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Extubation is removing an endotracheal tube (ETT), which is the last step in liberating a patient from the mechanical ventilator. Other terms related to extubation are 'weaning' and 'liberation.' To discuss the actual procedure of extubation, one also needs to review how to assess readiness for weaning and management before and after extubation. This activity reviews the overall process of extubation with a special focus on the assessment of readiness, spontaneous breathing trial, and a few complications related to the process. The activity highlights the role of the interprofessional team, including physicians, nurses, and respiratory therapists, in managing and improving care for all patients who undergo liberation from mechanical ventilation. Objectives: Identify clinical conditions which present a relative contraindication to the extubation. Describe methods to assess readiness to initiate a spontaneous breathing trial. Review the criteria for successfully passing a spontaneous breathing trial. Summarize some common complications and their management related to extubation that the interprofessional team may encounter and how collaboration will improve care. Access free multiple choice questions on this topic.

Extubation is removing an endotracheal tube, which is the last step in liberating a patient from the mechanical ventilator. To discuss the actual procedure of extubation, one also needs to understand how to assess readiness for weaning and management before and after extubation. Other terms related to extubation are 'weaning' and 'liberation.' Weaning is a gradual transition from full invasive ventilatory support to spontaneous ventilation with minimal support. Liberation, however, means the complete discontinuation of mechanical ventilation. The current trend is to use the term 'liberation' as opposed to 'weaning' in intensive care unit ventilator management because the goal is to liberate patients from the ventilator as soon as possible rather than weaning over several days to weeks. Weaning is more common in long-term, acute care settings.[1][2]

Adverse events relating to the procedure can be dichotomized into 3 categories: Respiratory: Exaggerated laryngeal reflexes causing coughing, bucking, or laryngospasm; aspiration, secondary to residual effects of drugs and inadequate relaxation, is the major cause of mortality as well as malpractice claims due to anesthesia-related adverse events Traumatic: Injury to the larynx, vocal cords, laryngeal nerves, dental trauma, lingual trauma, and emotional distress Hemodynamic: Post-extubation hemodynamic shift and increased intra-thoracic pressure following vigorous coughing [17] The most feared complications of extubation are the failure and immediate need for re-intubation and post-extubation stridor. Extubation Failure Extubation failure and the need to be re-intubated within 48 hours are noted in 10 to 20% of patients despite passing a spontaneous breathing trial and undergoing planned extubation.[18] Twelve to 14% of planned extubations. Extubation failure increases the length of mandatory ventilation, odds of the need for tracheostomy, medical expenditure, and the risk of mortality.[18][19] Risk factors for reintubation include a weak cough and frequent suctioning. Additional features that may predict reintubation include a rapid shallow breathing index over 58 breaths per minute per liter, a positive fluid balance during the 24 hours preceding extubation, and pneumonia as the reason for the initial intubation. Patients aged 65 and older with severe chronic cardiac or respiratory disease appear to be at particularly high risk for extubation failure. Extubation failure carries a higher risk of intensive care unit mortality.[20][21]. Recently, the use of non-invasive ventilation (NIV), mostly in the form of BPAP, has gained prominence. Current evidence favors prophylactic use of NIV immediately after extubation to prevent reintubation in only selected high-risk patients, like chronic obstructive pulmonary disease and hypercapnia. Otherwise, NIV use for post-extubation respiratory failure has not been shown to reduce reintubation rate or intensive care unit mortality.[22][23] In addition to using NIV, high-flow oxygen systems have gained popularity over the last few years in selected patients with hypoxemic respiratory failure. Studies have shown to reduce the re-intubation rate.[24][25][26][27][28][29] Various Clinical Parameters to Predict the Outcome Following Extubation

