in a waiting room vs in the waiting room

Examples:

• I sat in a waiting room for hours before I was called in for my appointment.
• There is always a TV in a waiting room to keep patients entertained.
• In a waiting room, you often find magazines to read while you wait.
• She felt anxious in a waiting room full of strangers.
• The children played quietly in a waiting room.

Alternatives:

• in the waiting room
• at a waiting room
• within a waiting room
• inside a waiting room
• within the waiting room

Examples:

• The doctor is currently with a patient in the waiting room.
• Please wait in the waiting room until your name is called.
• There is a water cooler in the waiting room for patients.
• In the waiting room, you can find brochures about various health topics.
• She saw her friend sitting in the waiting room.

Alternatives:

• in a waiting room
• at the waiting room
• within the waiting room
• inside the waiting room
• within a waiting room