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.
Patients that require PEEP while breathing spontaneously require a CPAP generator. BiPAP refers to maintaining constant airway pressure during both inspiration and expiration. This is a variant of Pressure Control ventilation in which the patient can breathe in and out during any phase of respiration.