SBT: A Case Study
Subject the patient to an SBT
Number of studies have emphasized the importance of the discontinuation assessments for optimal outcomes post extubation, failure of which could result in undue delay in ventilation withdrawal, leading to increased rise in infection, longer exposure to potentially toxic airway pressure and volume, excessive sedation needs, longer stay and higher costs (3,43,84,85). Then again, overly aggressive/premature ventilation withdrawal attempts have their own hazards of airway loss, compromised gas exchange, aspiration and inspiratory muscle fatigue (86). Only clinical assessment of the status of the patient’s respiratory failure are usually not enough to make decisions on discontinuation of support. In two large trials …show more content…
Esteban and colleagues in their study of over 500 patients, found no difference in re-intubation rate in SBT carried out using a T-tube or PSV (91). However the PSV group showed better tolerance for weaning and extubation most probably due to the fact that low levels of PS during SBT overcome the resistance of the ETT and which may enable patients to meet the weaning criteria even if they would not pass a T-tube SBT (66,75,91). In one study, Ezingeard and colleagues were able to extubate 68% of patients with PSV after failing T-tube trials within 30 minutes of SBT. These results may be flawed as the PSV trial was performed immediately following failure, and no patients were tested to see if a subsequent T-tube trial would have been successful. The trial however demonstrated a particular value in using PSV in COPD patients …show more content…
A consensus conference in 2005 recommended that patients who failed SBT should be ventilated with PS or assist-control modes of ventilation (63). In this mode, all breaths are spontaneous and patient-triggered, which are boosted by positive inspiratory pressure that decreases the WOB and provides comfort. PS further decreases the WOB by overcoming the additional work related to resistance in the ETT. PS, which usually starts at pressures of 15 to 25 cmH2O, is weaned down to 5 – 8 cm H2O, at which time the patient is ready for a SBT. Another school of thought claims that PS should not be weaned to less than 10 cmH2O, as the positive pressure below this will no longer overcome ETT resistance and therefore WOB might increase
Number of studies have emphasized the importance of the discontinuation assessments for optimal outcomes post extubation, failure of which could result in undue delay in ventilation withdrawal, leading to increased rise in infection, longer exposure to potentially toxic airway pressure and volume, excessive sedation needs, longer stay and higher costs (3,43,84,85). Then again, overly aggressive/premature ventilation withdrawal attempts have their own hazards of airway loss, compromised gas exchange, aspiration and inspiratory muscle fatigue (86). Only clinical assessment of the status of the patient’s respiratory failure are usually not enough to make decisions on discontinuation of support. In two large trials …show more content…
Esteban and colleagues in their study of over 500 patients, found no difference in re-intubation rate in SBT carried out using a T-tube or PSV (91). However the PSV group showed better tolerance for weaning and extubation most probably due to the fact that low levels of PS during SBT overcome the resistance of the ETT and which may enable patients to meet the weaning criteria even if they would not pass a T-tube SBT (66,75,91). In one study, Ezingeard and colleagues were able to extubate 68% of patients with PSV after failing T-tube trials within 30 minutes of SBT. These results may be flawed as the PSV trial was performed immediately following failure, and no patients were tested to see if a subsequent T-tube trial would have been successful. The trial however demonstrated a particular value in using PSV in COPD patients …show more content…
A consensus conference in 2005 recommended that patients who failed SBT should be ventilated with PS or assist-control modes of ventilation (63). In this mode, all breaths are spontaneous and patient-triggered, which are boosted by positive inspiratory pressure that decreases the WOB and provides comfort. PS further decreases the WOB by overcoming the additional work related to resistance in the ETT. PS, which usually starts at pressures of 15 to 25 cmH2O, is weaned down to 5 – 8 cm H2O, at which time the patient is ready for a SBT. Another school of thought claims that PS should not be weaned to less than 10 cmH2O, as the positive pressure below this will no longer overcome ETT resistance and therefore WOB might increase