggest that patients undergoing PS compared with T-piece SBTs were more likely to be extubated successfully and more likely to pass an SBT, after exclusion of an outlier trial. Pressure support SBTs were not associated with increased risk of reintubation. Future trials should compare SBT techniques that maximize differences in inspiratory support.

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

Reconnection to the ventilator for 1h 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. Does reconnection to the ventilator for 1h reverse alveolar derecruitment induced by SBT, and is alveolar derecruitment more pronounced with a T-piece than with pressure-support ventilation (PSV)? 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). 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 10min 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). 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 1h allowed complete recovery of alveolar derecruitment. ClinicalTrials.gov; No.: NCT04227639; URL: www. gov.

Utilization of spontaneous breathing trial, objective cough test, and diaphragmatic ultrasound results to predict extubation success: COBRE-US trial

BackgroundThe results of clinical and weaning readiness tests and the spontaneous breathing trial (SBT) are used to predict the success of the weaning process and extubation.MethodsWe evaluated the capacity of the cuff leak test, rate of rapid and shallow breathing, cough intensity, and diaphragmatic contraction velocity (DCV) to predict the success of the SBT and extubation in a prospective, multicenter observational study with consecutive adult patients admitted to four intensive care units. We used receiver operating characteristic (ROC) curves to assess the tests’ predictive capacity and built predictive models using logistic regression.ResultsWe recruited 367 subjects who were receiving invasive mechanical ventilation and on whom 456 SBTs were performed, with a success rate of 76.5%. To predict the success of the SBT, we derived the following equation: (0.56 × Cough) − (0.13 × DCV) + 0.25. When the cutoff point was ≥ 0.83, the sensitivity was 91.5%, the specificity was 22.1%, and the overall accuracy was 76.2%. The area under the ROC curve (AUC-ROC) was 0.63. To predict extubation success, we derived the following equation: (5.7 × SBT) + (0.75 × Cough) − (0.25 × DCV) − 4.5. When the cutoff point was ≥ 1.25, the sensitivity was 96.8%, the specificity was 78.4%, and the overall accuracy was 91.5%. The AUC-ROC of this model was 0.91.ConclusionObjective measurement of cough and diaphragmatic contraction velocity could be used to predict SBT success. The equation for predicting successful extubation, which includes SBT, cough, and diaphragmatic contraction velocity values, showed excellent discriminative capacity.

Physiological effects of high-flow nasal cannula oxygen therapy after extubation: a randomized crossover study

BackgroundProphylactic high-flow nasal cannula (HFNC) oxygen therapy can decrease the risk of extubation failure. It is frequently used in the postextubation phase alone or in combination with noninvasive ventilation. However, its physiological effects in this setting have not been thoroughly investigated. The aim of this study was to determine comprehensively the effects of HFNC applied after extubation on respiratory effort, diaphragm activity, gas exchange, ventilation distribution, and cardiovascular biomarkers.MethodsThis was a prospective randomized crossover physiological study in critically ill patients comparing 1 h of HFNC versus 1 h of standard oxygen after extubation. The main inclusion criteria were mechanical ventilation for at least 48 h due to acute respiratory failure, and extubation after a successful spontaneous breathing trial (SBT). We measured respiratory effort through esophageal/transdiaphragmatic pressures, and diaphragm electrical activity (ΔEAdi). Lung volumes and ventilation distribution were estimated by electrical impedance tomography. Arterial and central venous blood gases were analyzed, as well as cardiac stress biomarkers.ResultsWe enrolled 22 patients (age 59 ± 17 years; 9 women) who had been intubated for 8 ± 6 days before extubation. Respiratory effort was significantly lower with HFNC than with standard oxygen therapy, as evidenced by esophageal pressure swings (5.3 [4.2–7.1] vs. 7.2 [5.6–10.3] cmH2O; p < 0.001), pressure–time product (85 [67–140] vs. 156 [114–238] cmH2O*s/min; p < 0.001) and ΔEAdi (10 [7–13] vs. 14 [9–16] µV; p = 0.022). In addition, HFNC induced increases in end-expiratory lung volume and PaO2/FiO2 ratio, decreases in respiratory rate and ventilatory ratio, while no changes were observed in systemic hemodynamics, Troponin T, or in amino-terminal pro-B-type natriuretic peptide.ConclusionsProphylactic application of HFNC after extubation provides substantial respiratory support and unloads respiratory muscles.Trial registration January 15, 2021. NCT04711759.

