METHODS: A prospective observational study done on 220 adult patients eligible for extubation as decided by the attending physicians. Exclusion criteria : Pregnant and tracheostomised patients. Along with baseline parameters, following measurements were taken pre and post extubation. 1.Cardiac parameters including Simpsons method for ejection fraction, E/A, E/e’ (lateral) for diastolic function, TAPSE and TAD for Right ventricular function. All recordings were taken just before extubation and within six hours post extubation. 2.Just before extubation,high frequency linear ultrasound probe was used to measure the right sided DT at the zone of apposition(ZOA) between 8th to 10th intercostal spaces in mid-axillary line.The change in DT fraction(Δdtfrac_pre%) was calculated as DT(end-inspiration)-DT(end-expiration)/DT(end-expiration)x100.RSBI was simultaneously recorded. 3.Fluid balance 24 hours were recorded. Statistics:Logistic regression was used to develop a model with extubation failure as the outcome and change in DT(delta fraction), RSBI, E/e’, E/A , fluid balance 24 hrs and other patient covariates as predictors. Extubation failure was defined as re-intubation within 48 hrs of extubation.