Diaphragm electromyographic activity as a predictor of weaning failure
To compare breathing pattern descriptors and diaphragm electromyographic activity (EAdi)-derived indices obtained from a neurally adjusted ventilatory assist catheter during a spontaneous breathing trial (SBT) in patients successfully and unsuccessfully separated from the ventilator and to assess their performance as a potential marker to discriminate these two categories of patients.
Fifty-seven ready-to-wean patients were included in a prospective observational study. During a 30-min SBT (pressure support 7 cmH2O, zero end expiratory pressure), tidal volume (V T) and respiratory rate (RR) were obtained from the flow signal at baseline and at 3, 10, 20 and 30 min during the SBT. EAdi-derived indices were simultaneously computed: maximum of the EAdi (EAdimax), area under the inspiratory curve of EAdi (EAdiAUC), the difference between EAdimax and EAdimin (∆EAdi), EAdimax/V T, EAdiAUC/V T and ∆EAdi/V T. Patients, successfully (success group; n = 35) and unsuccessfully (failure group; n = 22) separated from the ventilator were compared.
At baseline, the breathing pattern was similar in the two groups, whereas EAdimax and EAdiAUC were significantly lower in the success group (p < 0.05). In the failure group, RR and RR/V T increased significantly during the trial, V T decreased, whereas EAdimax and EAdiAUC did not change. At 3 min, the areas under the receiver operating characteristic-curve of RR/V T and the EAdi-derived indices to predict weaning outcome were 0.83 for the rapid shallow breathing index (RSBI), 0.84 for EAdimax/V T , 0.80 for EAdiAUC/V T (0.80) and 0.82 for ∆EAdi/V T. The coefficient of variation for V T decreased in the failure group while that for EAdimax remained unchanged.
EAdi-derived indices provide reliable and early predictors of weaning outcome. However, the performance of these indices is not better than the RR/V T.
KeywordsMechanical ventilation Patient–ventilator weaning Neurally adjusted ventilator assist
Conflicts of interest
The Association pour le Développement et l’Organisation de la Recherche en Pneumologie et sur le sommeil, a non-profit structure that supports the research activities of the “Service de Pneumologie et Réanimation Médicale, Groupe Hospitalier Pitié-Salpêtrière”, has received an unrestricted research grant from Maquet France SA, Orléans, France, to support pathophysiological research studies on NAVA.
- 2.Tobin MJ, Jubran A (2006) Weaning from mechanical ventilation. In: Tobin MJ (ed) Principles and practice of mechanical ventilation. McGraw-Hill, New York, pp 1185–1220Google Scholar
- 22.Bien MY, Lin YS, Shih CH, Yang YL, Lin HW, Bai KJ, Wang JH, Kou YR (2011) Comparisons of predictive performance of breathing pattern variability measured during T-piece, automatic tube compensation, and pressure support ventilation for weaning intensive care unit patients from mechanical ventilation. Crit Care Med 39:2253–2262PubMedCrossRefGoogle Scholar