**20. IAB weaning**

IAB weaning is usually done when the following physiological parameters are observed in target patients.


IAB weaning is usually done when the following physiological parameters are observed in

1. No afterload reduction as seen on balloon waveform

3. Improved LV function and hemodynamics

Fig. 24. Early Deflation

Fig. 25. Late Deflation

**20. IAB weaning** 

2. Increased urine output

target patients.


The IAB is generally weaned by reducing the ratio from 1:1 to 1:3, after which the augmentation volume of the balloon catheter can be reduced. If the IAB volume is being decreased as a part of the weaning process, ensure adequate movement of the IAB catheter in order to minimize clotting or thrombus formation. The IAB is never turned off when the IAB catheter lies in the aorta due to the risk of thrombus formation. Afterload reduction by the IAB can be explained via numbers. The stroke volume of an average sized patients in normal health is usually 70 to 80 ml. In a patient in compromised cardio-vascular state, this stroke volume is reduced to 40 or 50ml. What a 40cc IAB catheter does is to complement the native stroke volume of 30-40ml until hibernating myocardium recovery and myocardial rest result in an increased stroke volume of that patient.
