Final answer:
Nitrous oxide is the inhaled anesthetic most affected by right-left pulmonary shunts, such as endobronchial intubation, because of its high blood solubility, while Isoflurane, Sevoflurane, and Desflurane are less affected.
Step-by-step explanation:
The anesthetic most affected by right-left pulmonary shunts, such as endobronchial intubation, is Nitrous oxide (Option 4). This is due to its high blood solubility, which means that it is more affected by changes in the lung's blood flow, such as those that occur with pulmonary shunts. In contrast, Isoflurane, Sevoflurane, and Desflurane are less soluble in blood and are therefore less affected by these shunt effects. These modern inhalant halogen-containing anesthetic compounds, including Isoflurane, Sevoflurane, and Desflurane, have replaced older anesthetics like diethyl ether due to their reduced flammability, reduced side effects, and better safety profile.