Decannulation Timing is an Expression of Neurological Recovery Time: The Need to Define a Performance within a Time Frame

Research Article

Phys Med Rehabil Int. 2022; 9(3): 1206.

Decannulation Timing is an Expression of Neurological Recovery Time: The Need to Define a Performance within a Time Frame

Lombardi F*, Briganti A, Colli G, Marchetti P, Massobrio M and Lusuardi M

Department of Neuromotor Rehabilitation, Azienda USLIRCCS di Reggio Emilia, Italy

*Corresponding author: Lombardi F, Department of Neuromotor Rehabilitation, Azienda USL-IRCCS di Reggio Emilia, Via Mandriolo Superiore 15, 42015 Correggio, Italy

Received: October 03, 2022; Accepted: October 31, 2022; Published: November 07, 2022


Introduction: The factors that influence the likelihood of tracheostomy tube weaning in patients with severe acquired brain injury (sABI) are fairly well known, and recently it has been pointed out that improving swallowing and cough resistance are among the most important. What has not yet been focused on is the “passage of time” factor and how much it affects weaning opportunities.

Objective: With this study, we wanted to analyze how the probability of decannulation varies over time, consistent with neurological improvement.

Method: We examined the tracheostomy database of our neurological rehabilitation unit, which reports data from 359 patients with sABI, hospitalized between 2000 and 2012, and all carriers of tracheostomy tube upon admission.

The sample was divided into two groups based on the time gap between the acute event and admission to rehabilitation, an Early Group = 60 days and a Late Group > 60 days. The probability of decannulation, both overall and subdivided by groups, was then evaluated.

Results: The E-Group showed better functional scores at discharge and a better percentage of decannulation compared with the L-Group. The differences were statistically significant, but later decannulations were not unusual: 12% late weanings versus 88% earlier.

The probability of decannulation increases over time and is a factor dependent on the degree of neurological and functional recovery. It is of primary importance to consider these aspects when making comparisons between different centers, defining a product standard or performing benchmarking analyses.

Conclusions: The rehabilitative prognosis for decannulation can be reliably judged only after a suitable and well-defined period of time, because the probability of tube weaning has been shown to be strongly dependent on the amount of time that passes. This study also showed that effective decannulations can be achieved even more than 6 months after the acute event, although with significantly lower probabilities.

Keywords: Severe Acquired Brain Injury; Neurorehabilitation; Tracheostomy, Decannulation; Dysphagia


sABI: severe Acquired Brain Injury; E-Group: Early Group; L-Group: Late Group; PEG: Percutaneous Endoscopic Gastrostomy; GOS: Glasgow Outcome Scale; FIM: Functional Independence Measure; LOS: Length of Stay; SBDT: Saliva Blue Dye Test; ICU: Intensive Care Unit


The probability of removing the tracheostomy tube in patients with severe acquired brain injury (sABI) depends on several factors.

A study conducted by our working group on decannulation prediction, based on a cohort of 463 inpatients with sABI, highlighted how age, saliva aspiration, ABI pathogenesis, altered state of consciousness, and cough score are predictive factors [1].

A more recent study conducted on the same topic involving 327 patients confirmed that age, etiology and consciousness influence the probability of decannulation, adding further factors such as entry scores of consciousness assessment scales (Coma Recovery Scale - Revised, Glasgow Coma Scale) and functional independence scores (Disability Rating Scale, Functional Independence Measure), in addition to the presence of Percutaneous Endoscopic Gastrostomy (PEG) or nasogastric tube [2].

This latter study had a further merit in extending the discussion on decannulation timing and in researching predictors of this variable [2]. The authors stressed that the traumatic etiology is indicative of a short time decannulation (median 50 days) against the remaining etiologies (110 days), a supratentorial trauma location is indicative of decreased decannulation timing, the presence of a nasogastric tube and PEG correlate with decannulation time respectively in a positive and negative direction, and the need and use of mechanical ventilation at admission increase the decannulation time from 95 days to 148 days [2].

An interesting graph from this study shows the decannulation timing of 186 events, and it is surprising to note that in the face of most decannulations occurring between 40 and 140 days (intuitive aspect of the result), there is a minority occurring between 140 and 300 days (peculiar aspect of the result).

The authors were not interested in this aspect and have rightly concentrated their interest on searching for the predictive factors of timing. At the same time, their cohort shows how the probability of decannulation extends over time and expresses the maximum potential over a very extensive period of time (about 1 year from the acute event).

If we focus on the performance of the decannulations, we can see that 186/327 (57%) were achieved at a follow-up time of 300 days (for some patients). What would the performance have been like if the study had been censored 4 months after the acute event? In our opinion, the timing of data censorship is an element that the literature has not yet properly focused on.

