It is advisable you book your accommodation early and close to the hospital.
There are a few options.
1. You can find good accommodation via AIRBnB. I found 3 options ranging from £ 20-100 per night 3 minutes walking distance from the hospital.
2. Local hotels. I stayed at The Hotel Britannia Airport Hotel, Manchester for 3 nights prior to the exam. It costed me approximately 45 pounds per night. The hotel is 10 mins away from the hospital by UBER/Cab (approximately 7-10 pounds per ride) which was the main reason why I booked the hotel room, it was important for me not to have the added stress of being delayed by traffic prior to the exam (which happened to other students). Also, there was a Tesco 10 mins by foot. It was a decent stay in general with free WiFi in the main lounge (where you can also study, although it is not quiet). You get 2 20 minutes free WiFi session in the room. After that you will be asked to pay a fees if you wish to continue.
If your exam is in the morning, it is good to start sleeping early days before the exam (if you are not an early bird), to reset your internal alarm clock.
Do not worry if you can not get a full sleep on the night of the exam. It happens to us all. Pack the night before (if you are leaving the next day), wake up at 6 am the next morning. You will have an hour to get ready , 15 mins to deposit your luggage downstairs in the storage room, and 10 mins to get to the hospital.