Lung aeration estimated by chest electrical impedance tomography and lung ultrasound during extubation

BackgroundThis study hypothesized that patients with extubation failure exhibit a loss of lung aeration and heterogeneity in air distribution, which could be monitored by chest EIT and lung ultrasound. Patients at risk of extubation failure were included after a successful spontaneous breathing trial. Lung ultrasound [with calculation of lung ultrasound score (LUS)] and chest EIT [with calculation of the global inhomogeneity index, frontback center of ventilation (CoV), regional ventilation delay (RVD) and surface available for ventilation] were performed before extubation during pressure support ventilation (H0) and two hours after extubation during spontaneous breathing (H2). EIT was then repeated 6 h (H6) after extubation. EIT derived indices and LUS were compared between patients successfully extubated and patients with extubation failure.Results40 patients were included, of whom 12 (30%) failed extubation. Before extubation, when compared with patients with successful extubation, patients who failed extubation had a higher LUS (19 vs 10, p = 0.003) and a smaller surface available for ventilation (352 vs 406 pixels, p = 0.042). After extubation, GI index and LUS were higher in the extubation failure group, whereas the surface available for ventilation was lower. The RVD and the CoV were not different between groups.ConclusionBefore extubation, a loss of lung aeration was observed in patients who developed extubation failure afterwards. After extubation, this loss of lung aeration persisted and was associated with regional lung ventilation heterogeneity.Trial registration Clinical trials, NCT04180410, Registered 27 November 2019—prospectively registered, https://clinicaltrials.gov/ct2/show/NCT04180410.

Sonometric assessment of cough predicts extubation failure: SonoWean—a proof-of-concept study

BackgroundExtubation failure is associated with increased mortality. Cough ineffectiveness may be associated with extubation failure, but its quantification for patients undergoing weaning from invasive mechanical ventilation (IMV) remains challenging.MethodsPatients under IMV for more than 24 h completing a successful spontaneous T-tube breathing trial (SBT) were included. At the end of the SBT, we performed quantitative sonometric assessment of three successive coughing efforts using a sonometer. The mean of the 3-cough volume in decibels was named Sonoscore.ResultsDuring a 1-year period, 106 patients were included. Median age was 65 [51–75] years, mainly men (60%). Main reasons for IMV were acute respiratory failure (43%), coma (25%) and shock (17%). Median duration of IMV at enrollment was 4 [3–7] days. Extubation failure occurred in 15 (14%) patients. Baseline characteristics were similar between success and failure extubation groups, except percentage of simple weaning which was lower and MV duration which was longer in extubation failure patients. Sonoscore was significantly lower in patients who failed extubation (58 [52–64] vs. 75 [70–78] dB, P < 0.001). After adjustment on MV duration and comorbidities, Sonoscore remained associated with extubation failure. Sonoscore was predictive of extubation failure with an area under the ROC curve of 0.91 (IC95% [0.83–0.99], P < 0.001). A threshold of Sonoscore < 67.1 dB predicted extubation failure with a sensitivity of 0.93 IC95% [0.70–0.99] and a specificity of 0.82 IC95% [0.73–0.90].ConclusionSonometric assessment of cough strength might be helpful to identify patients at risk of extubation failure in patients undergoing IMV.

