In The Movie 28 Days Later, A Patient (a Male

In the movie 28 Days Later, a patient (a male in his late 20s) is shown waking up in an operating theater with only an I/V drip (a single bag) in his arm. Assuming that this patient has been in a coma for the duration of four week (28 days), could it be possible for him to survive on only an I/V drip for this time? If so, what would the solution in the I/V bag most likely be?