Speaking roughly, normal levels of thyroid-stimulating hormone (TSH) are in the range of 0.4 to 4.0 mIU/L. However, each laboratory and test manufacturer identifies its own normal TSH range.
A common strategy is to combine SIMV with an additional ventilator mode known as pressure support ventilation (PSV) (Fig. 4). In this situation, inspiratory pressure is added to spontaneous breaths to overcome the resistance of the endotracheal tube or to increase the volume of spontaneous breaths.
PiP (the pressure outside the lungs) is not uniformly distributed. It is smaller at the base than the apex of the lung. A cause for this difference is the weight of the lung, which would result in a stronger pull from the chest wall at the apex.