Initial Spontaneous Breathing Trial Research Articles

Validity of A new Weaning Index of Discontinuation From Mechanical Ventilation in Intensive Care Unit

Abstract Background Failure to wean from mechanical ventilation (MV) is a frequent problem in the intensive care unit (ICU) setting. Herein, we investigate a new WI measured at the initial spontaneous breathing trial (SBT) in order to predict successful liberation from MV in mechanically ventilated ICU cases. Patients and methods This prospective cross-sectional study consisted of two phases; Phase I was designed to create a new WI from the criteria of 60 mechanically ventilated patients, while Phase II aimed to assess the accuracy of that index in another 40 patients. Patients aged older than 18 years who were receiving controlled-mode MV from day 3 to day 14 and planned to be weaned off MV were included in our study. Contrarily, patients with prior history of poor tolerance to SBT, weaning failure were excluded. Additionally, we also excluded patients with neurological or neuromuscular disorders, tracheostomy, pregnancy, or an active COVID-19 infection. Results The incidence of failed weaning was 33.3% in phase I, and 35% in phase II. Pulmonary causes were the most common indication in both groups. Multivariate regression analysis was done for phase I variables, and the following equation was created; (((Cough strength* 0.743) - 1.927) *0.05 + ((PaCO2 (mmHg)* - 0.126) + 6.786) *0.08 + ((mean airway pressure (CmH2O) * -1.304) + 14.119) *0.193 + ((PaO2/FIO2 * 0.268) - 58.555) *0.328 + ((rapid shallow breathing index * -0.485) + 24.406) *0.353). Using a cut-off value of > 0.69 and applying this index in phase II, it showed a mean value of -1.43 and 4.67 in the failure and success groups, respectively (p < 0.001). This new WI with cutoff value (> 0.69) had 88.5% sensitivity, 57.1% specificity, and a 77.5% accuracy to predict the success of weaning from MV. Conclusion We developed a new WI with good sensitivity and moderate specificity for predicting successful weaning from MV in ICU patients. Its use should be encouraged in the ICU setting, especially by less experienced ICU physicians.

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

BackgroundSpontaneous-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.MethodsIn this multicenter, open-label trial, we randomly assigned patients who had a high risk of extubation failure (i.e., were >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.ResultsA 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).ConclusionsAmong 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.)

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)

IntroductionIn 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...

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

Spontaneous breathing trial (SBT) using a T-piece remains the most frequently performed trial before extubation in ICUs. 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. 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. Among the 641 patients included in the original study, initial SBT was performed using PSV (7.0cm 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%vs10%, 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). 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.

Prophylactic noninvasive positive pressure ventilation in the weaning of difficult-weaning tracheotomy patients.

BackgroundProphylactic noninvasive positive pressure ventilation (NPPV) reduces reintubation in endotracheal intubation patients. However, the efficacy of using the prophylactic NPPV in the weaning of tracheotomy patients is unclear.MethodsWe performed prophylactic NPPV in 11 tracheotomy patients who passed a spontaneous breathing trial (SBT), removed the tracheotomy tube, and closed the incision (intervention group). We matched another 11 tracheotomy patients who also passed an SBT but weaning and removing of tracheotomy tube were managed as conventional methods (control group).ResultsPatients in the control group had reinstitution of mechanical ventilation 36 times after the initial SBT success. Compared with the control group, the interventional group had fewer weaning days (3.0±2.1 vs. 11.3±9.2, P=0.01) from initial SBT success to successful weaning and shorter intensive care unit (ICU) length of stay (11.6±4.2 vs. 20.3±11.6, P=0.03) after initial SBT success. The interventional group had lower nosocomial pneumonia rates after initial SBT success (0/11 vs. 2/11), lower ICU mortality (0/11 vs. 2/11), lower hospital mortality (0/11 vs. 3/11), and higher successful weaning rate (11/11 vs. 8/11), but it didn’t reach significant difference. Also, there was no significant difference between groups in total duration of ventilation (25.5±13.3 vs. 34.7±24.2 days), hospital stay after initial SBT success (24.0±22.3 vs. 37.4±31.3 days), total ICU stay (35.7±15.3 vs. 45.0±29.5 days), and total hospital stay (48.7±33.1 vs. 68.6±52.6 days).ConclusionsProphylactic NPPV may be useful to accelerate weaning, and shorten ICU stay after initial SBT success in tracheotomy patients.