Relación entre la fuerza de prensión manual y los músculos inspiratorios con el éxito la prueba de respiración espontánea

Introduction: In critically ill patients on mechanical ventilation, the loss of inspiratory and peripheral muscle strength is associated with prolonged mechanical ventilation and failed weaning. Objective: To determine the relationship between handgrip strength and inspiratory muscle strength with the success of the Spontaneous Breathing Trial in adults with ventilatory support greater than 48 hours. Methodology: Prospective observational cross-sectional study performed at a tertiary hospital in Colombia. Handgrip strength and Maximal Inspiratory Pressure were measured once a day before Spontaneous Breathing Trial testing. Pearson’s test and Cohen’s D test were used to analyze correlations. Results: A total of 51 patients were included, 57% male, with a mean age of 51.9±20 years. A positive correlation was identified between Maximal Inspiratory Pressure and grip strength; and a negative correlation between grip strength and Maximal Inspiratory Pressure with the days of stay in the intensive care unit, (r -0.40; p&lt;0.05) and (r -0.45; p&lt;0.05). Conclusions: Handgrip strength and Maximal Inspiratory Pressure were positively correlated with Spontaneous Breathing Trial success. The importance of these measures to guide ventilator disconnection processes is highlighted.

Association between microcirculation in spontaneous breathing trial and extubation success.

This study assessed the association between changes in sublingual microcirculation after a spontaneous breathing trial (SBT) and successful extubation. Sublingual microcirculation was assessed using an incident dark-field video microscope before and after each SBT and before extubation. Microcirculatory parameters before the SBT, at the end of the SBT, and before extubation were compared between the successful and failed extubation groups. Forty-seven patients were enrolled and analysed in this study (34 patients in the successful extubation group and 13 patients in the failed extubation group). At the end of the SBT, the weaning parameters did not differ between the two groups. However, the total small vessel density (21.2 [20.4-23.7] versus 24.9 [22.6-26.5] mm/mm2), perfused small vessel density (20.6 [18.5-21.8] versus 23.1 [20.9-25] mm/mm2), proportion of perfused small vessels (91 [87-96] versus 95 [93-98] %), and microvascular flow index (2.8 [2.7-2.9] versus 2.9 [2.9-3]) were significantly lower in the failed extubation group than in the successful extubation group. The weaning and microcirculatory parameters did not differ significantly between the two groups before the SBT. More patients are required to investigate the difference between baseline microcirculation before a successful SBT and the change in microcirculation at the end of the SBT between the successful and failed extubation groups. Better sublingual microcirculatory parameters at the end of SBT and before extubation are associated with successful extubation.

The predictive value of platelet-to-lymphocyte ratio for weaning failure in septic patients receiving mechanical ventilation

Objective: To determine the ability of the ratio of platelet to lymphocyte (PLR) for predicting extubation failure in septic patients receiving invasive mechanical ventilation (IMV). Methods: The retrospective cohort study was conducted in ICU at Beijing Chao-Yang Hospital Shijingshan District, Capital Medical University in China from January, 2010 to December, 2019, including patients with sepsis who received IMV. 180 patients were enrolled in the study, including 111 male and 69 female, with the age range of 23-93 years and the median age of 76 years, and with an average age of 71.22 years. The medical records were reviewed, such as age, sex, acute physiology and chronic health evaluation II (APACHEII), sequential organ failure assessment (SOFA), spontaneous breathing trial (SBT) outcome, weaning outcome, complete blood count before SBT. According to weaning outcome, patients were divided into weaning failure and weaning success group. The difference of PLR, white blood cell(WBC), C-reaction protein (CRP) and procalcitonin (PCT) were compared between weaning failure and success group. Receiver-operating characteristics (ROC) curves and multivariate logistical regression analysis were employed to analyze the performance of these inflammatory markers for predicting weaning failure in patients with sepsis. Results: 180 patients with sepsis were included in the study and 37 patients (20.5%) experienced weaning failure (31 SBT failure and 6 extubation failure after successful SBT). PLR was higher in weaning failure group than that in weaning success group (Z=-5.793,P<0.001). Other inflammation biomarkers such as WBC, CRP and PCT were also higher in weaning failure group than that in weaning success group(Z=-4.356, -3.118 and -2.743, P<0.001, 0.002 and 0.006, respectively). According to ROC curves, PLR has a better predictive ability for weaning failure (AUC=0.809,95%CI 0.733-0.885) when compared to WBC (AUC=0.773,95%CI 0.648-0.817), CRP (AUC=0.666,95%CI 0.577-0.755) and PCT (AUC=0.603,95%CI 0.508-0.698). The cutoff value of PLR for predicting weaning failure was 257.69 with sensitivity 78.38%, specificity 76.22%, and diagnostic accuracy 71.66%. According to multivariate logistic regression analyses, PLR>257.69 was an independent risk factor for predicting weaning failure in patients with sepsis. Conclusions: PLR may be a valuable biomarker for predicting weaning failure in septic patients receiving IMV, and the patients with higher PLR should be handled with caution since they are at higher risk of weaning failure, and some more effective treatment should be in consideration after extubation.