In a recent study, three different types of service organization: pre-tracheostomy service (baseline), tracheostomy service alone, and post-tracheostomy care bundle were compared, demonstrating increasing decannulation rates, from 8.2% to 14.5% and up to 26% in the bundled PTC, by implementing multidisciplinary evaluation and decision-making activities [3]. The outcome was collected “before discharge”, with comparable average length of stay between the three organizations at approximately 26 days.

How is it possible to compare two decannulations that take place at such different times?

The time within which “decannulation events” are collected probably represents a crucial element in the rate of success and is also a factor that contributes to generating relevant variability between different studies.

The probability of decannulation lies between the range of 24% of Klein [4] and 77% of Perin [5], going from 31.5% of Mackiewicz- Nartowicz [6] to 46.7% of Perin [7], 54% of Warnecke [8], 57% of Mannini [2], 58% of Citta-Pietrolungo [9], 65% of Matesz [10], 68.5% of De Mestral [11], 70% of Leung [12], 72% of Chan [13], and 73% of Reverberi [1].

In a neurological recovery process, the “time passing” is a very important variable because “as stroke shows various clinical manifestations and recovery processes, swallowing and cough functions also change and improve after a stroke over time” [14].

Some studies have focused on clinical factors that influence the probability of decannulation, including the improvement in swallowing and the strength of the cough reflex [14], the possibility of tracheostomy tube capping, endoscopy assessment of airway patency, instrumental swallowing assessment and the blue dye test [5], mean expiratory pressure, presence of spontaneous cough and, again, cough strength [7], saliva aspiration and cough score [1].

In light of this data and wanting to make a contribution to the scientific discussion on this topic, we reviewed the tracheostomy database of our neurological rehabilitation unit, which reports data between 2000 and 2012, in an attempt to correlate the probability of decannulation with the time elapsed from the acute event.


All patients admitted to our Neurological Intensive Rehabilitation Unit between December 2000 and March 2012, over 15 years of age, affected by sABI and having a tracheostomy tube in place at admission, were entered in the tracheostomy database.

The tracheostomy database comprises consecutive data collection of tracheostomized inpatients admitted with the goal of weaning from the tube. Patients for whom decannulation was judged not achievable were discharged with the tracheostomy tube in situ; some of them were later readmitted in order to re-evaluate the decannulation option after a longer period of time, using the same decision algorithm and the same criteria defined at the beginning of data collection. For this reason, our database documents both early and late decannulations of patients affected by sABI.

Demographic and clinical data were collected for each patient: the sABI etiology (traumatic, vascular, anoxic, other), the appearance of respiratory infections and obstructive complications, pre- and post-decannulation, removal of the tube and any conditions that impeded it, the severity of the functional impairment assessed using the Glasgow Outcome Scale (GOS) and Functional Independence Measure (FIM) at admission and discharge [15,16].

The temporal elements of clinical evolution identified were the date of acute injury, date of admission into neurological rehabilitation, date of decannulation, date of discharge from rehabilitation. With these elements we could calculate the following time intervals: time before rehabilitation, time of tube in situ (only for weaned inpatients), rehabilitation Length of Stay (LOS), and outcome time (time within which missed weaning was censored or in general discharge from hospital).

In the year 2000, a multidisciplinary panel of experts from our health care facility had defined a shared protocol of decannulation criteria, consisting of pre-requisites and evaluation tools in order to make a rational choice [17,18]:

1. Prerequisites: baseline oximetry not below 90-92% O2; no need for aspirations within 24 hours; “tube capped and cuff deflated” or use of speaking valves must be possible.

2. Clinical assessments: effectiveness of the cough reflex (reflexive or voluntary evocation), oximetry in condition of tube capped, saliva blue dye test (SBDT), swallowing efficacy for liquids and semisolids.

3. Instrument examinations: chest X-ray (optional), laryngeal and tracheal fiberoptic endoscopy to exclude endotracheal complications (mandatory).

The decision to decannulate the patient was based on the following decisional algorithm [17]:

- First choice: Remove the tube only after having recovered autonomy in saliva management and in semisolid consistency food swallowing (at least).

- Second choice: If sufficient swallowing is considered a difficult target to reach in a relatively short time (or an achievable goal only in a long time), but the tube can be removed early from the respiratory point of view, remove the tube as soon as possible, as long as the patient is able to independently manage his salivary secretions in the SBDT test.

In case of respiratory infection or obstructive complications demonstrated with endoscopy, the decision to decannulate was taken only after removing or overcoming the highlighted obstacles (antibiotic therapy, laser therapy, surgery).

All patients underwent swallowing and breathing treatment, neuromotor rehabilitation aimed at enhancing trunk and head control, recovery of the state of consciousness, communication ability and respiratory clearance [17].

To perform the analysis, the sample was split into two groups based on the gap between the acute event and admission to rehabilitation: Early Group ≤ 60 days (E-Group) and Late Group > 60 days (L-Group) (Table 1).