Prediction of extubation outcome in mechanically ventilated patients: Development and validation of the Extubation Predictive Score (ExPreS)

Abstract

Despite the best efforts of intensive care units (ICUs) professionals, the extubation failure rates in mechanically ventilated patients remain in the range of 5%–30%. Extubation failure is associated with increased risk of death and longer ICU stay. This study aimed to identify respiratory and non-respiratory parameters predictive of extubation outcome, and to use these predictors to develop and validate an “Extubation Predictive Score (ExPreS)” that could be used to predict likelihood of extubation success in patients receiving invasive mechanical ventilation (IMV). Derivation cohort was composed by patients aged ≥18 years admitted to the ICU and receiving IMV through an endotracheal tube for >24 hours. The weaning process followed the established ICU protocol. Clinical signs and ventilator parameters of patients were recorded during IMV, in the end phase of weaning in pressure support ventilation (PSV) mode, with inspiratory pressure of 7 cm H2O over the PEEP (positive end expiratory pressure). Patients who tolerated this ventilation were submitted to spontaneous breathing trial (SBT) with T-tube for 30 minutes. Those who passed the SBT and a subsequent cuff-leak test were extubated. The primary outcome of this study was extubation success at 48 hours. Parameters that showed statistically significant association with extubation outcome were further investigated using the receiver operating characteristics (ROC) analysis to assess their predictive value. The area under the curve (AUC) values were used to select parameters for inclusion in the ExPreS. Univariable logistic regression analysis and ROC analysis were performed to evaluate the performance of ExPreS. Patients’ inclusion and statistical analyses for the prospective validation cohort followed the same criteria used for the derivation cohort and the decision to extubate was based on the ExPreS result. In the derivation cohort, a total of 110 patients were extubated: extubation succeeded in 101 (91.8%) patients and failed in 9 (8.2%) patients. Rapid shallow-breathing index (RSBI) in SBT, dynamic lung compliance, duration of IMV, muscle strength, estimated GCS, hematocrit, and serum creatinine were significantly associated with extubation outcome. These parameters, along with another parameter—presence of neurologic comorbidity—were used to create the ExPreS. The AUC value for the ExPreS was 0.875, which was higher than the AUCs of the individual parameters. The total ExPreS can range from 0 to 100. ExPreS ≥59 points indicated high probability of success (OR = 23.07), while ExPreS ≤44 points indicated low probability of success (OR = 0.82). In the prospective validation cohort, 83 patients were extubated: extubation succeeded in 81 (97.6%) patients and failed in 2 (2.4%) patients. The AUC value for the ExPreS in this cohort was 0.971. The multiparameter score that we propose, ExPreS, shows good accuracy to predict extubation outcome in patients receiving IMV in the ICU. In the prospective validation, the use of ExPreS decreased the extubation failure rate from 8.2% to 2.4%, even in a cohort of more severe patients.

Biosignal-Based Digital Biomarkers for Prediction of Ventilator Weaning Success

“…The predictive performance decreases in patients with multi-organ dysfunction, older age, prolonged MV, and severe illness [26][27][28][29][30][31]. The lack of reliable weaning parameters is related to the heterogeneity of critically ill patients and their ever-changing clinical courses [32][33][34][35]. The causes of weaning failure are not exclusively attributable to oxygenation or ventilation insufficiency; cardiac function, volume status, muscle deconditioning, and the presence of delirium also affect weaning outcomes [9,23,[36][37][38][39][40].…”

Predictive Factors of Extubation Failure in COVID-19 Mechanically Ventilated Patients

“…Patients who tolerated the SBT for 30 min and presented a rapid shallow breath index (RSBI) < 105 breaths/min/L were extubated. 14 Inclusion, exclusion, weaning, and extubation criteria were defined based on a previously published study, 12 except for the inclusion of the COVID-19 diagnosis.…”

“…The Fisher Exact test was used to evaluate the association of extubation outcome at 48 h and during ICU stay in this cohort compared to the cohort of our previous published study. 12 The p-values were also presented considering a significance level of 5%. A post hoc power analysis yielded a statistical power of 0.96 (p2 = 0.78; p1 = 0.12; n = 77, α = 0.05 – Gpower 3.1).…”

“…In non-COVID-19 patients on MV, the extubation failure rate ranges from 5% to 30%, which doubles ICU stay duration and substantially increases the risk of death. 12 There is still no consensus on the characteristics of COVID-19 patients that can predict the success or failure of weaning and extubation. Knowledge of these predictors would allow ICU teams to identify patients that are at a higher risk of extubation failure to avoid reintubation and all its associated risks.…”

Intra-abdominal pressure for predicating extubation failure in mechanically ventilated patients: it does work

“…However, previous studies have shown that there are still 10% to 20% of patients who pass the SBT test and fail the extubation [3,4]. Extubation failure will cause incalculable physical and psychological harm to patients, and increase mortality and medical costs [5][6][7]. Therefore, reducing the extubation failure is vital to the prognosis of MV patients.…”