Pendelluft as a predictor of weaning in critically ill patients: An observational cohort study

Abstract

Objective: Weaning failure is associated with adverse clinical outcomes. This study aimed to evaluate the accuracy of pendelluft during the spontaneous breathing trials (SBT) as a predictor of weaning outcome of patients with mechanical ventilation.Methods: An observational cohort study included 60 critically ill patients who were eligible for extubation. Pendelluft and electrical activity of the diaphragm (Edi) were monitored at baseline and every 10 minutes for the first 30 min of SBT denoted as T0, T1, T2, and T3. The pendelluft was measured using electrical impedance tomography (EIT), and Edi parameters were collected by Edi catheter. Patients were followed up after extubation and were divided into success group and failure group. Pendelluft, Edi parameters, respiratory parameters, and clinical outcomes such as intensive care units (ICU) stay, mortality, and 28-day ventilator-free days were compared between the two groups. Receiver operating characteristic (ROC) curves were constructed to evaluate the ability of pendelluft to predict weaning outcome.Results: Fifty patients (50/60) were successfully weaned from the machine and 10 (10/60) failed, with weaning failure rate of 16.7%. Respiratory parameters such as rapid shallow breathing index (RSBI), respiratory rate (RR) and Edi parameters such as maximum value of Edi (Edimax), Edi variation between a maximum and minimum(ΔEdi) in the failure group were higher than those in the success group. The ICU stay and the 28-day ventilator-free days in the failure group were significantly longer than those in the success group. The 28-day mortality rate was higher in the failure group. The pendelluft mainly occurred in the early stage of SBT. Ventral pendelluft and total pendelluft in the failure group were higher than those in the success group at T1. Edimax and ΔEdi were positively correlated with pendelluft. The area under ROC curve (AUC) showed moderate predictive ability for ventral pendelluft in predicting weaning failure at T1 (AUC 0.76, 95% CI 0.58–0.94, cut-off value > 3% global tidal variation).Conclusion: Pendelluft is one of the factors leading to weaning failure, which may be related to diaphragm function. Measuring pendelluft volume maybe helpful to predict weaning.

Occurrence of pendelluft during ventilator weaning with T piece correlated with increased mortality in difficult-to-wean patients

“…In our current study of difficult-to-wean population, we observed a notable increase in the prevalence of pendelluft, rising to 70.4% during SBT. The occurrence of the pendelluft may be attributed to factors such as alveolar heterogeneity or excessive spontaneous breathing effort, leading to gas movement within the lung [ 7 , 8 , 21 , 22 ]. Throughout the weaning process, patients’ spontaneous breathing effort progressively intensifies, reaching its zenith when they are disconnected from the ventilator.…”

“…Given the absence of prior studies that specifically reported mortality among patients experiencing both pendelluft and difficulty in weaning, we referred to the varying mortality rates within the difficult-to-wean population, which ranged from 19.0% to 36.8% [ 1 ]. Wang et al previously reported a 28-day mortality of 70% for patients who failed SBT, compared to 4% for those who succeeded [ 8 ]. Similarly, our previous study indicated a mortality rate of 16% for patients with acute respiratory failure and pendelluft, contrasting with 9% for those without pendelluft [ 14 ].…”

“…It has even been proposed as a surrogate marker for vigorous inspiratory effort [ 16 ]. The presence of pendelluft can be conveniently detected through bedside EIT monitoring [ 7 , 8 , 14 , 15 ]. A recent study demonstrated that pendelluft occurred during high-flow nasal oxygen therapy could be alleviated by continuous positive airway pressure and further improved with noninvasive ventilation, along with reduced inspiratory effort [ 17 ].…”

Pendelluft in hypoxemic patients resuming spontaneous breathing: proportional modes versus pressure support ventilation

“…The small increase in dorsal fraction of ventilation observed in ventilatory cycles with high pendelluft magnitude is similar to the found in other physiological study [ 21 ], but of uncertain significance. To the best of our knowledge, only a few studies have explored the potential clinical impact of pendelluft [ 21 , 30 , 31 ]. In one of these studies, pendelluft was associated with a longer duration of mechanical ventilation among ICU patients with PaO 2 /FiO 2 ratio below 200 mmHg.…”

Hiccup-like Contractions in Mechanically Ventilated Patients: Individualized Treatment Guided by Transpulmonary Pressure

“…The higher the inhomogeneity of the lung, the greater the overdistention of dependent alveoli at the same magnitude of inspiratory effort [ 16 , 17 ]. Furthermore, recent studies have shown that the higher the intensity of diaphragmatic contraction, as measured via the electrical activity of the diaphragm (Edimax) or Pes, the higher the impact of pendelluft in lung overstretching [ 18 , 19 ]. Notwithstanding, the relationship between the magnitude of inspiratory effort and pendelluft is not as straightforward as recent data suggest [ 18 , 20 ].…”