Variation in the practice of discontinuing mechanical ventilation in critically ill adults: study protocol for an international prospective observational study

IntroductionResearch supports the use of specific strategies to discontinue mechanical ventilation (MV) in critically ill patients. Little is known about how clinicians actually wean and discontinue MV in practice or...

Predictors of failure of early shift from invasive to noninvasive ventilation in weaning chronic obstructive pulmonary disease patients who have failed the initial spontaneous breathing trial: a prospective cohort study

Noninvasive ventilation (NIV) is a well-established modality for difficult and prolonged weaning of chronic obstructive pulmonary disease (COPD) patients. Although several studies have addressed the early shifting to NIV, predictors of its success remain to be determined. The aim of the study was to find predictors of success of early shift of COPD patients who have failed the spontaneous breathing trail (SBT) to NIV. This investigation was designed as a double-centered prospective cohort study involving the ICUs of Critical Care Medicine of Cairo University and Shebin El-Kom Teaching Hospital. Consecutive COPD patients who failed the initial SBT were extubated and shifted to NIV. We compared arterial blood gases, lung mechanics, and spontaneous breathing parameters in successful patients with these parameters in those who failed the early shift to NIV. Out of the 30 patients, 21 (70%) were successfully weaned by early shift to NIV. The failed group had a significantly higher autopositive end-expiratory pressure (P<0.001), rapid shallow breathing index (RSBI) (P<0.05), and significantly lower static compliance and negative inspiratory pressure (NIP) (P<0.001) on admission. Admission RSBI and NIP were the only predictors of failure of early shift to NIV. Just before SBT, the failed group had a significantly higher autopositive end-expiratory pressure (P<0.001), RSBI (P<0.001), and airway resistance (Raw) (P<0.001) and significantly lower static compliance, NIP, and PO2/FIO2 (P/F) ratio. Raw and NIP before SBT were the only predictors of success of early shift to NIV. RSBI, NIP, and Raw, rather than arterial blood gases, are the most important predictors for success of early shift to NIV in COPD patients who have failed the initial SBT.

Predictors of failure of early shift from invasive to noninvasive ventilation in weaning chronic obstructive pulmonary disease patients who have failed the initial spontaneous breathing trial: a prospective cohort study

ContextNoninvasive ventilation (NIV) is a well-established modality for difficult and prolonged weaning of chronic obstructive pulmonary disease (COPD) patients. Although several studies have addressed the early shifting to NIV, predictors of its success remain to be determined.AimsThe aim of the study was to find predictors of success of early shift of COPD patients who have failed the spontaneous breathing trail (SBT) to NIV.Design and settingsThis investigation was designed as a double-centered prospective cohort study involving the ICUs of Critical Care Medicine of Cairo University and Shebin El-Kom Teaching Hospital.Patients and methodsConsecutive COPD patients who failed the initial SBT were extubated and shifted to NIV. We compared arterial blood gases, lung mechanics, and spontaneous breathing parameters in successful patients with these parameters in those who failed the early shift to NIV.ResultsOut of the 30 patients, 21 (70%) were successfully weaned by early shift to NIV. The failed group had a significantly higher autopositive end-expiratory pressure (P<0.001), rapid shallow breathing index (RSBI) (P<0.05), and significantly lower static compliance and negative inspiratory pressure (NIP) (P<0.001) on admission.Admission RSBI and NIP were the only predictors of failure of early shift to NIV. Just before SBT, the failed group had a significantly higher autopositive end-expiratory pressure (P<0.001), RSBI (P<0.001), and airway resistance (Raw) (P<0.001) and significantly lower static compliance, NIP, and PO2/FIO2 (P/F) ratio. Raw and NIP before SBT were the only predictors of success of early shift to NIV.ConclusionRSBI, NIP, and Raw, rather than arterial blood gases, are the most important predictors for success of early shift to NIV in COPD patients who have failed the initial SBT.

