Revise the sentence below on order to make them appropriate for an academic text.
the patient's not gonna see the doctor if he doesn't high tail to the hospital on time.

it is necessary to replace the informal expressions: gonna and  high tail

Explanation:

In order to make this sentence The patient's not gonna see the doctor if he doesn't high tail to the hospital on time, more appropriate for an academic text it is necessary to replace the informal expressions: gonna and  high tail.Furthermore, the contractions must not be used.

Here are two possible versions the first one a neutral style and the second one more formal.

1- if he does not rush to the hospital the patient will not be able to see the doctor.  

2-Should the patient have the wish to see the doctor on time, he must move with urgent haste.

The patient is not going to see the doctor If he does not high tail to the hospital on time.

Explanation:

It would be appropriate for an academic tex to avoid the abreviations because these show the reader that you are using informal language and when you want to write an academic text you must use formal language avoiding all kind of abreviations like the following:

-The patient's

-He doesn't

-Gonna