Final answer:
The most important criterion for a nurse to consider when deciding whether to give a patient a full or partial bed bath is the immediate need of the client.
Step-by-step explanation:
The most important criterion for a nurse to consider when deciding whether to give a patient a full or partial bed bath is the immediate need of the client. This means assessing the client's current level of cleanliness and any specific hygiene needs they may have. For example, if a patient is in pain or discomfort and requires immediate relief, a full bed bath may be necessary. On the other hand, if a patient is able to perform certain aspects of personal hygiene themselves, a partial bed bath may be more appropriate.