Prolonged tracheostomy may induce many late complications, including aggravation of dysphagia, bleeding, tracheal stenosis, granuloma, psychosocial side effects, etc. [3, 4]. There is broad variability in tracheostomy care and decannulation practices and a lack of a universally accepted decannulation protocol, especially for prolonged tracheostomy patients [10]. The present study investigated the success of decannulation in patients with prolonged tracheostomy referred to a rehabilitation hospital. According to the data of 3 years, after the evaluation of the multidisciplinary team, a total of 57/92 patients met the protocol criteria and underwent decannulation. The success rate of decannulation was 98.2%; only 1 patient needed recannulation, and the failure rate was 1.8%. The incidence of recannulation was lower than that in other studies (2–5%) [11], and no patient was intubated after 3 months of follow-up after decannulation. One reason was that the criteria for the decannulation protocol were very strict. After assessment, only 62.0% of patients met the criteria, which was lower than in the study by Pandian V [12], in which the decannulation rate was as high as 88%.

Because the patients referred to our department for tracheostomy decannulation had a long tracheostomy time, the mean time was 70.6 days, and the mean time of mechanical ventilation was 37.2 days, which was longer than any other study (days) [13, 14]. The evaluation of the upper airway is more important because there are many problems with upper airway patency in patients with long-term tracheostomy [5]. Clinicians evaluated airway patency directly by visualization through endoscopy or assumed a patent airway when a patient tolerated physiological decannulation, which was assessed by occlusion [9], a one-way speech value [15], or downsizing to smaller tubes [16]. Some researchers suggested upper airway endoscopy for all patients before tracheostomy decannulation [17]. However, the others did not use bronchoscopy or upper airway endoscopy, yet they successfully decannulated 60% of the patients [9]. Antony E Tobin et al. [15] mentioned in their study the use of the Passy-Muir valve to assess upper airway patency, but there are no details on how to use it, except in some patients still using tracheostomy tube occlusion. We routinely used a speaking valve instead of occlusion to determine the patency of the upper airway. The speaking valve is unidirectional, allowing air to be drawn through the tracheostomy tube during inspiration (with small inspiratory pressure) and has an automatic closure mechanism that directs airflow into the upper airway during the expiratory phase. When using a speaking valve, airflow changes, so the explanation of the process and how the valve works to the patient assists with reducing anxiety and encouraging normal breathing patterns. Guerlain et al. [18] considered fiberoptic endoscopy only in cases of repeated failed decannulation. We prescribed fiberoptic endoscopy only when the patient could not tolerate the deflation of the cuff and the use of a speaking valve. In our study, 70 patients passed the upper airway patency evaluation because they could tolerate the speaking valve. These patients did not undergo laryngoscopy, and 41 were successfully decannulated. One study reported that 67% of patients with tracheostomies were found to have airway abnormalities during airway endoscopy. Findings included tracheal granulomas, tracheomalacia, tracheal stenosis, and vocal cord dysfunction [19]. Some of the abnormalities visualized, such as minor mucosal trauma from the tracheostomy tube or suction catheter, may not be clinically important and usually do not prevent decannulation. It has been demonstrated that patients who successfully pass a tracheostomy tube occlusion protocol can be safely decannulated without first undergoing fiberoptic bronchoscopy [20]. One innovation of our study is that tolerance of tube occlusion was not used as the standard to be met in the decannulation protocol for any of the patients. Many studies state that the ability to tolerate tracheostomy tube occlusion is an important factor to ensure readiness prior to a patient undergoing decannulation [7, 12, 21,22,23]. It is common practice to cap the tracheostomy tube for 24 h to see whether the patients can breathe on their own [12]. However, occluding the tube leads to increased airway resistance, resulting in increased respiratory work in patients with marginal ventilation [24]. Moreover, this protocol may delay decannulation because some patients who do not meet the occlusion criteria may still be able to undergo decannulation successfully [25]. In addition, one study suggested that the failure of capping trials could lead to a sequence of clinical deterioration [12, 25]. Patients did not undergo capping trials, and the decision to decannulate was based on tolerance of the speaking valve continuously for 4 h. In addition, this criterion could evaluate secretion at the same time, which has also been reported in many studies. Decannulation failures could contribute to uncontrolled secretions and severe glottic stenosis. Pandian et al. [12] considered suctioning less frequently than every 4 h as a standardized tracheostomy decannulation protocol in patients with mixed abnormalities. For patients with acquired brain injury, some authors considered two suctions or less every 8 h as criteria [21]. Based on the clinical practice of our department, tolerance of a speaking valve continuously for 4 h instead of tube occlusion was proposed. This criterion may make it possible for patients with extremely poor pulmonary capacity and who are unable to tolerate tube occlusion to decannulate successfully. The cuff is the crucial interface between the tube and the trachea that may prevent leakage of secretions that lead to tracheal ischesis [26]. When patients with drooling used a speaking valve, cuff deflation would result in a large amount of saliva flowing into the airway, finally appearing as dyspnea, persistent cough, decreased oxygen saturation and so on. Such patients could not tolerate the speaking valve continuously for 4 h, required the administration of anticholinergics or botulinum neurotoxin A to reduce salivary secretion, and could then finally tolerate the speaking valve continuously for 4 h.

