Comparison of Adaptive Support Ventilation and Pressure Support Ventilation for Weaning and Extubation Outcomes in Critically Ill Patients in an Indian ICU: A Prospective Randomized Study

Study Title

Comparison of Adaptive Support Ventilation and Pressure Support Ventilation for Weaning and Extubation Outcomes in Critically Ill Patients in an Indian ICU – A Prospective Randomized Study

Study Summary

This prospective randomized study compares the effectiveness of Adaptive Support Ventilation ASV and Pressure Support Ventilation PSV in weaning critically ill patients from mechanical ventilation. The study population includes surgical and trauma patients with medical comorbidities. Previous studies have shown different outcomes between medical and surgical ICU patients under similar protocols.

Inclusion Criteria

Age above 18 years

Mechanically ventilated for 24 hours or more

APACHE II score between 5 and 30

Exclusion Criteria

Severe neurological or cardiac conditions

Pregnant women

Patients will be enrolled once their acute illness has resolved and the clinical team decides to start weaning. Consent will be obtained from the next of kin. Randomization will be done using permuted block randomization with concealed allocation through opaque sealed envelopes. Patients will be assigned to either ASV or PSV.

Weaning Criteria

Reversal of initial cause for ventilation

Hemodynamic stability with heart rate less than 120 and respiratory rate less than 35

pH greater than 735, tidal volume more than 5 ml per kg, minute volume less than 10 liters per minute

PEEP less than 5 cm H2O, PaO2 greater than 60 mmHg with FiO2 less than 0.4, and PaO2 to FiO2 ratio greater than 150

A standard ICU extubation protocol will be followed. Patients will be considered for extubation when they meet readiness criteria such as:

Hemodynamic stability with minimal or no vasopressors

Adequate oxygenation with PaO2 to FiO2 ratio above 150 to 200 and SpO2 above 92 percent on 40 percent FiO2 or less

Protective airway reflexes like cough and gag

Adequate mental status and ability to protect airway

Successful completion of a spontaneous breathing trial

All other ICU management including sedation, investigations, and resuscitation will be uniform across both groups. Most extubations will occur between 7 AM and 7 PM due to staff availability and institutional safety protocols. This timing is consistent across both groups and does not introduce bias.

Primary Outcome

Successful weaning defined as a composite of:

No need for reintubation within 48 hours

If NIV is needed, HACOR score less than 5

If HFNC is needed, ROX index greater than 285 at 2 hours

Secondary Outcomes

Total duration of mechanical ventilation

Time to successful extubation

ICU length of stay

ICU mortality

Number of manual ventilator adjustments

Number of ABG analyses required

Rate of ventilator associated pneumonia

This study aims to identify the better ventilatory strategy for improving weaning and extubation outcomes in surgical ICU patients.