Related Experiment Video
Updated: Jun 19, 2026

Inspiratory Muscle Training as an Adjunct to the Treatment of Weaning Failure in Critically Ill Patients: A Practical Guide
Published on: January 30, 2026
Spontaneous breathing trial with low pressure support protocol for weaning respirator in surgical ICU
Kaweesak Chittawatanarat1, Chaweewan Thongchai
1Division of Critical Care and Trauma, Department of Surgery, Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand.
Objective:
Compare the effectiveness between spontaneous breathing trial with low-pressure support protocol and liberal or non-protocol directed method.
Material And Method:
The authors conducted a retrospective study involving 577 patients who were arranged and appropriate to weaning from mechanical ventilation on general surgical intensive care unit between July 1, 2004 to June 30, 2007. Two hundred and twenty two patients were weaned by their host surgeons or team (liberal group). Three hundred and fifty five patients underwent once daily spontaneous breathing trial with low-pressure support protocol. Patients assigned to this protocol had the pressure support level decreased to 5-7 cm of water for up to two hours each day. If signs of intolerance occurred, the process was restrained while patients who tolerated the two-hour trial without signs of distress were extubated. The authors collected demographic data, cause of ICU admission, APACHE II score at arranged time to weaning, weaning process time, ventilator day, and ICU length of stay.
Results:
There was statistical difference between liberal and protocol in age (59.2 +/- 19.3 vs. 55.6 +/- 19.8; p = 0.03) but there was no statistical difference in gender (male 74.3 vs. 67.9%; p = 0.2) and APACHE II score at arranged time to wean (14.7 +/- 7.4 vs. 15.3 +/- 6.3; p = 0.2). The median (inter-quartile) range duration of weaning process (29.5 (48) vs. 2.25 (2.9), p < 0.001), ventilator day (3 (4) vs. 2 (3), p < 0.001), and length of ICU stay (5 (5) vs. 3 (3), p < 0.001) were shorter in the protocol group than the liberal group. Multivariate linear regression model also revealed significantly less duration of weaning process in the protocol group than the liberal group in terms of weaning time (-63.6 (-74.7 to -2.6) hours), ventilator day (-3.0 (-3.7 to -2.2) days), and length of ICU stay (-2.9 days (-3.7 to -2.0); p < 0.001) (95% confidence interval).
Conclusion:
Spontaneous breathing trial with low-pressure support protocol for liberal from mechanical ventilator was effective to reduce weaning time, ventilator day, and length of ICU stay in general surgical intensive care units.
Related Concept Videos
Mechanical Ventilation III: Noninvasive Ventilation
Noninvasive Positive-Pressure Ventilation (NIPPV)
Ventilatory Modes
There are three ventilatory modes: full support, partial support, and spontaneous. These are described below.
Full Support Modes
Full support modes include controlled mechanical ventilation, continuous mandatory...
Cardiopulmonary Resuscitation II: ACLS Airway Management
Mechanical Ventilation II: Invasive Ventilation
Negative-Pressure Ventilators
Negative-pressure ventilators create a vacuum around the chest or body to draw air into the lungs, simulating breathing. This method does not require an...
Mechanical Ventilation I: Indication and Settings
Endotracheal Tube Extubation
Procedure
Extubation removes the endotracheal tube (ETT) from the patient on mechanical ventilation. It requires a well-coordinated, multidisciplinary approach involving physicians, nurses, respiratory therapists, and other healthcare professionals.