Final answer:
The nurse should withhold the lipid emulsion if the client has an allergy to fish.
Step-by-step explanation:
The nurse should withhold the lipid emulsion and contact the health care provider if the client identifies an allergy to fish. Fish is a common allergen and can cause an allergic reaction in some individuals. It is important to ensure the client's safety and avoid administering any substances that may cause an allergic reaction.