Trials directly comparing alternative spontaneous breathing trial techniques: a systematic review and meta-analysis

BackgroundThe effect of alternative spontaneous breathing trial (SBT) techniques on extubation success and other clinically important outcomes is uncertain.MethodsWe searched MEDLINE, EMBASE, CENTRAL, CINAHL, Evidence-Based Medicine Reviews, Ovid Health Star, proceedings of five conferences (1990–2016), and reference lists for randomized trials comparing SBT techniques in intubated adults or children. Primary outcomes were initial SBT success, extubation success, or reintubation. Two reviewers independently screened citations, assessed trial quality, and abstracted data.ResultsWe identified 31 trials (n = 3541 patients). Moderate-quality evidence showed that patients undergoing pressure support (PS) compared with T-piece SBTs (nine trials, n = 1901) were as likely to pass an initial SBT (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.89–1.11; I2 = 77%) but more likely to be ultimately extubated successfully (RR 1.06, 95% CI 1.02–1.10; 11 trials, n = 1904; I2 = 0%). Exclusion of one trial with inconsistent results for SBT and extubation outcomes suggested that PS (vs T-piece) SBTs also improved initial SBT success (RR 1.06, 95% CI 1.01–1.12; I2 = 0%). Limited data suggest that automatic tube compensation plus continuous positive airway pressure (CPAP) vs CPAP alone or PS increase SBT but not extubation success.ConclusionsPatients undergoing PS (vs T-piece) SBTs appear to be 6% (95% CI 2–10%) more likely to be extubated successfully and, if the results of an outlier trial are excluded, 6% (95% CI 1–12%) more likely to pass an SBT. Future trials should investigate patients for whom SBT and extubation outcomes are uncertain and compare techniques that maximize differences in support.

Clinical study of rapid shallow breathing index as the switching point for sequential ventilation for patients with prolonged weaning after thoracolaparotomy

Objective To investigate the influencing factors of successfully switching to sequential ventilation in patients with prolonged weaning due to acute respiratory failure (ARF) after thoracolaparotomy based on the initial rapid shallow breathing index (RSBI) at 60 min after spontaneous breathing trial (SBT) , namely, the f/VT optimal value range of 80 -120 times/(min·L) , thus providing the basis for determining the ideal timing of weaning in clinical practice. Methods A prospective observational study of sequential ventilation [RSBI during the initial SBT (60 min) , 80 -120 breaths/(min·L) ] was carried out in 42 patients on mechanical ventilation (≥48 h) due to post-thoracolaparotomy ARF in the ICUs. According to the duration of the mechanical ventilation, the patients were divided into 2 groups: successfully prolonged weaning group (≥7 days, n =24) and refractory weaning group (<7 days, n =18). The patients with cardiac failure, aged less 18 or over 80, with hepatic dysfunction, or those needing gastrointestinal decompression after esophageal surgery or upper abdomen surgery were excluded. The demographics, APACHEⅡ scores and duration of mechanical ventilation of both groups were recorded, and the respiratory work and oxygen metabolism variables before the switch to sequential ventilation (within 24 hours after admission to ICU) and at the time of switching (24 hours in the ICU after admission) were recorded, respectively: clinical pulmonary infection score (CPIS) , assessment of cough severity, pH, PaO2, PaCO2 and PaO2/FiO2; hemodynamic and microcirculation-related variables: HR, MAP, fluid balance, BNP and Lac; endocrine and metabolism variables: Hb, ALB and random serum cortisol (COR). The clinical features and the changes of the above-mentioned variables before and at the time of switching were compared between both groups. The independent sample t test was used for the single factor comparison and Mann-Whitney U test was applied to the non-normal distributions. The Fisher exact probability test was used for the single factor comparison of ranked data such as categorical variables. Results There were no significant differences in age, gender and severity of disease between two groups ( P >0.05 ) ; the successfully prolonged weaning group had longer duration of invasive mechanical ventilation and ICU stay compared with the refractory weaning group ( P 0.05) ; while in the successfully delayed weaning group, there were significant decrease in CPIS, PaCO2, HR, MAP, BNP, fluid balance and Lac ( P <0.05) , and cough severity, pH, ALB and COR showed an upward trend ( P <0.05). Conclusions The key of successful sequential ventilation is within the values of RSBI ranging from 80 to 120 times/(min·L) during the initial SBT (60 min) selected as the switching point in patients with prolonged weaning after thoracolaparotomy. The major influencing factors for determining the ideal timing of switching include the matching status between respiratory endurance and respiratory work, the balance between myocardial strength and both cardiac preload and afterload, the severe disease associated with adrenal insufficiency, and malnutrition. Key words: Post-thoracolaparotomy; Prolonged weaning; Sequential ventilation; Switching point; Rapid shallow breathing index

