Final answer:
The insertion depth of an endotracheal (ET) tube is estimated based on the patient's height or a formula involving the patient's height.
Step-by-step explanation:
The insertion depth of an endotracheal (ET) tube is estimated based on the patient's height or a formula involving the patient's height. The tube should be inserted to a depth that allows it to reach the trachea but not enter the mainstem bronchus.
One method commonly used to estimate ET tube insertion depth is the formula:
ET tube insertion depth (cm) = patient's height (cm) / 10 + 4. This formula provides an approximate estimation of the tube's insertion depth.
For example, if a patient is 170 cm tall, the estimated ET tube insertion depth would be 17 + 4 = 21 cm.