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.
This pressure is typically set slightly higher than atmospheric pressure to prevent atelectasis, decrease inspiratory work of breathing, or improve gas exchange depending on the clinical scenario. This positive end-expiratory pressure (PEEP) is generated by a resistor in the exhalation port of the ventilator (Fig. 2).
For example, a patient with anauto-PEEP of 10 cmH 2 O and a set pressure trigger of -2 cmH 2 O (and no ap-plied PEEP) has to generate an alveolar pressure of 12 cmH 2 O to generateabreath.Assistedbreathsshouldbelimitedtolessthan8â10breathspermin-ute and adequate time should be allowed for exhalation.