What is the first action a nurse should take when a client begins having a tonic-clonic seizure?

The first action a nurse should take when a client begins having a tonic-clonic seizure is to lower the client to the floor. This action is crucial as it helps prevent injury from falls or contact with hard surfaces during the seizure. By ensuring the client is safely lowered, the nurse can minimize the risk of trauma, which is particularly important since tonic-clonic seizures involve violent muscle contractions and loss of consciousness.

Lowering the client on the floor allows for a safer environment where the seizure can occur without additional hazards. It provides the opportunity for the nurse to subsequently take other essential actions, such as moving objects away to avoid injury and preparing to implement further measures for the client’s safety and care once the seizure has ended.

Positioning, calling for help, and providing oral protection, while important, are actions that may follow the immediate need to ensure the client's physical safety during the seizure.