Discontinuous versus Continuous Weaning in Stroke Patients

Background: An increasing number of stroke patients have to be supported by mechanical ventilation in intensive care units (ICU), with a relevant proportion of them requiring gradual withdrawal from a respirator. To date, weaning studies have focused merely on mixed patient groups, COPD patients or patients after cardiac surgery. Therefore, the best weaning strategy for stroke patients remains to be determined. Methods: Here, we designed a prospective randomized controlled study comparing adaptive support ventilation (ASV), a continuous weaning strategy, with biphasic positive airway pressure (BIPAP) in combination with spontaneous breathing trials, a discontinuous technique, in the treatment of stroke patients. The primary endpoint was the duration of the weaning process. Results: Only the 40 (out of 54) patients failing in an initial spontaneous breathing trial (T-piece test) were included into the study; the failure proportion is considerably larger compared to previous studies. Eligible patients were pseudo-randomly assigned to one of the two weaning groups. Both groups did not differ regarding age, gender, and severity of stroke. The results showed that the median weaning duration was 10.7 days (±SD 7.0) in the discontinuous weaning group, and 8 days (±SD 4.5) in the continuous weaning group (p < 0.05). Conclusions: To the best of our knowledge, this is the first clinical study to show that continuous weaning is significantly more effective compared to discontinuous weaning in mechanically ventilated stroke patients. We suppose that the reason for the superiority of continuous weaning using ASV as well as the bad performance of our patients in the 2 h T-piece test is caused by the patients' compliance. Compared to patients on surgical and medical ICUs, neurological patients more often suffer from reduced vigilance, lack of adverse-effects reflexes, dysphagia, and cerebral dysfunction. Therefore, stroke patients may profit from a more gradual withdrawal of weaning.

Weaning by gradual pressure support (PS) reduction without an initial spontaneous breathing trial (SBT) versus PS-supported SBT: A pilot study

Background and aim: Studies on weaning strategies have yielded conflicting results regarding the superiority of different methods. The aim of this RCT was to compare the efficacy of gradual pressure support (PS) reduction without an initial spontaneous breathing trial (SBT) with PS-supported SBT. MethodsPatients mechanically ventilated for >24h were randomized to weaning by gradual reduction of PS without an initial SBT versus once daily SBT (PS 7cm H2O). The primary outcomes were the rates of successful weaning trial and time to successful extubation. The secondary outcomes were the ICU and hospital length of stay, hospital mortality and the occurrence of ventilator-associated pneumonia (VAP). ResultsOf the 120 patients (61 males, median age 35 years), 58 were assigned to PS and 62 to the SBT group. The median (IQR) duration of ventilation prior to weaning was 80.2 (50.5---175.6) h. The baseline characteristics were similar in the two groups except the PaO2/FiO2 ratio, which was significantly higher in SBT group. The rates of successful weaning trial (89.7% versus 69.4%) were significantly higher in the PS group. The median duration of weaning (66h versus 81.5h, P = 0.05) and the median duration of ICU stay (8 days versus 9.4 days, P = 0.027) were lower in the PS group. There was no difference in hospital stay, mortality rates or occur-rence of VAP in the two arms. On multivariate analysis, the duration of ventilation prior to weaning, baseline SOFA score and the weaning method were predictors of successful extubation. ConclusionsGradual reduction of PS without an initial SBT was found to be associated with better outcomes compared to once daily PS-supported SBT.

