The effects of tracheostomy cuff deflation during continuous positive airway pressure

Translating Dysphagia Evidence into Practice While Avoiding Pitfalls: Assessing Bias Risk in Tracheostomy Literature

Critically ill patients who require a tracheostomy often have dysphagia. Widespread practice guidelines have yet to be developed regarding the acute assessment and management of dysphagia in patients with tracheostomy. In order for clinicians to base their practice on the best available evidence, they must first assess the applicable literature and determine its quality. To inform guideline development, our objective was to assess literature quality concerning swallowing following tracheostomy in acute stages of critical illness in adults. Our systematic literature search (published previously) included eight databases, nine gray literature repositories and citation chasing. Using inclusion criteria determined a priori, two reviewers, blinded to each other, conducted an eligibility review of identified citations. Patients with chronic tracheostomy and etiologies including head and/or neck cancer diagnoses were excluded. Four teams of two reviewers each, blinded to each other, assessed quality of included studies using a modified Cochrane Risk of Bias tool (RoB). Disagreements were resolved by consensus. Data were summarized descriptively according to study design and RoB domain. Of 6,396 identified citations, 74 studies met our inclusion criteria. Of those, 71 were observational and three were randomized controlled trials. Across all studies, the majority (> 75%) had low bias risk with: participant blinding, outcome reporting, and operationally defined outcomes. Areas requiring improvement included assessor and study personnel blinding. Prior to translating the literature into practice guidelines, we recommend attention to study quality limitations and its potential impact on study outcomes. For future work, we suggest an iterative approach to knowledge translation.

Management of tracheostomies in the intensive care unit: a scoping review

OBJECTIVES

While there is an extensive body of literature surrounding the decision to insert, and methods for inserting, a tracheostomy, the optimal management of tracheostomies within the intensive care unit (ICU) from after insertion until ICU discharge is not well understood. The objective was to identify and map the key concepts relating to, and identify research priorities for, postinsertion management of adult patients with tracheostomies in the ICU.

DESIGN

Scoping review of the literature.

DATA SOURCES

PubMed, Embase and Cumulative Index to Nursing and Allied Health Literature were searched from inception to 3 October 2019. Additional sources were searched for published and unpublished literature.

ELIGIBILITY CRITERIA

We included studies of any methodology that addressed the a priori key questions relating to tracheostomy management in the ICU. No restrictions were placed on language or year of publication.

DATA EXTRACTION AND SYNTHESIS

Titles and abstracts were screened by two reviewers. Studies that met inclusion criteria were reviewed in full by two reviewers, with discrepancies resolved by a third. Data were extracted for included studies, and results mapped along the prespecified research questions.

RESULTS

6132 articles were screened, and 102 articles were included for detailed analysis. Protocolised weaning was found to be successful in liberating patients from the ventilator in several cohort studies. Observational studies showed that strategies that use T-pieces and high-flow oxygen delivery improve weaning success. Several lines of evidence, including one clinical trial, support early cuff deflation as a safe and effective strategy as it results in a reduced time to wean, shorter ICU stays and fewer complications. Early tracheostomy downsizing and/or switching to cuffless tubes was found to be of benefit in one study. A substantial body of evidence supports the use of speaking valves to facilitate communication. While this does not influence time to wean or incidence of complications, it is associated with a major benefit in patient satisfaction and experience. Use of care bundles and multidisciplinary team approaches have been associated with reduced complications and improved outcomes in several observational studies.

CONCLUSIONS

The limited body of evidence supports use of weaning protocols, early cuff deflation, use of speaking valves and multidisciplinary approaches. Clinical trials examining post-tracheostomy management strategies in ICUs are a priority.

Investigating Swallowing and Tracheostomy Following Critical Illness: A Scoping Review

OBJECTIVES

Tracheostomy and dysphagia often coexist during critical illness; however, given the patient's medical complexity, understanding the evidence to optimize swallowing assessment and intervention is challenging. The objective of this scoping review is to describe and explore the literature surrounding swallowing and tracheostomy in the acute care setting.

DATA SOURCES

Eight electronic databases were searched from inception to May 2017 inclusive, using a search strategy designed by an information scientist. We conducted manual searching of 10 journals, nine gray literature repositories, and forward and backward citation chasing.

STUDY SELECTION

Two blinded reviewers determined eligibility according to inclusion criteria: English-language studies reporting on swallowing or dysphagia in adults (≥ 17 yr old) who had undergone tracheostomy placement while in acute care. Patients with head and/or neck cancer diagnoses were excluded.

DATA EXTRACTION

We extracted data using a form designed a priori and conducted descriptive analyses.

