Final answer:
The best action is to order the lab work as prescribed for the patient with acute renal failure and then complete an incident report to document the missed prescription transcription.
Step-by-step explanation:
When a nurse discovers that a prescription for serum potassium levels has not been transcribed by the previous shift, the best immediate action to take is to order the lab work as prescribed and follow procedures for completing an incident report. This ensures that the patient's care is not compromised and the healthcare team is made aware of the error so that steps can be taken to prevent future omissions.
Contacting the healthcare provider is not the most immediate action as it may cause further delay, and contacting the nurse responsible for the error at home is not appropriate as it does not address the patient's immediate needs. Notifying the supervisor is a subsequent step after attending to the patient's needs.