Referral letters tend to contain the same sorts of phrases - try to learn these. Examples are:
independent with his personal care
requires assistance with
mobile with a walking frame / walking stick
has a past history of
poorly controlled diabetes
not compliant with treatment / medication
needs reminding / prompting
has a tendency to wander / become aggressive/ become tearful
and many more.
Remember that the word limit only allows you to write 3 or 4 sentences in each paragraph.
Practise handwriting a paragraph of writing. Then, count how many words, on average, you write per line. This will give you an idea of how long 180-200 words is, in your handwriting.