DATA SYNTHESIS

We identified 6,396 citations, of which 725 articles were reviewed and 85 (N) met inclusion criteria. We stratified studies according to content domains with some featuring in multiple categories: dysphagia frequency (n = 38), swallowing physiology (n = 27), risk factors (n = 31), interventions (n = 21), and assessment comparisons (n = 12) and by patient etiology. Sample sizes (with tracheostomy) ranged from 10 to 3,320, and dysphagia frequency ranged from 11% to 93% in studies with consecutive sampling. Study design, sampling method, assessment methods, and interpretation approach varied significantly across studies.

CONCLUSIONS

The evidence base surrounding this subject is diverse, complicated by heterogeneous patient selection methods, design, and reporting. We suggest ways the evidence base may be developed.

Clinical indicators associated with successful tracheostomy cuff deflation

BACKGROUND

Tracheostomy cuff deflation is a necessary stage of the decannulation pathway, yet the optimal clinical indicators to guide successful cuff deflation are unknown.

OBJECTIVES

The study aims were to identify (1) the proportion of patients tolerating continuous cuff deflation at first attempt; (2) the clinical observations associated with cuff deflation success or failure, including volume of above cuff secretions and (3) the predictive capacity of these observations within a heterogeneous cohort.

METHODS

A retrospective review of 113 acutely tracheostomised patients with a subglottic suction tube in situ was conducted.

RESULTS

Ninety-five percent of patients (n=107) achieved continuous cuff deflation on the first attempt. The clinical observations recorded as present in the 24h preceding cuff deflation included: (1) medical stability, (2) respiratory stability, (3) fraction of inspired oxygen ≤0.4, (4) tracheal suction ≤1-2 hourly, (5) sputum thin and easy to suction, (6) sputum clear or white, (7) ≥moderate cough strength, (8) above cuff secretions ≤1ml per hour and (9) alertness≥eyes open to voice. Using the presence of all 9 indicators as predictors of successful cuff deflation tolerance, specificity and positive predictive value were 100%, although sensitivity was only 77% and negative predictive value 19%. Refinement to a set of 3 clinically driven criteria (medical and respiratory stability, above cuff secretions ≤1ml/h) provided high specificity (100%), sensitivity (95%), positive predictive value (100%) and an improved negative predictive value (55%).

CONCLUSIONS

Key criteria can help guide clinical decision-making on patient readiness for cuff deflation.

Above cuff vocalisation: A novel technique for communication in the ventilator-dependent tracheostomy patient

A significant proportion of patients admitted to intensive care units require tracheostomies for a variety of indications. Continual cuff inflation to facilitate mechanical ventilatory support may mean patients find themselves awake, cooperative and attempting to communicate but unable to do so effectively. Resulting frustration and anxiety can negatively impact upon care. Through participation in the Global Tracheostomy Collaborative, our unit rapidly implemented novel techniques facilitating communication in such patients. In carefully selected and controlled situations, the subglottic suction port of routinely available tracheostomy tubes can be used to deliver a retrograde flow of gas above the cuff to exit via the larynx, facilitating speech. The resulting above cuff vocalisation is described in detail for five general ICU patients at our institution, highlighting the benefits of multidisciplinary care and the increasingly important role of the speech and language therapists in the critically ill.

The use of tracheostomy speaking valves in mechanically ventilated patients results in improved communication and does not prolong ventilation time in cardiothoracic intensive care unit patients

PURPOSE

The aim of this study was to assess the effect of the introduction of in-line tracheostomy speaking valves (SVs) on duration of mechanical ventilation and time to verbal communication in patients requiring tracheostomy for prolonged mechanical ventilation in a predominantly cardiothoracic intensive care unit (ICU).

MATERIALS AND METHODS

We performed a retrospective preobservational-postobservational study using data from the ICU clinical information system and medical record. Extracted data included demographics, diagnoses and disease severity, mechanical ventilation requirements, and details on verbal communication and oral intake.

RESULTS

Data were collected on 129 patients. Mean age was 59 ± 16 years, with 75% male. Demographics, case mix, and median time from intubation to tracheostomy (6 days preimplementation-postimplementation) were unchanged between timepoints. A significant decrease in time from tracheostomy to establishing verbal communication was observed (18 days preimplementation and 9 days postimplementation, P <.05). There was no difference in length of mechanical ventilation (20 days preimplementation-post) or time to decannulation (14 days preimplementation-postimplementation). No adverse events were documented in relation to the introduction of in-line SVs.

CONCLUSIONS

In-line SVs were successfully implemented in mechanically ventilated tracheostomized patient population. This resulted in earlier verbal communication, no detrimental effect on ventilator weaning times, and no change in decannulation times.