Weaning by gradual pressure support (PS) reduction without an initial spontaneous breathing trial (SBT) versus PS-supported SBT: A pilot study

Background and aim Studies on weaning strategies have yielded conflicting results regarding the superiority of different methods. The aim of this RCT was to compare the efficacy of gradual pressure support (PS) reduction without an initial spontaneous breathing trial (SBT) with PS-supported SBT. Methods Patients mechanically ventilated for >24 h were randomized to weaning by gradual reduction of PS without an initial SBT versus once daily SBT (PS 7 cm H 2O). The primary outcomes were the rates of successful weaning trial and time to successful extubation. The secondary outcomes were the ICU and hospital length of stay, hospital mortality and the occurrence of ventilator-associated pneumonia (VAP). Results Of the 120 patients (61 males, median age 35 years), 58 were assigned to PS and 62 to the SBT group. The median (IQR) duration of ventilation prior to weaning was 80.2 (50.5–175.6) h. The baseline characteristics were similar in the two groups except the PaO 2/FiO 2 ratio, which was significantly higher in SBT group. The rates of successful weaning trial (89.7% versus 69.4%) were significantly higher in the PS group. The median duration of weaning (66 h versus 81.5 h, P = 0.05) and the median duration of ICU stay (8 days versus 9.4 days, P = 0.027) were lower in the PS group. There was no difference in hospital stay, mortality rates or occurrence of VAP in the two arms. On multivariate analysis, the duration of ventilation prior to weaning, baseline SOFA score and the weaning method were predictors of successful extubation. Conclusions Gradual reduction of PS without an initial SBT was found to be associated with better outcomes compared to once daily PS-supported SBT.

Autonomic Tone in Medical Intensive Care Patients Receiving Mechanical Ventilation and During a CPAP Weaning Trial

Mechanical ventilator support and the resumption of spontaneous ventilation or weaning create significant alterations in alveolar and intrathoracic pressure that influence thoracic blood volume and flow. Compensatory autonomic tone alterations occur to ensure adequate tissue oxygen delivery, but autonomic responses may produce cardiovascular dysfunction with subsequent weaning failure. The authors describe autonomic responses of critically ill patients (n = 43) during a 24-hr period of mechanical ventilatory support and during the 24 hr that included their initial spontaneous breathing trial using continuous positive airway pressure. Nearly two thirds of these patients demonstrated abnormal autonomic function and this dysfunction was more severe in those patients who were unable to sustain spontaneous ventilation (n = 15). With further systematic study, autonomic responses may be useful in the identification of patients who are likely to develop cardiac dysfunction with the resumption of spontaneous breathing.

Validation of Dysfunctional Ventilatory Weaning Response

PURPOSETo further clinically validate the defining characteristics of dysfunctional ventilatory weaning response (DVWR) in patients requiring long‐term mechanical ventilation.METHODSThe Weaning Readiness Assessment Scale (WRAS), a 28‐item, 60‐point scale used to assess patients' readiness to wean from mechanical ventilation, was used to collect data on a large data set of 533 patients who were on mechanical ventilation &gt;4 days. Data were collected every other day until the patient was weaned, discharged, or expired. The WRAS is comprised of two subscales: the physiological/behavioral (PPBB) subscale and ventilatory subscale (VVV).FINDINGSA content validity index of 0.88 indicated that the variables and their scoring ranges were appropriate for the study population. Interrater and test‐retest reliability measures were 0.93 and 0.92, respectively. Internal consistency (Cronbach's alpha, p&lt;0.05) for the PPBB and VVV subscales were .69 and .76, respectively. Data were available on 533 subjects and analyzed by principal component extraction with varimax rotation, resulting in a two‐factor solution with strong loadings for 17 variables. In addition, preliminary one‐way analysis of variance showed statistical significance (p&lt;0.05) on these 17 variables. Where statistical significance was not present, the trend was in the expected direction.DISCUSSIONThese data imply that 10 of the 17 variables alone and in combination affect weaning from mechanical ventilation and lend support to the existing defining characteristics of DVWR. In addition, data revealed 7 statistically significant symptom variables affecting weaning from mechanical ventilation that are currently not listed as defining characteristics for DVWR: need for multiple vasopressors, fluid overload, multiple antibiotic use, bronchodilator use, need for high FiO2, and high PEEP levels.CONCLUSIONSFor most patients, weaning from mechanical ventilation is a smooth transition. Patients who require &gt;3 days of mechanical ventilation are an expensive patient population for acute care hospitals. Forty percent to 42% of mechanically ventilated patients either fail the initial spontaneous breathing trial (24%) or are extubated and require reintubation (16%–18%). The weaning process for long‐term mechanically ventilated patients has fiscal and psychosocial ramifications for the patient, family and friends, and healthcare providers.