The cough assessment is fundamental in the weaning process as it gives information on the possibility to expel food and secretion out from the airways. The majority of persons suffering from severe acquired brain injury are not able to cough voluntary due to severe cognitive deficit. In the present study, it would be evaluated the intensity of the reflex cough (RC) and the results would be correlated with weaning outcome.

All the participants will undergo firstly to the RC assessment. RC would be trigged by the inhalation of 0.4M of citric acid solution using the ultrasonic nebulizer (MO-03 Norditalia Elettromedicali). The face mask would be connected with the spirometer and the nebulizer via a bidirectional valve in order to measure Peak of Cough Expiratory Flow (PCEF) of the RC. Secondly, it would be assessed parameters of the weaning protocol in order to verify the feasible of removing the tracheostomy cannula. Hence, if the previous assessments are positive, the cannula 's patients would be removed. The follow-up would be taken after 96 hours from the decannulation in order to verify the outcome of weaning.

In this study, it would be recruited a number of 30 consecutive patients admitted to IRCCS Ospedale San Camillo. The data would be firstly analyzed using Kolmogorov-Smirnov test in order to verify the distribution. Secondly it would be chosen to t-test for parametric outcomes or Wilcoxon non parametric outcomes. Thirdly, the correlation between the Peak of Cough Expiratory Flow of the RC and the weaning outcome would be completed using Pearson Test (parametric) or Spearman test (non parametric).

Inclusion Criteria:

• diagnosis of Acquired Brain Injury
• presence of tracheostomy cannula and positive cupping trial
• provide informed consent independently

Exclusion Criteria:

• presence of allergy to citrus;
• presence of asthma
• presence of mechanical ventilation;
• presence of trachomalacia
• presence of laryngeal stenosis