High-Flow Nasal Cannula as an Alternate Weaning Strategy: A Randomized Controlled Trial.

Background Extubation failure is associated with increased morbidity and poor outcomes. This study aimed to ascertain the effectiveness of a high-flow nasal cannula (HFNC) as a weaning method compared to conventional weaning. Methodology A total of 60 mechanically ventilated patients, aged 18-65 years, who were ventilated for 48 hours and whose underlying pathology had either resolved or was improving, were enrolled in this study. They were randomized in a 1:1 ratio to participate in the HFNC weaning method or receive conventional weaning. Patients in Group A were extubated and oxygen was provided via HFNC. Group B patients were given a spontaneous breathing trial (SBT) per the standard protocol and extubated after a successful SBT. Results Weaning failure was found in five patients and was higher in the conventional group (three patients in the conventional group and two patients in the HFNC group). The duration of stay of patients in intensive care units was significantly higher in the conventional group than in the HFNC group. Conclusions HFNC is a better alternative to conventional weaning through SBT.

Diaphragmatic ultrasonography-based rapid shallow breathing index for predicting weaning outcome during a pressure support ventilation spontaneous breathing trial

BackgroundThe optimum timing to wean is crucial to avoid negative outcomes for mechanically ventilated patients. The rapid shallow breathing index (RSBI), a widely used weaning index, has limitations in predicting weaning outcomes. By replacing the tidal volume of the RSBI with diaphragmatic excursion (DE) and diaphragm thickening fraction (DTF) assessed by ultrasonography, we calculated two weaning indices, the diaphragmatic excursion rapid shallow breathing index (DE-RSBI, respiratory rate [RR]/DE) and the diaphragm thickening fraction rapid shallow breathing index (DTF-RSBI, RR/DTF). The aim of this study was to evaluate the predictive values of DTF-RSBI, DE-RSBI and traditional RSBI in weaning failure.MethodsThis prospective observational study included patients undergoing mechanical ventilation (MV) for > 48 h and who were readied for weaning. During a pressure support ventilation (PSV) spontaneous breathing trial (SBT), right hemidiaphragmatic excursion and DTF were measured by bedside ultrasonography as well as RSBI. Weaning failure was defined as: (1) failing the SBT and (2) SBT success but inability to maintain spontaneous breathing for more than 48 h without noninvasive or invasive ventilation. A receiver operator characteristic (ROC) curve was used for analyzing the diagnostic accuracy of RSBI, DE-RSBI, and DTF-RSBI.ResultsOf the 110 patients studied, 37 patients (33.6%) failed weaning. The area under the ROC (AUROC) curves for RSBI, DE-RSBI, and DTF-RSBI for predicting failed weaning were 0.639, 0.813, and 0.859, respectively. The AUROC curves for DE-RSBI and DTF-RSBI were significantly higher than for RSBI (P = 0.004 and P < 0.001, respectively). The best cut-off values for predicting failed weaning were RSBI > 51.2 breaths/min/L, DE-RSBI > 1.38 breaths/min/mm, and DTF-RSBI > 78.1 breaths/min/%.ConclusionsIn this study, two weaning indices determined by bedside ultrasonography, the DE-RSBI (RR/DE) and DTF-RSBI (RR/DTF), were shown to be more accurate than the traditional RSBI (RR/VT) in predicting weaning outcome during a PSV SBT.