Extubation failure and the need to be re-intubated within 48 hours are noted in 10 to 20% of patients despite passing a spontaneous breathing trial and undergoing planned extubation.[18] Twelve to 14% of planned extubations. Extubation failure increases the length of mandatory ventilation, odds of the need for tracheostomy, medical expenditure, and the risk of mortality.[18][19] Risk factors for reintubation include a weak cough and frequent suctioning. Additional features that may predict reintubation include a rapid shallow breathing index over 58 breaths per minute per liter, a positive fluid balance during the 24 hours preceding extubation, and pneumonia as the reason for the initial intubation. Patients aged 65 and older with severe chronic cardiac or respiratory disease appear to be at particularly high risk for extubation failure. Extubation failure carries a higher risk of intensive care unit mortality.[20][21]. Recently, the use of non-invasive ventilation (NIV), mostly in the form of BPAP, has gained prominence. Current evidence favors prophylactic use of NIV immediately after extubation to prevent reintubation in only selected high-risk patients, like chronic obstructive pulmonary disease and hypercapnia. Otherwise, NIV use for post-extubation respiratory failure has not been shown to reduce reintubation rate or intensive care unit mortality.[22][23] In addition to using NIV, high-flow oxygen systems have gained popularity over the last few years in selected patients with hypoxemic respiratory failure. Studies have shown to reduce the re-intubation rate.[24][25][26][27][28][29] Various Clinical Parameters to Predict the Outcome Following Extubation Glasgow coma scale-Glasgow Coma Scale before extubation has been observed to be the most significant variable governing the outcome following extubation.[18][30][31] Cough strength, level and consistency of secretion, and status of gag reflex [31] Indexes such as heart rate, acidosis, consciousness, oxygenation, and respiratory rate (HACOR) [32] Point of care holistic ultrasound- to assess left ventricular function), number of B-lines, and diaphragm thickening fraction; diaphragmatic excursion with a cut-off value of 1.25 cm and diaphragmatic thickening fraction with a cut-off value of 21.5% indexes during the diaphragmatic US have high positive predictive values [33][34][35][36]

Point of care holistic ultrasound- to assess left ventricular function), number of B-lines, and diaphragm thickening fraction; diaphragmatic excursion with a cut-off value of 1.25 cm and diaphragmatic thickening fraction with a cut-off value of 21.5% indexes during the diaphragmatic US have high positive predictive values [33][34][35][36] Synchronization between the thoracic and the abdominal wall movement[36] Changes in ΔPCO2 (Δ - ΔPCO2) and central venous oxygen saturation (ΔScvO2) during spontaneous breathing trials[36] Weaning Failure Weaning failure means that the patient cannot tolerate the SBT, which is different from extubation failure, where the patient can pass the spontaneous breathing trial leading to successful extubation, which later fails. An international consensus conference proposed a classification of patients based on the difficulty and length of the weaning process.[1] Accordingly, patients are categorized into three groups: simple, difficult, and prolonged weaning.[1] The simple weaning group (30% to 58% of patients) is easy to wean and able to be extubated after the first SBT. The difficult weaning group (26 to 40% of patients) requires up to 3 SBTs or up to 7 days to achieve successful weaning. Both of these groups have relatively lower mortality of 0% to 13%. The prolonged weaning group (6% to 30% of patients) requires more than 3 SBTs or more than seven days to achieve successful weaning. The third group has a higher mortality of 13% to 22%. Any weaning failure should prompt physicians to comprehensively assess the patient for all potential problems that can cause weaning failure. Subsequent SBT should only occur when these presumed predisposing factors have been addressed.[37][38] Unexpected Extubation A systematic review and meta-analysis have shown the pooled prevalence of unplanned endotracheal extubation at around 7%, with almost 70% occurring despite being preventable.[39] Preventive measures such as restraint and proper fixation of the tracheal tube are paramount to preventing such adverse events.[39] Post-Extubation Stridor Post-extubation stridor is uncommon and seen only in less than 10% of unselected critically ill patients and correlates with increased rates of reintubation, prolonged duration of mechanical ventilation, and longer length of intensive care unit stay. Stridor is the result of laryngeal edema.

A systematic review and meta-analysis have shown the pooled prevalence of unplanned endotracheal extubation at around 7%, with almost 70% occurring despite being preventable.[39] Preventive measures such as restraint and proper fixation of the tracheal tube are paramount to preventing such adverse events.[39] Post-Extubation Stridor Post-extubation stridor is uncommon and seen only in less than 10% of unselected critically ill patients and correlates with increased rates of reintubation, prolonged duration of mechanical ventilation, and longer length of intensive care unit stay. Stridor is the result of laryngeal edema. Several identified risk factors include: Prolonged intubation (36 hours to 6 days or more) Older adults: 80 years and older A large ETT (greater than 8 mm in men and over 7 mm in women) A ratio of ETT to the laryngeal diameter of more than 45% A GCS score higher than 8 or traumatic intubation Female sex Medical history of asthma Improper fixation of the tube Inadequate or lack of sedation Aspiration The presence of an orogastric or nasogastric tube The cuff-leak test is used to predict the occurrence of post-extubation stridor.[40] It should be performed if any of the risks mentioned above are identified. Some providers do the cuff-leak test regularly, but there is insufficient evidence to suggest its regular use. The 2 methods of performing the cuff-leak test are: Qualitatively by just listening to the leak of air by a stethoscope over the upper trachea on deflation of the balloon. Quantitatively, placing the patient on volume control mode and calculating the difference between inspired and expired air. If the cuff leak is less than 110 mL or less than 25% of the delivered tidal volume, it suggests an increased risk of laryngeal edema. Management of Post-extubation Stridor

