WEANING (VENTILATOR) : PROF LEO HEUNKS, NETHERLAND

00:00:00 intro
00:03:00 basic physiology
00:05:20 trial 1
00:13:28 weaning criteria
00:14:40 trial 2
00:19:41 wean safe study
00:27:30 weaning failure, ultrasound
00:30:30 cardiac this function
00:36:50 muscle weakness, ultrasound
00:47:14 discussion
Weaning Patients From Mechanical Ventilation
PROF Leo Heunks discussed the challenges and importance of weaning patients from mechanical ventilation. He highlighted the need for appropriate timing to switch from controlled to assisted ventilation, as this period is crucial for the patient's respiratory drive and effort. Leo presented a recent study that showed early transition to assisted ventilation resulted in a higher percentage of patients being successfully extubated at day 28 and reduced the duration of invasive mechanical ventilation. He also emphasized the need for a standardized approach to the first spontaneous breathing trial, as it is a critical milestone in the patient's trajectory.
Early Screening Tests
Leo discussed the importance of early screening tests for patients on invasive mechanical ventilation. He highlighted the benefits of a successful Spontaneous Breathing Trial (Sbt) in allowing patients to be extubated. Leo emphasized that an Sbt should be a screening test that is negative in many cases, otherwise it doesn't make sense to screen a patient. He presented data from two studies comparing different Sbt strategies, concluding that patients were often weaned too late. Leo also discussed the WeanSafe study, which found that only 65% of patients on invasive ventilation for more than two days were successfully weaned within 90 days. He identified modifiable risk factors for delayed weaning, including the use of sedation and a delay between meeting weaning eligibility criteria and performing the first Sbt. Leo stressed the importance of considering an Sbt when a patient meets the criteria, even if it fails, as it is better than not performing one.
Weaning Failure Algorithm and Ultrasound
Leo discussed the challenges of spontaneous breathing trials (SBTs) and the importance of maintaining a balance between the capacity and load imposed on the cardiopulmonary system. He introduced the ABC of weaning failure algorithm to identify potential issues in the airway, brain function, cardiac function, diaphragm, and endocrine metabolic function. Leo emphasized the role of ultrasound in assessing the airway, chest wall, and lung parenchyma during the weaning process. He also highlighted the importance of treating delirium in patients before extubation to prevent weaning failure.
Cardiac Function
Leo discussed cardiac function, particularly in patients with limited cardiac reserve. He highlighted the potential for myocardial ischemia and pulmonary edema during weaning, which can lead to hypoxemia and dyspnea. Leo suggested various diagnostic methods, including ECG, Swan-Ganz catheter, BNP measurement, and hemoglobin changes, to identify cardiac failure as a reason for SBT failure. He also presented a study demonstrating the effectiveness of nitroglycerin administration in improving weaning outcomes in patients with hypertension and COPD.
Respiratory Muscle Function
Leo discussed the importance of respiratory muscle function in patients with prolonged weaning from mechanical ventilation. He highlighted that respiratory muscle weakness is highly prevalent at the time of the first SBT and is not necessarily accompanied by peripheral muscle weakness. Leo also explained the pathophysiology of diaphragm weakness in ICU patients, which involves atrophy, neuromuscular junction failure, neuropathy of the phrenic nerve, dysfunction of contractile proteins, inflammation, fibrosis, and hibernation or stunning of the diaphragm. He demonstrated how to measure inspiratory muscle function in ventilated patients using handheld devices or ultrasound. Leo also discussed the use of inspiratory muscle strength training in patients difficult to wean from mechanical ventilation, highlighting that there was no significant clinical benefit in a recent study. He concluded by mentioning an ongoing large, international, randomized, controlled trial to show the benefit on clinical relevant out
Weaning Strategies Discussed
He recommends using T-piece spontaneous breathing trials (SBTs) over pressure support, as they better simulate post-extubation conditions. For failed weaning attempts, Leo emphasizes the importance of diagnostics to understand the cause of failure, including arterial blood samples and ultrasound. He suggests prolonging SBTs incrementally for difficult cases, potentially after tracheostomy. For COPD patients, Leo notes that some can be extubated to non-invasive ventilation after 48 hours, while others may require prolonged ventilation. In neurological patients, Leo stresses assessing cough adequacy over SBTs. He also addresses anxiety during weaning, emphasizing the need to understand and treat its underlying causes.