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.
Tidal volume and respiratory rate are commonly used to set pressure-support ventilation. A reasonable level of inspiratory effort is an inspiratory pressure-time product (PTP) < 125 cmH2O.sec/minute. Pressure time product could be measured using the simultaneous recording of flow, volume and esophageal pressure.