What should a nurse instruct regarding the administration of NPH insulin?

When administering NPH insulin, it is important for the nurse to instruct that a vial should be discarded if the medication appears cloudy. NPH insulin is a suspension, which means it can become cloudy due to the presence of the protein that is used to prolong its effect. However, any changes in appearance beyond its normal cloudy state, such as floating particles or significant precipitation, can indicate that the insulin is no longer safe to use. Therefore, if the medication appears excessively cloudy or contains particulate matter, it should not be administered and should be discarded.

The other choices contain information that may lead to incorrect practices. While it is indeed crucial to store NPH insulin appropriately, it should not be stored at room temperature for extended periods; instead, it should be refrigerated until opened and can be kept at room temperature for a limited time after being opened. Mixing NPH with regular insulin can be done but should happen before administration rather than stating it should only be mixed with regular insulin; this can help provide immediate coverage with the regular insulin while allowing the long-acting effects of the NPH to take over. Administering insulin immediately after meals is not correct; NPH has a delayed onset and should be given approximately 30 minutes before meals to align with its