PURPOSE

The purpose of the study was to compare tracheostomy outcomes in mechanically ventilated patients in a cardiothoracic ICU preintroduction and postintroduction of in-line SVs. It was hypothesized that in-line SVs would improve communication and swallowing specific outcomes with no increase in average time to decannulation or the number of adverse events.

A simple mechanical device reduces subglottic injury in ventilated animals

OBJECTIVES/HYPOTHESIS

To test whether a simple inexpensive device that dynamically minimizes endotracheal cuff pressure throughout the respiratory cycle reduces endotracheal cuff pressure-related subglottic injury.

STUDY DESIGN

Hypoxic animal model with one control and one experimental group.

METHODS

Twelve S. scrofa domesticus piglets (14-16 kg) were intubated with standard endotracheal tubes and maintained in a hypoxic state to accelerate airway injury. Animals in the control group (n = 6) were ventilated with a constant pressure of 20 cm H₂O in the endotracheal tube cuff. Animals in the experimental group (n = 6) were ventilated using a custom-designed circuit that altered the pressure in the endotracheal tube cuff in synchrony with the ventilatory cycle. Larynges were harvested at the end of the experiment and examined histologically to determine the degree of airway injury induced by the endotracheal cuff.

RESULTS

Animals in the experimental group suffered significantly less airway damage than those in the control group. The differences were seen primarily in the subglottis (aggregate damage score 6.5 vs. 12, P <0.05), where the experimental endotracheal tube cuff exerted the least pressure. There was no difference in damage to the glottic or supraglottic structures.

CONCLUSIONS

A simple, reliable, and inexpensive means of modulating endotracheal tube cuff pressure with the ventilatory cycle led to a substantial decrease in airway injury in our animal model. Such reduction in cuff pressure may prove important for humans, particularly those in intensive care units who tend to have underlying conditions predisposing them to tracheal damage from the endotracheal tube cuff.

Influence of the cuff pressure on the swallowing reflex in tracheostomized intensive care unit patients

BACKGROUND

Because recovery of an efficient swallowing reflex is a determining factor for the recovery of airway protective reflexes, we have studied the influence of the tracheostomy tube cuff pressure (CP) on the swallowing reflex in tracheotomized patients.

METHODS

Twelve conscious adult intensive care unit (ICU) patients who had been weaned from mechanical ventilation were studied. Simultaneous EMG of the submental muscles with measurement of peak activity (EMGp) and amplitude of laryngeal acceleration (ALA) were performed during reflex swallows elicited by pharyngeal injection of distilled water boluses during end expiration. After cuff deflation, characteristics of the swallowing reflex (latency time: LaT, EMGp, and ALA) were measured at CPs of 5, 10, 15, 20, 25, 30, 40, 50, and 60 cm H(2)O.

RESULTS

LaT and CP were linearly related (P<0.01). CP was inversely correlated (P<0.01) to both ALA and EMGp.

CONCLUSIONS

We demonstrated that LaT, EMGp, and ALA of the swallowing reflex were influenced by tracheostomy tube CP. The swallowing reflex was progressively more difficult to elicit with increasing CP and when activated, the resulting motor swallowing activity and efficiency at elevating the larynx were depressed.

Incidence of tracheal aspiration in tracheotomized patients in use of mechanical ventilation

CONTEXT

Many patients in use of mechanical ventilation show clinical complications due to tracheal aspiration. Assessment and early methods are necessary, so that preventive and safety measures apply to this patients.

OBJECTIVE

To study the incidence of tracheal aspiration of saliva in tracheotomized patients treated in intensive care unit using two modes of mechanical ventilation and with different sedation levels.

METHOD

Prospective study with 14 tracheotomized non-neurological patients using mechanical ventilation. The sample was divided into two groups based on ventilation mode: pressure support ventilation and pressure controlled ventilation. Those two groups were subdivided into two others according to sedation level. The speech pathology evaluation was completed via the blue dye test in order to analyze the incidence of tracheal aspiration of saliva.

RESULTS

Sedation levels and mechanical ventilation time related to tracheal aspiration were not statistically significant in this study. On the other hand, ventilation mode and tracheal aspiration showed statistical significance, and there was a higher incidence of tracheal aspiration in the pressure controlled ventilation mode.

CONCLUSION

It was possible to observe a significant relationship between tracheal aspiration incidence and pressure controlled ventilation mode, which means the inclusion of those patients in the risk group for oropharyngeal dysphagia and their insertion in prevention protocols. The relationship between tracheal aspiration and sedation level, as well as tracheal aspiration and mechanical ventilation, were not statistically significant in this sample, needing further research.