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.
A bi-level CPAP system delivers two different positive pressure levels--an inspiratory positive airway pressure, or IPAP, and an expiratory positive airway pressure, or EPAP The difference between these two pressure levels is commonly referred to as the pressure support.