What type of complication does a large tongue or goiter in hypothyroidism patients commonly cause during induction?

The presence of a large tongue (macroglossia) or goiter in patients with hypothyroidism is significant because these anatomical features can obstruct the airway. During induction, especially when the patient is in a supine position, a large tongue can overhang the oropharynx, making visualization of the vocal cords challenging. A goiter can also compress the trachea or distort the surrounding anatomy, further complicating the intubation process.

Difficulty with intubation can lead to increased time to secure the airway and potentially result in hypoxia if adequate ventilation is not maintained. Intubation in patients with these conditions requires special techniques or equipment, demonstrating why this option is the most relevant complication associated with induction in this context.

The other options, while they may pose risks in different clinical situations, are not primarily associated with the challenges presented by a large tongue or goiter during induction. Oxygen desaturation could occur as a result of intubation difficulty but is a secondary consequence rather than a primary complication. Cardiovascular instability and an increase in blood viscosity are less directly related to the physical airway obstruction caused by the patient's anatomical features. Thus, the focus on intubation difficulties makes this answer the most appropriate choice.