Qualitatively by just listening to the leak of air by a stethoscope over the upper trachea on deflation of the balloon. Quantitatively, placing the patient on volume control mode and calculating the difference between inspired and expired air. If the cuff leak is less than 110 mL or less than 25% of the delivered tidal volume, it suggests an increased risk of laryngeal edema. Management of Post-extubation Stridor For patients with no cuff leak when tested before extubation, a short course of steroids (methylprednisolone 20 mg every 4 hours for four doses) may be helpful. This course has support from a few studies and meta-analyses.[41][42] For patients who develop post-extubation stridor, nebulized epinephrine, intravenous methylprednisolone, high flow O2, and CPAP are options if clinically stable. Otherwise, prompt reintubation is warranted if significant airway obstruction is suspected. Following reintubation, a short course of steroids is the recommendation, with a re-assessment of the cuff leak. If a leak is present, extubation is generally safe. If cuff leak is reduced or absent, extubation over an airway exchange catheter should be considered, usually in consultation with bedside anesthesiology or an ear, nose, and throat consultant.[43]

The ventilator liberation process is long and involves many factors that require the attention of multiple members of the patient interprofessional care team. This team includes clinicians, nursing, and respiratory technicians. Coordination between different providers is essential. The SBT cannot be conducted without first conducting a spontaneous awakening trial.[44][45] This trial requires close coordination between the bedside nurse and the bedside respiratory therapist. As a part of the daily morning assessments, "sedation vacation" should be included to the point that the patient is alert, awake, and able to follow commands.[46] While the nurse is doing daily sedation vacations or spontaneous awakening trials, the respiratory therapist assesses readiness to wean and initiate the spontaneous breathing trial. Communication between all team members is crucial so everyone knows their roles and responsibilities. A team-centered, interprofessional approach to care during extubation that includes physicians, nurses, respiratory therapists, and pharmacists is the best approach to achieving a positive patient outcome, irrespective of the events during extubation. Several studies have demonstrated a significant reduction in the intensive care unit length of stay and ventilatory days if the team follows certain protocols and policies, although other studies have argued against using protocolized weaning. In practical terms, protocols save significant time in the decision-making process and facilitate quicker liberation. All patients need to have a respiratory therapy-driven liberation pathway in place, followed by all patients except when ordered by the physician-in-charge not to follow.[47][48][49] The American Thoracic Society and the American College of Chest Physicians Clinical Practice Guidelines for Liberation from Mechanical Ventilation in Critically Ill Adults The summary of these clinical practice guidelines applicable to acutely hospitalized adults on mechanical ventilators for more than 24 hours is as follows: Management with a ventilator liberation protocol is suggested. Protocolized rehabilitation directed towards early mobilization is suggested. Performance of the cuff-leak test is suggested in those who meet the criteria for extubation but are deemed a high risk for the complication of post-extubation stridor.

The summary of these clinical practice guidelines applicable to acutely hospitalized adults on mechanical ventilators for more than 24 hours is as follows: Management with a ventilator liberation protocol is suggested. Protocolized rehabilitation directed towards early mobilization is suggested. Performance of the cuff-leak test is suggested in those who meet the criteria for extubation but are deemed a high risk for the complication of post-extubation stridor. Administration of systemic steroids for at least 4 hours before extubation is suggested in those who fail the cuff-leak test but are otherwise ready to be extubated.[42] Although the recommendations suggested by the American Thoracic Society and the American College of Chest Physicians, published in 2017, are conditional and not strong, they certainly will benefit healthcare professionals in decision-making in the ICU setting. The chapter on the approach to extubation from mechanical ventilation by Alistair Nichol and colleagues in the book "Evidence-Based Practice of Critical Care" is an essential reference for healthcare professionals involved in managing critically ill patients.