Assessment of cough strength is an important criterion for considering tracheostomy decannulation. Bach and Saporito [27] found that only the ability to generate a PCF of at least 160 L/min predicted the success of decannulation. In our study, the mean PEF of patients whose cough strength was enough to clear sputum was 107.7 L/min. Therefore, we conjectured that a PCF or PEF of at least 100 L/min would predict the effectiveness of coughing. The results confirmed that the patients (PCF/PEF > 100 L/min) were successfully decannulated, and reintubation after a follow-up of 3 months did not occur.

Many studies confirmed that failing a swallow examination predicted failure of decannulation [28]. However, we found that as long as patients can effectively manage oral secretions and have the ability to cough, even if they have swallowing dysfunction, they can still decannulate successfully and nasogastric tube, jejunal tube or percutaneous gastrostomy can remain. In addition, because tracheostomy may increase the risk of aspiration as it interferes directly in the pharyngeal phase of swallowing, the failure of a swallowing evaluation does not indicate that the tube cannot be decannulated [29]. In this study, 29 patients could not pass the swallowing evaluation, but after the evaluation, the tracheostomy cannula was successfully decannulated, the gastric tube was retained in 23 cases, the jejunal tube was retained in 3 cases, and gastrostomy was retained in 3 cases and removed in 3 cases after swallowing function was recovered.

Due to the limited medical resources in the intensive care unit, many patients with tracheostomy are transferred to a weaning facility, such as a step-down unit or a long-term care hospital. However, it was reported that ICU patients who received tracheostomies and were sent to the ward had significantly higher odds of death than those patients decannulated in the ICU prior to discharge. Many systematic reviews also pointed out that the multidisciplinary tracheostomy team is the most appropriate team for tracheostomy management and is associated with a shorter time from the ICU to the general ward and tracheostomy decannulation for patients [15]. Ilaria Zivi et al. [30] stated that an early neurorehabilitation protocol helps to reduce the time to decannulation in tracheostomized patients with severe acquired brain injury. Most multidisciplinary research teams include ICU physicians, otolaryngologists and respiratory physicians [12]. As in Antony E’s study, physiotherapists were included in our multidisciplinary team [15]. In weaning facilities, a multidisciplinary team manages medical care and rehabilitation, which is conducive to weaning from ventilation and tracheostomy decannulation. All patients referred to undergo tracheostomy decannulation in our center were evaluated by our multidisciplinary rehabilitation team, and a pulmonary rehabilitation program was started after assessment. As long as the patient was clinically stable, they routinely started personalized pulmonary rehabilitation tailored to their assessment. Because of long-term tracheostomy, many patients could not master the physiological way of breathing from the upper airway when deflating the cuff, especially when wearing the speaking valve. The physiotherapist could help moderate the breathing mode and gradually prolong the wearing time. When the patients had many secretions, physiotherapists used a variety of airway clearance techniques to help the patients remove the secretions in the trachea, which was helpful for decannulation. If the strength of cough was weak, physiotherapists could increase cough training and mechanical inhalation and exhalation. Successful implementation of a rehabilitation and weaning protocol is dependent on careful planning and detailed communication between the rehabilitation specialist and clinicians during the pulmonary rehabilitation process.

The main limitation of this study was the prospective design in a single center. There was no randomized control method to confirm noninferiority of speaking valves to tube occlusion and to clarify the role of pulmonary rehabilitation in tracheostomy decannulation.